bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating the Synthesis Pathway of a Disordered Rocksalt Phase Via in Situ X-Ray Characterization
Authors: Liang Zhilin , Marques Otavio , Masina Sikhumbuzo , Paredes Mellone Oscar , Sokaras Dimosthenis , Weker Johanna Nelson , Stone Kevin
Published: August 2024

Recently, Li-rich disordered rocksalt (DRX) materials have gathered a lot of attention as prospective Li-ion battery cathode materials owing to their high electrochemical storage capacity and high specific energy. In contrast to the current commercialized layered Li-ion battery cathode materials (e.g. LiCoO2, LiNixMnyCo1-x-yO2), which contain toxic and expensive metals, DRX can accommodate a large variety of transition metals, such as Mn and Ti, which are cheap and earth abundant. These characteristics make them a cheaper and a more sustainable alternative to the current commonly used layered cathodes.

Unlike the commercial Li-ion battery cathodes, where the transition metals and the Li are arranged in an ordered manner, DRX exhibits a highly disordered cation framework. Fluorine incorporation into DRX was extensively studied, where the fluorine anions are distributed disorderly at the anion sites. Previous studies have shown that the electrochemical performance of DRX cathodes can be enhanced via fluorination, as fluorine can effectively suppress the oxygen redox activity observed in many Li-rich cathodes. However, a large degree of fluorine incorporation into DRX was found to be difficult. As a result, it is important to study the mechanism in which fluorine is incorporated into the structure, and the role of LiF during synthesis of DRX.

In addition to fluorination, the degree and type of short-range cation ordering (SRO) presenting in the materials were also found to have a significant impact on the electrochemical performance of DRX materials. The SRO present can be modified with synthesis techniques, where samples annealed at the synthesis temperature for a longer period exhibit a higher degree of SRO. This observation has demonstrated that the synthesis conditions and SRO are highly correlated. It is hence possible to control the SRO in DRX materials via varying synthesis conditions, thereby enhancing their electrochemical performance. Keeping this in mind, it is hence important to understand the mechanism by which DRX is formed.

In this work, we have performed in situ synchrotron X-ray diffraction monitoring the phase progression during the solid-state synthesis of Li1.1Mn0.8Ti0.1O1.9F0.1 DRX oxyfluoride. We have observed several crystalline intermediate phases emerged before the formation of the DRX phase. Coupled with X-ray absorption spectroscopy, we are able to gain additional insights into the intermediate phases formed during the synthesis. This poster will describe the investigation of the synthesis pathway of Li1.1Mn0.8Ti0.1O1.9F0.1 DRX oxyfluoride using X-ray characterization techniques. The formation mechanism of this DRX phase will also be discussed.
Self-Healing Stretchable Li-Ion Battery Based on a High-Voltage Hydrogel Electrolyte
Authors: He Peisheng , Park Jong Ha , Fang Chao , Toor Anju , Lin Liwei
Published: August 2024

Safe and deformable soft batteries are desirable for future wearable electronic devices. However, current Li-ion batteries on the commercial market are rigidly packaged and hermetically sealed to prevent moisture penetration and the leakage of toxic and flammable organic electrolytes. Since the modulus of elasticity and gas permeability of materials are inextricably linked, stretchable batteries often experience significant performance degradation over time in the ambient due to inevitable moisture penetration. Furthermore, the polymer-based flexible packaging materials can be easily damaged resulting in electrolyte leakage that poses significant safety concerns. Here we report a non-toxic, aqueous hydrogel electrolyte instead of its organic counterpart that is demonstrated to 1) enable highly safe operations due to its non-toxic and non-flammable nature; 2) alleviate the moisture penetration problem from the outside environment; (3) have a high-voltage working window of ~2.97V; and (4) allow the construction of stretchable batteries by using elastic polymer packaging materials instead of rigid hermetic seals. The prototype batteries have shown good stretchability (50% strain) and flexibility (radius of curvature < 2mm) to enable conformal attachments to a wide range of geometric surfaces. The prototype battery also shows outstanding cyclic stability, retaining ~90% of the original capacity after 100 cycles for over 2 months in the ambient environment without using any rigid hermetic sealing package. Finally, a prototype battery with a self-healing elastomer package remains functional after being punctured by a needle 5 times at different locations in the package. Furthermore, it can recover >90% of its capacity after being cut through by a razor blade and subsequently healed at 70 for 10 minutes. Such safe and highly stretchable batteries would be useful for several wearable electronic applications such as blood glucose monitoring, hearing rate monitoring, temperature monitoring, wireless charging, smart clothing, etc.

Figure 1
(Invited) Advancing Carbon Nanotube Synthesis: A Data-Driven Strategy to Overcome Trade-Offs
Authors: Futaba Don N.
Published: August 2024

Materials and their synthesis play pivotal roles in energy storage and conversion. In particular, carbon nanotubes (CNTs) have exhibited potential due to their unique multifunctionality, positioning them as promising elements in this field. However, despite advance in the application of CNTs, challenges persist in both synthesis and processing. The advent of artificial intelligence (AI) has emerged as a transformative tool, empowering researchers and showing promise to expedite scientific breakthroughs. In this presentation, I will briefly discuss our development of a two-stage CNT synthesis process. In addition, I will discuss the application of AI to augment researchers’ capabilities in synthesis and processing. As examples, I will discuss our effort to apply a data-driven approach to attempt to break through synthetic trade-offs in single wall CNT forest growth. I will also discuss our development of a tool to determine dispersants for CNT processing.
(Nanocarbons Division Poster Award, 1st Place) Nd2O3 Templated Carbon Nanostructures for Energy Storage
Authors: Umer Arslan , Balkus Kenneth J. , Ferraris John
Published: August 2024

Increased energy consumption has triggered the development of various energy storage devices. Supercapacitors have gained attention as energy storage devices due to their high-power density and long cycle life. The energy density of supercapacitor can be increased by combining electric double layer capacitance (EDLC) and pseudocapacitance (PC). A hybrid material based on rare-earth metal oxide templated carbon will be presented that combines both EDLC and PC within the same material. Specifically, neodymium hydroxide (Nd(OH)3) reacted with acetylene and steam to form carbon coated Nd2O3. Both Nd(OH)3 nanorods and nanospheres were used to prepared templated carbon followed by partial or complete washing of metal oxide. The resulting carbon exhibit the surface area of 1245 m2/g. Asymmetric coin cell was constructed with capacitance of 180.5 F/g and energy density of 76.8 Wh/kg This work paves the door to develop novel hybrid supercapacitors.
(Invited) Electron Transport in Nanocarbon Networks for Energy Conversion and Storage Applications
Authors: Bahk Je-Hyeong , Akinboye Oluwasegun Isaac , Kondapalli Vamsi Krishna Reddy , Shanov Vesselin
Published: August 2024

Carbon nanostructures have attracted great attention in recent years as novel electrode materials in batteries with increased capacity and conductivity as well as enhanced material stability. In these nanostructures, nanocarbons such as carbon nanotubes and graphene nanoplatelets are interconnected to construct their three-dimensional networks around the host materials for Li deposition. This work focuses on the study of electron transport phenomena in these nanocarbon networks with two model material systems: (1) single-walled carbon nanotube (SWCNT) networks co-embedded with silica microparticles (Fig. (a)), and (2) free-standing three-dimensional graphene (3DG) structures with polymeric surface modifications (Fig. (b)). We characterize the materials for electrical conductivity and thermopower with varying material contents in the composites to reveal several key factors determining their energy-dependent carrier transport characteristics. It is found that in these three-dimensional nanocarbon networks, carrier tunneling at the junctions between nanocarbons along with the network morphology predominantly determines the transport properties. Simultaneous increase in electrical conductivity and thermopower is achieved for SWCNT networks co-embedded with silica microparticles by increasing silica content up to 40 w.t.% at a fixed CNT content. The enhanced electron transport is attributed to the reduced junction distances due to the intimate network formation on the surface of silica particles with a polymer binder. Our transport theory based on the Landauer formalism for junction tunneling reveals that the junction modification with polymer can alter the potential barrier heights for both electrons and holes at the junction to significantly change the transport properties of the composite. Doping of nanocarbons is also investigated for their impacts on the junction transport and the geometric factor of the networks. Finally, we also investigate the use of these carbon nanostructures in solid-state thermoelectric (TE) energy harvesters and ionic TE capacitors to harvest thermal energy from temperature gradients and fluctuations.

Figure 1
The Impact of Biomass-Derived Graphene-like Porous Carbon Decorated with NiO Nanoparticles on the Electrochemical Performance of Lithium-Sulfur Batteries
Authors: Sultanov Fail , Dangaliyeva Akmaral , Tatykayev Batukhan , Mentbayeva Almagul , Bakenov Zhumabay
Published: August 2024

Lithium-sulfur batteries are considered a promising next-generation energy storage system, boasting high theoretical capacity and energy density, approximately double that of LiBs [1,2]. However, challenges such as low sulfur conductivity, significant volume expansion during cycling, and the lithium polysulfides shuttle effect hinder their practical use [3]. These issues result in side reactions, irreversible loss of active material, and anode degradation, leading to a rapid decline in cell capacity stability [4].

In this research, we successfully developed a sulfur cathode carbon matrix and separator modifier from rice husk through carbonization and thermal activation. The resulting graphene-like porous carbon (GPC) exhibited high efficiency as a sulfur host, enhancing the electrochemical performance of the cathode. The GPC-NiO composite also served effectively as a separator modifier, catalyzing lithium polysulfides' redox reactions and improving the overall cycling stability of lithium-sulfur batteries. In particular, the GPC@S/GPC-NiO-20 cell demonstrated an excellent initial discharge capacity of 1519 mAh g-1 at 0.2 C. Also, it delivered excellent long-term cycling, maintaining a discharge capacity of 661 mAh g-1 even after 400 cycles at 1 C, with a Coulombic efficiency exceeding 97%. It exhibited a promising rate capability of 568 mAh g-1 at 2 C and retained a discharge capacity of 603 mAh g-1 over 100 cycles at 0.2 C with a sulfur loading of 4.0 mg cm-2.

Acknowledgments

This research is funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. AP19677708).

References

[1] H. Li, S. Ma, J. Li, F. Liu, H. Zhou, Z. Huang, S. Jiao, Y. Kuang, Altering the reaction mechanism to eliminate the shuttle effect in lithium-sulfur batteries, Energy Storage Materials. 26 (2020) 203–212. https://doi.org/10.1016/j.ensm.2020.01.002.

[2] F. Sultanov, A. Mentbayeva, S. Kalybekkyzy, A. Zhaisanova, S.-T. Myung, Z. Bakenov, Advances of graphene-based aerogels and their modifications in lithium-sulfur batteries, Carbon. 201 (2023) 679–702. https://doi.org/10.1016/j.carbon.2022.09.069.

[3] M. Zhao, Y.-Q. Peng, B.-Q. Li, X.-Q. Zhang, J.-Q. Huang, Regulation of carbon distribution to construct high-sulfur-content cathode in lithium–sulfur batteries, Journal of Energy Chemistry. 56 (2021) 203–208. https://doi.org/10.1016/j.jechem.2020.07.054.

[4] Y. Hu, W. Chen, T. Lei, Y. Jiao, J. Huang, A. Hu, C. Gong, C. Yan, X. Wang, J. Xiong, Strategies toward High‐Loading Lithium–Sulfur Battery, Adv. Energy Mater. 10 (2020) 2000082. https://doi.org/10.1002/aenm.202000082.
Designing Switchable Transition Metal Nitrides/Carbides from High-Entropy PBA Derivative As Bifunctional Oxygen Electrocatalyst for Rechargeable Zinc-Air Batteries
Authors: Tanmathusorachai Wuttichai , Rinawati Mia , Aulia Sofiannisa , Chiu Yen-Shuo , Yeh Min-Hsin
Published: August 2024

In response to the growing energy and environmental challenges, considerable endeavors have been directed towards the development of sustainable and eco-friendly energy technologies as alternatives to fossil fuels. Moreover, rechargeable zinc-air batteries (RZABs) stand out due to their high energy density and environmental friendliness, although the sluggish cathode oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics restrict RZABs performance. Prussian blue analogues (PBAs), owing to their highly porous structure and tunable morphology, are often utilized as the precursors of the materials. Particularly, high-entropy PBAs (HEPBAs), formed by blending five or more metals in a random lattice, have achieved enhanced thermal and chemical stability via a robust structure with multiple transition metal ions. Meanwhile, transition metal carbides (TMCs) were investigated for ZAB applications due to their higher catalytic activity. Herein, we introduced CNT into HEPBA nanoparticles, followed by calcination processes, resulting in the synthesis of high-entropy metal carbides on CNT (HE-TMCs/CNT) which are effective for the bifunctional OER and ORR performance. HE-TMCs/CNT demonstrate superior activity towards the ORR (E1/2 = 0.77 V) in a 0.1 M KOH solution and OER (η = 330 mV @10 mA cm−2) in a 1 M KOH solution. The ZAB with HE-TMCs/CNT as the cathode demonstrated an open-circuit voltage of 1.39 V, providing a high energy density of 71 mW cm-2 under a current density of 102 mA cm-2. It exhibited the ability to be charged and discharged in cycles for up to 40 hours, revealing good stability under an applied current density of 5 mA cm-2. These results offer a straightforward pathway for the development of efficient bifunctional electrocatalysts for high-performance RZABs.

Figure 1
Effects of Extreme Low Temperatures on Carbon-Based Supercapacitors
Authors: Limsukhon Apichanont , Wuamprakhon Phatsawit , Tejangkura Worapol , Sangsanit Thitiphum , Tuantranont Adisorn , Sawangphruk Montree
Published: August 2024

This comprehensive study delves into the effects of severe cold exposure, specifically liquid nitrogen temperatures, on the functionality of carbon-based supercapacitors. It identifies a slight reduction in capacitance, a direct consequence of the degradation of electrode materials. This degradation is linked to the glass transition in the styrene butadiene rubber binder, leading to decreased adhesion of the active materials in the electrodes. The study highlights the escalated charge transfer resistance post-exposure, pointing to a decrease in efficiency. Significantly, this research emphasizes the crucial role of binder materials in supercapacitor design for low-temperature environments, suggesting that both electrolytes and binders should be equally considered in the development of supercapacitors for harsh climates. The findings contribute valuable insights into enhancing supercapacitor resilience and performance in extreme conditions, paving the way for more robust energy storage solutions.

Figure 1
(Invited) Energy Storage in Ti3C2T
x
MXene in a Wide Temperature Range
Authors: Wang Ruocun , Anayee Mark , Naseer Muhammad Nihal , Zhang Teng , Zhang Yuan , Shekhirev Mikhail , Shevchuk Kateryna , Hu Yong-Jie , Gogotsi Yury
Published: August 2024

Pseudocapacitors have the potential to achieve high energy and high power density simultaneously, a holy grail for electrochemical energy storage. MXene-based pseudocapacitors have made major progress in the last decade, achieving better energy and power density than carbon supercapacitors using the double-layer charge storage mechanism. However, one obstacle facing pseudocapacitors is their shorter lifetime. In MXene-based pseudocapacitors, which showed up to 500,000 cycles lifetime in aqueous electrolyte at room temperature, this concern is pronounced particularly at high temperatures due to the limited stability of the active material in aqueous solutions. This work shows that Ti3C2T
x
MXene electrodes in 5 M H2SO4 possess excellent rate capabilities from -50 °C to 100 °C but also a sufficient lifetime at 70 °C when using a float test holding at -0.9 V vs. Hg/Hg2SO4. Post-mortem characterization using X-ray photoelectron spectroscopy and Raman spectroscopy showed negligible signs of oxidation in the bulk of the film. This work suggests sufficient stability of Ti3C2T
x
MXene as a negative electrode in protic aqueous electrolytes across a wide temperature range rooted in thermodynamics, making it promising for pseudocapacitor energy storage.
(Invited) Sensing the Nanoscale Dynamics and Dimensionality of Brain Tissue By 3D Localization Microscopy of Diffusing Carbon Nanotubes
Authors: Grésil Quentin , Nandi Somen , Mangalwedhekar Rohit , Simon Apolline A. , Cognet Laurent
Published: August 2024

Elucidating how the nanometric structure of complex environments shapes the mesoscopic motion of the nano-objects within them is a fascinating but still open question. Due to a lack of knowledge of nanoscale details, diffusion properties are often described as anomalous. This applies to many systems, including the brain extracellular space that is the focus of this study. Its structure is indeed heterogeneous and tortuous, and ions, nutrients and signaling molecules diffuse in it for proper function of the brain.

In recent years we have developed a strategy based on single-particle localization microscopy using SWIR emitting single-walled carbon nanotubes (SWCNTs) to decypher this brain compartment[1] but also pathological livers[2]. We now show that 3D tracking is essential to link the anomalous diffusion often observed at the macroscale to the local microscopic topologies of the edifices. We will present our recent results for the study of brain extracellular space [3], and other applicable structures including biophysical structures.

References

[1] Godin et al Nat Nano 12 (2017) 238 ; Soria et al Nat Commun 11 (2020)3440 ; Paviolo et al, Nano Lett. (2022) 6849-6856

[2] A.A. Simon 10.26434/chemrxiv-2023-15tgf.

[3] Gresil et al, in preparation
(Invited) Developing a Graphene Field-Effect Biosensor for Genetic Biomarkers: Simulations Unveil How the Device Sensitivity Is Related to DNA-Graphene Interactions at the Nanoscale
Authors: Cote Sebastien , Tremblay Louis , Sauvage Madline , Bouilly Delphine
Published: August 2024

Graphene field-effect transistor biosensors (GFETs) offer a promising platform to detect cancer DNA biomarkers at low concentration [1]. At their core, they have an electronic circuit containing a graphene sheet – a two-dimensional nanomaterial made of a single layer of carbon atoms – whose electronic properties are very sensitive to nearby electric charges. Leveraging that feature, the electrical current generated by a GFET can thus be made very sensitive to the concentration of a specific DNA sequence in a biological sample. To achieve this, the complementary DNA sequence is linked to the graphene to bind specifically the target DNA. In most GFETs, the link is done using 1-pyrenebutanoic acid succinimidyl ester (PBASE) because its pyrene group stacks on the graphene through pi-pi interactions, without disrupting the electronic properties of the graphene. However, recent experiments in the Bouilly group have shown variations in GFET sensitivity depending on the incubation time of graphene with PBASE.

Here, we use a computational approach developed in our previous work [2] to investigate at the nanoscale the role of PBASE linker molecules on the sensitivity of the GFET. First, we use molecular dynamics simulations to characterize the conformational ensemble of a 10-nt single-stranded DNA sequence linked to a graphene sheet using PBASE. Second, we estimate the electrical response of the GFET from the electrostatic potential generated by these DNA conformations on the graphene, as determined using electrostatic Poisson-Boltzmann simulations. Our results show that the conformational ensemble of DNA is strongly affected by the presence of other PBASE adsorbed on the graphene, thus changing the electrostatic potential generated on the graphene. The predicted change of the electrostatic potential should impact measurably the detection signal of the GFET.

We are now using these simulations to explain the experimental characterizations of a GFET designed to detect a genetic biomarker important in breast cancer profiling. Our simulations have the potential to support the development of GFETs with better sensitivity for DNA detection.

[1] Béraud, A., Sauvage, M., Bazán, C. M., Tie, M., Bencherif, A., and Bouilly, D. (2021) Graphene field-effect transistors as bioanalytical sensors: design, operation and performance. Analyst. 146:403-428.

[2] Côté, S., Mousseau, N., and Bouilly, D. (2022) The molecular origin of the electrostatic gating of single-molecule field-effect biosensors investigated by molecular dynamics simulations. Phys. Chem. Chem. Phys. 24:4174-4186.
(Invited) Photoluminescence Modulation of Quantum Well Defects for Biomedicine
Authors: Heller Daniel A. , Kim Mijin , Yaari Zvi , Randall Ewelina , Chen Chen
Published: August 2024

Improved measurements of biomarkers, drugs, and metabolites in live cells and organisms would allow for improvements in disease detection, drug development, and biomedical research. Quantum well-modified carbon nanotubes (QWNTs) have exciting optical properties for applications as sensors for use in live cells and in vivo, including the potential to increase quantum yield over pristine SWCNTs, and to improve control over photoluminescence modulation in response to the local environment. To develop QWNTs into sensors, we devised new methods to encapsulate them for biocompatibility, as well as new instrumentation for measurements. We also investigated mechanisms of QWNT photoluminescence environmental responsivity, including the dependence of electrostatic charge on spectral red-shifting. We found that this mechanism can amplify measurements of biomarkers, enhancing the development of sensors.
The Decompositions of Fluorescent Defects and Pristine Structure in (6,5) Carbon Nanotubes Using Various Oxidants
Authors: Lin Yen-Hsuan , Liu Te-I , Sun Han-Sheng , Nguyen Ai-Phuong , Lin Ching-Wei
Published: August 2024

Fluorescent quantum defects in single-wall carbon nanotubes (SWCNTs) are outstanding candidates as fluorophores for in vivo biomedical imaging applications such as image-guided surgeries and single-cell tracking. Their longer wavelength emission in the short-wave infrared penetrates biological tissues deeper than visible and NIR light. In addition, fluorescent quantum defects can enhance fluorescence brightness by a factor of ~9 compared to the pristine SWCNT emission. Besides their exceeding optical properties, the degradations of SWCNTs in biological and environmental systems are also of importance, but still not well understood yet. This study utilizes sodium hypochlorite (NaClO) and hydrogen peroxide (H2O2) to examine the chemical decompositions of pristine and defect-containing SWCNTs. We found that the oxidation rate of NaClO is ~5 times faster than that of H2O2, showing an obvious oxidant-dependent degradation kinetics. It is also worth mentioning that when using NaClO as the oxidant, the oxidation rate is significantly increased under acidic conditions, probably due to the increased concentration of hypochlorous acid (HOCl). In contrast, H2O2 prefers to oxidize the pristine structure. It is also found that SWCNT coating materials including SDS, SC, and ssDNA might protect the surface structures, especially the defects, from oxidant attacks. We believe our study will lead to a better understanding of the SWCNT degradation, providing valuable insights for future clinical applications.
(Invited) Controlled Charged Management in SWNTs
Authors: Setaro Antonio , Fiebor Alphonse , Adeli Mohsen , Reich Stephanie
Published: August 2024

Gaining control of the doping level of SWNTs at the single particle level opens up new possibilities for their applications. Electrochemical gating allows fine tuning of the desired position of the Fermi level but can be implemented on ensembles of tubes. Filling the tubes with charge-transfer molecules, on the other side, allows doping at the single nanotube level but lacks fine control over the amount of charges transferred. Here we report our approach based on covalently attached ad-hoc synthesized charge-transfer compounds. This approach does not perturb the pi-conjugation of the carbon network, preserving their optoelectronic properties. By controlling the number of groups attached onto the SWNTs, we can set the amount of charges transferred into them, spanning from p-doping to n-doping in a straightforward way.
Single-Walled Carbon Nanotubes As Fluorescent Probes for Supramolecular Self-Assembly Complexes
Authors: Bisker Gili
Published: August 2024

Semiconducting single-walled carbon nanotubes (SWCNTs) are distinguished by their fluorescence in the near-infrared range, which overlaps with the transparency window of biological samples, and they do not photobleach or blink. Utilizing their unique optical properties, SWCNTs can be rendered optical probes for the characterization and analysis of bio-inspired peptide-based hydrogels. Peptide hydrogels, formed through the supramolecular self-assembly of conjugated amino acids, provide versatile three-dimensional scaffolds for applications in cell culture, tissue engineering, and regenerative medicine. The inherent properties of these amino acids or peptides, notably their limited solubility in water, drive them to self-assemble into elongated fibrillary nanostructures, ultimately creating self-supporting hydrogel matrices. We integrate near-infrared fluorescent SWCNTs into these peptide hydrogels as dynamic fluorescent probes, offering real-time insights into the morphological and structural evolution of the hydrogels. This approach not only enhances our understanding of the self-assembly mechanisms at play but also opens new avenues in supramolecular science. The integration of SWCNTs into the supramolecular structures showcases their potential as a powerful tool for long-term, non-invasive monitoring, with immense promise for numerous biomedical applications.
Preparation and Assembly of Carbon Nanotube/Silica Core-Shell Nanowires to Realize High-Density and Well-Aligned Nanotube Arrays with Uniform and Tunable Pitch
Authors: Yun Yeojeong , Cao Qing
Published: August 2024

This study introduces a novel method to fabricate high-density, well-aligned arrays of carbon nanotubes (CNTs) with tunable pitch, utilizing a core-shell nanowire structure of CNTs and silica. The approach involves a modified Stober process to achieve controlled deposition of silicon dioxide around individual CNTs, forming robust core-shell nanowires. By optimizing the Stober process, the shell size can be precisely controlled down to sub 10nm scale while maintaining the individualized nature of the CNTs. Densely packed and precisely aligned CNT arrays are created using Langmuir-Schaefer process. After assembly, the silica shell, acting as a physical spacer, can be easily removed by HF etching, exposing the CNTs while maintaining their alignment. The developed high-density, well-aligned CNT arrays with tunable pitch show significant promise for applications in nanoelectronics, sensors, and other emerging technologies. This methodology offers a robust and scalable approach for CNT array fabrication, opening avenues for tailoring array properties to meet specific application requirements.
SC-CNTs: Thin Film Transistors for High-Performance, Low-Power, Flexible Electronics
Authors: Humes Jefford Jason
Published: August 2024

Single Walled Carbon Nanotubes (SWNTs) have gained a great deal of media attention over the past almost-two decades. From their theoretical usage as the foundational material for space elevators that would take travelers beyond earth’s atmosphere, to an active material that would allow engineers to create nanobots that internally repair or treat the human body, applications for SWNTs are numerous and have resonated within the imagination of scientists and the media alike. Fast forwarding to the modern era, we find that nanotubes still have a great deal of technological promise, some of which parallel those usages that were theoretically conceived many years ago.

For over a decade, NanoIntegris Technologies Inc. has been at the forefront of synthesizing high-purity, electronically enriched SWNT’s and, during that time, has found that our materials have proven to transcend from the theoretical to practical-usage realm. With over 1,900 publications citing the usage of NanoIntegris’ high performance materials, we have not only seen the beneficial properties of our materials studied via techniques such as scanning electron microscopy but have also received many positive use-cases for our materials such as being an additive of highly-conductive, electrode (anode/ cathode) slurries of next-generation lithium-ion batteries, to being used as an active for the highly-sensitive detection of COVID antigens.

Within my talk, I will display the usage of our high-purity semiconducting (≥99%) single walled carbon nanotubes to make the next generation of high-performance electronics. I will focus upon the usage of our IsoSol-S100 semiconducting solution that served as the spin-coated semiconducting layer within a short channel (<10 µm) thin film transistor with ON/OFF of 104, a device thickness of 400 nm, and a mobility of 39 cm2V-1s-1. I will further discuss the usage of our IsoNanotubes-S 99% solution to serve as the active material within a low-power, wearable Radio Frequency biosensor that covers the GSM spectra, with an operation frequency up to 2.1GHz, and that can serve as both a frequency multiplier and mixer.
GPU-Enabled Exascale Quantum Transport Modeling of Carbon Nanotube Devices
Authors: Sawant Saurabh , Leonard Francois , Yao Zhi , Nonaka Andrew
Published: August 2024

The work will describe our efforts to develop an exascale electrostatic-quantum transport framework, Quantum-eXstatic (https://github.com/AMReX-Microelectronics/eXstatic), currently supporting the modeling of carbon nanotube field-effect transistors (CNTFETs). The framework is capable of modeling realistic three-dimensional structures, efficiently, using CPU/GPU heterogeneous architectures of state-of-the-art supercomputers. It is built on top of the AMReX library, which is a GPU-enabled software library containing functionality for writing particle-mesh applications on structured grids. The Quantum-eXstatic framework comprises three major components: the electrostatic module, the quantum transport module, and the part that self-consistently couples the two modules. The electrostatic module using a finite-volume multigrid solver to compute the electrostatic potential induced by charges on the surface of carbon nanotubes, as well as by source, drain, and gate terminals, which can be modeled using an embedded boundary approach to allow for intricate shapes. The quantum transport module uses the Nonequilibrium Green's Function (NEGF) method to model induced charge. Currently, it supports coherent (ballistic) transport, mode-space approximation for subbands of nanotube, contacts modeled as semi-infinite leads, and Hamiltonian representation using the tight-binding approximation. Special features are being included for accurate modeling of long nanotubes, such as adaptive refinement of integration contours to resolve van Hove singularities in long channels. Particular attention is paid to overlap computations with communication to optimize GPU performance. The self-consistency between the two modules is achieved using Broyden's modified second algorithm, which is parallelized using CPUs and GPUs. Preliminary scaling studies show that the code exhibits ~77% weak-scaling efficiency on 512 NVIDIA A100 GPUs of Perlmutter supercomputer for modeling gate-all-around CNTFETs with a channel length of 13.5 microns at equilibrium conditions. This case involved computations of electrostatic potential in 14.5 billion computational cells and Green’s function computation for a Hamiltonian of size 131,072 x 131,072. For problems of this large size, the code takes about 5 min to reach self-consistency.

Figure 1
(Invited) Exciton Dissociation in Mixed-Dimensionality SWCNT-Based Heterojunctions
Authors: Blackburn Jeff , Myers Alexis , Hermosilla Palacios Martha Alejandra , Johnson Justin
Published: August 2024

Quantum-confined semiconductors provide highly tunable optical and electrical properties for a wide variety of emerging applications. Semiconducting single-walled carbon nanotubes (s-SWCNTs) have shown tremendous potential in applications ranging from digital logic, biological imaging, quantum information processing, photovoltaics, and thermoelectric energy harvesting. Energy harvesting applications rely critically upon the creation of tailored interfaces that enable the movement of energetic species (excitons, electrons, holes) in specified directions. In this talk, I will discuss the use of a variety of rationally designed “mixed-dimensionality” heterojunctions between s-SWCNTs and transition metal dichalcogenide (TMDC) monolayers to harvest visible/near-infrared photons and convert these excitations into long-lived charge-separated states. Type-II heterojunctions between s-SWCNTs and TMDCs enable rapid exciton dissociation and microsecond charge-separated state lifetimes. We have developed new TMDC/SWCNT/TMDC trilayer architectures that enable charge transfer cascades for improving charge separation yield and lifetime. These trilayer architectures allow us to probe out-of-plane carrier diffusion in the nanotube layer and the degree to which bound interfacial excitons impact the photophysics in these mixed-dimensionality heterostructures. I will also discuss the methodology by which we attempt to quantify the photoinduced exciton dissociation quantum yields in these nanoscale heterostructures. Using several heterostructure results, we are attempting to narrow in on appropriate ways to quantify the local dielectric constant and exciton size in both the SWCNT and TMDC components, each of which impact the estimated charge carrier yields. Taken together, these studies provide fundamental insights into the links between ground-state thermodynamics and excited-state dynamics for model nanoscale heterojunctions used to harvest solar energy and produce long-lived charge-separated states.
P-Doped Carbon Nanotubes As Light Absorbers and Electron Donors in Photovoltaics
Authors: Blackwell Christopher J. , Dhavamani Abitha , Faitz Zac , Zanni Martin , Arnold Michael S.
Published: August 2024

Doping is a ubiquitous and powerful tool used to alter a material’s electronic properties. Conventional Si solar cells would not exist without it, and it has been used to increase the efficiency of organic and inorganic photovoltaics alike. While doped carbon nanotubes (CNTs) have been the subject of numerous spectroscopic studies, few investigations have examined their performance in photovoltaic devices. Here, we incorporate chemically p-doped CNTs into photovoltaic heterojunctions with C60. In a conventional CNT–C60 heterojunction device, photocurrent can be produced when photogenerated excitons in the CNT layer diffuse to the CNT–C60 heterointerface. The offset in conduction band energy drives dissociation of these excitons via photoelectron transfer from CNT to C60, which yields separated charges that can be collected. Our objective here was to determine the following: 1) does p-doping increase or decrease the efficiency with which excitons dissociate into electrons and holes? 2) Do p-dopants trap excitons and inhibit their diffusion to the heterointerface? 3) How efficiently can a photogenerated trion (exciton coupled to an injected hole) be dissociated to produce a photocurrent?

To answer these questions, we fabricated polymer wrapped (6,5) CNT–C60 heterojunctions over a range of CNT thickness with various levels of p-doping introduced by triethyloxonium hexachloroantimonate treatment. We measured photocurrent to quantify relative photoelectron transfer efficiency for both excitons and trions and compared this to photoluminescence and transient absorbance measurements on doped CNT films. We found that p-doping decreases photocurrent because injected holes bleach the CNTs’ S11 transition and decrease the amount of light absorbed. Meanwhile, the photogenerated exciton to collected electron transfer efficiency remains unchanged for doping densities up to 50μm-1. In contrast, photoluminescence quantum yield drops by over 90% at an equivalent doping density. We attribute this disparity to the fast electron transfer at the CNT–C60 interface, which occurs on the order of femtoseconds. We also found that moderate doping can promote photocurrent at the trion peak, with a photogenerated trion to collected electron transfer efficiency about 1/4 that of the photogenerated exciton to collected electron transfer efficiency. Photocurrent at the trion absorption peak is invariant with reverse bias up to 0.3 V, despite the charged nature of the trion, supporting evidence for the immobile nature of trions. These results indicate that p-CNTs are a viable material for use in photovoltaics, albeit with weaker absorption, and that photocurrent from trions is possible, although with lower quantum efficiency.

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Microbiome modifications by steroids during viral exacerbation of asthma and in healthy mice
Authors: Yagi Kazuma , Ethridge Alexander D. , Falkowski Nicole R. , Huang Yvonne J. , Elesela Srikanth , Huffnagle Gary B. , Lukacs Nicholas W. , Fonseca Wendy , Asai Nobuhiro
Published: August 2024

These studies outline a novel finding that airway treatment with fluticasone, a commonly used inhaled steroid, has significant effects on not only the local lung environment but also on the mucosal microbiome, which may have significant disease implications. The findings further provide data to support that pulmonary viral exacerbations of asthma with or without steroid treatment alter the lung and gut microbiome, which have an impact on the circulating metabolome that likely alters the trajectory of disease progression.
Comparative biophysical study of clinical surfactants using constrained drop surfactometry
Authors: Zuo Yi Y.
Published: August 2024

A thorough investigation into the biophysical properties of four animal-derived clinical surfactant preparations was conducted through constrained drop surfactometry under physiologically relevant conditions. This comparative study unveiled unique in vitro biophysical characteristics among these clinical surfactants, establishing correlations between their chemical composition, lateral film structure, and biophysical functionality. The acquired knowledge offers essential insights for the precise and personalized design of clinical surfactant for the treatment of respiratory distress syndrome and other respiratory conditions.
Low-dose sufentanil does not affect tolerance to LBNP-induced central hypovolemia or blood pressure responses during a cold pressor test
Authors: Jarrard Caitlin P. , McKenna Zachary J. , Atkins Whitley C. , Foster Josh , Hendrix Joseph M. , Jouett Noah P. , Oldham Zachary R. , LeBlanc Benjamin J. , Watso Joseph C. , Crandall Craig G.
Published: August 2024

Addressing two unique aims, we observed that sublingual sufentanil administration does not impair tolerance or cardiovascular responses to lower-body negative pressure (LBNP)-induced progressive central hypovolemia. Second, despite pain perception being reduced, sublingual sufentanil did not attenuate mean blood pressure responses to a cold pressor test (CPT).
Enhancing Sustainability of Water‐Emulsified Diesel–Hydrogen Carrier Biogas as Fuel in Dual‐Fuel Engines through the Parametric Optimization
Authors: Bora Bhaskor J , Sharma Prabhakar , Alruqi Mansoor , Paramasivam Prabhu
Published: August 2024

This study investigates the usage of biodiesel‐based emulsified fuel as pilot fuel and waste‐derived biogas as prime fuel to run dual‐fuel engines at varying compression ratios (17, 17.5, 18), injection timing (23°, 26°, 29°, 32° BTDCs), and engine loads (20%, 40%, 60% 80%, 100%). Mahua biodiesel, surfactants, and water were used to produce two‐phase stable emulsification. The findings showed that using biodiesel‐based emulsified fuel as pilot fuel combined at the compression ratio of 18 and advanced fuel injection time of 29° BTDC increased performance and lowered emissions. Additionally, response surface methodology with variance analysis was used to create prediction models for all engine outputs with a robust R2 value (0.8927–0.9974). The engine operation was optimized employing the desirability approach to be 85.3% of engine load, compression ratio of 18, and injection timing of 29° BTDC. At optimal settings, the anticipated engine outputs were 17.46% for brake thermal efficiency, 318.5°C for exhaust gas temperature, 76.1% for liquid fuel replacement, 45.3 bar of peak in‐cylinder pressure, 3.97 vol.% carbon dioxide, 137.43 ppm carbon monoxide, 132 ppm hydrocarbon, and 42 ppm oxides of nitrogen. The lab‐based engine testing found that the results were well within 7.14% of the projected values at these optimal operating parameters.
Temporal, Drug Dose, and Sample Size Trends in the Efficacy of Omalizumab for Chronic Spontaneous Urticaria: A Cumulative Meta‐Analysis
Authors: Qin Haiyan , Xiao Xianjun , Qin Di , Cao Wei , Wang Lu , Xi Menghan , Zou Zihao , Yang Qian , Chen Sijue , Liu Huilin , Li Ying , Shi Yunzhou
Published: August 2024

What is Known and Objective. Omalizumab is a humanized anti‐IgE antibody, which is used in the treatment of chronic spontaneous urticaria (CSU). This study aims to investigate the trends in the efficacy of omalizumab for CSU, focusing on temporal aspects, drug dosages, and sample sizes. Methods. Cochrane, OVID MEDLINE, Embase, Web of Science, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) from 1900 to January 2023. The primary outcome was the percentage of complete responders (defined as the weekly urticaria activity score as 0, UAS7 = 0). Secondary outcomes included the percentage of patients with UAS7 ≤ 6, the percentage of patients achieving a minimally necessary difference in weekly itch severity score (defined as a reduction from baseline in ISS7 of ≥5 points, ISS7 MID), and adverse events (AEs). A cumulative meta‐analysis was performed with pooled risk ratio (RR) and 95% confidence intervals (CI). Publication bias was assessed by the contour‐enhanced funnel plots with the trim‐and‐fill method, alongside Begg’s and Egger’s tests. Results and Discussion. Twelve randomized, placebo‐controlled studies encompassing 2166 patients were analyzed. Compared with the placebo group, the omalizumab group exhibited significant increases in the proportion of patients achieving UAS7 = 0 [RR 5.18, 95% CI (3.97, 6.75), I2 = 14%], UAS7 ≤ 6 [RR 3.21, 95% CI (2.69, 3.83), I2 = 30%], and ISS7 MID responders [RR 1.50, 95% CI (1.39, 1.63), I2 = 33%]. AEs were similar between the omalizumab group and placebo group [RR 0.96, 95% CI (0.89, 1.03), I2 = 4%]. What is New and Conclusion. The cumulative meta‐analysis confirmed that the efficacy outcomes for omalizumab have remained consistent over time, across different drug doses and sample sizes, with improved precision from newer studies. Omalizumab is confirmed to be safe and effective for CSU. It is also suggested to minimize redundant RCTs to conserve scientific and medical resources efficiently.
Radar Target Detection with K‐Nearest Neighbor Manifold Filter on Riemannian Manifold
Authors: Zhou Dongao , Yang Weilong , Liu Zhaopeng , Sun Manhui
Published: August 2024

In this paper, we propose a K‐nearest neighbor manifold filter on the Riemannian manifold and apply it to signal detection within clutter. In particular, the correlation and power of sample data in each cell are modeled as an Hermitian positive definite (HPD) matrix. A K‐nearest neighbor filter that performs the weight average of the set of K‐nearest neighbor HPD matrices of each HPD matrix is proposed to reduce the clutter power. Then, the clutter covariance matrix is estimated as the Riemannian mean of a set of secondary HPD matrices. Signal detection is considered as distinguishing the matrices of clutter and target signal on the Riemannian manifold. Moreover, to speed up the convergence of matrix equation of Riemannian mean, we exploit a strategy to choose the initial input matrix and step size of this equation. Numerical results show that the proposed detector achieves a detection performance improvement over the conventional detector as well as its state‐of‐the‐art counterpart in nonhomogeneous clutter.
Cost‐Effectiveness of Routine Histopathological Analysis of Doughnuts after Colorectal Surgery Three‐Year Single‐Centre Experience
Authors: Ur Rehman Masood , Moussa Reem , Siaw Lin Cindy , Ahmed Naeem , Rehman Abdul , Malik Kamran , Ahmed Jamil
Published: August 2024

Aim. This study aimed to assess the impact of routine histological examination of stapled colorectal anastomotic doughnuts in patients undergoing rectal cancer surgery (RCS). Justification of biopsy examination could form part of the strategies of NHS net zero practice with effort to reduce wastage and carbon footprint. Method. A data analysis of all patients undergoing RCS during 2019–2021 at our institute was performed. We also analysed the cost of preparing and reviewing histology slides. Results. 52 patients underwent anterior resection during the aforementioned period. Doughnuts were sent in 37 (71%) patients. 23 (62%) patients were male, and 14 (38%) were female. The median age at diagnosis was 68 (range 54–84) years. All resected specimens were adenocarcinomas. Of the 37 patients, 18 (49%) underwent low anterior resection and 19 (51%) underwent high anterior resection. Proximal doughnuts were sent in 26 (70%) patients, whereas distal doughnuts were sent in all cases. Mean distal microscopic resection margin from tumour was 22 mm (range 6–45 mm). Each doughnut required 3 slides, each costing £50 and requiring 82 minutes to fix and read. This incurred a cost of £13,650 and required 19,656 hours of preparation time. All of the doughnuts as well as resection margins were negative for malignancy. Conclusion. Routine histopathological examination of doughnuts is time and cost‐intensive however provides little or no clinical value (particularly analysis of the proximal doughnut). Distal doughnuts should only be sent for histological examination in exceptional circumstances.