Mechanically-robust and humidity-tunable self-destructive polymers enabled by hydrogen-bond nanoconfinement

Domain: physics
Published: 2025-12-03
Editorial outcome: major_revision

Abstract
Conventional materials typically maintain a stable solid state under specific application conditions. However, materials that combine high mechanical strength with reversible switching states are highly desirable for advanced technologies. Here, we present hydrogen-bond nanoconfined self-destructive polymers (HNSPs) that have robust mechanics and reversible solid-fluid switching capability at 25 °C. Upon exposure to moisture, HNSPs spontaneously transition from solid to fluid, with humidity-tunable switching rates. HNSPs with weight ratios (Rm) of 1.7 is 1.69 times higher self-destructive rate than those with Rm of 2.1, and at 90% relative humidity (RH), Rm = 2.0 samples exhibit an 804.27% higher self-destructive efficiency than at 60% RH. Heating can reverse the fluid back to a solid, enabling reversible, humidity-programmable behavior. Mechanistically, large ordered hydrogen-bond clusters, reduced chain entanglement, and abundant hydrophilic groups collectively facilitate switching. This work provides a simple yet versatile strategy for designing robust, switchable self-destructive polymers, broadening their potential in next-generation devices.

Introduction
Achieving long-term stability, high performance, and consistent functionalization with minimal variability stands as the paramount objective in the design and development of advanced materials1–4. However, specific demands emerge when materials must undergo self-deconstruction or physical dissolution upon mission completion, or when immediate destruction is required. These increasing needs arise for the elimination of electronic waste5,6, the protection of sensitive information7, and the reduction of secondary surgeries associated with implantable medical devices8,9. This research addresses the urgent need for these advanced materials capable of controlled self-deconstruction, which is crucial for applications ranging from electronic waste reduction and data security to minimizing invasive medical procedures.

One traditional approach to achieve self-destructive behaviors involves applying external stimuli, such as light10, heat11, magnetic12, or electricity, to induce phase transition that led to physically melting or sublimation. For instance, thermoplastic polymers undergo distinct phase transitions during crystallization melting or glass transition, enabling a reversible transformation from solid to fluid states13,14. Despite these materials show promise, they typically require continuous external stimulation to maintain the phase change, often involving the formation of high-energy intermediates. Consequently, once the external stimulus is removed, these materials are unable to sustain their “self-destructive” state and quickly revert to their original form15,16. Alternatively, the development of biodegradable or soluble materials offers another potential solution. Those materials such as polylactic acid (PLA)17,18, silk fibroin (SF)19, and starch-based polymers20 can degrade in response to external stimuli like light, heat and enzymes, etc. These stimuli will break the chemical bonds within the polymer chains, progressively reducing large molecules into low molecular weight fragments, ultimately resulting in physical disappearance or self-destruction21,22. However, these molecular-level self-destructive behavior also relies on continuous stimulation (special solvents or biological fluids), leading to an uncontrollable destruction over the “Self-destructive process”, which is passively controlled by the chemical dissolution or stimulated destruction of functional materials associated with self-destructive behavior23,24. Thus, developing transient materials or device capable of self-deconstruction or controlled dissolution at specific times and rates remains a significant challenge.

To address these limitations, researchers have increasingly focused on the materials capable of achieving reversible switching between different states while maintaining stability without continuous passively stimulation under the same environmental conditions25–28. Worrell et al.29 developed a new responsive material that can undergo a transition between a dynamic and a permanent network upon exposure to light, resulting in a stable switch between fluid and solid states at room temperature. However, this stable phase transition is unidirectional once the material transforms from a solid to a fluid state under stimulation, but it cannot revert to its solid state. Similarly, Yang et al. 30 introduced a polymer impregnated with a supercooled salt solution, enabling reversible changes between soft and hard states through nucleation stimulation or heating. Notably, this phase transition is both reversible and stable with the materials in the hard state being 104 times harder than in the soft state. Despite these advancements, the switching capability of such materials remains limited, failing to achieve the significant transformations akin to solid-liquid phase transitions. Moreover, these materials exhibit a fixed switching rate and suffer from poor mechanical performance, with fracture strengths only reaching the kilopascal level. In addition, their self-destructive processes often need specialized stimuli, such as specific wavelength of light or seed crystals, rendering their applicability in diverse environments. Therefore, there is a pressing need to develop systems that provide materials with superior mechanical properties, utilize mild and widely applicable stimulation methods, and offer controllable switching rate. Such innovations would enable reversible solid-liquid phase change, broadening the applicability and functionality of advanced materials.

Moisture, as an abundant and environmentally benign resource, has significant advantages in triggering mechanical responses due to its low energy cost, wide range of application, easy of control, and mild operating conditions31–34. In nature, spider silk exhibits remarkable sensitivity to moisture, a phenomenon known as super-contraction, which arises from the presence of hydrophilic peptide segments in spider silk proteins and surface coatings35,36. When exposed to water or high humidity, spider silk can shrink up to 50%. This behavior occurs because water molecular disrupt hydrogen bonds, thereby increasing molecular mobility and driving the rearrangement of amorphous regions into lower energy configurations through enhanced molecular entropy37,38. As illustrated in Fig. 1a, hydrogen bonds play a critical role in imparting the excellent mechanical properties of spider silk, as they facilitate the self-assembly of stable and ordered nanostructures (β-sheet nanocrystals), forming interlocked regions that enhance cohesive energy and enable effective load transfer along molecular chains39–41.

Inspired by spider silks, we hypothesized that introducing dense hydrogen bonds between polymer chains through molecular structure design, alongside the establishment of ordered nanostructures, could impart exceptional mechanical properties to the material. Concurrently, by designing polymer chains with hydrophilic characteristics, the material can spontaneously absorb moisture from the surrounding environment. The absorbed water molecules would significantly disrupt the interactions between polymer chains while establishing new and strong interactions, resulting in the dissipation of nanostructures and enabling autonomous self-destructive behavior. Furthermore, the strong interaction between water molecules and polymer chains are not easily reversed by removing moisture stimuli, those restoration to the original state necessitate the application of strong heating and pressure.

In this study, we report the synthesis of hydrogen-bond nanoconfined self-destructive polymers (HNSPs) that exhibit controllable self-destruct behavior alongside excellent mechanical strength. The compressive yield strength of HNSPs reaches up to 14.66 MPa, with a maximum Young’s modulus of 165.21 MPa. Under the ambient conditions (25 °C), the system undergoes two reversible yet stable phase transitions. HNSPs can maintain their structural integrity for hours or even days at room temperature, contingent on the environmental humidity. In high humidity environments, the designed HNSPs can spontaneously absorb moisture, triggering a phase transition from a solid to a fluid state. Upon removal of the moisture stimulus, the system does not revert to its original state. Instead, restoration to the solid state occurs only upon the application if intense heating, facilitating the fluid-to-solid transition. Especially, this phase-switching process can be repeated multiple times. We believe that the exploration of reversible and stable HNSPs opens new avenues for innovative and practical strategies in fabricating stiffness-modulating polymers, thereby broadening their application fields in next-generation smart devices.

Results
Hydrogen-bond nanocluster assembly of HNSPs
Hydrogen-bond nanocluster self-destructive polymers (HNSPs) were synthesized via a one-step polymerization process in deionized water, those detailed synthesis process were elaborated in the Supplementary Information. As illustrated in Fig. S1 tetraethylenepentamine (TEPA) was reacted with acrylamide (AM) and N-methylolacrylamide (NMA) through the Aza-Michael reaction to obtain the final product. The detailed compositions of HNSPs with weight ratios (Rm) of NMA and Am to TEPA ranging from 1.7 to 2.1 were listed in Table S1 Rm is defined as the molar ratio of NMA (equimolar with AM) to TEPA, with Rm = 2.0 corresponding to an NMA:AM:TEPA ratio of 2:2:1.

The C=O stretching vibration in the amide group at 1652 cm-1 was observed in Fourier transform infrared (FTIR) spectra and the stretching vibration peak of N-C can be observed at around 1407 cm-1 and 1125 cm-1, which belong to the amide group and the adipose group secondary amine, respectively. The results of nuclear magnetic resonance (NMR) manifested that the multi overlapping peaks at 2.80 ppm to 2.17 ppm are attributable to the -CH2 on the main chains in the 1H-NMR spectroscopy (Fig. S3 and S4), and the characteristic peaks from at 54.2 ppm to 50.33 ppm belong to -N-CH2- groups in the 13C-NMR spectroscopy (Fig. S5). Additionally, the results of 1H detected heteronuclear multiple bond correlation (HMBC) and heteronuclear single quantum coherence (HSQC) confirmed the correspondence between 1H-NMR and 13C-NMR (Fig. S6). The above results indicated that these HNSPs have been successfully synthesized via the Aza-Michael reaction.

To further characterize the elements and groups on HNSPs, we performed X-ray photoelectron spectroscopy (XPS) experiments (Fig. S7). The XPS spectra shows that there is only C, N and O elements on the surface of HNSPs surface, including four types of binding of C in XPS spectrum of C1s corresponding to C-C, C-N, C-OH and C=O. And there are two types of binding of N in HNSPs, the characteristic peaks of 399.04 eV and 400.02 eV correspond to N-C amines and N-C=O, respectively. Meanwhile, two types of binding of O in HNSPs with characteristic peaks of 531.08 eV and 532.09 eV are correspond to O-H and O=N-C group. The XPS data further confirmed that HNSPs have abundant oxygen-containing groups and nitrogen-containing groups on the surface, which helps to provide sufficient hydrogen bonding sites. Above analysis results indicate that HNSPs containing multiple hydrogen bonds have been successfully synthesized.

As illustrated in Fig. 1b and Fig. S8 the hydrogen bond structures and supramolecular organization within hydrogen-bonded nanocluster self-destructive polymers (HNSPs) have been elucidated. The molecular segments of the target HNSPs primarily consisted of relatively flexible TEPA segments, which were covalently linked through main or side chains - aligned perpendicularly relatively to TEPA segments - to more rigid components such as NMA and AM. These rigid components offered numerous hydrogen bond donors and acceptors. Furthermore, due to their shorter chain length and lower molecular weight compared with conventional polymers, HNSP molecular segments exhibited reduced entanglement, thus facilitating enhanced molecular mobility. Consequently, this distinctive structural arrangement promotes the formation of high-density hydrogen-bonded nanoclusters characterized by smaller dimensions yet densely populated hydrogen bonds, ultimately resulting in mechanically robust, humidity-responsive self-destructive polymers enabled by hydrogen-bond nanoconfinement.

Simultaneously, all-atom molecular dynamics (MD) simulations were conducted to theoretically elucidate the categories and aggregation structures of HNSPs. As shown in Fig. 1c and Fig. S9, the simulated systems comprise 30 polymer chains contains abundant hydrogen bonding sites and these hydrogen bonds are formed through the N and O groups on the molecular chains. The radial distribution function (RDF) can depict distribution with distance of other particles around a particle, which can reflect the number of hydrogen bonds42. The g(r) value of N groups at 0~1 Å is higher than that of O groups, which reflect the number of hydrogen bonds formed by N is greater than that of O in the HNSPs system with the fraction of H-bonded in N and O being 70% and 30%, respectively. The average bond energy of hydrogen bonds is −7.714 kJ/mol. The simulated HNSPs chain showed dense aggregation with irregular spherical shapes (nanometer scale), inducing the complexation of HNSPs molecules into aggregated nanoclusters through hydrogen-bond interactions43–45.

As shown in Fig. 1d, Transmission electron microscope (TEM) images reveal densely and uniform hydrogen-bonded nanoclusters with an average radial size of 8 nm. Compared with other structures (sheet or brick), spherical nanoclusters have better fluidity and specific surface area, which provides more hydrogen bonding sites to establish the physical cross-linking structures46. Those results are consistent with that of MD simulations, revealing the formation of nanoclusters due to the densely hydrogen bond in HNSPs. Obviously, as the weight ratio Rm increases, the hydrogen-bonded nanoclusters process more pronounced outline and larger diameters (Fig. S10). This result is also in good agreement with the all-atom MD simulations: the more AM and NMA will increase the hydrogen bond density, resulting the severe aggregation of hydrogen bonds that form bigger nanoclusters. Similarly, the cryo-scanning electron microscopy (cryo-SEM) images also show the regular and orderly arrangement of these nanoclusters, which act as nano-armor, conferring high mechanical strength and hardness to HNSPs (Fig. 1e and Fig. S11).

As depicted in Fig. 1f, a HNSP’s sample (50×50×3 mm3) is capable of easily supporting a 500 g weights without deformation or breaking, demonstrating excellent mechanical properties. Additionally, the thermal properties of HNSPs were also studied through a variety of testing methods. The results of differential scanning calorimetry (DSC) reveal that HNSPs have a glass transition temperature (Tg) around room temperatures (Fig. S12). As Rm increases, the Tg of HNSPs markedly increased, those higher Tg could be attributed to the increased cohesion energy of numerous hydrogen bonds within the HNSP. The thermogravimetric analyses (TGA) results reveal that HNSPs begin to lose their weight over 250 °C, also featuring excellent thermal stability (Fig. S13). Furthermore, X-ray diffraction (XRD) spectra display no sharp crystalline diffraction peaks, indicating that HNSPs possess typical amorphous structures regardless of different Rm values (Fig. S14). The above results indicate that the designed HNSPs have hydrogen bond nanoclusters with spider silk structure.

Mechanical and self-destructive properties of HNSPs
The mechanical properties of HNSPs are heavily depend on the characteristics of the hydrogen-bond clusters. To elucidate the superior mechanical properties of HNSPs with different Rm values, both their original structures and those under deformation were investigated in Fig. 2a. As shown in Fig. 2a, after compression testing, the thickness of the molded sample exhibited a reduction in height to 25% of its original dimension, accompanied by proportional increases in length and width, confirming the inherent ductility and plasticity of HNSPs. The stress-strain curves exhibit three distinct regions: an initial elastic deformation phase where stress significantly increases with strain, a subsequent strain-hardening phase characterized by a gradual increase in strain with a slower rise in stress, and a final densification stage where strain increases slowly while stress rises sharply (Fig. 2b). The yield strength of HNSPs, defined as the stress corresponding to 10% residual deformation, is found to be as high as 14.66 MPa. Furthermore, the Young’s modulus of HNSPs markedly increases with increasing Rm in Fig. 2c. The highest Young’s modulus of the HNSPs up to 165.21 MPa is calculated in the low-strain region (<10% strain) of the stress-strain curve. Notably, as Rm increases further, the HNSPs exhibit enhanced strength and stiffness, while this is accompanied by increased brittleness (Fig. S15). This may be attributed to the fact that the strength and stiffness of the HNSPs increase because of higher hydrogen bond density forming hydrogen-bond nanocluster. The specific mechanism responsible for the excellent mechanical properties and notable ductility of HNSPs are attributable to the densely hydrogen-bond nanocluster acted as physical cross-linking points, providing robust resistance to deformation and fracture, and the dynamic nature of these hydrogen bonds enables molecular units to absorb mechanical energy and undergo plastic deformation through relative slippage and rearrangement under stress, thereby preventing brittle fracture.

As confirmed in Fig. 2d, the results of zeta potential measurements reveal that HNSPs have a negative surface charge, ascribed to the abundant oxygen-containing groups on their surface. Moreover, as Rm increases, the absolute value of the zeta potential gradually decreases, suggesting that the hydrogen-bonded nanoclusters become more closely packed and the interactions between them are strengthen47,48. The schematic diagram of the hydrogen-bond nanocluster within HNSPs bearing external stress is conceptually depicted in Fig. 2e. It shows that when Rm is low, the hydrogen-bonded clusters are relatively small and widely spaced, rendering them insufficient to bear applied loads effectively49. The weak interactions between clusters ensures the load transfer through molecular chains, leading to the destruction of hydrogen-bonded clusters and resulting in lower mechanical performance. In contrast, at higher Rm values, the hydrogen-bonded clusters become larger and more tightly packed, adequately supporting the applied load. The strong interactions between the clusters promote the simultaneous stiffening of multiple hydrogen-bonded clusters, thereby improving excellent mechanical properties. Consequently, by adjusting the Rm value, the properties of the hydrogen-bonded clusters and, in turn, the mechanical properties of HNSPs can be easily controlled.

Due to the abundance of hydrophilic groups in their molecular structure, HNSPs can spontaneously absorb water molecules from the environment. Surprisingly, HNSPs can achieve reversibly transition between two states of matter, shifting from a sturdy and tough solid to a viscoelastic liquid and back. As shown in Fig. 2f a cured HNSP sample was placed on a metal grid and maintained shape stability in a dry environment, demonstrating the system integrity. Upon exposure to a high-humidity environment, the HNSPs will spontaneously enter a self-destructive state, forming viscoelastic liquids that gradually drip and migrate beneath the metal grid over time. To investigate the dynamic mechanical behavior of HNSPs during their self-destructive, we analyzed their rheological properties of HNSPs (Fig. S16). Upon exposure to high humidity, HNSPs exhibited spontaneous self-destructive behavior, reflected in the progressive decrease of their storage modulus (G′) and loss modulus (G″) relative to the original state. This gradual reduction in modulus indicates an increased fluidity of the polymer matrix, attributed directly to moisture-induced weakening of intermolecular hydrogen bonds, which are critical for maintaining the mechanical integrity and stiffness of HNSPs. To obtain deeper insights into the molecular and microstructural evolution occurring during the self-destructive process, wide-angle X-ray scattering (WAXS) was conducted (Fig. S17). Upon exposure to moisture-induced self-destructive, the scattering intensity became significantly weaker and broader, indicating moisture infiltration gradually disrupts intermolecular hydrogen bonded nanoclusters, leading to a loosened and disordered microstructure. The UV-vis spectra showed a characteristic peak at ~370 nm, corresponding to n-π* transitions of C=N and C=O groups (Fig. S18). As self-destructive time increased, the absorption peak intensity progressively decreased, indicating dispersion of HNSP molecular fragments into the aqueous phase, leading to a reduction in the concentration of chromophoric groups (C=N and C=O). Furthermore, to achieve secondary recycling under special applications, the self-destructive system can recover its initial state through high-temperature drying, as evidenced by macroscopic shape transformation and the restoration to a sturdy solid (Fig. S19).

Additionally, further experiments were conducted to assess the self-destructive rate of HNSPs, defined as the mass decreases speed of HNSPs (passing through a specified aperture sieve) over time and can be expressed to the amount of mass loss per unit time (g/h). As shown in Fig. 2g, with increasing Rm at a relative humidity of 80%, the self-destructive rate gradually declined and ultimately stabilized within a narrow range. The difference in self-destructive rates between the fastest (Rm = 1.7) and slowest (Rm = 2.1) systems is 1.69 times. When exposed to varying external humidity levels (Fig. 2h), HNSPs (Rm = 2.0) exhibits more significant changes, achieving a self-destructive efficiency of 804.27% at 90% RH compared to 60% RH. Therefore, by adjusting both humidity and Rm, we can effectively control the self-destructive rate of HNSPs over a broad range.

Based on the controlled self-destructive rate of HNSPs under moisture, the experimental model of temporary buildings, self-destructive Quick Response (QR) code and transience devices were designed to elaborate the significance and practical benefits (Fig. S20). A model of temporary bridge can sustain a standard weight of 100 g yet leads to the structural destruction of itself induced by moistures under 75% RH at 25 °C for 180 min (Fig. S20a). Intriguingly, a self-destructive QR code consisted of the black and white squares that arranged according to specific coding rules gradually become unrecognizable liquid mixtures due to the self-destructive behavior of HNSPs under moisture, realizing the self-erasure of information and the protection of information leakage (Fig. S20b). The moisture-triggered self-destructive transience devices that were constructed by mixing HNSPs with Ni powder, can be easily connected in series to the circuit and light up the small light bulbs, but ultimately became a diluted liquid and Ni powder after absorbing moisture, effectively reduce the pollution of electronic waste (Fig. S20c).

Hygroscopicity kinetics of HNSPs
To elucidate the mechanism of reversible transformation between the drying stability and high humidity-induced self-destructive, the hygroscopicity kinetics of HNSPs were further investigated50–52. as shown in Fig. 3a. The adsorption equilibrium points of HNSPs with different Rm values at 25 °C is presented. At lower humidity (RH < 40%), the weight of HNSPs shows minimal change, indicating limited water adsorption. As humidity increases, the water absorption capability of HNSPs progressively enhanced, with a maximum weight increase of 68.65% obsessed at 90% RH. Moreover, as Rm increases, the water absorption capability of HNSPs decreases gradually, with a 12.34% difference in the highest and lowest water adsorption values. During the desorption process, HNSPs gradually release water molecules, resulting in a decrease in total mass as humidity decreases. The residual mass of HNSPs with different Rm values shows minor variations, generally ranging between 16% and 19%. Fig. 3c illustrates the mass change of HNSPs (Rm = 2.0) throughout the adsorption-desorption cycle. The absorption rate significantly exceeds the desorption rate, and the mass cannot revert to the initial state of HNSPs. Table S2 details the mass changes of HNSPs in the adsorption-desorption cycle (The RH range from 0% to 90%), showing the phenomenon of desorption hysteresis. This hysteresis phenomenon may result from the formation of strong intermolecular force between water molecules and HNSP molecules, hindering water desorption. HNSPs exhibit a sensitive response to humidity changes, with notable differences in the equilibrium times of the two states (Fig. 3d). The equilibrium time of adsorption is longer than that of desorption, likely attributed to the process of breaking the existing hydrogen bonds between HNSPs molecular chains and then forming new hydrogen bonds during adsorption.

Additionally, the moisture diffusion behavior of HNSPs during the self-destructive process was conducted through Two-dimensional concentration diffusion simulation based on lattice Boltzmann method (LBM) (Fig. S21). At low humidity, the internal concentration of HNSPs remained nearly constant, with slightly lower concentration at boundaries. Increasing humidity elevated boundary concentrations, which then diffused inward, reaching equilibrium. Under constant high humidity (90% RH), initially, only boundaries exhibited high concentration, with low internal concentration. Over time, moisture diffused inward, leading most regions to equilibrium except a small central area. Simulation results closely matched experimental data, confirming Fickian diffusion behavior.

Moreover, to further elucidate above mechanism, low-field nuclear magnetic resonance (LF-NMR) was used to characterize the state changes of water during the adsorption-desorption process, distinguishing free water, immobilized water, and bound water by measuring proton relaxation times (Fig. 3e). Initially, HNSPs contained only trace amounts of immobilized water, with no detectable bound or free water, due to spontaneous moisture absorption during testing and sampling process. Upon moisture adsorption, the total water absorption mass of HNSPs increases, and the internal structural composition of the moisture changes. As depicted in Fig. 3f, when the proportion of bound water reaches 52%, immobilized water accounts for 43%, and free water constitutes a minor fraction of 5%. Over time, as the water absorption mass of HNSPs continues to increase (Fig. 3f), the proportion of bound water content further rises to 63%, while immobilized water decreases to 31%, and the proportion of free water remains nearly unchanged. This phenomenon suggests that immobilized water transforms into bound water during the adsorption process, indicating that HNSPs initially forms weak interactions with water molecules (immobilized water). As time progresses, more water molecules infiltrate between HNSP molecular chains, disrupting existing interactions and forming stronger hydrogen bonding (bound water). Subsequently, samples subjected to room temperature vacuum treatment (to more rigorously simulate desorption at low humidity) exhibit a significant reduction in total moisture absorption mass, accompanied by a marked decrease in water molecules across all three states (Fig. 3g). Additionally, the composition of water molecules in HNSPs undergoes significant changes, with an increase in the proportion of bound water and a sharp decrease in the proportion of immobilized and free water. This indicates that HNSPs preferentially remove free water and weaker immobilized water during the desorption process, due to the weak hydrogen bonding forces between some water molecules and HNSPs molecules. In contrast, bound water is difficult to remove, attributed to the presence of more abundant and stronger hydrogen bonds between certain water molecules and HNSP molecules, preventing water detachment during the desorption process53.

As shown in Figs. 3h, i, the interactions between water molecules and the hydrogen-bond clusters of HNSPs are also investigated. In-situ Fourier-transform infrared (FT-IR) spectroscopy under consistent RH conditions is used to examine changes in hydrogen bonds during water adsorption. In high-humidity environments (RH = 95%), the infrared absorption peak corresponding to the N-H stretching vibrations shifts from 3370 cm-1 to 3430 cm-1 over time, indicating that the pre-existing hydrogen-bonded state of the amino groups gradually convert to free amino groups. Additionally, as shown in Fig. 3i, the shift of the 1410 cm-1 peaks to a lower wavenumber further indicates the gradual dissociation of the stretching vibration peak of N-C, which belong to the amide group. These results reveal that exposure of HNSPs to high humidity leads to the breaking of hydrogen bonds within HNSPs by water molecules.

Self-destructive mechanism of HNSPs
The hydrogen-bond nanoclusters in HNSPs are the primary contributors to their exceptional mechanical properties, formed through dense hydrogen bonds. To better reveal elucidate the inherent driving forces and mechanisms behind the self-destructive behavior of HNSPs, molecular dynamics (MD) stimulations using the all-atom OPLS force field is conducted to model the kinetic behavior of hydrogen-bond nanocluster structures under varying environmental conditions54,55. As shown in Fig. 4a, molecular segments autonomously aggregated under dry conditions, resulting in the formation of highly aggregated and overlapping hydrogen bond nanocluster structures. Surprisingly, when HNSPs are exposed to prolonged high humidity, water molecules will naturally infiltrate between the molecular chains, causing the hydrogen-bond clusters to relax. This infiltration can even lead to the detachment of individual molecular chains detaching from the cluster aggregates, causing them to disperse into the surrounding aqueous environment.

To further investigate the self-destructive mechanisms at molecular scale, the dynamics of individual molecular segments were analyzed during the transition from the initial state to the self-destructive state. The mean-square radius of gyration (Rg) and end-to-end distance (Å) are used to quantify the degree of molecular curling and the rigidity or flexibility of the molecular chains. As depicted in Fig. 4b, the Rg and the end-to-end distance of HNSPs increase by 123.53% and 170.82%, respectively, in the self-destruct state compared to in the initial state. As shown in Fig. S22 and Fig. S23, The longest end-to-end distance in the initial state is 15.46 Å, while it increases to 24.10 Å in the self-destructive state, which is 56% higher than that in the initial state. This suggests that the molecular segments are becoming more and more loose, indicating a major alteration in molecular configuration, with a stretching behavior in the self-destructive state and a curling behavior in the initial state. Notably, the change in hydrogen bonds is a key factor responsible for the pronounced differences between these two states. In dry environment, the hydrogen bonds between HNSP chains are tightly bound, maintaining a high number of hydrogen bonds. However, under high humidity conditions, the number of hydrogen bonds within the clusters sharply decreases, leading to a loose cluster structure (Fig. 4c). These hydroxyl and amide groups in HNSPs, released from the clusters, will further interact with the water molecules to form new hydrogen-bond configurations, significantly increasing the number of hydrogen bonds in the water molecules (Fig. 4d). Concurrently, the lifetime of hydrogen bonds decreases when transitioning from the initial state to the self-destructive state (Fig. 4e).

The self-destructive mechanism for HNSPs was proposed to reveal how microscopic changes strongly influence their macroscopic physical properties (Fig. 4f). In the initial state, polymer chains are firmly interlocked through high-density hydrogen bonds, forming large and ordered hydrogen bond clusters that can endow HNSPs with excellent mechanical properties. The molecular chains are curled, possessing high Gibbs free energy, which compromises the system’s stability56. However, environmental changes that trigger the self-destructive mode allow water molecules to infiltrate the cluster aggregates, breaking the internal high-density hydrogen bonds. As water molecules peel molecular segments away, new hydrogen bonds form, leading to the dissociation of hydrogen-bond clusters. The dissociative molecular chain stretch, resulting in a lower Gibbs free energy (ΔG = −41.837 KJ mol-1 compared to the initial state) and an increase in system stability. According to the trend of decreasing Gibbs free energy and increasing entropy, HNSPs will spontaneously transition from an initial state to the self-destructive state upon exposure to water molecules. This transition is manifested as a macroscopic self-destructive phenomenon, characterized by a reduction in mechanical properties and a change in the state of matter.

Methods
Materials
Tetraethylenepentamine (TEPA, C8H23N5, Mw = 189.30, technical grade purity, CAS No. 112-57-2), Acrylamide (AM, C3H5NO, Mw = 71.08, 99.0% purity, CAS No. 79-06-1), N-Methylolacrylamide (NMA, C4H7NO2, Mw = 101.1, 98% purity, CAS No. 924-42-5), Deuterated dimethyl sulfoxide (DMSO-d6, 99.8% purity) and Deuterium oxide (D2O, ≥99 atom% D) were purchased from Aladdin (Shanghai) Chemistry Co., Ltd. Deionized water (conductivity < 0.5 us/cm) was bought from the Chengdu Kelong chemical plant (China). Ni powder purchased from Brofos Nanotechnology Co. Ltd. All reagents were used as received without further purification unless otherwise noted.

Synthesis of HNSPs
Taking the molar weight ratio Rm = 2.0 as an example, the addition amount of NMA and AM were 20.22 g (0.2 mol) and 14.22 g (0.2 mol), respectively. The addition amount of TEPA was 18.93 g (0.1 mol). Deionized water was used as the solvent with an addition amount of 22.5 g, and the concentration of all synthesized samples were controlled at 70%. NMA and AM were added to the three-neck round bottom flask and dissolved in Deionized water. Consequently, TEPA was evenly dripped into flask and further kept at 25 °C for 2 h under stirring. The obtained mixture was heated at 40 °C and stirring for 3 h and then heated to 65 °C for 4 h. The as-obtained viscous polymer solution was next poured into homemade silicone mold and then heated on a hot plate at 80 °C and finally placed in a vacuum oven at 100 °C for 12 h to remove the deionized water to obtain the final materials.

Characterization
General Characterization. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy (Nicolet is50, Thermo fisher Scientific) with the scanning range from 4000−400 cm-1.

X-ray photoelectron spectroscopy (XPS PHI 5000 VersaProbe III) can effectively detect the elemental composition and chemical valence state.

Proton-1 and carbon-13 nuclear magnetic resonance (1H-NMR) (AV III HD 400 MHz) were used to determine the chemical composition of the obtained materials The ideal molecular structure HNSPs measured in DMSO-d6 and D2O. HMBC (1H detected heteronuclear multiple bond correlation) and HSQC (Heteronuclear Single Quantum Coherence) were measured in DMSO-d6.

X-ray diffraction measurements were carried out on an Ultima IV X-Ray diffractometer (Rigaku) with Cu Kα radiation (λ = 0.15418 nm) at the accelerating voltage of 35 KV and emission current of 30 mA at a scanning range of 5°−55° and a scanning rate of 5° min-1.

Differential scanning calorimetry (DSC, Netsch DSC 204F) was used to measure the glass transition temperature. The whole test procedure is that the temperature increased from 25 °C to 80 °C, followed by isothermal at 120 °C for 3 min, and then cooled down to −50 °C while maintaining at −50 °C for 3 min. Finally, the sample was heated to 120 °C again. Both the heating rate and cooling rate were 10 °C·min−1. The nitrogen flow rate is 50 mL·min−1.

Thermogravimetric analyses (TGA) were performed on the SDT Q600 instrument in the temperature range from 25 °C to 600 °C at the heating rate of 10 °C min-1 in a nitrogen atmosphere.

The compress tests were implemented at room temperature using a universal testing machine (Instron 5966, 10 KN) with 5 mm min-1 rate. The mechanical tests were performed at a strain rate of 5 mm min-1 at room temperature with a humidity of 40−50%. The specimens were model into dimensions of 25 mm × 10 mm × 10 mm. The result was obtained by averaging five specimens.

Cryogenic scanning electron microscopy (Cryo-SEM) experiments were performed on a ThermoFisher Scientific (FEI)-Apreo S HiVoc scanning microscope (FEI Company, US) equipped with a Quorum cryo-stage PP3010T. The samples for observation were prepared by a freeze-drying method: samples were first frozen in liquid nitrogen (−185 °C) for 30 s, and then were transferred to a chamber to sublimate the moisture under vacuum at −90 °C for 10 min. Subsequently, the samples do not need to be coated (like Au) and then observed at −140 °C at an acceleration voltage of 5 kV. The reason why the samples do not need to be coated is that the size of the gold nanoparticles is much larger than the observed microstructure, which can affect the observation of the sample. Due to the lack of gold coating, there may be a decrease in image contrast and an increase in signal noise during sample observation.

Zeta potential measurements were conducted using a Malvern Zetasizer Nano ZSE instrument by detecting back-scattered light at an angle of 173°, equipped with a 4 mW He-Ne laser operating at 633 nm. Aqueous dispersions of the copolymer nanoparticles were diluted to 0.10% w/v using deionized water. Aqueous electrophoresis measurements were conducted using disposable folded capillary cells supplied by Malvern (DTS1070) using the same instrument.

Transmission Electron Microscope (TEM) images were obtained by depositing droplets of 0.5% w/v aqueous dispersion of HNSPs onto carbon-coated cooper grids using a JEOL/JEM-1400 Flash instrument at an operating voltage of 120 kV.

Rheological measurement was carried out using a rheometer (ThermoFisher, Mars 60) with a parallel plate geometry (20 mm diameter rotating top plate). storage modulus (G′) and loss modulus (G″) and temperature (80 °C) with an increase in frequency (from 0.1−100 rad s-1) were obtained.

The wide-angle X-ray scattering (WAXS) measurements were performed on a synchronous diffraction laboratory instrument, Nano-inXider (Xenocs, France), equipped with a micro-focus source generating X-rays of a wavelength λ = 1.542 Å (Genix 3D), operating at 50 kV and 0.6 mA.

The UV-vis spectra of HNSPs were observed on a UV-3600 Spectrophotometer (Shimadzu).

The water vapor sorption is tested with a dynamic vapor sorption (DVS) system under constant humidified airflow. The sorption-desorption performance was measured by a DVS system (Surface Measurement Systems LTD, DVS Adventure). The airflow of DVS is fixed at 200 mL min-1 for all samples as the standard setting. The sorption-desorption performance was measured by a DVS system (Surface Measurement Systems LTD, DVS Adventure). The test samples are preheated at 105 °C, 0% RH for 5 hours in the testing chamber for completed drying, and then placed at 25 °C for 2 hours stabilization. The mass of test HNSPs sample was about 30 mg, and the adsorption-desorption performance was measured at 25 °C with the humidity range from 0% to 90% and then to 0%, conducted at a humidity rate of 10% as a step. When the weight of the sample is finally stable at a certain humidity (the change in the mass of the sample within 10 min is less than 0.01% of the absolute dry mass), the sample is considered to reach a moisture content equilibrium state at that humidity, then the testing program adjusts RH adjusted to the next level for repeated testing.

Low-field 1H nuclear magnetic resonance (NMR) was used to reflect the existence and distribution of water molecules. By measuring the relaxation time to elucidating the interaction between structural heterogeneity and mobility of molecules. In general, the relaxation time of free water is long, while that of bound water is short. LF-NMR spectra were measured on a VTMR20-010V-I NMR analyzer (Su-zhou Niumag Analytical Instrument Corporation, Suzhou, China).

In-situ FTIR: The Fourier transform infrared spectra were collected on a Thermo Fisher Nicolet iS20 spectrometer equipped with a glow bar source, KBr beam splitter and a liquid-nitrogen-cooled mercury cadmium telluride detector. Furthermore, all the spectra were collected in the ATR mode on a self-supported wafer of the sample using a custom-built infrared cell. The sample atmosphere was controlled by a mass flow controller and a pressure gauge.

Self-destructive efficiency test
The parameters of HNSPs used for self-destructive tests are as follows: diameter ≈ 20 mm, thickness ≈ 1 mm, and mass ≈ 0.4–0.8 g. The samples were placed on a stainless-steel mesh (aperture ≈ 3.8 mm, wire diameter ≈ 0.5 mm) and placed in a Temperature-Humidity Test Chamber (DHT-500, computer-controlled). By adjusting the humidity of the testing environment through Temperature-Humidity Test Chamber, the shape and weight decay of the sample with humidity changes were recorded. And we observe the remaining HNSPs samples on the stainless-steel sieve, and determine the self-destructive efficiency of HNSPs (with different Rm) at different humidity levels.

Here, we have defined that the self-destructive rate of HNSPs as follows: The speed that the decreases mass of the test sample (passing through a specified aperture sieve) over time, in which the standard sample perform the programmed self-destruction behavior triggered by moistures under the same temperature and humidity conditions. It can demonstrate the self-destructive speed of materials under the environmental conditions, which can express in terms of the amount of mass loss per unit time (g/h) or the percentage of mass loss (%/h). The calculation formula is X = (MI - Mc) / T (X: Self-destructive speed; MI: Initial mass (g); Mc: Current mass (g); T: Time (hours)). Considering the hygroscopicity of HNSPs, we have deducted the additional hygroscopic mass generated by the hygroscopic process to obtain the current mass of the material (Mc) (based on the DVS experimental data or the percentage of overall device hygroscopicity mass). Notably, the above results are the results of testing the relative self-destructive rates of different Rm, which may be affected by the size of the aperture line diameter.

Molecular dynamics (MD) simulations
Models and computational details. In this work, a standard molecular mechanics’ potential model was used with the following functional form:

u(rN) = Σ bonds k/2(li - li,0)2 + Σ angles k/2(θi - θi,0)2 + Σ torsions Vn/2(1 + cos(nω - γ))

+ Σi=1N Σj=i+1N (4εij [(σij/rij)12 - (σij/rij)6] + qiqj/rij)

where the first three terms are the bonded interactions, including bond, angle, and torsion interactions, and the second terms are non-bonded interactions, including van der Waals and Coulombic interactions. For different kinds of atoms, the Lorentz-Berthelot mix rules were adopted for van der Waals interactions, which is following the equation:

σij = 1/2(σii + σjj); εij = (εii * εjj)1/2

According to the experimental conditions, two systems were constructed. In the system, 30 molecules were placed randomly in a cubic box with dimensions of 6×6×6 nm3. The simulations were performed using GROMACS package (version 2023.3)57–60 with the all-atom OPLS force field61. The steep descent method was used to minimize the energy of the system. Then, molecular dynamic simulations under NVT ensemble at 298 K were performed for 20 ns for the first system. After the simulation, all 30 molecules have aggregated into a cluster. Water molecules were filled into the box to build the initial configuration of the second system. Then, molecular dynamic simulations under NPT ensemble were performed for 20 ns for the second system. LINCS algorithm62 was applied to constraint the bond lengths of other components. Periodic boundary conditions were applied in all three directions. The temperature was maintained using the V-rescale thermostat algorithm63. The cut-off distance for the Lennard-Jones and electrostatic interactions was 1.2 nm. Particle mesh Ewald method was used to calculate the long-range electrostatic interactions64. Configurations were visualized using Visual Molecular Dynamics software65.

Two-dimensional concentration diffusion simulation based on lattice Boltzmann method (LBM)
Background. Diffusion phenomena are widely observed in both natural and engineering contexts, such as groundwater solute migration, geotechnical contamination dispersion, and mass transfer in chemical reactions. Fundamentally, concentration diffusion is a mass transport process driven by the random thermal motion of molecules, typically described by Fick’s second law:

∂C/∂t = D∇2C

where C(x, y, t) represents the solute concentration at a given time and position, D is the diffusion coefficient, and ∇² is the Laplacian operator in two dimensions.

Traditional numerical methods such as the Finite Difference Method (FDM) and Finite Element Method (FEM) can encounter limitations when dealing with complex boundaries or coupled physical processes. The Lattice Boltzmann Method (LBM), a mesoscopic numerical approach based on kinetic theory, simulates the propagation and collision of particles on a discrete lattice to solve the macroscopic diffusion equation indirectly. It offers several advantages:

– High numerical stability;
– Well-suited for parallel computing;
– Efficient handling of complex boundaries and multi-physics coupling;
– Naturally accommodates anisotropy and spatial heterogeneity due to its inherent structure.

Modeling principle of lattice Boltzmann method. The D2Q9 model utilizes nine discrete velocity directions: one rest particle, four along the Cartesian axes, and four diagonals. The evolution equation is given by:

fi(x + eiΔt, t + Δt) = fi(x, t) - 1/τ (fi - fi eq)

Where, fi eq = wi * C. The macroscopic concentration C = Σ fi

The relationship between the diffusion coefficient D and the relaxation time τ is as follows66:

D = c2(τ - 0.5)Δt, c = 1/√3

Numerical implementation process. The model was implemented in MATLAB. The main computational steps are:

(1) Initialization of the concentration field and distribution functions
(2) Collision computation
(3) Streaming (propagation) step
(4) Application of boundary conditions
(5) Calculation of macroscopic concentration
(6) Iteration over time steps until the simulation ends

Boundary conditions and initial conditions. A 150×150 square domain was established, with each grid cell representing 40 micrometers. The simulated scenario is an absorption process under 90% relative humidity. Initially, all boundary nodes are set to a high concentration corresponding to equilibrium at 90% RH (157%), while the internal nodes are initialized to a low concentration corresponding to 80% RH (137%).

Peer review rounds
[{"round": 1, "reviewer_comments": {"reviewer_1": "This work introduces a novel concept in the design of mechanically bistable self-destructive polymers. The effects of relative humidity on the overall mechanical response and properties are discussed in detail. I have several technical suggestions as follows:\n(1)The presentation of the designed materials' important demand and superiority is insufficient in this paper. The authors need to provide more in-depth analysis and evidence to convince the readers of the materials' significance and practical benefits, such as some demonstrative experiment.\n(2) The author can summarize conventional responsive polymers from the aspects of polymer network structure and its dynamic behavior more scientifically, to illustrate the difference with this materials.\n(3) Hydrogen-bond nanocluster serve as the critical factor influencing mechanical response; therefore, its dynamic mechanical behavior investigation would enhance the study.\n(4) Response behaviors of conventional phase transition materials rely on a well-defined characteristic relaxation behavior, such as glass transition. Instead, the material is actually affected by both humidity and temperature, and its mechanical properties are highly correlated with these conditions. Therefore, authors may need reconsider using the “bistable” concept.\nThank you for giving me the chance of reading your work. I sincerely hope these suggestions will assist you in improving the quality of your article.", "reviewer_2": "The authors present an efficient and conceptually novel approach for constructing hydrogen-bonded nanocluster self-destructive polymers (HNSPs) that integrate high mechanical strength with controllable self-destruction. The reported materials exhibit impressive mechanical properties, including a compressive strength of 15 MPa and a Young’s modulus of 165 MPa, and demonstrate reversible moisture-responsive behavior. This study introduces an intriguing system with potential implications for smart materials design. However, in order to fully evaluate the scientific significance and practical relevance of the work, the following points should be addressed:\n1. Practical Applicability and Environmental Conditions:\nWhile the self-destructive behavior triggered by humidity is scientifically interesting, the practical utility of such materials in real-world environments remains unclear. Humidity is inherently variable and often difficult to control in natural settings. The authors are encouraged to clearly define the range of environmental conditions (e.g., humidity thresholds, temperature dependence) under which the HNSP system functions effectively. This would significantly strengthen the applicability of the work.\n2. Structural Changes in Response to Humidity:\nA deeper analysis of how nanoclusters respond to varying humidity levels is critical. In particular, a detailed discussion supported by transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS) data regarding cluster size evolution and dissolution upon moisture exposure would enhance understanding of the material’s structural dynamics.\n3. Anisotropy and Mechanical Behavior:\nSpider silk is often cited as a benchmark for its mechanical anisotropy. It would be valuable to determine whether the HNSP films exhibit any anisotropic mechanical properties. Furthermore, can anisotropy be induced by stretching or spinning, and if so, is the process reversible? Clarifying this aspect would add an important dimension to the study.\n4. Controllability of Nanocluster Size:\nThe possibility of tuning the nanocluster size through variations in fabrication conditions could be a promising avenue for tailoring mechanical performance. The authors should discuss whether processing parameters influence nanocluster dimensions, and consequently, how these changes correlate with the mechanical properties of the films.\n5. Moisture Absorption and Volume Expansion:\nThe manuscript would benefit from a quantitative analysis of water uptake and its spatial distribution within the film. Does the absorbed moisture penetrate uniformly throughout the material, or is it localized at the surface? This distinction is crucial for understanding the observed volume expansion and mechanical deformation behavior.\n6. Origin of Orange Coloration and Optical Properties:\nThe cause of the orange coloration observed in the films remains unclear. The authors are encouraged to investigate whether a shift in the optical absorption spectrum occurs upon phase transition from solid to liquid. Such analysis would not only clarify the coloration mechanism but also potentially provide an optical signature of the transition behavior.\nOverall, the manuscript presents a promising material system with interesting responsive features. Addressing the points above would significantly enhance the clarity, completeness, and impact of the work.\nDoes the work support the conclusions and claims, or is additional evidence needed?\nYes\nAre there any flaws in the data analysis, interpretation and conclusions? Do these prohibit publication or require revision?\nNo\nIs the methodology sound? Does the work meet the expected standards in your field?\nYes\nIs there enough detail provided in the methods for the work to be reproduced?\nYes", "reviewer_3": "Summary. This manuscript presents an interesting strategy of molecular structure design to form self-destructive polymer materials based on hydrogen-bond nanoconfined within the matrix (HNSPs). The authors report the synthesis of a supramolecular polymer capable of forming hydrogen bonds and exhibiting hydrophilic characteristics. These materials demonstrate remarkable mechanical properties, attributed to the presence of hydrogen-bond clusters, and exhibit bistable solid–liquid like switching behavior. This switching is enabled by the sensitivity of the system to moisture. It has been demonstrated that the self-destructive behavior can be modulated by varying the formulation and the surrounding humidity, offering a high level of control over the degradation response. The study includes measurements of the structural, mechanical, and moisture-responsive properties of the materials, along with a comprehensive investigation of the mechanism governing the transition. In addition, molecular dynamics simulations are performed to support and further elucidate the molecular level interaction.\nIn conclusion, the study is original and well conducted. However, further details are needed to support the conclusions. We recommend the publication of the manuscript after major revision.\nStrengths of the Manuscript. A major strength is the simplicity of the reaction (one-step in water) and the ability to easily tune the formulations, which in turn modifies the hydrogen-bonded cluster architecture and therefore the mechanical properties and functional responses of the HNSPs.\nAnother strength of the manuscript lies in the reversibility of the phase transition. At the same time, this reversibility is not immediate and the material remains in its degraded state even after the moisture is removed, and reversing the process requires more severe environmental conditions. This behavior is useful for applications that require stable and lasting changes, while still allowing the material to be reversed under specific conditions if necessary.\nComprehensive Experimental Approach: The authors have conducted different experiments to validate their concept, including structural, mechanical, and moisture-responsiveness analyses. In addition, the study clearly investigates the mechanism behind the transition. Molecular mobility was explored by measuring relaxation times, offering insight into the type of water molecule. This experimental approach is also supported by molecular dynamics simulations, which provide valuable information on the role of hydrogen bonding and water interactions at the molecular scale.\nInsufficient details.\nThe concentration used during the polymer synthesis is not mentioned.\nThe supramolecular structure is not clear. The manuscript mentions that polymerization is limited to the structure shown in Figure S1 and that the supramolecular organization is formed by hydrogen bonding. However, the nature of the chains connecting the clusters is not clear.\nReversibility of the Transition:\nThe authors provide some information on water molecule types and desorption behavior using DVS, which is useful.\nHowever, they do not show whether the material fully recovers its original mechanical properties or hydrogen-bonding structure. Additional data would help confirm the claimed reversibility.\nThe authors also mention that the phase-switching process can be repeated multiple times, but no experimental data or characterization is provided to support this claim. Showing the behavior over many cycles, especially regarding structure or mechanical performance, would be important to confirm this.\nIt’s important to mention the plasticity of the material, especially if there is any residual deformation. This could help better understand the mechanical behavior of the material.\nTerm self-destruction efficiency/ self-destruction rate: it is not clear how it was quantitatively defined or measured (diffusion of moisture !!). It would be helpful if the authors could specify this.\nIt would be useful to do DSC analysis at higher temperatures (up to 200 °C) to check for a possible endothermic transition related to hydrogen bond breaking.\nSpecific Comments. At first reading of the abstract, the introduction of the term weight ratios (Rw) without a prior definition may cause some confusion. It would be preferable to define it explicitly upon its first appearance.\nPlease indicate the solvent used for the NMR analysis in the experimental section or at the beginning of the legend of Figure S3. It is only mentioned at the end of the page, which may cause confusion or make it harder for the reader to locate this important information.\n1H-NMR spectra. NMR spectra not clear.\nIt would may be useful to add both the spectrum of polymer and of the individual monomers.\nThe peak assignments in the NMR spectrum appear to be questionable. Based on the expected chemical shifts for the functional groups present, some of the assignments may need to be revised or further justified. For example, peak 2 in structure 1-1, corresponding to the CH₂OH group generally appears around 3.5 ppm, but it is reported at approximately 2.5 ppm in the manuscript.\nIn addition, the integration of the signals could be mentioned, as it can help confirm the polymer structure and gives a way to quantify the ratio between different possible structures.\n13C-NMR spectra. The carbonyl groups 15 from structure 1-2 and 4 from structure 1-1 have a very similar chemical environment and are likely to appear together. In fact, the peak at 173 ppm corresponds to the other carbonyl group: 2 in structure 1-2 and 17 in structure 1-1.\nTo confirm all this assignment, HMBC and HSQC experiments are strongly recommended.\nThe assignment to position 23 appears to be an error; it should be position 13 instead.\nThe peak at 62.4 ppm belongs to -CH2 groups (2) at both ends of the 1-1 structure backbone: yes but also 17 of the structure 1-2.\nThe peaks corresponding to position 12 in structure 1-1 and position 10 in structure 1-2 are not assigned; they are expected to appear around 50 ppm.\nWhile the XPS analysis confirms the presence of C, O, and N and their functional groups, it’s not clear what new or useful information it adds. Also, deconvolution methods should be described at least briefly.\nFigure 2c, 2d and 2g add Rw to the x-axis and figure 2h RH\nIn Figure 2c, no error bars are shown for the modulus values, although the tests were performed on five samples. Including error bars would be helpful to show the reproducibility of the mechanical data.\nIn Figure 2d, it appears that equilibrium may not have been completely reached at each humidity step. In several segments, the sample mass still appears to be changing. It would be better to ensure that the mass stabilizes at each step before moving to the next RH level, or to provide details on the equilibrium criteria used.\nIn Figure 3f and 3g, the color coding related to the different types of water is not indicated directly in the figure or legend. Although the different types of water corresponding to each percentage are explained in the text, including a legend is necessary. Furthermore, it is not clear which sample the data correspond to, and no information is provided in the figure, the legend, or the main text.\nLine 278 The authors should avoid referring the IR peak to a hydrogen bond peak. It would be more accurate to describe it as the N–H stretching vibration, which shifts due to the presence or absence of hydrogen bonding.\nSome minor corrections.\nLine 280 Additionally, as shown in Figure 3b Figure 3i, the shift of the 1410 cm-1 281 peaks to a higher wavenumber further indicates the 282 gradual dissociation of hydrogen bonds.\nLine 259 Over time, as the water absorption mass of HNSPs continues to increase (Figure 3g) (Figure 3f)\nLine 47 (SI) For the sample showing the surface morphology, which was prepared by touching one edge of the sample and with no spraying sentence is incomplete, needs correction.\nLine 93 Under ambient conation?\nLine 285 Figure 3. Influence of hygroscopicity kinetics on self-destruction performance for HNSPs. (a) Adsorption and desorption isotherms measured using the DVS analyzer. (b) Desorption isotherms measured using the DVS analyzer.\nLine 244 0 to 90% RH)", "reviewer_4": "I co-reviewed this manuscript with one of the reviewers who provided the listed reports. This is part of the Nature Communications initiative to facilitate training in peer review and to provide appropriate recognition for Early Career Researchers who co-review manuscripts."}, "author_response": "Authors’ response to decision letter for our Research Article, Paper ID: NCOMMS-25-14076.\n“Mechanically Bistable and Humidity-Tunable Self-Destructive Polymers Enabled by Hydrogen-Bond\nNanoconfinement”\nResponses to the reviewers’ comments\nOn behalf of all my co-authors, thank the editor and all reviewers for their constructive comments and\nsuggestions on the original manuscript, which can help us to greatly improve the quality of this work.\nWe have revised the manuscript substantially as per the reviewers’ suggestions, examined the whole\nmanuscript carefully and made corrections accordingly. The changes are highlighted in yellow in the\nresubmitted version and the point-to-point response to reviewers is listed as following:\nReviewer #1\nGeneral Comment. This work introduces a novel concept in the design of mechanically bistable self-\ndestructive polymers. The effects of relative humidity on the overall mechanical response and properties\nare discussed in detail. I have several technical suggestions as follows:\nReply: We thank the reviewer for very positive feedback for our manuscript and the insightful comments.\nWe have revised the manuscripts by addressing the constructive suggestions noted by the reviewer as\ndetailed below. We believe that these changes have substantially improved the quality of our manuscript.\nComment 1. The presentation of the designed materials' important demand and superiority is insufficient\nin this paper. The authors need to provide more in-depth analysis and evidence to convince the readers\nof the materials' significance and practical benefits, such as some demonstrative experiment.\nReply: Thank you for your helpful comment.\n(1) Firstly, in the revised manuscript, we added more statements in the introduction section of the revised\nmanuscript to elaborate the important demand and superiority of HNSPs.\nChanges (p. 2): In Page 2 of the introduction section\n“This research addresses the urgent need for advanced materials capable of controlled self-\ndeconstruction, which is crucial for applications ranging from electronic waste reduction and data\nsecurity to minimizing invasive medical procedures.”\nChanges (p.3): In Page 3 of the introduction section\n“Thus, developing transient materials or device capable of self-deconstruction or controlled dissolution\nat specific times and rates remains a significant challenge.”\n(2) Secondly, we have added some demonstrative experiments to describe the potential application\nperformance of HNSPs with as per the Reviewer’s suggestions for further elaborating the materials'\nsignificance and practical benefits. The experimental process and results of demonstrative experiments\nare shown in Fig. S20 (Supplementary Information). Simultaneously, we have added the description and\nexplanation of the Fig. S20 in results section of “Mechanical and Self-destructive Properties of HNSPs”\nin Page 15. It follows:\nChanges (p.15):\n“Based on the controlled self-destructive rate of HNSPs under moisture, the experimental model of\ntemporary buildings, self-destructive Quick Response (QR) code and transience devices were designed\nto elaborate the significance and practical benefits (Fig. S20). A model of temporary bridge can sustain\na standard weight of 100 g yet leads to the structural destruction of itself induced by moistures under 75%\nRH at 25 ℃ for 180 min (Fig. S20a). Intriguingly, a self-destructive QR code consisted of the black and\nwhite squares that arranged according to specific coding rules gradually become unrecognizable liquid\nmixtures due to the self-destructive behavior of HNSPs under moisture, realizing the self-erasure of\ninformation and the protection of information leakage (Fig. S20b). The moisture-triggered self-\ndestructive transience devices that were constructed by mixing HNSPs with Ni powder, can be easily\nconnected in series to the circuit and light up the small light bulbs, but ultimately became a diluted liquid\nand Ni powder after absorbing moisture, effectively reduce the pollution of electronic waste (Fig. S20c).”\nFig. R1 (Supplementary Fig. S20) The multi-functional applications of HNSPs. The self-destructive\nbehavior of the HNSPs substrates can be tuned by controlling the environmental conditions (humidity).\n(a) Schematic diagram of temporary building and corresponding self-destructive behavior. We have\nmixed HNSPs with ordinary sands in a 1:1 ratio and added a certain amount of water to adjust the\nviscosity of the mixtures. Subsequently, the mixtures were stirred evenly and placed in a predetermined\nmold, which need to dry at high temperature to obtain the required temporary building. We have\nconstructed a temporary bridge shaped building (length 8.4cm * width 2cm * height 3cm) that can\nsustain a standard weight of 100g. When the temporary building model is induced by moistures (25 ℃,\n75% RH, 180 min), which triggered the self-destructive behavior of HNSPs and the structural changes,\nultimately leading to the failure of the temporary building. As the self-destructive time increases, we have\napplied a certain external force to the \"destroyed\" temporary building to make it \"fragment\". (b)\nSchematic illustration of information loading through mold forming technique and corresponding self-\nerasure of information. We have mixed HNSPs with different inks and poured them into customized QR\n(Quick Response) code molds. After drying, we can obtain HNSPs loaded with hidden information, which\ncan be recognized by scanning the QR code to obtain the inside information (specific content:\nInformation Encryption). With the self-destructive of HNSPs, the black and white squares arranged\naccording to specific coding rules are also gradually self-destructed and become unrecognizable liquid\nmixtures, realizing the self-erasure of information. The transient appearance of information can\neffectively prevent information leakage. (c) Moisture-triggered self-destructive behavior of transience\ndevices. We have mixed HNSPs with Ni powder in a ratio of 1:2 and obtained electronic composite\nmaterials through high-temperature treatment. The resistance value of the prepared composite materials\nis in the range of 102 Ω, which can be easily connected in series to the circuit and light up the small light\nbulbs in the circuit, proving the good conductivity of the material and the potential in electronic devices.\nAdditionally, the device can spontaneously absorb moisture and induced the self-destructive behavior,\nwhich can change the shape of the device to ultimately become a diluted liquid and Ni powder, achieving\nthe moisture-triggered self-destructive of electronic devices.\nComment 2. The author can summarize conventional responsive polymers from the aspects of polymer\nnetwork structure and its dynamic behavior more scientifically, to illustrate the difference with this\nmaterials.\nReply: Thank you for your thoughtful suggestion.\n(1) Firstly, Responsive polymer materials with variable mechanical properties have similarities with the\nself-destructive behavior mentioned in this manuscript. These smart responsive polymer materials still\nface a common limitation that their mechanical response is passive sustained only when an intense\nexternal stimulus (for example, heat, light, or electric potential). Their response mechanisms of common\nresponsive polymer materials are often through the passive introduction of dynamic bonds, glass\ntransition, crystallization melting transition and phase separation. When external stimulus is removed,\nresponsive polymers inevitably return to their original state rather than continuing to maintain their self-\ndestructive state.\nSecondly, the HNSPs mentioned in this manuscript can actively trigger their self-destructive behavior\nunder mild external stimuli (moisture), which can maintain this self-destructive state even after removing\nmoisture stimuli. Our devised HNSPs can make the self-destructive state stable without continuous\nstimulation under the same conditions (an external stimulus is required to trigger the self-destructive\nbehavior, rather than maintain the stimulus state.), simultaneously achieving the transformation from a\nhard solid to a fluid like state. At the same time, the moisture serves as a stimulus that can actively trigger\nself-destructive behavior, which is different from the common passive stimulus method that trigger\nmechanoresponsive polymers. Especially, the stiffness switching performance of responsive polymer is\nlimited, and it is almost impossible to achieve such a huge transition from solid to fluid. The mechanism\nof this self-destructive materials is achieved by the transformation of HNSPS hydrogen bonds and\nmolecular chain configurations induced by moisture.\n(2) In the results section of “Self-destructive Mechanism of HNSPs”, we have illustrated the difference\nbetween conventional responsive polymers with our designed self-destructive polymers. It follows (p.\n23): “In the initial state, polymer chains are firmly interlocked through high-density hydrogen bonds,\nforming large and ordered hydrogen bond clusters that can endow HNSPs with excellent mechanical\nproperties. The molecular chains are curled, possessing high Gibbs free energy, which compromises the\nsystem's stability. However, environmental changes that trigger the self-destructive mode allow water\nmolecules to infiltrate the cluster aggregates, breaking the internal high-density hydrogen bonds. As\nwater molecules peel molecular segments away, new hydrogen bonds form, leading to the dissociation\nof hydrogen-bond clusters. The dissociative molecular chain stretch, resulting in a lower Gibbs free\nenergy (ΔG= -41.837 KJ mol-1 compared to the initial state) and an increase in system stability.”\nComment 3. Hydrogen-bond nanocluster serve as the critical factor influencing mechanical response;\ntherefore, its dynamic mechanical behavior investigation would enhance the study.\nReply: We would like to express our sincere thanks for your constructive suggestion. We have added\nrheological performance test experiment to study its dynamic mechanical behavior of HNSPs as per the\nReviewer’s suggestion. (1) Firstly, it is worth noting that at conventional temperatures (25 ℃), HNSPs\nexhibit a hard solid shape with high modulus, making it difficult to determine and analyze the viscous\nbehavior of HNSPs through rheological testing. Therefore, we selected a higher temperature (80 ℃) to\ntest and compare the rheological properties of HNSPs with different Rm, which all keep in fluid state. At\nthe same time, the rheological curves of the samples after self-destructive at different times were also\ntested, and the testing conditions remained the same as above.\n(2) Secondly, we have added the experimental testing process in the section of “General Characterization”\nin the Supplementary Information. It follows:\nChanges (p. 5, Supplementary Information):\n“Rheological measurement was carried out using a rheometer (Thermo Fisher, Mars 60) with a parallel\nplate geometry (20 mm diameter rotating top plate). storage modulus (G′) and loss modulus (G″) and\ntemperature (80℃) with an increase in frequency (from 0.1 to 100 rad s-1) were obtained.”\n(3) Thirdly, the rheological performance test experiment of HNSPs were shown in Fig. S16 of the\nSupplementary Information. Simultaneously, we have added the description and explanation of the Fig.\nS16 in results section of “Mechanical and Self-destructive Properties of HNSPs” in Page 14. It follows:\nChanges (p. 14):\n“To investigate the dynamic mechanical behavior of HNSPs during their self-destructive, we analyzed\ntheir rheological properties of HNSPs (Supplementary Fig. S16). Upon exposure to high humidity,\nHNSPs exhibited spontaneous self-destructive behavior, reflected in the progressive decrease of their\nstorage modulus (G′) and loss modulus (G″) relative to the original state. This gradual reduction in\nmodulus indicates an increased fluidity of the polymer matrix, attributed directly to moisture-induced\nweakening of intermolecular hydrogen bonds, which are critical for maintaining the mechanical integrity\nand stiffness of HNSPs.”\nFig. R2 (Supplementary Fig. S16) The rheological properties of HNSPs. (a) Rheological curves of the\nHNSPs with different Rm values. It can be found that both storage modulus (G′) and loss modulus (G″)\nof HNSPs increase with the increase of the Rm in the HNSPs. This result indicates that the rigidity of the\nHNSPs increases with the increase of the fraction of the AM/NMA. At 80 °C, the G″ of all HNSPs is\ngreater than G′, indicating that the HNSPs are dominated by viscous behavior, the energy dissipation\ncapacity exceeds the elastic energy storage capacity, and the materials tend to exhibit fluidity. (b)\nRheological curves of the HNSPs with different self-destructive time (Rm=2.0). When exposed to high\nhumidity, HNSPs will spontaneously perform self-destructive behavior. Compared with the HNSPs in the\noriginal state, the G′ and G″ of HNSPs decreased gradually with the increase of the self-destructive time.\nThis phenomenon shows that the fluidity of HNSPs gradually increase and the moisture weakens the\nhydrogen bonding interaction between molecules, which is the main source of its mechanical properties\nand stiffness.\nComment 4. Response behaviors of conventional phase transition materials rely on a well-defined\ncharacteristic relaxation behavior, such as glass transition. Instead, the material is actually affected by\nboth humidity and temperature, and its mechanical properties are highly correlated with these conditions.\nTherefore, authors may need reconsider using the “bistable” concept.\nReply: We have carefully considered this suggestion of the reviewer, and found that the concept of\n“bistable” mentioned in this paper can indeed cause some confusion and misunderstanding. Therefore,\nafter careful consideration, we have decided to eliminate the term “bistable” and have made\ncorresponding changes to the article as follows.\n(1) Firstly, we have modified the original title “Mechanically Bistable and Humidity-Tunable Self-\nDestructive Polymers Enabled by Hydrogen-Bond Nanoconfinement” into “Mechanically-Robust and\nHumidity-Tunable Self-Destructive Polymers Enabled by Hydrogen-Bond Nanoconfinement.”\n(2) Secondly, we have deleted the expression of “bistable” in whole revised manuscript for a better\nunderstanding.\nReviewer #2\nGeneral Comment. The authors present an efficient and conceptually novel approach for constructing\nhydrogen-bonded nanocluster self-destructive polymers (HNSPs) that integrate high mechanical strength\nwith controllable self-destruction. The reported materials exhibit impressive mechanical properties,\nincluding a compressive strength of 15 MPa and a Young’s modulus of 165 MPa, and demonstrate\nreversible moisture-responsive behavior. This study introduces an intriguing system with potential\nimplications for smart materials design. However, in order to fully evaluate the scientific significance\nand practical relevance of the work, the following points should be addressed:\nReply: We thank the reviewer for very positive and constructive feedback for our manuscript. We have\nrevised the manuscripts by addressing the suggestions noted by the reviewer as detailed below and\nbelieve that these changes have substantially improved our manuscript.\nComment 1. Practical Applicability and Environmental Conditions:\nWhile the self-destructive behavior triggered by humidity is scientifically interesting, the practical utility\nof such materials in real-world environments remains unclear. Humidity is inherently variable and often\ndifficult to control in natural settings. The authors are encouraged to clearly define the range of\nenvironmental conditions (e.g., humidity thresholds, temperature dependence) under which the HNSP\nsystem functions effectively. This would significantly strengthen the applicability of the work.\nReply: We would like to express our sincere thanks for your constructive suggestion.\n(1) Firstly, we have added some demonstrative experiments to describe the potential application\nperformance of HNSPs in the revised manuscript. The experimental model of temporary buildings, self-\ndestructive Quick Response (QR) code and transience devices were designed to elaborate the practical\nutility of this materials in real-world environments, as shown in Fig. S20 of the Supplementary\nInformation. Simultaneously, we have added the description and explanation of the Fig. S20 in results\nsection of “Mechanical and Self-destructive Properties of HNSPs” in Page 15. It follows:\nChanges (p. 15):\n“Based on the controlled self-destructive rate of HNSPs under moisture, the experimental model of\ntemporary buildings, self-destructive Quick Response (QR) code and transience devices were designed\nto elaborate the significance and practical benefits (Supplementary Fig. S20). A model of temporary\nbridge can sustain a standard weight of 100 g yet leads to the structural destruction of itself induced by\nmoistures under 75% RH at 25 ℃ for 180 min (Supplementary Fig. S20a). Intriguingly, a self-destructive\nQR code consisted of the black and white squares that arranged according to specific coding rules\ngradually become unrecognizable liquid mixtures due to the self-destructive behavior of HNSPs under\nmoisture, realizing the self-erasure of information and the protection of information leakage\n(Supplementary Fig. S20b). The moisture-triggered self-destructive transience devices that were\nconstructed by mixing HNSPs with Ni powder, can be easily connected in series to the circuit and light\nup the small light bulbs, but ultimately became a diluted liquid and Ni powder after absorbing moisture,\neffectively reduce the pollution of electronic waste (Supplementary Fig. S20c).”\nFig. S20 The multi-functional applications of HNSPs. The self-destructive behavior of the HNSPs\nsubstrates can be tuned by controlling the environmental conditions (humidity). (a) Schematic diagram\nof temporary building and corresponding self-destructive behavior. We have mixed HNSPs with ordinary\nsands in a 1:1 ratio and added a certain amount of water to adjust the viscosity of the mixtures.\nSubsequently, the mixtures were stirred evenly and placed in a predetermined mold, which need to dry at\nhigh temperature to obtain the required temporary building. We have constructed a temporary bridge\nshaped building (length 8.4cm * width 2cm * height 3cm) that can sustain a standard weight of 100g.\nWhen the temporary building model is induced by moistures (25 ℃, 75% RH, 180 min), which triggered\nthe self-destructive behavior of HNSPs and the structural changes, ultimately leading to the failure of\nthe temporary building. As the self-destructive time increases, we have applied a certain external force\nto the \"destroyed\" temporary building to make it \"fragment\". (b) Schematic illustration of information\nloading through mold forming technique and corresponding self-erasure of information. We have mixed\nHNSPs with different inks and poured them into customized QR (Quick Response) code molds. After\ndrying, we can obtain HNSPs loaded with hidden information, which can be recognized by scanning the\nQR code to obtain the inside information (specific content: Information Encryption). With the self-\ndestructive of HNSPs, the black and white squares arranged according to specific coding rules are also\ngradually self-destructed and become unrecognizable liquid mixtures, realizing the self-erasure of\ninformation. The transient appearance of information can effectively prevent information leakage. (c)\nMoisture-triggered self-destructive behavior of transience devices. We have mixed HNSPs with Ni\npowder in a ratio of 1:2 and obtained electronic composite materials through high-temperature treatment.\nThe resistance value of the prepared composite materials is in the range of 102 Ω, which can be easily\nconnected in series to the circuit and light up the small light bulbs in the circuit, proving the good\nconductivity of the material and the potential in electronic devices. Additionally, the device can\nspontaneously absorb moisture and induced the self-destructive behavior, which can change the shape\nof the device to ultimately become a diluted liquid and Ni powder, achieving the moisture-triggered self-\ndestructive of electronic devices.\n(2) Secondly, the moisture-triggered self-destructive behavior of HNSPs has several advantages: (i) The\nself-destructive behavior can be modulated by changing the polymer composition or moisture level; (ii)\nThe self-destructive process does not require external energy input, and can be actively triggered by\nambient humidity; (iii) Moisture is natural and harmless, without additional chemical reagents or special\ntreatment, can reduce environmental pollution; (iv) The self-destructive process can be started naturally\nby humidity change to avoid the traces of human intervention, which helps to achieve concealment and\nsecurity. In the results section of “Hygroscopicity Kinetics of HNSPs” in revised manuscript, we have\nconducted a detailed study on the moisture absorption behavior of HNSPs under different humidity levels\nand supplemented the moisture absorption diffusion mode, clarifying the applicable conditions for\nmoisture in the self- destructive process.\n(3) Additionally, regarding the temperature dependence mentioned by the reviewers, we have emphasized\nthat the temperature cannot induce self-destructive behavior comparable to humidity-induced effects.\nAlthough the HNSPs belong to thermoplastic materials, which require sustained thermal stimulation to\nkeep phase transition. Notably, when the thermal input is removed, HNSPs spontaneously reverted to\ntheir original state rather than maintaining the self-destructive state. As shown in Fig. R2 (Supplementary\nFig. S16 “The rheological properties of HNSPs”), our rheological analysis revealed that HNSPs exhibit\nVisco fluidic behavior at 80°C, thereby establishing this temperature as the upper threshold for long-term\noperational stability. Concerning humidity thresholds, the HNSPs demonstrated minimal hygroscopic\nmass gain (<5%) at relative humidity (RH) below 40%, which can maintain structural integrity without\ntriggering self-destructive behavior. Conversely, when exposed to RH exceeding 60%, a substantial\nhygroscopic mass increase (>10%) initiates the self-destructive behavior. Therefore, we proposed that\nmaintaining ambient humidity below 40% RH for stable HNSPs preservation. To address these\nenvironmental sensitivities, we recommend to implement encapsulation strategies to isolate the\nhumidity-sensitive HNSPs layer. Importantly, HNSPs can be stored in a drying oven with low humidity\nfor a long time. This approach preserves material stability under normal conditions while enabling precise\nactivation of self-destructive through controlled exposure to predetermined humidity triggers in target\nenvironments.\nComment 2. Structural Changes in Response to Humidity:\nA deeper analysis of how nanoclusters respond to varying humidity levels is critical. In particular, a\ndetailed discussion supported by transmission electron microscopy (TEM) and small-angle X-ray\nscattering (SAXS) data regarding cluster size evolution and dissolution upon moisture exposure would\nenhance understanding of the material’s structural dynamics.\nReply: We would like to express our sincere thanks for your constructive suggestion. (1) Firstly, we\nbelieve that a deeper analysis would enhance understanding of HNSPs’ structural dynamics upon\nmoisture exposure. Obviously, using the Transmission electron microscopy (TEM) to test the samples\nmust be detected under high vacuum, but nanoparticles of HNSPs cannot be directly measured in aqueous\nsolutions because of forming a homogeneous aqueous solution. Usually, a microgrid or copper mesh is\nused to scoop up the sample, then place it in a sample pre-extractor to dry, and put it into an electron\nmicroscope for testing. Therefore, TEM cannot observe the real-time evolution of internal hydrogen bond\nclusters when HNSPs exposed to moisture environments. Additionally, it is difficult to observe\nsignificant changes in the SAXS test because of the small size of the hydrogen nanoclusters. Thus, we\nwill adopt wild-angle X-ray scattering (WAXS) to analyze the cluster size evolution and dissolution upon\nmoisture exposure in the revised manuscript.\n(2) Secondly, we have added the experimental testing process of WAXS in the section of 1.3\nCharacterization in the Supplementary Information. It follows:\nChanges (p. 5, Supplementary Information)\n“The wide-angle X-ray scattering (WAXS) measurements were performed on a synchronous diffraction\nlaboratory instrument, Nano-inXider (Xenocs, France), equipped with a micro-focus source generating\nX-rays of a wavelength λ = 1.542 Å (Genix3D), operating at 50 kV and 0.6 mA.”\n(3) Thirdly, the results of WAXS data were demonstrated in Fig. S17. Simultaneously, we have added the\ndescription and explanation of the Fig. S17 in results section of “Mechanical and Self-destructive Properties\nof HNSPs” in Page 14. It follows:\nChanges (p. 14):\n“To obtain deeper insights into the molecular and microstructural evolution occurring during the self-\ndestructive process, wide-angle X-ray scattering (WAXS) was conducted (Supplementary Fig. S17). Upon\nexposure to moisture-induced self-destructive, the scattering intensity became significantly weaker and\nbroader, indicating moisture infiltration gradually disrupts intermolecular hydrogen bonded\nnanoclusters, leading to a loosened and disordered microstructure.”\nFig. R3 (Supplementary Fig. S17) The WAXS of initial and self-destructive state. The WAXS data of the\n2𝜋\nHNSPs exhibited a broad peak at 14.5 nm−1, corresponding to distances 4.3 Å (Bragg's formula: d= ;\n𝑞∗\nd- the domains spacing, q*-the position of the scattering peak ;1 nm=10 Å), which related to the\nanticipated spacing between hydrogen bond. As the sample was self-destructed induced by moisture, the\nscattered signal intensity significantly becomes weaker and widens, which suggests the gradual looseness\nof hydrogen bonded nanoclusters formed by hydrogen bonding, that occurs during self-destructive\nprocess. This phenomenon suggests that the molecular segments are becoming more and more loose,\nindicating a major alteration in molecular aggregation configuration, with a stretching behavior in the\nself-destructive state and a curling behavior in the initial state. This is consistent with the molecular\nstructural changes of HNSPs in the MD simulations.\nComment 3. Anisotropy and Mechanical Behavior:\nSpider silk is often cited as a benchmark for its mechanical anisotropy. It would be valuable to determine\nwhether the HNSP films exhibit any anisotropic mechanical properties. Furthermore, can anisotropy be\ninduced by stretching or spinning, and if so, is the process reversible? Clarifying this aspect would add\nan important dimension to the study.\nReply: We would like to express our sincere thanks for your constructive suggestion. (1) The production\nprocess of spider silk is as follows: Firstly, the spider silk micelles form liquid crystals with a high protein\nconcentration. Secondly, under constant elongational flow, the micelles can be stretched into an\nanisotropic structure with rich 𝛽-sheet crystals. Thirdly, the alignment of fibers is further fixed by\nsurrounding ions due to the Hofmeister effect liquid crystals with high protein concentration are formed\nthrough. The anisotropy of spider silk (the difference in mechanical properties in different directions)\nstems from the nanofibrillar structure, consisting of highly oriented “hard” nanofibrils along the fiber\naxis embedded in a softer non-crystalline matrix. Therefore, we believed that the anisotropy of spider\nsilk is determined by the complex multi-scale structure and the orderly arrangement of the structure\nduring spinning. This manuscript was inspired by spider silk hydrogen bond clusters, which is only a\nsmall part of the multi-hierarchical structure of spider silk. At the same time, the processing of HNSPs\ndoes not involve the complex and special process of spider silk spinning. Instead of the multi-scale\nstructure of spider silk, the structure of HNSPs is uniform, which are forming through uniform solution\ndrying method rather than the complex spinning process, so the HNSPs do not have anisotropy.\n(2) Firstly, we have adopted Polarizing microscope (POM) to investigate the anisotropy properties of\nHNSPs as per the Reviewer’s suggestion. Polarizing microscope (POM) is a method of microscopic\nexamination in which ordinary light is changed to polarized light to identify whether a substance is single\n(isotropic) or birefringent (anisotropic). We have added the POM images of HNSPs in Fig. R4. The POM\nimages displayed a uniform red background state, indicating that the original state of HNSPs is isotropic.\nSecondly, to further investigate the anisotropy of HNSPs induced by stretching or spinning, we have\nadded the POM images of HNSPs after stretching. The POM image shows that this part presents a similar\nred background, indicating that simple stretching cannot induce the formation of anisotropic structures\nin HNSPs. This phenomenon may be attributed to the fact that the HNSPs hold a hard and brittle (with\nsome ductility) solid state at room temperature, and can only be stretched or rotated by heating. This may\naffect the orientation structure of its stretched molecular chains, resulting in no significant anisotropy\nobserved in the POM image.\nFig. R4 Polarizing microscope of HNSPs. POM image displayed presents a uniform red background\nstate, indicating that the original state of HNSPs is isotropic. After stretching the sample, the POM image\nshows that this part presents a similar red background, indicating that simple stretching cannot induce\nthe formation of anisotropic structures in HNSPs.\nComment 4. Controllability of Nanocluster Size:\nThe possibility of tuning the nanocluster size through variations in fabrication conditions could be a\npromising avenue for tailoring mechanical performance. The authors should discuss whether processing\nparameters influence nanocluster dimensions, and consequently, how these changes correlate with the\nmechanical properties of the films.\nReply: Thank you very much to the reviewer. We emphasized the controllability of nanocluster size in\nthe revised manuscript.\n(1) Firstly, in results section of “Hydrogen-bond nanocluster assembly of HNSPs”, we have illustrated\nthat the hydrogen-bonded nanocluster size of HNSPs can be regulated by controlling the ratio of\nmonomers (Rm), confirming by the results of TEM images. It follows (p. 9): “Obviously, as the weight\nratio Rm increases, the hydrogen-bonded nanoclusters process more pronounced outline and larger\ndiameters (Supplementary Fig. S10). This result is also in good agreement with the all-atom MD\nsimulations: the more AM and N-Am will increase the hydrogen bond density, resulting the severe\naggregation of hydrogen bonds that form bigger nanoclusters.”\n(2) Secondly, in the results section of “Mechanical and Self-destructive Properties of HNSPs”, we\nhave elaborated that he hydrogen-bonded nanocluster size of HNSPs is closely related to their mechanical\nproperties. It follows (p. 12): “The mechanical properties of HNSPs are heavily depend on the\ncharacteristics of the hydrogen-bond clusters. To elucidate the superior mechanical properties of HNSPs\nwith different Rm values, both their original structures and those under deformation were investigated in\nFig. 2a. As shown in Fig. 2a, after compression testing, the thickness of the molded sample exhibited a\nreduction in height to 25% of its original dimension, accompanied by proportional increases in length\nand width, confirming the inherent ductility and plasticity of HNSPs. The stress-strain curves exhibit\nthree distinct regions: an initial elastic deformation phase where stress significantly increases with strain,\na subsequent strain-hardening phase characterized by a gradual increase in strain with a slower rise in\nstress, and a final densification stage where strain increases slowly while stress rises sharply (Fig. 2b).\nThe yield strength of HNSPs, defined as the stress corresponding to 10% residual deformation, is found\nto be as high as 14.66 MPa. Furthermore, the Young’s modulus of HNSPs markedly increases with\nincreasing Rm in Fig. 2c. The highest Young’s modulus of the HNSPs up to165.21 MPa is calculated in\nthe low-strain region (<10% strain) of the stress-strain curve. Notably, as Rm increases further, the\nHNSPs exhibit enhanced strength and stiffness, while this is accompanied by increased brittleness\n(Supplementary Fig. S15). This may be attributed to the fact that the strength and stiffness of the HNSPs\nincrease because of higher hydrogen bond density forming hydrogen-bond nanocluster.”\nComment 5. Moisture Absorption and Volume Expansion:\nThe manuscript would benefit from a quantitative analysis of water uptake and its spatial distribution\nwithin the film. Does the absorbed moisture penetrate uniformly throughout the material, or is it localized\nat the surface? This distinction is crucial for understanding the observed volume expansion and\nmechanical deformation behavior.\nReply: Thank you for pointing out the moisture absorption and volume expansion behavior of HNSPs.\n(1) To address this issue, we have conducted new experiments to characterize the diffusion process of\nmoisture absorption as the Reviewer suggested. Computer-aided engineering (CAE) refers to the use of\ncomputer-aided solution to analyze the structural mechanical properties of complex engineering and\nproducts, and to optimize structural properties. Here, we have simulated the process of spontaneous\nmoisture absorption of HNSPs in humid environment by computer modeling, and effectively observe the\ndetailed diffusion process of water in HNSPs, which is consistent with Fick's second diffusion law, it is\nproved that the HNSPs is a global moisture absorption mechanism, which is in good agreement with the\nexperimental results in the text.\n(2) We have added the simulation calculation process in section of “1.3.4 Two-dimensional\nconcentration diffusion simulation based on lattice Boltzmann method (LBM) in the Supplementary\nInformation. It follows:\nChanges (p. 8, Supplementary Information):\n(i) Background\nDiffusion phenomena are widely observed in both natural and engineering contexts, such as\ngroundwater solute migration, geotechnical contamination dispersion, and mass transfer in chemical\nreactions. Fundamentally, concentration diffusion is a mass transport process driven by the random\nthermal motion of molecules, typically described by Fick’s second law:\n∂C/∂t = D ∇²C\nwhere C (x, y, t) represents the solute concentration at a given time and position, D is the diffusion\ncoefficient, and ∇² is the Laplacian operator in two dimensions.\nTraditional numerical methods such as the Finite Difference Method (FDM) and Finite Element\nMethod (FEM) can encounter limitations when dealing with complex boundaries or coupled physical\nprocesses. The Lattice Boltzmann Method (LBM), a mesoscopic numerical approach based on kinetic\ntheory, simulates the propagation and collision of particles on a discrete lattice to solve the macroscopic\ndiffusion equation indirectly. It offers several advantages:\n- High numerical stability;\n- Well-suited for parallel computing;\n- Efficient handling of complex boundaries and multi-physics coupling;\n- Naturally accommodates anisotropy and spatial heterogeneity due to its inherent structure.\n(ii): Modeling principle of lattice Boltzmann method\nThe D2Q9 model utilizes nine discrete velocity directions: one rest particle, four along the Cartesian\naxes, and four diagonals. The evolution equation is given by:\nf (x+e, iΔt, t+Δt) = f(x, t) - (1/τ)(f - feq)\ni i i i\nWhere, feq = w * C. The macroscopic concentration C = ∑fi\ni i\nThe relationship between the diffusion coefficient D and the relaxation time τ is 1:\nD = c ²(τ - 0.5) Δt, c = 1/√3。\ns s\n(iii): Numerical implementation process\nThe model was implemented in MATLAB. The main computational steps are:\n1. Initialization of the concentration field and distribution functions\n2. Collision computation\n3. Streaming (propagation) step\n4. Application of boundary conditions\n5. Calculation of macroscopic concentration\n6. Iteration over time steps until the simulation ends\n(iv): Boundary conditions and initial conditions\nA 150 × 150 square domain was established, with each grid cell representing 40 micrometers. The\nsimulated scenario is an absorption process under 90% relative humidity. Initially, all boundary nodes\nare set to a high concentration corresponding to equilibrium at 90% RH (157%), while the internal nodes\nare initialized to a low concentration corresponding to 80% RH (137%).”\n(3) Based on based on lattice Boltzmann method (LBM), the results of the simulation calculation were\nadded in Fig. S21 (Supplementary Fig. S21). It follows:\nChanges (p.32 Supplementary Information):\nFig. R5 (Supplementary Fig. S21) The moisture diffusion behavior during the self-destructive process of\nHNSPs. (a). Diffusion behavior of moisture in HNSP with different humidity. (Because the initial moisture\nabsorption of HNSPs is weak, Concentration is expressed as the increase ratio of total mass in a given\ngrid cell to its initial value.) At lower humidity, the internal concentration of HNSPs remains basically\nunchanged, with only the boundary showing a certain low concentration. As the humidity increases, the\nconcentration at the surrounding boundaries also increases, gradually affecting the concentration at the\ncenter. At the same time, the high concentration at the boundary also diffuses towards the center until to\nreach equilibrium. (b) Detailed moisture absorption behavior of HNSPs at 90% humidity. Through\ncomparison with experimental data, it was found that the simulation best matches measurements when\nthe diffusion coefficient is set to 9.99 × 10⁻¹² m²/s. To align with the experimental conditions, the\nsimulation time (T=2100-2600min) corresponds to the moment 90% RH is applied. Concentration is\nexpressed as the ratio of total mass in a given grid cell to its initial value. Initially, only the boundaries\nexhibit high concentration, while the interior remains at low concentration (T=2100min). Over time, the\nhigh concentration at the boundaries diffuses toward the center. By 2600 minutes, only a small central\nregion has yet to reach equilibrium, while most of the domain has stabilized. (c) Comparison between\nsimulated data and DVS data. The simulated moisture absorption curve closely matches the experimental\ndata, which also generally conforms to Fickian diffusion. Possible Causes of Deviation in the Initial\nStage:1. The internal structure of the specimen may contain micro-pores and cracks, where additional\nforces such as capillarity may interfere, making the process deviate from pure Fickian diffusion at early\ntimes. 2. The boundary conditions in the experiment may not have maintained a perfectly constant\nhumidity level.\n(4) We have added the explanation of the simulation calculation results in results section of\n“Hygroscopicity Kinetics of HNSPs” in the revised manuscript. It follows:\nChanges (p. 18):\n“Additionally, the moisture diffusion behavior of HNSPs during the self-destructive process was\nconducted through Two-dimensional concentration diffusion simulation based on lattice Boltzmann\nmethod (LBM) (Supplementary Fig. S21). At low humidity, the internal concentration of HNSPs remained\nnearly constant, with slightly lower concentration at boundaries. Increasing humidity elevated boundary\nconcentrations, which then diffused inward, reaching equilibrium. Under constant high humidity (90%\nRH), initially, only boundaries exhibited high concentration, with low internal concentration. Over time,\nmoisture diffused inward, leading most regions to equilibrium except a small central area. Simulation\nresults closely matched experimental data, confirming Fickian diffusion behavior.”\nComment 6. Origin of Orange Coloration and Optical Properties:\nThe cause of the orange coloration observed in the films remains unclear. The authors are encouraged to\ninvestigate whether a shift in the optical absorption spectrum occurs upon phase transition from solid to\nliquid. Such analysis would not only clarify the coloration mechanism but also potentially provide an\noptical signature of the transition behavior.\nReply: We would like to express our sincere thanks for your constructive suggestion.\n(1) Firstly, we would like to emphasized that the color of HNSPs is between deep yellow and orange.\nDue to the influence of sample thickness and surrounding light, it will lead to a certain color difference\nof HNSPS, which will not affect the structure and properties of the material. The color change that occurs\nduring the solid-liquid transition can be attributed to gradual dilution of the “high concentration” HNSPs\nby water, resulting in its color fading.\n(2) Secondly, as per the Reviewer’s suggestion, we have added experiments investigate whether a shift\nin the optical absorption spectrum occurs upon phase transition from solid to liquid by using UV-Visible\nSpectroscopy. The results of UV-Visible Spectroscopy were added in Fig. S18 of the Supplementary\nInformation. It follows:\nChanges (p.5, Supplementary Information)\n“The UV-vis spectra of HNSPs were observed on a UV-3600 Spectrophotometer (Shimadzu).”\n(3) We have added the explanation of UV-Visible Spectroscopy in results section of “Mechanical and\nSelf-destructive Properties of HNSPs” in revised manuscript. It follows:\nChanges (p. 14, Supplementary Information):\n“The UV-vis spectra showed a characteristic peak at ~370 nm, corresponding to n–π* transitions of C=N\nand C=O groups (Supplementary Fig. S18). As self-destructive time increased, the absorption peak\nintensity progressively decreased, indicating dispersion of HNSP molecular fragments into the aqueous\nphase, leading to a reduction in the concentration of chromophoric groups (C=N and C=O).”\nFig. R6 (Supplementary Fig. S18) UV/Vis absorption spectra of HNSPs under moisture adsorption. UV-\nvis absorption spectroscopy showed that HNSP exhibits a distinct absorption peak near 370nm, which\ncan be attributed to the n-π * band of C=N and C=O. Following moisture induced, a dramatic decrease\nof n-π * band at 370 nm was observed, corresponding to the HNSP molecules segment are dispersed into\nthe water phase, which leads to the decrease of its chromophore concentration and directly reduces the\nabsorbance.\nReviewer #3\nGeneral Comment. Summary. This manuscript presents an interesting strategy of molecular structure\ndesign to form self-destructive polymer materials based on hydrogen-bond nanoconfined within the\nmatrix (HNSPs). The authors report the synthesis of a supramolecular polymer capable of forming\nhydrogen bonds and exhibiting hydrophilic characteristics. These materials demonstrate remarkable\nmechanical properties, attributed to the presence of hydrogen-bond clusters, and exhibit bistable solid–\nliquid like switching behavior. This switching is enabled by the sensitivity of the system to moisture. It\nhas been demonstrated that the self-destructive behavior can be modulated by varying the formulation\nand the surrounding humidity, offering a high level of control over the degradation response. The study\nincludes measurements of the structural, mechanical, and moisture-responsive properties of the materials,\nalong with a comprehensive investigation of the mechanism governing the transition. In addition,\nmolecular dynamics simulations are performed to support and further elucidate the molecular level\ninteraction.\nIn conclusion, the study is original and well conducted. However, further details are needed to support\nthe conclusions. We recommend the publication of the manuscript after major revision.\nStrengths of the Manuscript. A major strength is the simplicity of the reaction (one-step in water) and the\nability to easily tune the formulations, which in turn modifies the hydrogen-bonded cluster architecture\nand therefore the mechanical properties and functional responses of the HNSPs.\nAnother strength of the manuscript lies in the reversibility of the phase transition. At the same time, this\nreversibility is not immediate and the material remains in its degraded state even after the moisture is\nremoved, and reversing the process requires more severe environmental conditions. This behavior is\nuseful for applications that require stable and lasting changes, while still allowing the material to be\nreversed under specific conditions if necessary.\nComprehensive Experimental Approach: The authors have conducted different experiments to validate\ntheir concept, including structural, mechanical, and moisture-responsiveness analyses. In addition, the\nstudy clearly investigates the mechanism behind the transition. Molecular mobility was explored by\nmeasuring relaxation times, offering insight into the type of water molecule. This experimental approach\nis also supported by molecular dynamics simulations, which provide valuable information on the role of\nhydrogen bonding and water interactions at the molecular scale.\nReply: We thank the reviewer for very positive and constructive feedback for our manuscript. We have\nrevised the manuscripts by addressing the suggestions noted by the reviewer as detailed below and\nbelieve that these changes have substantially improved our manuscript.\nComment 1. The concentration used during the polymer synthesis is not mentioned.\nReply: We would like to express our sincere thanks for your constructive suggestion.\n(1) Firstly, we have added the concentration used during the polymer synthesis in the section of “1.\nMaterials and Methods” in the Supplementary Information, including all the missing specifications\nrelated to polymer synthesis in whole revised manuscript. It follows:\nChanges (p. 2, Supplementary Information):\n“Tetraethylenepentamine (TEPA, C8H23N5, Mw =189.30, technical grade purity, CAS No. 112-57-2),\nAcrylamide (AM, C3H5NO, Mw =71.08, 99.0% purity, CAS No. 79-06-1), N-Methylolacrylamide (NMA,\nC4H7NO2, Mw =101.1, 98% purity, CAS No. 924-42-5), Deuterated dimethyl sulfoxide (DMSO-d6, 99.8%\npurity) and Deuterium oxide (D2O, ≥99 atom% D) were purchased from Aladdin (Shanghai) Chemistry\nCo., Ltd. Deionized water (conductivity < 0.5 us/cm) was bought from the Chengdu Kelong chemical\nplant (China). All reagents were used as received without further purification unless otherwise noted.”\n(2) Secondly, we have also added the concentration of the synthesized sample during the polymer\nsynthesis in section of “1.2 Synthesis of HNSPs” in the Supplementary Information. It follows:\nChanges (p. 2, Supplementary Information):\n“Taking the molar weight ratio Rm = 2.0 as an example, the addition amount of NMA and AM were\n20.22g (0.2 mol) and 14.22 g (0.2 mol), respectively. The addition amount of TEPA was 18.93 g (0.1 mol).\nDeionized water was used as the solvent with an addition amount of 22.5 g, and the concentration of all\nsynthesized samples were controlled at 70%.”\nComment 2. The supramolecular structure is not clear. The manuscript mentions that polymerization is\nlimited to the structure shown in Figure S1 and that the supramolecular organization is formed by\nhydrogen bonding. However, the nature of the chains connecting the clusters is not clear.\nReply: We would like to express our sincere thanks for your constructive suggestion.\n(1) We have added a new hydrogen bond structure diagram to complement the description of the\nhydrogen bond connection mode, making the supramolecular structure clearer, as shown in Fig. S8 in\nSupplementary Information.\n(2) We have added new explanations the supramolecular structure of HNSPs in Fig. 1b of the revised\nmanuscript. It follows:\nChanges (p. 8):\n“As illustrated in Fig. 1b and Fig. S8 (Supplementary Information), the hydrogen bond structures and\nsupramolecular organization within hydrogen-bonded nanocluster self-destructive polymers (HNSPs)\nhave been elucidated. The molecular segments of the target HNSPs primarily consisted of relatively\nflexible TEPA segments, which were covalently linked through main or side chains-aligned\nperpendicularly relative to TEPA segments-to more rigid components such as NMA and AM. These rigid\ncomponents offered numerous hydrogen bond donors and acceptors. Furthermore, due to their shorter\nchain length and lower molecular weight compared with conventional polymers, HNSP molecular\nsegments exhibited reduced entanglement, thus facilitating enhanced molecular mobility. Consequently,\nthis distinctive structural arrangement promotes the formation of high-density hydrogen-bonded\nnanoclusters characterized by smaller dimensions yet densely populated hydrogen bonds, ultimately\nresulting in mechanically robust, humidity-responsive self-destructive polymers enabled by hydrogen-\nbond nanoconfinement.”\nFig. 1 Schematic diagram of Hydrogen-bond nanocluster self-destructive polymers inspired by\nspider silk. a Schematic diagram of spider silk with a hierarchical structure. b Schematic structure of\nHNSPs composed of dense hydrogen-bond nanoclusters. c Molecular dynamics (MD) simulations of the\nmicrostructure of HNSPs system with the corresponding H-bond categories diagram. d TEM images of\nthe HNSPs (Inset: size distributions of hard segment clusters.). e Cryo-SEM images of the HNSPs. f\nOptical images of the HNSPs (Rm = 2.0) can easily lift a weight of 500 g.\nFig. R7 (Supplementary Fig. S8) The hydrogen bond structures of HNSPs. The red segment belongs to\nthe NMA segment and the blue segment belongs to the AM segment.\nComment 3. Reversibility of the Transition:\nThe authors provide some information on water molecule types and desorption behavior using DVS, which is useful.\nHowever, they do not show whether the material fully recovers its original mechanical properties or hydrogen-bonding structure. Additional data would help confirm the claimed reversibility.\nReply: We would like to express our sincere thanks for your constructive suggestion. Firstly, we would\nlike to emphasize that the design of self-destructive materials is mainly used for disposable (transient)\nuse scenarios, such as temporary buildings, self-destructive Quick Response (QR) code and transience\ndevices. The recovery of self-destructive material are only needed in some special scenarios, because it\nis difficult to collect the self-destructive material again. Secondly, we agree that the change of hydrogen\nbond structure and mechanical properties during the self-destructive cycle can help us gain a deeper\nunderstanding of the self-destructive process, which play an important role in the multi-cycle use and\nlong-term stability of the material.\n(1) To illustrate the reversibility, we have added new experiments to test their chemical structure and\nmechanical properties by IR, NMR and the compress tests during the self-destructive cycle, and the\nresults were shown in Fig. S19 of the Supplementary Information.\n(2) We have added more details and explanations of the results section “Mechanical and Self-\ndestructive Properties of HNSPs” in the revised manuscript. It follows:\nChanges (p. 14, Supplementary Information)\n“Furthermore, to achieve secondary recycling under special applications, the self-destructive system can\nrecover its initial state through high-temperature drying, as evidenced by macroscopic shape\ntransformation and the restoration to a sturdy solid (Supplementary Fig. S19)”\nFig. R8 (Supplementary Fig. S19) Comparison of structure and mechanical properties of HNSPs during\nmultiple self-destructive/remodeling cycles (a)ATR-FTIR spectroscopy, (b)1H-NMR, and (c)Compress\ntests. After undergoing the self-destructive / re-construction cycles, the structure of HNSPs remains\nunchanged, and mechanical properties decreased slightly, but still maintaining over 70% of their original\nstate. The reasons for the decrease in mechanical properties during the cycles may be attributed to the\ndestruction of hydrogen bond clusters and hydrogen bond sites induced by external conditions (moisture,\nhigh temperature), which leads to irreversible changes and defects in molecular structure (stress\nconcentration), reducing the overall strength and toughness of the material.\nComment 4. The authors also mention that the phase-switching process can be repeated multiple times,\nbut no experimental data or characterization is provided to support this claim. Showing the behavior over\nmany cycles, especially regarding structure or mechanical performance, would be important to confirm\nthis.\nReply: We would like to express our sincere thanks for your constructive suggestion.\n(1) We have added new experiments to investigate the changes in structure and mechanical properties of\nHNSPs by IR, NMR and the compress tests during multiple phase-switching processes, as shown in Fig.\nS19. After undergoing the self-destructive /re-construction cycles, the structure of HNSPs remains\nunchanged, and mechanical properties decreased slightly, but still maintaining over 70% of their original\nstate. The reasons for the decrease in mechanical properties during the cycles may be attributed to the\ndestruction of hydrogen bond clusters and hydrogen bond sites induced by external conditions (moisture,\nhigh temperature), which leads to irreversible changes and defects in molecular structure (stress\nconcentration), reducing the overall strength and toughness of the material.\n(2) We have added more details and explanations of the results section “Mechanical and Self-\ndestructive Properties of HNSPs” in the revised manuscript. It follows (p.15): “Furthermore, to achieve\nsecondary recycling under special applications, the self-destructive system can recover its initial state\nthrough high-temperature drying, as evidenced by macroscopic shape transformation and the restoration\nto a sturdy solid (Supplementary Fig. S19).”\nFig. R8 (Supplementary Fig. S19) Comparison of structure and mechanical properties of HNSPs during\nmultiple self-destructive/remodeling cycles (a)ATR-FTIR spectroscopy, (b)1H-NMR, and (c)Compress\ntests.” After undergoing the self-destructive /re-construction cycles, the structure of HNSPs remains\nunchanged, and mechanical properties decreased slightly, but still maintaining over 70% of their original\nstate. The reasons for the decrease in mechanical properties during the cycles may be attributed to the\ndestruction of hydrogen bond clusters and hydrogen bond sites induced by external conditions (moisture,\nhigh temperature), which leads to irreversible changes and defects in molecular structure (stress\nconcentration), reducing the overall strength and toughness of the material.\nComment 5. It’s important to mention the plasticity of the material, especially if there is any residual\ndeformation. This could help better understand the mechanical behavior of the material.\nReply: We would like to express our sincere thanks for your constructive suggestion.\n(1) Firstly, in the revised manuscript, we have clarified the plasticity of HNSPs. When the external force\nexceeds the elastic limit of the material, plastic deformation begins to occur in HNSPs. In this state, the\ndeformation of HNSPs is no longer reversible, even if the external force disappears, HNSPs cannot be\nfully restored to the original state, which conforms to the characteristics of plastic deformation. It follows:\n“As shown in Fig. 2a, after compression testing, the thickness of the compression test sample (10 * 10 *\n25mm) made through molds became 25% of the original height, and the length and width increased\nproportionally, which confirmed that HNSPs have a certain degree of ductility/plasticity properties. The\ndeformation caused by this external force is irreversible, and HNSPs cannot be immediately restored to\ntheir original state.”\n(2) Secondly, polymer materials possessing excellent elasticity, like synthetic rubber, typically exhibit\nthe following characteristics: (i) High molecular weight. The long molecular chain can facilitate\nentanglement between molecular chains and forced to transition from a high entropy (chaotic curling)\nstate to a low entropy (relative stretching) state during stretching. After the external force is removed, the\nentropic elasticity causes the chain segment to undergo intense motion and quickly retract to a curled\nstate. (ii) Sufficient permanent cross-linking. The cross-linking points can fix the relative positions of the\nmolecular chains, preventing permanent slippage of the molecular chains.\n(3) Thirdly, in this manuscript, we proposed that HNSPs with excellent mechanical properties and certain\nductility. The specific mechanism is as follows: (i) The dense hydrogen bond. The densely hydrogen\nbonds can serve as physically cross-linked point and provide strong resistance to deformation and fracture\nto HNSPs (ii) The dynamic nature of hydrogen bonds. The dynamic nature of hydrogen bonds allows\nmolecular units to absorb energy and undergo plastic deformation through relative slip and rearrangement\nunder stress, avoiding brittle fracture. The main reasons to HNSPs do not exhibit significant resilience is\nas follows. (i) The low molecular weight. The HNSPs cannot have a strong entropic elasticity to drive\nthe material to quickly and spontaneously recover to its original shape. (ii) The “Hysteresis” of hydrogen\nbonds. The recovery process relies on slow recombination of hydrogen bonds, accompanied by viscous\ndissipation and permanent structural changes, making it impossible to achieve rapid and complete\nentropy elastic recovery. (iii) The lack of sufficient permanent chemical cross-linking points. The HNSPs\ndo not have sufficient permanent chemical crosslinking points to fix the relative motion of molecular\nsegments.\n(2) We have added the description of the plasticity of these materials in the results section of\n“Mechanical and Self-destructive Properties of HNSPs” in the revised manuscript. It follows:\nChanges (p. 12)\n“As shown in Fig. 2a, after compression testing, the thickness of the molded sample exhibited a reduction\nin height to 25% of its original dimension, accompanied by proportional increases in length and width,\nconfirming the inherent ductility and plasticity of HNSPs.”\n“The specific mechanism responsible for the excellent mechanical properties and notable ductility of\nHNSPs are attributable to densely hydrogen-bond nanocluster acted as physical cross-linking points,\nproviding robust resistance to deformation and fracture, and the dynamic nature of these hydrogen bonds\nenables molecular units to absorb mechanical energy and undergo plastic deformation through relative\nslippage and rearrangement under stress, thereby preventing brittle fracture.”\nFig. 2 (a) Image of the HNSPs upon compressing (The Rm is 2.0.).\nComment 6. Term self-destruction efficiency/ self-destruction rate: it is not clear how it was\nquantitatively defined or measured (diffusion of moisture !!). It would be helpful if the authors could\nspecify this.\nReply: We would like to express our sincere thanks for your constructive suggestion.\n(1) We have now added the testing details and related definitions of self-destructive efficiency.\nThe following statement was added to the last paragraph of the section “1.3.2 Self-destructive efficiency\ntest” in the Supplementary Information.\nChanges (p. 7 Supplementary Information)\n“Here, we have defined that the self-destructive rate of HNSPs as follows: The speed that the decreases\nmass of the test sample (passing through a specified aperture sieve) over time, in which the standard\nsample perform the programmed self- destruction behavior triggered by moistures under the same\ntemperature and humidity conditions. It can demonstrate the self-destructive speed of materials under\nthe environmental conditions, which can express in terms of the amount of mass loss per unit time (g/h)\nor the percentage of mass loss (%/h). The calculation formula is 𝑋 =\n𝑀𝐼−𝑀𝑐\n(X: Self-destructive speed;\n𝑇\nM Initial mass (g); M : Current mass (g); T: Time (hours)). Considering the hygroscopicity of HNSPs,\nI: c\nwe have deducted the additional hygroscopic mass generated by the hygroscopic process to obtain the\ncurrent mass of the material (Mc) (based on the DVS experimental data or the percentage of overall\ndevice hygroscopicity mass). We have illustrated the customized testing standards in section of “1.3.2\nSelf-destructive efficiency test” in the Supplementary Information. It follows: “The parameters of HNSPs\nused for self-destructive tests are as follows: diameter ≈ 20 mm, thickness ≈ 1 mm, and mass ≈ 0.4-0.8 g.\nThe samples were placed on a stainless-steel mesh (aperture ≈ 3.8 mm, wire diameter ≈ 0.5 mm) and\nplaced in a Temperature-Humidity Test Chamber (DHT-500, computer-controlled).”\n(2) We have modified the expression in results section of “Mechanical and Self-destructive Properties\nof HNSPs” in the revised manuscript. It follows:\nChanges (p. 15):\n“Additionally, further experiments were conducted to assess the self-destructive rate of HNSPs, defined\nas the mass decreases speed of HNSPs (passing through a specified aperture sieve) over time and can be\nexpressed to the amount of mass loss per unit time (g/h). As shown in Fig. 2g, with increasing Rm at a\nrelative humidity of 80%, the self-destructive rate gradually declined and ultimately stabilized within a\nnarrow range.”\nComment 7. It would be useful to do DSC analysis at higher temperatures (up to 200 °C) to check for a\npossible endothermic transition related to hydrogen bond breaking.\nReply: We would like to express our sincere thanks for your constructive suggestion. According to this\nrecommendation, we have performed additional DSC analysis over an extended temperature range (from\n-40 °C up to 200 °C) to investigate potential hydrogen-bond-related transitions, as shown in Fig. R9. The\nnew DSC results at higher temperatures (up to 220 °C) were consistent with our previous low-\ntemperature DSC analysis, indicating no additional significant endothermic transitions related to\nhydrogen bond breaking within this extended range. It is difficult to characterize hydrogen bond breaking\nusing DSC, which is only applicable to some crystalline polymers (such as starch)2, 3.\nFig. R9 DSC curves of HNSPs at higher temperatures (Rm=2.0).\nComment 8. Specific Comments. At first reading of the abstract, the introduction of the term weight\nratios (Rw) without a prior definition may cause some confusion. It would be preferable to define it\nexplicitly upon its first appearance.\nReply: We would like to express our sincere thanks for your constructive suggestion.\n(1) After careful consideration, we have decided to change the wording of Rw to Rm, which was defined\nas the molar ratio of NMA (AM)/TEPA, where NMA and AM always maintain the same molar mass.\nWhen Rm = 2.0, NMA: AM: TEPA is synthesized at a molar ratio of 2:2:1. All positions in the\nmanuscript where Rm has appeared have been modified into Rm. Additional, we have explicitly\nredefined the term Rm in its first appearance.\n(2) We have added a prior definition of “Rm” in the results section of “Hydrogen-bond nanocluster\nassembly of HNSPs” in the first paragraph of revised manuscript. It follows:\nChanges (p. 7):\n“Rm is defined as the molar ratio of NMA (equimolar with AM) to TEPA, with Rm=2.0 corresponding\nto an NMA:AM:TEPA ratio of 2:2:1.”\nComment 9. Please indicate the solvent used for the NMR analysis in the experimental section or at the\nbeginning of the legend of Figure S3. It is only mentioned at the end of the page, which may cause\nconfusion or make it harder for the reader to locate this important information.\nReply: We would like to express our sincere thanks for your constructive suggestion.\n(1) We have specified in detail the solvents used for nuclear magnetic resonance analysis in the\nexperimental section and at the beginning of the legend in Fig. S4 (Original Figure 3), and made\ncorresponding corrections. We need to acknowledge Fig. S3b (original) is the 1H-NMR was measured\nin DMSO-d6. In addition, is the 13C-NMR was measured in D O environment (Fig. S3C, original).\n2\n(2) We have added more experiment to analysis in the structural of HNSPs (13C-NMR experiment\nmeasured in DMSO-d6 and 1H-NMR in D O). The subsequent two-dimensional nuclear magnetic\n2\nresonance (HSBC and HSQC) will be based on the spectrum in DMSO-d6. We repeated all the NMR ( H\n13 2\nS3 and S4 as follows. Please refer to the specific changes for details Comment 11 and Comment 12.\n(3) We have added the solvent used for the NMR analysis in the experimental section of the\nSupplementary Information. It follows:\nChanges (p. 2, Supplementary Information):\n“Deuterated dimethyl sulfoxide (DMSO-d6, 99.8% purity) and Deuterium oxide (D O, ≥99 atom% D)\n2\nwere purchased from Aladdin (Shanghai) Chemistry Co., Ltd.”\nChanges (p. 3, Supplementary Information):\n“Proton-1 and carbon-13 nuclear magnetic resonance (1H-NMR) (AV III HD 400 MHz) were used to\ndetermine the chemical composition of the obtained materials The ideal molecular structure of HNSPs\nmeasured in DMSO-d6 and D O. HMBC (1H detected heteronuclear multiple bond correlation) and\nChanges (p. 10, Supplementary Information): The following statement was added to the Fig. S4:\n“Fig. S4. (a) The ideal molecular structure of HNSPs measured in DMSO-d6 and D O.”\nIt would may be useful to add both the spectrum of polymer and of the individual monomers.\nReply: Thank you for your thoughtful suggestion. We agree that a more detailed discussion on the\nspectrum of polymer and of the individual monomers would enhance the manuscript.\nAccording to this recommendation, we have added the study of the 1H-NMR of the individual monomers\nused in the synthesis, determining the structure of the product, as shown in Fig. R11 (Fig. S3) of the\nSupplementary Information. The NMR results showed that the tested positions of the 1H-NMR peak of\nthe monomers were consistent with the actual positions, and the chemical structure of HNSPs is\nconsistent with the preset structure.\nChange (p. 14, Supplementary Information)\nFig. R11 (Supplementary Fig. S3) The 1H-NMR spectrum of polymer and of the individual monomers\nmeasured in DMSO-d6. (a) 1H-NMR of AM. (b) 1H-NMR of NMA. (c) 1H-NMR of TEPA. (d) 1H-NMR\nof HNSPs. The NMR results showed that the tested positions of the 1H-NMR peak of the monomers were\nconsistent with the actual positions, and the chemical structure of HNSPs is consistent with the preset\nstructure.\nComment 11. The peak assignments in the NMR spectrum appear to be questionable. Based on the\nexpected chemical shifts for the functional groups present, some of the assignments may need to be\nrevised or further justified. For example, peak 2 in structure 1-1, corresponding to the CH₂OH group\ngenerally appears around 3.5 ppm, but it is reported at approximately 2.5 ppm in the manuscript. In\naddition, the integration of the signals could be mentioned, as it can help confirm the polymer structure\nand gives a way to quantify the ratio between different possible structures.\nReply: We would like to express our sincere thanks for your constructive suggestion. We would like to\nemphasize that the purity of the synthetic monomers and the multiple reaction sites of the synthetic\nsystem, resulting that HNSPs possess some isomer. Due to the complexity of the system, there may be a\nlittle minor error in the assignment of specific peaks, which do not affect the overall analysis results.\n(1) We have repeatedly checked and corrected the relevant 1H-NMR spectroscopic analysis to confirm\nthe correct results in the revised manuscript. The 1-1 structure are labeled with the English symbols and\n1-2 structure are labeled with numbers. “The peak 2” in structure 1-1, corresponding to the CH₂OH\ngroup, are labeled into “The peak b”.\n(2) We have modified the results expression of “Hydrogen-bond nanocluster assembly of HNSPs” in\nthe revised manuscript. It follows:\n“The results of nuclear magnetic resonance (NMR) showed that the multi overlapping peaks at 2.80 ppm\nto 2.17 ppm are attributable to the -CH2 on the main chains in the 1H-NMR spectroscopy\n(Supplementary Fig. S4), and the characteristic peaks from at 54.2 ppm to 50.33 ppm belong to -N-CH2-\ngroups in the 13C-NMR spectroscopy (Supplementary Fig. S5). Additionally, the results of 1H detected\nheteronuclear multiple bond correlation (HMBC) and heteronuclear single quantum coherence (HSQC)\nconfirmed the correspondence between 1H-NMR and 13C-NMR (Supplementary Fig. S6). The above\nresults indicated that these HNSPs have been successfully synthesized via the aza-Michael reaction.”\nChanges (p. 15, Supplementary Information):\n“The multi overlapping peaks at 4.70 ppm to 3.36 ppm are the -CH2 on the branches structure of 1-1 (b,\no, p) and 1-2 (13, 14, 17). While the multi overlapping peaks at 2.79 ppm to 2.17 ppm are the -CH2 on\nthe main chains of 1-1 (f, h, l; e, i, k）and 1-2 (4, 6, 10; 3, 7, 9) structure.”\nChangs (p. 15, Supplementary Information): Revised Supplementary Fig. S4\nFig. R12 (Supplementary Fig. S4) (a) The ideal molecular structure of HNSPs measured in DMSO-d6\nand D O. (1-1 labeled with the English symbols and 1-2 labeled with numbers.). (b)1H-NMR spectra of\n2\nthe 1H-NMR spectra of HNSPs in different environments (DMSO-d6 and D O). We can find that the\n2\npeaks with a chemical shift greater than 6.5 ppm disappears (D O), indicating that the peaks belong to\n2\nthe active hydrogen of HNSPs. Therefore, this part of the peaks belongs to -OH structure, -NH structure\n2\nand -NH structure, which corresponds to the 1-1 structure (a, r, c) and 1-2 structure (18, 1, 16),\nrespectively. The small peaks at 6.50 ppm to 5.00 ppm are impurity peaks or byproduct peaks. The multi\noverlapping peaks at 4.70 ppm to 3.36 ppm are the -CH on the branches structure of 1-1 (b, o, p) and\n2\n1-2 (13, 14, 17). While the multi overlapping peaks at 2.80 ppm to 2.17 ppm are the -CH on the main\n2\nchains of 1-1 (f, h, l; e, i, k）and 1-2 (4, 6, 10; 3, 7, 9) structure. In addition, the peak at 2.50 ppm is the\npeak of deuterated dimethyl sulfoxide (DMSO-d6). The small peak at 1.23 ppm is the broken impurity -\nCH .\n3\n(2) In view of our design of HNSPs, the reaction system has a variety of reaction sites, resulting in their\nproducts mixture with isomers. The chemical shifts of HNSPs have many similar sites, resulting in\nmultiple correspondences at the same position. Therefore, it is difficult to determine quantify the ratio\nbetween different possible structures by the integration of the signal.\nComment 12. 13C-NMR spectra. The carbonyl groups 15 from structure 1-2 and 4 from structure 1-1\nhave a very similar chemical environment and are likely to appear together. In fact, the peak at 173 ppm\ncorresponds to the other carbonyl group: 2 in structure 1-2 and 17 in structure 1-1. To confirm all this\nassignment, HMBC and HSQC experiments are strongly recommended.\nReply: We would like to express our sincere thanks for your constructive suggestion.\n(1) We agree that a more detailed discussion on the 13C-NMR spectra of HNSPs would enhance the\nmanuscript. We have repeatedly checked and corrected the relevant 13C-NMR spectroscopic analysis to\nconfirm the correct results in the revised manuscript.\n(2) In addition, to maintain the consistency with the testing environment of 1H-NMR and subsequent\nHMBC (HSQC) experiment, we have used 13C-NMR in DMSO-d6 as the main evidence (Fig. S5 b).\nAnd the original 13C-NMR spectra measured in D O (Fig. S3, original) was used as supplementary data\n2\nto indirectly explain the structure. As shown in Figure R13 (Fig. S5c), the peak shapes of 13C -NMR\nspectra in different testing environments remain consistent, which have a slight deviation in the chemical\nshift of the corresponding peak, due to the standard peak error in different environments.\n(3) To address the issue of difficult correspondence between the two structures in nuclear magnetic\nresonance analysis, we have modified the nuclear magnetic resonance images, with peaks 1-1 labeled\nwith the English symbols b and peaks 1-2 labeled with numbers.\nAccording to the suggestion of the reviewers, we have revised some interpretations of 13C-NMR.\nThe specific changes are as follows. “The peak 4” and “The peak 17” in structure 1-1 are labeled\ninto “The peak d'” and “The peak q'”, respectively.\n“The peak 15” and “The peak 2” in structure 1-2 are labeled into “The peak 15'” and “The peak\n2'”, respectively.\nChanged (p. 16, Supplementary Information):\n“DMSO-d6: Firstly, the peak at 174.08 ppm belongs to amide groups on the 1-2 (15') and 1-1 (d').\nThe peak at 168.95 ppm is attributed amide groups on the 1-1 (q') and 1-2 (2').”\n“D O: The peak at 177.8 ppm belongs to amide groups on the 1-2 (15') and 1-1(d').\nChanges (p. 16, Supplementary Information): The analysis of 13C-NMR spectroscopic as follows:\nFig. R13 (Supplementary Fig. S5) The ideal molecular structure of HNSPs. (a) The ideal molecular\nstructure of HNSPs (b)The 13C-NMR spectra of HNSPs measured in DMSO-d6. (c) Comparison of\n13C -NMR spectra of HNSPs in different environments (DMSO-d6 and D2O). DMSO-d6: Firstly, the\npeak at 174.08 ppm belongs to amide groups on the 1-2 (15') and 1-1 (d'). The peak at 168.95 ppm is\nattributed amide groups on the 1-1 (q') and 1-2 (2'). The peak at 63.79 ppm belongs to -CH groups\n2\n(b') at both ends of the 1-1 structure backbone, which also belongs to -CH groups (17') of 1-2 structure.\n2\n10', 13'). The peaks from 45.00 ppm to 29.90 ppm belong to the -CH - groups of 1-1 (f', h', e') and 1-2\n2\n(3', 4', 6',). D2O: The peak at 177.8 ppm belongs to amide groups on the 1-2 (15') and 1-1(d'). The\npeak at 173.0 ppm is attributed to amide groups on the 1-1 (q') and 1-2 (2'). The peak at 62.4 ppm\nbelongs to -CH2 groups (b') at both ends of the 1-1 structure backbone, which also belongs to -CH2\ngroups (17') of 1-2 structure. The peaks from 54.2 ppm to 50.33 ppm belong to -N-CH2- groups of 1-\n1 (i', k', l', o') and 1-2 (7', 9', 10', 13'). The peaks from 49.78 ppm to 27.70 ppm belong to the -CH2-\ngroups of 1-1 (f', h', e') and 1-2 (3', 4', 6').\n(4) Especially, we have now added HMBC and HSQC experiments to confirm the chemical structure\nfor HNSPs, as shown in Fig. S6 of the Supplementary Information. It follows:\nFig. R14 (Supplementary Fig. S6). (a) HMBC spectra of HNSPs (1H detected heteronuclear multiple\nbond correlation). The carbon atoms at 174.05/174.01 ppm are strongly correlated with the hydrogen\natoms at 2.18 ppm and 2.64 ppm, which is consistent with the carbon atom in the 1-1 structure (d') and\nthe adjacent hydrogen structures at e and f (1-1). The carbon atom at 169.01/168.94 ppm is strongly\ncorrelated with the hydrogen atom at 2.20 ppm and 2.80 ppm, which is consistent with the carbon atom\nin the 1-2 structure (2') and the hydrogen structures of adjacent 3 and 4 (1-2). The carbon atoms at 51.02\nppm are strongly correlated with the hydrogen atoms at 2.64 ppm, which is consistent with the carbon\natom in the 1-1 structure (k') and the adjacent hydrogen structure of l position (1-1). The carbon atoms\nat 49.49 ppm are strongly correlated with the hydrogen atoms at 2.18 ppm, which is consistent with the\ncarbon atoms in the 1-2 structure (6') and the adjacent hydrogen structures 7 position (1-2).\n(b) HSQC (Heteronuclear Single Quantum Coherence) spectra of HNSPs. The carbon atom at 33.59 ppm\nis directly connected to the hydrogen atom at 2.18 ppm, which is consistent with the carbon atom of the\n1-2 (4' and 6') and 1-1 (f' and h'). The carbon atom at 51.04 ppm is directly connected to the hydrogen\natom at 2.66 ppm, which is consistent with the carbon atom of 1-2 (7' and 9') and 1-1 (i' and k'). The\ncarbon atom at 52.25 ppm is directly connected to the hydrogen atom at 2.47 ppm, which is consistent\nwith the carbon atom of 1-2 (10') and 1-1 (l'). The carbon atom at 63.76 ppm is directly connected to the\nhydrogen atom at 3.87 ppm, which is consistent with the carbon atom of 1-2 (17') and 1-1 (b').\nComment 13. The assignment to position 23 appears to be an error; it should be position 13 instead.\nReply: We would like to express our sincere thanks for your constructive suggestion.\n(1) We have repeatedly checked and corrected the relevant 1H-NMR spectroscopic analysis. We have\nmodified the assignment at position 23 into position 13.\n(2) In addition, to address the issue of difficult correspondence between the two structures in nuclear\nmagnetic resonance analysis, we have modified the nuclear magnetic resonance images, with peaks 1-1\nlabeled with the English symbols b and peaks 1-2 labeled with numbers. The specific changes are as\nfollows. The reviewer's comment corresponds to the following sentence (p.10, Supplementary Fig. S3,\noriginal): “The peaks from 54.2 ppm to 50.33 ppm belong to -N-CH2- groups of 1-1 (9, 11, 15) and 1-2\n(positions 7, 9, 23).” “The peak 13” in structure 1-2 are labeled into “The peak 13'”.\nChanges (p. 16, Supplementary Fig. S5):\n“D O: The peaks from 54.2 ppm to 50.33 ppm belong to -N-CH - groups of 1-1 (i', k', l', o') and 1-2 (7',\n2 2\n9', 10', 13').”\n“DMSO-d6: The peaks from 53.90 ppm to 48.40 ppm belong to -N-CH - groups of 1-1 (i', k', l', o') and\n2\n1-2 (7', 9', 10', 13').”\nComment 14. The peak at 62.4 ppm belongs to -CH2 groups (2) at both ends of the 1-1 structure\nbackbone: yes but also 17 of the structure 1-2.\nThe peaks corresponding to position 12 in structure 1-1 and position 10 in structure 1-2 are not assigned;\nthey are expected to appear around 50 ppm.\nReply: Thank you very much to the reviewer. We have repeatedly checked and corrected the relevant\n13C-NMR spectroscopic analysis. In addition, to address the issue of difficult correspondence between\nthe two structures in nuclear magnetic resonance analysis, we have modified the nuclear magnetic\nresonance images, with peaks 1-1 labeled with the English symbols and peaks 1-2 labeled with numbers.\nThe specific changes are as follows:\n(1) The reviewer's comment corresponds to the following sentence (p.10, Supplementary Fig. S3,\noriginal): “The peak at 62.4 ppm belongs to -CH2 groups (2) at both ends of the 1-1 structure backbone.”\n“The peak 2” in structure 1-1 are labeled into “The peak b'”.\n“The peak 17” in structure 1-2 are labeled into “The peak 17'”.\nChanges (p. 16, Supplementary Fig. S5):\n“D O: The peak at 62.4 ppm belongs to -CH groups (b') at both ends of the 1-1 structure backbone,\n2 2\nwhich also belongs to -CH groups (17') of 1-2 structure.”\n2\n“DMSO-d The peak at 63.79 ppm belongs to -CH groups (b') at both ends of the 1-1 structure backbone,\n6: 2\nwhich also belongs to -CH groups (17') of 1-2 structure”\n2\n(2) The reviewer's comment corresponds to the following sentence (p.10, Supplementary Fig. S3,\noriginal): “The peaks from 54.2 ppm to 50.33 ppm belong to -N-CH2- groups of 1-1 (9, 11, 15) and 1-2\n(positions 7,9,23).” “The peak 12” in structure 1-1 are labeled into “The peak l'”.\n“The peak 10” in structure 1-2 are labeled into “The peak 10'”.\nChanges (p. 16, Supplementary Fig. S5):\n“D O: The peaks from 54.2 ppm to 50.33 ppm belong to -N-CH - groups of 1-1 (i', k', l', o') and 1-2 (7',\n2 2\n9', 10', 13').”\n“DMSO-d6: The peaks from 53.90 ppm to 48.40 ppm belong to -N-CH - groups of 1-1 (i', k', l', o') and\n2\n1-2 (7', 9', 10', 13').”\nComment 15. While the XPS analysis confirms the presence of C, O, and N and their functional groups,\nit’s not clear what new or useful information it adds. Also, deconvolution methods should be described\nat least briefly.\nReply: Thank you very much to the reviewer. (1) We added references to the discussion on hydrogen\nbond, as related to XPS analysis4, 5, 6, 7, 8. These works can effectively confirm the existence of hydrogen\nbonds through XPS analysis. Accordingly, we are sure that our method based on XPS analysis could be\na general method to scrutinize the mechanism of hydrogen-bond formation.\n(2) We have added the description of the deconvolution methods in Fig. S7 of the Supplementary\nInformation. It follows:\nChanges (p. 20, Supplementary Information)\n“For all experiments, the assignments of characteristic peaks were obtained by deconvolution of the\nexperimental curve with a series of Gaussian functions. Before XPS spectra were deconvoluted by\nXPSPEAK software, the binding energy of C1s was calibrated to 284.5eV, with hydroxyl, and carbonyl\ngroups shifted approximately 1.5 and 3eV higher, respectively. Deconvolution of the O1s spectrum is\nperformed based on the assignments given by references an aliphatic C-O group positioned at 532.5-\n532.9 eV. Deconvolution of the N1s spectrum is places a N-C amines at 399.04 eV with an aliphatic N-\nC=O group positioned at 400.02 eV.”\nComment 16. Figure 2c, 2d and 2g add Rw to the x-axis and figure 2h RH.\nReply: We would like to express our sincere thanks for your constructive suggestion. We have added the\ncorresponding data and made corrections in Fig. 2. As mentioned in Comment 8, we have decided to\nchange the wording of Rw to Rm, which was defined as the molar ratio of NMA (AM)/TEPA, where\nNMA and AM always maintain the same molar mass. We have added Rm to Fig. 2c, 2d and 2e and added\nRH in Fig. 2h. It follows:\nFig. 2 Mechanical performance and Self-destructive behavior of the HNSPs. a Image of the HNSPs\nupon compressing (The Rm is 2.0.). b Representative stress-strain curves of the HNSPs with different\nRm values. c Dependence of elastic modulus on the Rm of the HNSPs. d Zeta potential of the HNSPs\nwith different Rm values. e Schematic illustration of the mechanically enhanced performance of the\nHNSPs based on effective load transfer, supported by H-bond nanoclusters (F represents the applied\nforce.). f Images of HNSPs with macro self-destructive phenomenon upon moisture stimulation. g Self-\ndestructive rate of the HNSPs with different Rm values. h Self-destructive rate of the HNSPs (The Rm\nis 2.0.) with different ambient humidity.\nComment 17. In Figure 2c, no error bars are shown for the modulus values, although the tests were\nperformed on five samples. Including error bars would be helpful to show the reproducibility of the\nmechanical data.\nReply: We would like to express our sincere thanks for your constructive suggestion. Following your\nsuggestion, we have added error bars in Fig. 2c of the revised manuscript. It follows:\nFig. 2c Dependence of elastic modulus on the Rm of the HNSPs.\nComment 18. In Figure 2d, it appears that equilibrium may not have been completely reached at each\nhumidity step. In several segments, the sample mass still appears to be changing. It would be better to\nensure that the mass stabilizes at each step before moving to the next RH level, or to provide details on\nthe equilibrium criteria used.\nReply: We would like to express our sincere thanks for your constructive suggestion. Firstly, we guess\nthat the moisture absorption equilibrium process you wish to express should belong to Fig. 3d. Secondly,\nto dispel your doubts, we have added more details about the parameter settings and equilibrium\nconditions during the DVS test in the section of “1.3.1 General Characterization” in the Supplementary\nInformation. It follows:\nChanges (p. 5, Supplementary Information)\n“The sorption-desorption performance was measured by a DVS system (Surface Measurement Systems\nLTD, DVS Adventure). The test samples are preheated at 105 °C, 0% RH for 5 hours in the testing\nchamber for completed drying, and then placed at 25°C for 2 hours stabilization. The mass of test HNSPs\nsample was about 30 mg, and the adsorption-desorption performance was measured at 25 °C with the\nhumidity range from 0% to 90% and then to 0%, conducted at a humidity rate of 10% as a step. When\nthe weight of the sample is finally stable at a certain humidity (the change in the mass of the sample\nwithin 10 min is less than 0.01% of the absolute dry mass), the sample is considered to reach a moisture\ncontent equilibrium state at that humidity, then the testing program adjusts RH adjusted to the next level\nfor repeated testing.”\nComment 19. In Figure 3f and 3g, the color coding related to the different types of water is not indicated\ndirectly in the figure or legend. Although the different types of water corresponding to each percentage\nare explained in the text, including a legend is necessary. Furthermore, it is not clear which sample the\ndata correspond to, and no information is provided in the figure, the legend, or the main text.\nReply: We would like to express our sincere thanks for your constructive suggestion. We have a legend\nin Fig. 3f and 3g, which can clearly illustrate different types of water in the adsorption process. It follows:\nFig. 3f The composition of water in the adsorption process.\nFig. 3g The composition of water in the desorption process.\nComment 20. Line 278 The authors should avoid referring the IR peak to a hydrogen bond peak. It\nwould be more accurate to describe it as the N–H stretching vibration, which shifts due to the presence\nor absence of hydrogen bonding.\nReply: We would like to express our sincere thanks for your constructive suggestion. We sincerely thank\nthe reviewer for this constructive suggestion. Following your advice, we have revised our description of\nthe IR peak in line 278, clarifying that this peak corresponds to the N-H stretching vibration. The\nmanuscript has been updated accordingly for improved accuracy. It follows:\nChanges (p. 19):\n“In-situ Fourier-transform infrared (FT-IR) spectroscopy under consistent RH conditions is used to\nexamine changes in hydrogen bonds during water adsorption. In high-humidity environments (RH =\n95%), the infrared absorption peak corresponding to the N-H stretching vibration shifts from 3370 cm-1\nto 3430 cm-1 over time, indicating that the pre-existing hydrogen-bonded state of the amino groups\ngradually convert to free amino groups. Additionally, as shown in Fig. 3i, the shift of the 1410 cm-1 peaks\nto a lower wavenumber further indicates the gradual dissociation of the stretching vibration peak of N-\nC, which belong to the amide group.”\nComment 21. Some minor corrections.\nLine 280 Additionally, as shown in Figure 3b Figure 3i, the shift of the 1410 cm-1 281 peaks to a higher\nwavenumber further indicates the 282 gradual dissociation of hydrogen bonds.\nLine 259 Over time, as the water absorption mass of HNSPs continues to increase (Figure 3g) (Figure\n3f)\nLine 47 (SI) For the sample showing the surface morphology, which was prepared by touching one edge\nof the sample and with no spraying sentence is incomplete, needs correction.\nLine 93 Under ambient conation?\nLine 285 Figure 3. Influence of hygroscopicity kinetics on self-destruction performance for HNSPs.\n(a) Adsorption and desorption isotherms measured using the DVS analyzer. (b) Desorption isotherms\nmeasured using the DVS analyzer.\nLine 244 0 to 90% RH)\nReply: We would like to express our sincere thanks for your constructive suggestion. We have examined\nthe whole manuscript carefully and made corrections accordingly in the revised manuscript.\n(1) Line 280 Additionally, as shown in Figure 3b Figure 3i, the shift of the 1410 cm-1 281 peaks to a\nhigher wavenumber further indicates the 282 gradual dissociation of hydrogen bonds.\nChanges (p. 19): The following statement was correct:\n“Additionally, as shown in Fig. 3i, the shift of the 1410 cm-1 peaks to a lower wavenumber further\nindicates the gradual dissociation of the stretching vibration peak of N-C, which belong to the amide\ngroup.”\n(2) Line 259 “Over time, as the water absorption mass of HNSPs continues to increase (Figure 3g), the\nproportion 268 of bound water content further rises to 63%, while immobilized water decreases to 31%,\nand the 269 proportion of free water remains nearly unchanged.”\nChanges (p. 18): The following statement was correct:\n“Over time, as the water absorption mass of HNSPs continues to increase (Fig. 3f), the proportion of\nbound water content further rises to 63%, while immobilized water decreases to 31%, and the proportion\nof free water remains nearly unchanged.”\n(3) Line 47 (SI) For the sample showing the surface morphology, which was prepared by touching one\nedge of the sample and with no spraying sentence is incomplete, needs correction.\nChanges (p. 4, Supplementary Information): The following statement was correct:\n“Cryogenic scanning electron microscopy (Cryo-SEM) experiments were performed on a\nThermoFisherScientific (FEI)-Apreo S HiVoc scanning microscope (FEI Company, US) equipped with a\nQuorum cryo-stage PP3010T. The samples for observation were prepared by a freeze-drying method:\nsamples were first frozen in liquid nitrogen (-185°C) for 30 s, and then were transferred to a chamber to\nsublimate the moisture under vacuum at -90°C for 10 min. Subsequently, the samples do not need to be\ncoated (like Au) and then observed at-140°C at an acceleration voltage of 5 kV. The reason why the\nsamples do not need to be coated is that the size of the gold nanoparticles is much larger than the\nobserved microstructure, which can affect the observation of the sample. Due to the lack of gold coating,\nthere may be a decrease in image contrast and an increase in signal noise during sample observation.”\n(4) Line 93 Under ambient conation?\nChanges (p. 6): The following statement was correct:\n“Under the ambient conditions (25 ℃), the system undergoes two reversible yet stable phase transitions.”\n(5) Line 285 Figure 3. Influence of hygroscopicity kinetics on self-destruction performance for HNSPs.\n(a) Adsorption and desorption isotherms measured using the DVS analyzer. (b) Desorption isotherms\nmeasured using the DVS analyzer.\nChanges (p. 20): The following statement was correct:\n“Fig. 3 Influence of hygroscopicity kinetics on self-destructive performance for HNSPs. (a) Adsorption\nisotherms and (b) Desorption isotherms of HNSPs with different Rm.”\n(6) Line 244 0 to 90% RH)\nChanges (p. 17): The following statement was correct:\n“Table S2 (Supplementary Information) details the mass changes of HNSPs in the adsorption-desorption\ncycle (The RH ranges from 0% to 90%), showing the phenomenon of desorption hysteresis.”\nReviewer #4\nGeneral Comment. I co-reviewed this manuscript with one of the reviewers who provided the listed\nreports. This is part of the Nature Communications initiative to facilitate training in peer review and to\nprovide appropriate recognition for Early Career Researchers who co-review manuscripts.\nReply: We sincerely appreciate the Reviewer for evaluating our paper, providing positive feedback, and\noffering constructive suggestions. In response, we have revised the manuscript to enhance the\npresentation and clarity of our work, incorporating the suggested improvements as outlined below.\nReferences:\n1. He X, Guo Y, Li M, Pan N, Wang M. Effective gas diffusion coefficient in fibrous materials by\nmesoscopic modeling. Int J Heat Mass Tran 107, 736-746 (2017).\n2. Wang W, Wang H, Jin X, Wang H, Lin T, Zhu Z. Effects of hydrogen bonding on starch granule\ndissolution, spinnability of starch solution, and properties of electrospun starch fibers. Polymer 153, 643-\n652 (2018).\n3. Zhiguang C, Junrong H, Huayin P, Keipper W. The Effects of Temperature on Starch Molecular\nConformation and Hydrogen Bonding. Starch - Stärke 74, 2100288 (2022).\n4. Ji C, et al. Hydrogen Bond‐Mediated Self‐Assembly of Carbon Dots Enabling Precise Tuning of\nParticle and Cluster Luminescence for Advanced Optoelectronic Applications. Adv Mater 37, 2414450\n(2024).\n5. Zhuo Y, et al. Simultaneously Toughening and Stiffening Elastomers with Octuple Hydrogen\nBonding. Adv Mater 33, 2008523 (2021).\n6. Ayiania M, Smith M, Hensley AJR, Scudiero L, McEwen J-S, Garcia-Perez M. Deconvoluting the\nXPS spectra for nitrogen-doped chars: An analysis from first principles. Carbon 162, 528-544 (2020).\n7. Smith M, Scudiero L, Espinal J, McEwen J-S, Garcia-Perez M. Improving the deconvolution and\ninterpretation of XPS spectra from chars by ab initio calculations. Carbon 110, 155-171 (2016).\n8. Lu Y, Fan D, Shen Z, Zhang H, Xu H, Yang X. Design and performance boost of a MOF-\nfunctionalized-wood solar evaporator through tuning the hydrogen-bonding interactions. Nano Energy\n95, 107016 (2022).\nAuthors’ response to decision letter for our Research Article, Paper ID: NCOMMS-25-14076A.\n“Mechanically-Robust and Humidity-Tunable Self-Destructive Polymers Enabled by Hydrogen-\nBond Nanoconfinement” in Nature Communications.\nResponses to the reviewers’ comments\nOn behalf of all my co-authors, thank the editor and all reviewers for their constructive comments and\nsuggestions on revised manuscript, which can help us to greatly improve the quality of this work. We\nhave revised the manuscript substantially as the editor’s and reviewers’ suggestions, examined the whole\nmanuscript carefully and made corrections accordingly. The changes are highlighted in yellow in the\nresubmitted version and the point-to-point response to reviewers is listed as following:\nReviewer #1 (Remarks to the Author):\nI carefully reviewed the author's responses to all the other reviewers. Regrettably, a direct and\ncomprehensive analysis and verification of this structure is still lacking, making the design concepts\nproposed by the author lack strong persuasiveness. Besides, the performance advantages of this material\nare still not powerfully demonstrated, e.g., the superiority over other similar materials in key performance\nparameters.\nReply: We thank the reviewer for very positive feedback for our manuscript and the insightful comments.\nWe have revised the manuscripts by addressing the constructive suggestions noted by the reviewer as\n1\ndetailed below. We believe that these changes have substantially improved the quality of our manuscript.\nThus, we hope to get your approval!\n(1) Response Regarding Structural Characterization and Verification\nThe reviewer noted that a direct and comprehensive analysis and verification of the proposed structure\nis still lacking. We appreciate this comment and have further clarified our structural characterization\nefforts in the revised manuscript. As detailed in this manuscript, the structure of the material, particularly\nthe unique hydrogen-bonded clusters, was thoroughly characterized using multiple complementary\ntechniques. Specifically:\nThe C=O stretching vibration in the amide group at 1652 cm-1 was observed in Fourier transform\ninfrared (FTIR) spectra (Supplementary Fig. S2) and the stretching vibration peak of N-C can be\nobserved at around 1407 cm-1 and 1125 cm-1, which belong to the amide group and the adipose group\nsecondary amine, respectively. The results of nuclear magnetic resonance (NMR) manifested that the\nmulti overlapping peaks at 2.80 ppm to 2.17 ppm are attributable to the -CH on the main chains in the\n2\n1H-NMR spectroscopy (Supplementary Fig. S3 and S4), and the characteristic peaks from at 54.2 ppm\nto 50.33 ppm belong to -N-CH - groups in the 13C-NMR spectroscopy (Supplementary Fig. S5).\nheteronuclear single quantum coherence (HSQC) confirmed the correspondence between 1H-NMR\nand 13C-NMR (Supplementary Fig. S6). The above results indicated that these HNSPs have been\nsuccessfully synthesized via the Aza-Michael reaction. We have performed X-ray photoelectron\nspectroscopy (XPS) experiments (Supplementary Fig. S7). The XPS data further confirmed that HNSPs\n2\nhave abundant oxygen-containing groups and nitrogen-containing groups on the surface, which helps to\nprovide sufficient hydrogen bonding sites. Above analysis results indicate that HNSPs containing\nmultiple hydrogen bonds have been successfully synthesized. Simultaneously, all-atom molecular\ndynamics (MD) simulations were conducted to theoretically elucidate the categories and aggregation\nstructures of HNSPs. As shown in Fig. 1c and Fig. S9 (Supplementary Information), the simulated\nsystems comprise 30 polymer chains contains abundant hydrogen bonding sites and these hydrogen\nbonds are formed through the N and O groups on the molecular chains. As shown in Fig. 1d,\nTransmission electron microscope (TEM) images reveal densely and uniform hydrogen-bonded\nnanoclusters with an average radial size of 8 nm. Compared with other structures (sheet or brick),\nspherical nanoclusters have better fluidity and specific surface area, which provides more hydrogen\nbonding sites to establish the physical cross-linking structures. Additionally, in contrast to small\nmolecules with relatively simple structures, the structural characterization of macromolecules is often\nmore complex, involving multi-level validation of structure-activity relationships. Nevertheless, in this\nstudy, we have systematically employed a range of complementary characterization techniques (such as\nFTIR, 1H-NMR, 13C-NMR, HMBC and HSQC, XPS, TEM, and even MD simulations) to thoroughly\nanalyze the structure of HNSPs. The experimental results showed that all measured structural parameters\nwere highly consistent with the intended molecular design, thereby providing strong experimental\nevidence supporting the accuracy and reliability of the proposed molecular structures.\nCollectively, these results provide a multi-faceted and consistent body of evidence that directly verifies\nthe formation and specificity of the hydrogen-bonded cluster structure central to our material’s design.\n3\n(2) Response Regarding Performance Demonstration and Advantages\nThe reviewer expressed that the performance advantages, particularly the superiority over other similar\nmaterials, are not powerfully demonstrated. We thank the reviewer for this observation and have\nexpanded our discussion to better highlight the material's distinctive performance profile and its novel\nmechanistic origin.\n(ⅰ) The advantage of the mechanism: Most of the transient (self-destructive) materials (for example,\nsilk fibroin, poly (lactic acid), poly (e-caprolactone), and poly (vinyl alcohol) achieve their transience\nthrough chemical dissolution with the device submerged in aqueous solutions or biofluids with little\ncontrol over the transience period, where the transience is passively governed by chemical dissolution or\nmechanical destruction of the functional devices associated with the degradation process. However, the\nHNSPs mentioned in this manuscript can actively trigger their self-destructive behavior under mild\nexternal stimuli (moisture), which can maintain this self-destructive state even after removing moisture\nstimuli. Our devised HNSPs can make the self-destructive state stable without continuous stimulation\nunder the same conditions (an external stimulus is required to trigger the self-destructive behavior, rather\nthan maintain the stimulus state.), simultaneously achieving the transformation from a hard solid to a\nfluid like state. At the same time, the moisture serves as a stimulus that can actively trigger self-\ndestructive behavior, which is different from the common passive stimulus method that transient (self-\ndestructive) materials. Especially, the stiffness switching performance of responsive polymer is\nlimited, and it is almost impossible to achieve such a huge transition from solid to fluid. The mechanism\nof this self-destructive material is achieved by the transformation of HNSPS hydrogen bonds and\nmolecular chain configurations induced by moisture.\n(ⅱ) The advantage of their properties: The yield strength of HNSPs, defined as the stress\ncorresponding to 10% residual deformation, is found to be as high as 14.66 MPa. Furthermore, the\nYoung’s modulus of HNSPs markedly increases with increasing Rm in Fig. 2c. The highest Young’s\nmodulus of the HNSPs up to165.21 MPa is calculated in the low-strain region (<10% strain) of the stress-\nstrain curve. Compared to common transient materials (such as silk protein)1, 2, 3, 4, 5, HNSPs have\nexcellent mechanical performance advantages and can be widely used in more complex scenarios.\n(ⅲ) The advantage of their functions: The common transient materials are used as substrates or\ncoatings for some transient devices6, 7, 8, while the functions of the device are achieved through other\ncomponents. The designed HNSPs can be directly compounded with other materials, thus enabling the\ndevelopment of transient materials that integrate transient performance and functionality. Based on the\ncontrolled self-destructive rate of HNSPs under moisture, the experimental model of temporary buildings,\nself-destructive Quick Response (QR) code and transience devices were designed to elaborate the\nsignificance and practical benefits (Fig. S20). A model of temporary bridge can sustain a standard weight\nof 100 g yet leads to the structural destruction of itself induced by moistures under 75% RH at 25 ℃ for\n180 min (Fig. S20a). Intriguingly, a self-destructive QR code consisted of the black and white squares\nthat arranged according to specific coding rules gradually become unrecognizable liquid mixtures due to\nthe self-destructive behavior of HNSPs under moisture, realizing the self-erasure of information and the\nprotection of information leakage (Fig. S20b). The moisture-triggered self-destructive transience devices\nthat were constructed by mixing HNSPs with Ni powder, can be easily connected in series to the circuit\nand light up the small light bulbs, but ultimately became a diluted liquid and Ni powder after absorbing\nmoisture, effectively reduce the pollution of electronic waste (Fig. S20c).\nIn summary, we believe that this work provides a simple yet versatile strategy for designing robust,\nswitchable self-destructive polymers, which provides a new and compelling paradigm for the\ndevelopment of future transient materials. We also hope that these clarifications and the additional\ncontext provided in the revised manuscript adequately address the reviewer’s concerns. Thus, we hope\nto get your approval!\nReviewer #2 (Remarks to the Author):\nThe manuscript is revised well, and I recommend this manuscript for publication in Nature\nCommunications as is.\nReply: We thank the reviewer for very positive feedback for our manuscript and the insightful comments.\nReviewer #5 (Remarks to the Author):\nThis manuscript reports the design of hydrogen-bond nanoconfined self-destructive polymers (HNSPs)\nthat combine high mechanical robustness with humidity-tunable reversible transitions between solid and\nfluid states. The authors demonstrate that moisture exposure triggers a controlled self-destruction process,\nwhich can be reversed by heating, and the switching rate is tunable by humidity.\nstrong mechanical performance with stimulus-responsive degradability. Such materials expand the\npossibilities for next-generation applications, including transient devices, recyclable systems, and\nenvironmentally adaptive polymers.\nI have carefully read the authors’ rebuttal, with particular attention to the concerns raised by Reviewer\n#3, as specifically requested. In addition, I also reviewed the entire revised manuscript to evaluate the\noverall quality and clarity of the work.\nThe authors have responded appropriately and convincingly to all of Reviewer #3’s comments. Their\nrevisions and explanations are well reasoned and supported by additional data and discussion where\nnecessary. The concerns that were previously raised have been adequately addressed, and I find no\nremaining major issues.\nMoreover, the manuscript as a whole is now clear, logically organized, and scientifically sound. The\nproposed concept of hydrogen-bond nanoconfined self-destructive polymers is novel and well supported\nby the experimental results. The revisions have strengthened the work and improved its readability.\nI recommend the acceptance of this manuscript for publication in Nature Communications.\nReply: We thank the reviewer for very positive feedback for our manuscript and the insightful comments.\nReference\n7\n1. Han WB, Lee JH, Shin JW, Hwang SW. Advanced Materials and Systems for Biodegradable,\nTransient Electronics. Adv Mater 32, e2002211 (2020).\n2. Ye C, et al. Sustainable Silk Fibroin Ionic Touch Screens for Flexible Biodegradable Electronics\nwith Integrated AI and IoT Functionality. Adv Mater, e2412972 (2024).\n3. Chae JW, et al. Silk Fibroin, Sericin, and Conductive Silk Composites for Skin-Attachable\nTransient Electronics. ACS Applied Electronic Materials 6, 1746-1756 (2024).\n4. Zhou J, et al. Humidity-sensitive, shape-controllable, and transient zinc-ion batteries based on\nplasticizing gelatin-silk protein electrolytes. Materials Today Energy 21, (2021).\n5. Xia Z, et al. Toward Versatile Transient Electronics: Electrospun Biocompatible Silk\nFibroin/Carbon Quantum Dot-Based Green-Emission, Water-Soluble Piezoelectric Nanofibers.\nPolymers 17, (2025).\n6. Dong M, et al. Transient Starch‐Based Nanocomposites for Sustainable Electronics and\nMultifunctional Sensing. Adv Funct Mater 35, (2024).\n7. Teng L, Ye S, Handschuh‐Wang S, Zhou X, Gan T, Zhou X. Liquid Metal‐Based Transient\nCircuits for Flexible and Recyclable Electronics. Adv Funct Mater 29, (2019).\n8. Ye G, Song D, Song J, Zhao Y, Liu N. A Fully Biodegradable and Biocompatible Ionotronic Skin\nfor Transient Electronics. Adv Funct Mater 33, (2023).\n8"}, {"round": 2, "reviewer_comments": {"reviewer_1": "I carefully reviewed the author's responses to all the other reviewers. Regrettably, a direct and comprehensive analysis and verification of this structure is still lacking, making the design concepts proposed by the author lack strong persuasiveness. Besides,the performance advantages of this material are still not powerfully demonstrated, e.g., the superiority over other similar materials in key performance parameters.", "reviewer_2": "The manuscript is revised well, and I recommend this manuscript for publication in Nature Communications as is.", "reviewer_5": "This manuscript reports the design of hydrogen-bond nanoconfined self-destructive polymers (HNSPs) that combine high mechanical robustness with humidity-tunable reversible transitions between solid and fluid states. The authors demonstrate that moisture exposure triggers a controlled self-destruction process, which can be reversed by heating, and the switching rate is tunable by humidity.\nThe scientific significance of this work lies in establishing a simple yet versatile strategy to integrate strong mechanical performance with stimulus-responsive degradability. Such materials expand the possibilities for next-generation applications, including transient devices, recyclable systems, and environmentally adaptive polymers.\nI have carefully read the authors’ rebuttal, with particular attention to the concerns raised by Reviewer #3, as specifically requested. In addition, I also reviewed the entire revised manuscript to evaluate the overall quality and clarity of the work.\nThe authors have responded appropriately and convincingly to all of Reviewer #3’s comments. Their revisions and explanations are well reasoned and supported by additional data and discussion where necessary. The concerns that were previously raised have been adequately addressed, and I find no remaining major issues.\nMoreover, the manuscript as a whole is now clear, logically organized, and scientifically sound. The proposed concept of hydrogen-bond nanoconfined self-destructive polymers is novel and well supported by the experimental results. The revisions have strengthened the work and improved its readability.\nI recommend the acceptance of this manuscript for publication in Nature Communications."}, "author_response": ""}]

Decision letter