# Direct assembly of micrometer-long polymeric cylinders in water via supramolecular sticker engineering

Sébastien Berruée, Jean-Michel Guigner, Cécile Huin, Jan Patrick Calupitan, Laurent Bouteiller, Lydia Sosa Vargas, Jutta Rieger

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Sébastien Berruée, Jean-Michel Guigner, Cécile Huin, Jan Patrick Calupitan, Laurent Bouteiller, et al. Direct assembly of micrometer-long polymeric cylinders in water via supramolecular sticker engineering. Macromolecular Rapid Communications, 2025, 10.1002/marc.202500478. hal-05335729

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https://hal.sorbonne-universite.fr/hal-05335729v1

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# Direct assembly of micrometer-long polymeric cylinders in water via supramolecular sticker engineering

Sébastien Berruée<sup>A</sup>, Jean-Michel Guigner<sup>B</sup>, Cécile Huin<sup>A,C</sup>, Jan Patrick Calupitan<sup>A</sup>, Laurent Bouteiller<sup>A</sup>, Lydia Sosa Vargas<sup>A*</sup>, Jutta Rieger<sup>A*</sup>

**SB, CH, JPC, LB, LSV, JR – A** – Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM), F-75005, Paris, France

**JMG – B** – Sorbonne Université, CNRS, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), F-75005 Paris, France

**CH – C** – Université Evry Paris-Saclay, 91000 Evry, France

E-mail: lydia.sosa-vargas@sorbonne-universite.fr; jutta.rieger@sorbonne-universite.fr

**Keywords:** Perylene diimide (PDI), RAFT polymerization, Self-assembly, Anisotropic nanostructures, Supramolecular Structure-Directing Unit (SSDU)

**Abstract.**

We report a direct, solvent-free method to produce micrometer-length, well-organized polymer nanocylinders in water. To achieve this, a hydrophilic poly(N,N-dimethylacrylamide) (PMDAc) was functionalized at one chain-end with a perylene diimide (PDI) sticker using RAFT polymerization. Two PDI RAFT agents were prepared and studied: one featuring two tri(ethylene glycol) (TEG) units at the PDI bay-positions and one without. The corresponding PDI-PDMAc conjugates spontaneously self-assemble in water, driven by π-π interactions made of H-aggregates, and show a morphological evolution from cylinders to spheres when increasing the polymer chain length. The introduction of TEG units was found to be important
to avoid the clustering of nanocylinders or the formation of ill-defined assemblies, which
were observed in the TEG-free system. Moreover, we found that the PDI-TEG~2~-PDMAc with
degrees of polymerization (DP~n~) below 24 self-assembled into micrometer-long
nanocylinders. By heating the aqueous polymer solution, this process can be accelerated and
is accompanied by a large increase in viscosity. Fluorescence spectroscopy revealed an
excimer emission signal for the PDI polymers in water, with a higher emission for cylinders,
suggesting better organization within the PDI H-aggregates. This strategy provides a
sustainable approach for developing functional nanomaterials with precise morphological
control, eliminating organic solvents and complex processing.

**1. Introduction**

In recent years, π-conjugated organic materials have regained momentum as promising
candidates for optoelectronic applications, thanks to their tunability, lower processing costs,
sustainability, and the ability to produce flexible devices; advantages that set them apart from
their inorganic counterparts.¹,² To tune and optimize their properties, precise control over
molecular conformation and long-range organization is essential.³,⁴ A deep understanding of
supramolecular π-π interactions is therefore key to achieve long, well-organized one-
dimensional (1D) nanostructures.⁵,⁶ For example, Ghosh et al. used a naphthalene diimide
(NDI) supramolecular structure-directing unit (SSDU), assisted by an amide capable of
hydrogen bonding, to drive the self-assembly of hydrophilic polymers in water towards the
cylindrical morphology.⁷⁻⁹ Bis-urea was also used to strengthen NDI aggregation and form
polymeric cylinders in water.¹⁰ Other SSDUs, such as squaramides¹¹, ureido-pyrimidinone¹²,
benzene tris-urea¹³, and benzene tris-peptide¹⁴, were also functionalized at the end/core of the
polymer chain to drive their self-assembly in water towards 1D nanostructures. However,
developing long-range, π-conjugated 1D nanostructures using eco-friendly methods, including
the use of water as a solvent, is still a current challenge.¹⁵,¹⁶
Among π-conjugated materials, perylene diimide (PDI) dyes stand out for their exceptional properties, including high thermal and photostability.¹⁷ PDI molecules are well-known electron acceptors and have already been widely incorporated in optoelectronic devices.¹⁸,¹⁹ Due to their strong π-π interactions, their self-assembling properties in both solution and solid state have been explored.²⁰

1D PDI assemblies in particular have been obtained in organic solvents, through diverse methods such as heating/aging process,²¹ sonication²² or through the use of co-solvents.²³,²⁴ Other reported approaches for achieving 1D PDI assemblies include seeding processes in methylcyclohexane (MCH),²⁵ or isopropanol:chloroform mixtures (9:1 iPrOH:CHCl₃)²⁶, phase-transfer crystallization between hexane and chloroform,²⁷⁻²⁹ and interfacial assembly between chloroform and methanol.³⁰,³¹ Additionally, 1D assemblies have been formed by co-assembling PDI with porphyrins *via* ionic self-assembly³² as well as with pyrene to form organogels in CHCl₃.³³

To achieve assemblies in aqueous solutions, co-solvent methods have been developed. Using such approaches, the formation of helical cylinders from PDI molecules functionalized with carbohydrate groups,³⁴⁻³⁶ or micrometer-long nanocylinders from a (methoxy)bay-functionalized PDI was reported.³⁷ Li *et al*. also demonstrated the formation of 1D, rod-like structures of micrometer lengths using a PDI dimethacrylate monomer, triggered by slow addition of water to a THF solution and followed by polymerization initiated by AIBN.³⁸ Peptide-driven assembly of PDIs has also emerged as a promising technique to obtain cylindrical structures in water,³⁹ sometimes facilitated by co-solvents⁴⁰ or ultrasonication.⁴¹,⁴² Functionalizing PDI (or other chromophores) with ionic groups⁴³, neutral hydrophilic groups⁴⁴, or polymer chains⁴⁵ is an effective strategy to enhance water solubility and enable the formation of such nanostructures in aqueous media. In particular, functionalizing PDI with flexible and water-soluble poly(ethylene glycol) (PEG) chains or oligo(ethylene oxide), such as triethylene oxide chains, seems promising for steering PDI assembly in water.⁴⁶
Rybtchinski *et al.* developed a series of PEG-functionalized PDI derivatives that self-assemble into 1D nanostructures in water, mainly using THF as co-solvent.<sup>47-52</sup> In subsequent studies, they also demonstrated that these PEG-functionalized PDIs can form stable fibrous nanostructures at 10<sup>-4</sup> mol/L in water.<sup>53</sup> In our recently reported work, we have shown that PDI-polymer conjugates can be obtained *via* RAFT polymerization, which spontaneously form ribbon-like assemblies through direct dissolution in water.<sup>54</sup> Achieving micrometer-long nanocylinders through direct dissolution in water necessitates the design of an SSDU that strikes a balance: hydrophilic substituents are needed for dissolution in water, but excessively long or bulky substituents can hinder the assembly process.<sup>55</sup>

In this work, we aim to design a PDI sticker that serves as an SSDU to drive the formation of micrometer-long cylindrical (1D) polymeric assemblies by direct dissolution in water. To achieve this, a non-symmetrical PDI is functionalized on one *N*-imide position by a universal RAFT agent (Figure 1a), then used in the polymerization of *N*,*N*-dimethylacrylamide (DMAc), leading to hydrophilic polymeric chains functionalized on one chain end with the PDI sticker. In contrast to our previously reported systems, where the polymers were grown from both *N*-positions,<sup>54</sup> having the polymer chain attached to only one side of the PDI should reduce the steric hindrance generated by the polymer chain and allow us to form 1D assembly over a greater length (Figure 1b). We studied the morphology and properties of the nanostructures formed in water as a function of the polymer chain length by cryo-TEM, SAXS, UV/Vis absorbance, and fluorescence emission spectroscopy.
<figure><img src="image_2.png" /><figcaption>**Figure 1:** a) Chemical structure of perylene diimide with the different positions that can be functionalized on the perylene core. b) Comparison of previous work on PDI functionalized at the core of polymer<sup>54</sup> and this work, where PDI is functionalized at one chain end.</figcaption></figure>

**2. Results and discussion**

**2.1. Synthesis and self-assembly of PDI end-capped poly(N,N-dimethylacrylamide), PDI-PDMAc.**

First, a perylene diimide monofunctional RAFT agent, named **PDI-TTC**, was synthesized in six steps: (**Scheme S1**). The PDI is non-symmetrical and bears two different groups at the *N*-imide positions: an ethylhexyl chain on one side and a trithiocarbonate (TTC) function on the other. The bay positions remain unsubstituted to preserve the planar aromatic structure of the PDI, which is expected to induce a strong aggregation in water.<sup>56</sup> All the procedures and characterizations are reported in the Supporting Information section (**Figures S1-S5 and S12a-c**).
This PDI precursor was then used for the synthesis of a series of PDI-PDMAcs (Scheme 1, procedure in the SI). Three polymers with various $DP_n$ were prepared using the PDI-TTC (Table 1 and S1). The polymerizations were deliberately stopped at relatively low conversions to guarantee a very high chain end fidelity. The final polymers were characterized by size exclusion chromatography (SEC) (Figure S14a-c) and ¹H NMR (Figure S15a-c). Comparing the SEC traces of the RI and UV/Vis detector (at 520 nm, where the PDI strongly absorbs) revealed the incorporation of the PDI into the polymer chain.

<figure><img src="image_3.png" /><figcaption>**Scheme 1.** Synthesis of PDI end-capped PDMAc by RAFT-mediated polymerization in the presence of PDI-TTC.</figcaption></figure>

<table><caption>**Table 1.** Characteristics of the PDI end-capped PDMAcs: chemical characterization and results for the self-assembly in water.</caption><thead><tr><th>Entry</th><th>DP<sub>n</sub>, NMR<sup>a</sup></th><th>M<sub>n</sub>, NMR<sup>a</sup><br>[kg/mol]</th><th>M<sub>n</sub>, SEC<sup>b</sup><br>[kg/mol]</th><th>D<sup>b</sup></th><th>Morpho.<br>Cryo-TEM<sup>c</sup></th><th>D<sub>cryo-TEM</sub><sup>c</sup><br>[nm]</th><th>Morpho. SAXS<sup>d</sup></th><th>D<sub>SAXS</sub><sup>d</sup><br>[nm]</th><th>L<sub>SAXS</sub><sup>d</sup><br>[nm]</th></tr></thead><tbody><tr><td>P1</td><td>17</td><td>2.5</td><td>1.9</td><td>1.20</td><td>Cylinders</td><td>7.1 ± 1.6</td><td>Cylinders</td><td>7.4 (0.21)</td><td>n.d.</td></tr><tr><td>P2</td><td>24</td><td>3.2</td><td>2.6</td><td>1.22</td><td>Spheres<br>(+Cylinders)</td><td>n.d.</td><td>Spheres (62%) +<br>Cylinders (38%)</td><td>S = 12.5 (0)<br>C = 8.6 (0)</td><td>C = 45<br>(0)</td></tr><tr><td>P3</td><td>134</td><td>14.1</td><td>8.8</td><td>1.42</td><td>Spheres</td><td>n.d.</td><td>Spheres</td><td>15.4 (0.10)</td><td>n.d.</td></tr></tbody></table>

a) Number-average degree of polymerization, $DP_n$, and number average molar mass, $M_n$, of the purified polymers determined by ¹H NMR in CDCl₃. b) $M_n$ and dispersity, $D$, of the purified polymers determined by SEC in DMF (+ LiBr 1g/L) using PMMA standards. c) Morphology of the nano-objects identified on cryo-TEM pictures (Figure 2a-c), with the diameters of the nano-objects and standard deviations determined using imageJ from cryo-TEM pictures, with at least 30 measurements. d) SasView models used to fit the SAXS experimental data (Figure 2d-f), with the diameter (D) and length (L) of the nano-objects determined by fitting data, with lognormal polydispersity in parentheses. * (0) means that no polydispersity was considered in the fitting.

The three polymers were dissolved in water at 10 g/L. **P2** and **P3** dissolved spontaneously in less than 5 minutes, and the solutions were stable over time. **P1**, the compound with the lowest $DP_n$ (17), did not dissolve immediately, but visually dissolved after stirring overnight
(at 20 °C), while the formation of a precipitate was observed over time in the absence of stirring.

The aqueous polymer solutions were first analyzed by cryo-TEM (Figure 2a-c). For P1, a great majority of 1D cylindrical objects were observed, with some of them forming bundles (Figure 2a). In some regions of the TEM grid, a few isolated spherical objects, supposedly vesicles, were observed in addition to the cylindrical assemblies (Figure S16). The SAXS data could be well fitted with a simple cylinder model, confirming a majority of cylindrical assemblies in sample P1 (Figure 2d, Table 1). The increase of $DP_n$ to 24 (sample P2) resulted in a mixture of short cylinders and spheres (Figure 2b). Simple sphere or cylinder models were not sufficient to fit the data over the whole q range (Figure S17), hence a model combining sphere and cylinder models was used (Figure 2e). The high proportion of spheres observed by cryo-TEM was confirmed by SAXS (> 60% of spheres), using this model (Table 1). For both P1 and P2, the upturn at low q values suggests the presence of larger aggregates.

Finally, for sample P3 with the longest polymer chain ($DP_n$ = 134), only spherical objects with a diameter close to 15 nm were observed by cryo-TEM and confirmed by SAXS data (Figure 2c, f). The loss of anisotropic morphologies is expected when SSDUs are combined with high molar mass polymers, as longer and bulkier polymer chains can override directed supramolecular interactions due to steric hindrance effects.⁵⁷,⁵⁸,⁵⁵

UV/Vis spectroscopy was also used as a tool to probe the PDI aggregation within the nanostructures (Figure 2g-i). Both the PDI and the polymer are soluble in THF, and the spectra obtained correspond to the fully dissolved PDI unimers, with an $A_{0-0}/A_{0-1}$ ratio around 1.5, typically observed for aggregate-free PDI samples.⁵⁹,⁴³ In water, however, a clear change could be observed for all polymers due to the PDI aggregation. The spectra obtained are typical of co-facially stacked PDIs, or H-aggregates, with an $A_{0-0}/A_{0-1}$ ratio observed below 0.7.⁵⁹,⁶⁰ The presence of these H-aggregates was expected, as we observed by cryo-TEM and
SAXS that PDI-PDMAcs form cylinders or spheres in H₂O.⁵⁴ Almost no change in the A₀-/A₀-1 ratio was noticed over time, demonstrating the strength of the PDI-driven aggregation in water (Figure S18).

<figure><img src="image_4.png" /><figcaption>**Figure 2.** (left) Representative cryo-TEM pictures of the 10 g/L aqueous solutions of a) **P1**, b) **P2**, c) **P3**. The dark spots are surface contaminations stemming from water crystals. (middle) SAXS traces of d) **P1**, e) **P2**, f) **P3** solutions at 10 g/L in H₂O. The black lines are models fitting the data (details shown in **Table 1**). (right) Normalized UV/Vis absorbance spectra of g) **P1**, h) **P2**, i) **P3** at 0.1 g/L in THF (black, dashed lines) and in H₂O (color, solid line).</figcaption></figure>
Although UV/Vis experiments reveal that the PDI sticker forms H-aggregates in all cases, the morphology of the assemblies strongly depends on the polymer $DP_n$. When the polymer chain is short, 1D-nanostructures are formed in the aqueous media, but they are not colloidally stable over time, and as a result, bundles of cylinders are observed. By increasing the $DP_n$, secondary aggregation is prevented, and the nano-objects remain individual. However, presumably due to steric hindrance, the formation of 1D-assemblies only is hampered, since spheres are also present. These results suggest that the PDI sticker is too hydrophobic, and the single polymer chains grafted, regardless of their length, are not able to stabilize the nanocylinders in water.

## 2.2. Synthesis and self-assembly of PDI-TEG₂ end-capped poly(N,N-dimethylacrylamide), PDI-TEG₂-PDMAc

To increase the solubility and colloidal stability of the PDI-PDMAc assemblies, two tri(ethylene glycol) monomethyl ether units (MeTEG) were grafted to the bay positions of the PDI. A new monofunctional perylene diimide RAFT agent, named **PDI-TEG₂-TTC**, was synthesized in eight steps (**Scheme S2**). All the procedures and characterizations are reported in the Supporting Information section (**Figures S1, S6-S12d-f**). The structure is similar to the **PDI-TTC** and differs only by the two MeTEG units located at the bay positions. The bay-functionalization leads to a slight distortion of the planar, aromatic core of the PDI as reported in the literature.⁵⁶ According to DFT calculations on simplified structures of the RAFT agents, a PDI functionalized with two ethylene glycols at the bay-position displays a dihedral angle of 15° compared to the planar, unsubstituted PDI (**Figure S13**). We expect that this small distortion induced by the TEG groups should maintain the $π-π$ stacking between the PDIs, while the TEG groups should help to stabilize the PDI assemblies individually in water and avoid the aggregation of the cylinders formed (bundling).
The **PDI-TEG₂-TTC** was then used for the synthesis of a series of PDI-TEG₂ functional PDMAcs (**Scheme 2**, procedure in the SI). Three polymers, with *DP*n comparable to the (TEG-free) PDI-PDMAcs, were prepared via RAFT polymerization under the same conditions (**Table 2 and S1**). The final polymers were characterized by SEC and ¹H NMR (**Figures S14 and S15**). The SEC results showed a quantitative incorporation of the PDI-TEG₂ unit into the polymer chain (UV/Vis detector at 560 nm), suggesting good control of the polymerizations.

<figure><img src="image_5.png" /><figcaption>**Scheme 2.** Synthesis of PDI-TEG₂ end-capped PDMAc by RAFT-mediated polymerization in the presence of **PDI-TEG₂-TTC**.</figcaption></figure>

<table><caption>**Table 2.** Characteristics of the PDI-TEG₂ end-capped PDMAcs: chemical characterization and results for their self-assembly in water.</caption><thead><tr><th>Entry</th><th>DP<sub>n</sub>, NMR<sup>a</sup></th><th>M<sub>n</sub>, NMR<sup>a</sup><br>[kg/mol]</th><th>M<sub>n</sub>, SEC<sup>b</sup><br>[kg/mol]</th><th>D<sup>b</sup></th><th>Morpho.<br>Cryo-TEM<sup>c</sup></th><th>D<sub>cryo-TEM</sub><sup>c</sup><br>[nm]</th><th>Morpho.<br>SAXS<sup>d</sup></th><th>D<sub>SAXS</sub><sup>d</sup><br>[nm]</th><th>L<sub>SAXS</sub><sup>d</sup><br>[nm]</th></tr></thead><tbody><tr><td>P1-TEG</td><td>15</td><td>2.6</td><td>2.4</td><td>1.20</td><td>Cylinders</td><td>7.8 ± 1.1</td><td>Cylinders</td><td>8.2 (0.15)</td><td>&gt; 100 (0)</td></tr><tr><td>P2-TEG</td><td>24</td><td>3.6</td><td>3.4</td><td>1.19</td><td>Cylinders</td><td>8.1 ± 1.3</td><td>Cylinders</td><td>8.6 (0.24)</td><td>36 (0)</td></tr><tr><td>P3-TEG</td><td>120</td><td>13.1</td><td>8.6</td><td>1.16</td><td>Spheres</td><td>n.d.</td><td>Spheres</td><td>13 (0.20)</td><td>n.d.</td></tr></tbody></table>

a) Number-average degree of polymerization, *DP*n, and number average molar mass, *M*n, of the purified polymers determined by ¹H NMR in CDCl₃. b) *M*n and dispersity, *D*, of the purified polymers determined by SEC in DMF (+ LiBr 1g/L) using PMMA standards. c) Morphology of the nano-objects identified on cryo-TEM pictures (**Figure 3a-c**), with the diameters of the nano-objects and standard deviations determined using imageJ from cryo-TEM pictures, with at least 30 measurements. d) SasView models used to fit the SAXS experimental data (**Figure 3d-f**), with the diameter (D) and length (L) of the nano-objects determined by fitting data, with lognormal polydispersity in parentheses. * (0) means that no polydispersity was considered in the fitting.
All polymers dissolved spontaneously at 10 g/L in H₂O in less than 5 min, except for the **P1-TEG**, which, visually, took 15 min to dissolve. All PDI-TEG₂-PDMAcs remained colloidally stable over time (no precipitate observed).

Cryo-TEM analyses were performed on these aqueous polymer solutions (**Figure 3a-c**). Pure cylinders with a diameter of *ca*. 8 nm are observed for **P1-TEG** and **P2-TEG**, having a *DP*n 15 and 24, respectively (**Figure 3a, b, Table 2**). When the *DP*n is further increased, only small sphere-like objects were obtained for **P3-TEG** (**Figure 3c**). SAXS confirmed the morphologies observed by cryo-TEM (**Figure 3d-f**). **P1-TEG** and **P2-TEG** showed a clear *q*⁻¹ decay for low *q* values and were well-fitted with a cylinder model, with diameters close to those determined from cryo-TEM images (**Table 2**). A sphere model was used to fit the data of **P3-TEG** and confirmed the small size of the aggregates (13 nm).
<figure><img src="image_6.png" /><figcaption>**Figure 3.** (left) Representative cryo-TEM pictures of the 10 g/L aqueous solutions of a) **P1-TEG**, b) **P2-TEG**, c) **P3-TEG**. The dark spots are surface contaminations stemming from water crystals. (middle) SAXS traces of d) **P1-TEG**, e) **P2-TEG**, f) **P3-TEG** solutions at 10 g/L in H₂O. The black lines are models fitting the data (details shown in **Table 2**). (right) Normalized UV/Vis absorbance spectra of g) **P1-TEG**, h) **P2-TEG**, i) **P3-TEG** at 0.1 g/L in THF (black, dashed lines) and in H₂O (color, solid line).</figcaption></figure>

Compared to their TEG-free analogues, the UV/Vis absorbance spectra of the PDI-TEG₂-PDMAc showed distinct spectral features in THF (Figure S19). First, due to the bay-functionalization, the absorption maximum is slightly red-shifted, by 40 nm (522 to 562 nm), and the signals are broader. Differences could also be observed when the spectra were
recorded in water (Figure 2g-i and Figure 3g-i). As expected, UV/Vis spectroscopy measurements indicated the presence of H-aggregates in water (Figure 3g-i). Compared to THF, where the A₀₀/A₀₁ ratio was again close to 1.5 (unimers), the A₀₀/A₀₁ ratio was around 0.4 in H₂O and once again confirms the PDI aggregation.⁵⁹,⁶⁰ This ratio was also constant over time, suggesting no significant change in aggregation (Figure S20).

We can conclude that the hydrophilic MeTEG units introduced at the bay positions of the PDI effectively improved the colloidal stability of the assemblies in water: no bundles of cylinders were observed, while π-π stacking is still efficient and responsible for the 1D assembly in water. Overall, the results show that both PDI-TEG₂-PDMAc and PDI-PDMAc, assemblies in H₂O are driven by H-aggregates of PDI; for similar low *DP*<sub>n</sub> (≤ 24), the formation of nanocylinders is favored in the case of PDI-TEG₂-PDMAc.

To confirm the stability of the PDI-TEG₂-PDMAc nanocylinders and the absence of bundling over time, cryo-TEM analysis was again performed 10 months after dissolution of **P1-TEG** in water (Figure 4a, b). The cryo-TEM images showed the presence of unaggregated, but considerably longer cylinders with similar diameters to the initial sample (Table S2). We also found that this unexpected effect can be accelerated by thermal treatment. Heating the freshly dissolved 10 g/L solution for only 10 min at 60 °C is sufficient to drive the formation of micrometer-long cylinders (Figure 4c, Table S2, Figure S21). Visually, this transition is accompanied by an increase in the viscosity. The relative viscosity of a 3 g/L solution of **P1-TEG** was determined using capillary viscometry and showed a large increase above 60 °C (Figure S22). Interestingly, we can see by cryo-TEM that the long nanocylinders maintain their length and diameter even after cooling down from 60 °C and storing for two months (Figure 4d and Table S2). However, no significant changes could be observed by UV/Vis spectroscopy upon heating to 60 °C (Figure S23). The low proportion of additional H-aggregates formed upon heating could explain this observation.
<figure><img src="image_7.png" /><figcaption>**Figure 4.** Representative cryo-TEM pictures of the 10 g/L aqueous solutions of **P1-TEG** a) 1 day and b) 10 months after dissolution, c) after heating 10 min at 60 °C the 10 g/L solution 1 day after dissolution and d) 2 months after heating the solution. The dark spots are surface contaminations stemming from water crystals.</figcaption></figure>

An increase in the length of the nanocylinders upon heating was also observed for **P2-TEG**, despite the presence of some spheres among a majority of cylinders (**Figure S24 and Table S3**). These experiments were also conducted on the (TEG-free) PDI-PDMAcs; however, no clear changes were observed after the thermal treatment (**Figure S25**). For **P1**, the presence of
the bundles of cylinders and a few vesicular aggregates could still be observed (Figure S25a, b), while P2 was again containing a mixture of spheres and cylinders (Figure S25c, d). These observations for the P1-TEG system suggest that a thermodynamically more stable structure (long cylinders) is formed over a prolonged period after dissolution, and that the kinetics of this process can be accelerated by heating. Also, it highlights the key role that the MeTEG functionalization plays for low $DP_n$. It allows the controlled formation of micrometer-long nanocylinders, compared to their TEG-free analogues, which only form a majority of cylindrical bundles.

Finally, to study more deeply the PDI aggregates, fluorescence spectra were recorded in water (Figure 5). In THF (Figure S19), the absorbance ($\lambda_{max}=562$) and emission ($\lambda_{max}=588$, Stokes shift = 1360 cm$^{-1}$) spectra were characteristic of the isolated unimers in solution. Meanwhile, in water, larger Stokes shifts were observed, and the spectra were no longer mirror images of each other, giving us an indication that the emission signal was greatly affected by the PDI aggregation. Various examples of 1D systems, where the conjugated π-stacked cores are co-facially aligned, show that an excimer (excited-state dimer) or excimer-like species can be observed by fluorescence.⁵² The spectral signature of this excimer species is characterized by a broad emission band, greatly red-shifted compared to the monomer/unimer emission.⁶¹ The fluorescence spectra obtained for the PDI-TEG₂-PDMAc in water are quite different from those obtained in THF (Figure S19b), and display two bands. The first band, at 630 nm (Stokes shift = 3,500 cm$^{-1}$), is attributed to the monomer emission, whereas the red-shifted band at 740 nm (Stokes shift = 5,700 cm$^{-1}$) could be attributed to the excimer emission.²⁰,⁶² An $I_E/I_M$ ratio was used to quantify the excimer emission, similarly to other systems using a pyrene probe.⁶³,⁶⁴ For P1-TEG and P2-TEG, which form cylinders, the ratio was above 6, whereas for P3-TEG, which contains spheres, this ratio decreased to 0.7. This suggests that the PDIs are organized differently, supposedly closer, with stronger aggregation within the (1D) cylinders compared to the spheres. As detailed in the SI, similar
results were obtained for the (TEG-free) PDI-PDMAcs, which confirm this hypothesis
(Figure S27).

<figure><img src="image_8.png" /><figcaption>**Figure 5.** Normalized absorbance (solid lines) and fluorescence emission (dashed lines) spectra at 7.5 10⁻⁶ mol/L in H₂O of a) **P1-TEG**, b) **P2-TEG**, c) **P3-TEG**. The small insert at the top of the spectra shows the ratio between excimer (E) and monomer (M) emission intensity. λexcitation was set at 520 nm. It is important to compare these fluorescence spectra at the same molar concentration, as the I_E/I_M ratio decreases with concentration (**Figure S26**).</figcaption></figure>

**3. Conclusion**

In summary, we have demonstrated that long, co-facially stacked 1D cylinders can be
formed using PDI-functional PDMAcs by direct dissolution in water. We studied two
analogous systems that differ only by the presence of two MeTEG units at the bay-position of
the PDI sticker. Cryo-TEM and SAXS analyses of the aqueous polymer solutions showed the
formation of cylinders for the lowest DPn, whereas spheres were formed when increasing the
polymer chain length. This study reveals the importance of MeTEG functionalization of the
PDI sticker, as without them, the cylinders obtained are not colloidally stable and tend to
bundle. We suggest that the presence of TEG protects the PDI core from lateral hydrophobic
aggregation and facilitates controlled assembly. For all the nanostructures observed, UV/Vis
spectroscopy helped us reveal the presence of H-aggregates. For the PDI-TEG2-PDMAc, the
formation of long (micrometric) cylinders could be observed upon aging of the solution or via
thermal treatment. This transition was accompanied by a threefold increase in relative
viscosity, associated with the formation of longer nano-objects.
Finally, fluorescence emission spectroscopy revealed the formation of excimer-like species in water, due to the strong π-π interactions of the PDI units. Higher excimer emission in the cylinders was observed compared to the spheres, suggesting better organization and co-facial alignment in the cylinders.

This work demonstrated a simple and solvent-free method to obtain long-range 1D nanostructures based on PDI. This introduces new structuration and processing techniques of organic π-conjugated materials for optoelectronic applications.

## Acknowledgements

For SAXS experiments, the authors gratefully acknowledge the financial support from DIM-MaTerRE and the Carnot ARTS Institute, which enabled the acquisition of the Nano-inXider SW system from Xenocs. For HRMS, the authors acknowledge Gilles Clodic from the MS³U platform at Sorbonne Université. This work was granted access to the HPC resources of the SACADO MeSU platform at Sorbonne Université.

## Author contributions

JR, LSV and SB contributed to the conceptualization of the work presented in the manuscript. JMG and SB were responsible for the data curation; with CH (SAXS) and JPC (DFT) also involved in the formal analysis of the data presented. Data visualization was executed by SB and LSV. The investigation was carried out by SB and JMG. Resources were provided by JMG, CH (cryo-TEM and SAXS respectively). JR and LSV obtained the funding and supervised the work. Finally, the initial draft was written by SB, JR and LSV; with SB, JR, LSV, LB and JPC involved in the final review and editing of the submitted version.
References

(1) Moliton, A.; Hiorns, R. C. Review of Electronic and Optical Properties of Semiconducting π-Conjugated Polymers: Applications in Optoelectronics. *Polym. Int.* **2004**, *53* (10), 1397–1412. https://doi.org/10.1002/pi.1587.

(2) Tuncel, D. π-Conjugated Nanostructured Materials: Preparation, Properties and Photonic Applications. *Nanoscale Adv.* **2019**, *1* (1), 19–33. https://doi.org/10.1039/C8NA00108A.

(3) Botiz, I.; Stingelin, N. Influence of Molecular Conformations and Microstructure on the Optoelectronic Properties of Conjugated Polymers. *Materials* **2014**, *7* (3), 2273–2300. https://doi.org/10.3390/ma7032273.

(4) Vohra, V.; Anzai, T. Molecular Orientation of Conjugated Polymer Chains in Nanostructures and Thin Films: Review of Processes and Application to Optoelectronics. *J. Nanomater.* **2017**, *2017* (1), 3624750. https://doi.org/10.1155/2017/3624750.

(5) Kim, F. S.; Ren, G.; Jenekhe, S. A. One-Dimensional Nanostructures of π-Conjugated Molecular Systems: Assembly, Properties, and Applications from Photovoltaics, Sensors, and Nanophotonics to Nanoelectronics. *Chem. Mater.* **2011**, *23* (3), 682–732. https://doi.org/10.1021/cm102772x.

(6) Zhang, K.; Wucher, P.; Marszalek, T.; et al. Long-Range Molecular Self-Assembly from π-Extended Pyrene-Functionalized Diketopyrrolopyrroles. *Chem. Mater.* **2018**, *30* (15), 5032–5040. https://doi.org/10.1021/acs.chemmater.8b01276.

(7) Pramanik, P.; Ray, D.; Aswal, V. K.; Ghosh, S. Supramolecularly Engineered Amphiphilic Macromolecules: Molecular Interaction Overrules Packing Parameters. *Angew. Chem. Int. Ed.* **2017**, *56* (13), 3516–3520. https://doi.org/10.1002/anie.201611715.

(8) Dey, P.; Rajdev, P.; Pramanik, P.; Ghosh, S. Specific Supramolecular Interaction Regulated Entropically Favorable Assembly of Amphiphilic Macromolecules. *Macromolecules* **2018**, *51* (14), 5182–5190. https://doi.org/10.1021/acs.macromol.8b01025.

(9) Dey, P.; Rajdev, P.; Pramanik, P.; Haag, R.; Ghosh, S. Synthesis of a Cylindrical Micelle from Hydrophilic Polymers Connected with a Single Supramolecular Structure-Directing Unit. *Macromolecules* **2020**, *53* (16), 7044–7052. https://doi.org/10.1021/acs.macromol.0c01493.

(10) Choisnet, T.; Canevet, D.; Sallé, M.; et al. Robust Supramolecular Nanocylinders of Naphthalene Diimide in Water. *Chem. Commun.* **2019**, *55* (64), 9519–9522. https://doi.org/10.1039/C9CC04723A.

(11) Saez Talens, V.; Englebienne, P.; Trinh, T. T.; Noteborn, W. E. M.; Voets, I. K.; Kieltyka, R. E. Aromatic Gain in a Supramolecular Polymer. *Angew. Chem. Int. Ed.* **2015**, *54* (36), 10502–10506. https://doi.org/10.1002/anie.201503905.

(12) Hendrikse, S. I. S.; Wijnands, S. P. W.; Lafleur, R. P. M.; et al. Controlling and Tuning the Dynamic Nature of Supramolecular Polymers in Aqueous Solutions. *Chem. Commun.* **2017**, *53* (14), 2279–2282. https://doi.org/10.1039/C6CC10046E.

(13) Gruschwitz, F. V.; Fu, M.-C.; Klein, T.; et al. Unraveling Decisive Structural Parameters for the Self-Assembly of Supramolecular Polymer Bottlebrushes Based on Benzene Tritureas. *Macromolecules* **2020**, *53* (17), 7552–7560. https://doi.org/10.1021/acs.macromol.0c01361.

(14) Klein, T.; Ulrich, H. F.; Gruschwitz, F. V.; et al. Impact of Amino Acids on the Aqueous Self-Assembly of Benzenetrispeptides into Supramolecular Polymer Bottlebrushes. *Polym. Chem.* **2020**, *11* (42), 6763–6771. https://doi.org/10.1039/D0PY01185A.

(15) Diegelmann, S. R.; Gorham, J. M.; Tovar, J. D. One-Dimensional Optoelectronic Nanostructures Derived from the Aqueous Self-Assembly of π-Conjugated
Oligopeptides. J. Am. Chem. Soc. **2008**, *130* (42), 13840–13841.
https://doi.org/10.1021/ja805491d.

(16) Duan, C.; Zhang, K.; Zhong, C.; Huang, F.; Cao, Y. Recent Advances in Water/Alcohol-Soluble π-Conjugated Materials: New Materials and Growing Applications in Solar Cells. *Chem. Soc. Rev.* **2013**, *42* (23), 9071–9104. https://doi.org/10.1039/C3CS60200A.

(17) Li, C.; Wonneberger, H. Perylene Imides for Organic Photovoltaics: Yesterday, Today, and Tomorrow. *Adv. Mater.* **2012**, *24* (5), 613–636.
https://doi.org/10.1002/adma.201104447.

(18) Huang, C.; Barlow, S.; Marder, S. R. Perylene-3,4,9,10-Tetracarboxylic Acid Diimides: Synthesis, Physical Properties, and Use in Organic Electronics. *J. Org. Chem.* **2011**, *76* (8), 2386–2407. https://doi.org/10.1021/jo2001963.

(19) Kozma, E.; Catellani, M. Perylene Diimides Based Materials for Organic Solar Cells. *Dyes Pigments* **2013**, *98* (1), 160–179. https://doi.org/10.1016/j.dyepig.2013.01.020.

(20) Würthner, F.; Saha-Möller, C. R.; Fimmel, B.; Ogi, S.; Leowanawat, P.; Schmidt, D. Perylene Bisimide Dye Assemblies as Archetype Functional Supramolecular Materials. *Chem. Rev.* **2016**, *116* (3), 962–1052. https://doi.org/10.1021/acs.chemrev.5b00188.

(21) Symons, H. E.; Hagemann, M. J. L.; Harniman, R. L.; Faul, C. F. J. Thionated PDI Supramolecular Polymers: Controlling Aggregation Mechanisms, Morphology and Function. *J. Mater. Chem. C* **2022**, *10* (7), 2828–2837.
https://doi.org/10.1039/D1TC04518K.

(22) Kumar, J.; Nakashima, T.; Kawai, T. Inversion of Supramolecular Chirality in Bichromophoric Perylene Bisimides: Influence of Temperature and Ultrasound. *Langmuir* **2014**, *30* (21), 6030–6037. https://doi.org/10.1021/la500497g.

(23) Zhang, Y.; Zheng, Y.; Xiong, W.; et al. Morphological Transformation between Nanocoils and Nanoribbons via Defragmentation Structural Rearrangement or Fragmentation-Recombination Mechanism. *Sci. Rep.* **2016**, *6* (1), 27335.
https://doi.org/10.1038/srep27335.

(24) Guo, Z.; Wang, K.; Yu, P.; Zhang, S.; Sun, K.; Li, Z. Role of Intrinsic Hydrogen Bonds in the Assembly of Perylene Imide Derivatives in Solution and at the Liquid–Solid Interface. *Phys. Chem. Chem. Phys.* **2017**, *19* (34), 23007–23014.
https://doi.org/10.1039/C7CP04928E.

(25) Kotha, S.; Sahu, R.; Yadav, A. C.; et al. Noncovalent Synthesis of Homo and Hetero-Architectures of Supramolecular Polymers via Secondary Nucleation. *Nat. Commun.* **2024**, *15* (1), 3672. https://doi.org/10.1038/s41467-024-47874-5.

(26) Jarrett-Wilkins, C.; He, X.; Symons, H. E.; Harniman, R. L.; Faul, C. F. J.; Manners, I. Living Supramolecular Polymerisation of Perylene Diimide Amphiphiles by Seeded Growth under Kinetic Control. *Chem. – Eur. J.* **2018**, *24* (58), 15556–15565.
https://doi.org/10.1002/chem.201801424.

(27) Balakrishnan, K.; Datar, A.; Oitker, R.; Chen, H.; Zuo, J.; Zang, L. Nanobelt Self-Assembly from an Organic n-Type Semiconductor: Propoxyethyl-PTCDI. *J. Am. Chem. Soc.* **2005**, *127* (30), 10496–10497. https://doi.org/10.1021/ja052940v.

(28) Balakrishnan, K.; Datar, A.; Naddo, T.; et al. Effect of Side-Chain Substituents on Self-Assembly of Perylene Diimide Molecules: Morphology Control. *J. Am. Chem. Soc.* **2006**, *128* (22), 7390–7398. https://doi.org/10.1021/ja061810z.

(29) Che, Y.; Datar, A.; Balakrishnan, K.; Zang, L. Ultralong Nanobelts Self-Assembled from an Asymmetric Perylene Tetracarboxylic Diimide. *J. Am. Chem. Soc.* **2007**, *129* (23), 7234–7235. https://doi.org/10.1021/ja071903w.

(30) Boobalan, G.; Imran, P. K. M.; Manoharan, C.; Nagarajan, S. Fabrication of Highly Fluorescent Perylene Bisimide Nanofibers through Interfacial Self-Assembly. *J. Colloid Interface Sci.* **2013**, *393*, 377–383. https://doi.org/10.1016/j.jcis.2012.10.053.
(31) Boobalan, G.; Imran, P. K. M.; Nagarajan, S. Luminescent One-Dimensional Nanostructures of Perylene Bisimides. *Spectrochim. Acta. A. Mol. Biomol. Spectrosc.* **2013**, *113*, 340–345. https://doi.org/10.1016/j.saa.2013.05.010.

(32) Li, Y.; Wang, W.; Leow, W. R.; et al. Optoelectronics of Organic Nanofibers Formed by Co-Assembly of Porphyrin and Perylenediimide. *Small* **2014**, *10* (14), 2776–2781. https://doi.org/10.1002/smll.201302964.

(33) Wang, K.; Guo, Z.; Zhang, L.; et al. Co-Assembly of Donor and Acceptor towards Organogels Tuned by Charge Transfer Interaction Strength. *Soft Matter* **2017**, *13* (10), 1948–1955. https://doi.org/10.1039/C6SM02691E.

(34) Huang, Y.; Hu, J.; Kuang, W.; Wei, Z.; Faul, C. F. J. Modulating Helicity through Amphiphilicity—Tuning Supramolecular Interactions for the Controlled Assembly of Perylenes. *Chem. Commun.* **2011**, *47* (19), 5554–5556. https://doi.org/10.1039/C1CC0220F.

(35) Sun, K.; Xiao, C.; Liu, C.; Fu, W.; Wang, Z.; Li, Z. Thermally Sensitive Self-Assembly of Glucose-Functionalized Tetrachloro-Perylene Bisimides: From Twisted Ribbons to Microplates. *Langmuir* **2014**, *30* (37), 11040–11045. https://doi.org/10.1021/la502532g.

(36) Liu, X.; Huang, Z.; Huang, Y.; Zhu, L.; Fu, J. Tunable Supramolecular Helical Aggregate and Optoelectrical Properties of Perylene Diimides by Stereoisomerism of Sugar. *J. Phys. Chem. C* **2017**, *121* (13), 7558–7563. https://doi.org/10.1021/acs.jpcc.7b02014.

(37) Wolf, T.; Niazov-Elkan, A.; Sui, X.; et al. Free-Standing Nanocrystalline Materials Assembled from Small Molecules. *J. Am. Chem. Soc.* **2018**, *140* (14), 4761–4764. https://doi.org/10.1021/jacs.7b13638.

(38) Sun, Y.; Li, Z. In Situ Polymerization of Supramolecular Nanorods Assembled from Polymerizable Perylene Bisimide. *Polym. Chem.* **2017**, *8* (30), 4422–4427. https://doi.org/10.1039/C7PY00895C.

(39) Adam, M. K.; Jarrett-Wilkins, C.; Beards, M.; et al. 1D Self-Assembly and Ice Recrystallization Inhibition Activity of Antifreeze Glycopeptide-Functionalized Perylene Bisimides. *Chem. – Eur. J.* **2018**, *24* (31), 7834–7839. https://doi.org/10.1002/chem.201800857.

(40) Sun, Y.; He, C.; Sun, K.; et al. Fine-Tuned Nanostructures Assembled from l-Lysine-Functionalized Perylene Bisimides. *Langmuir* **2011**, *27* (18), 11364–11371. https://doi.org/10.1021/la202107r.

(41) Eakins, G. L.; Gallaher, J. K.; Keyzers, R. A.; et al. Thermodynamic Factors Impacting the Peptide-Driven Self-Assembly of Perylene Diimide Nanofibers. *J. Phys. Chem. B* **2014**, *118* (29), 8642–8651. https://doi.org/10.1021/jp504564s.

(42) Cui, L.; Jiao, Y.; Wang, A.; Zhao, L.; Dong, Q.; Yan, X.; Bai, S. Regulating Morphologies and Near-Infrared Photothermal Conversion of Perylene Bisimide via Sequence-Dependent Peptide Self-Assembly. *Chem. Commun.* **2018**, *54* (18), 2208–2211. https://doi.org/10.1039/C8CC00177D.

(43) Burian, M.; Rigodanza, F.; Amenitsch, H.; et al. Structural and Optical Properties of a Perylene Bisimide in Aqueous Media. *Chem. Phys. Lett.* **2017**, *683*, 454–458. https://doi.org/10.1016/j.cplett.2017.03.056.

(44) Molla, M. R.; Ghosh, S. Aqueous Self-Assembly of Chromophore-Conjugated Amphiphiles. *Phys. Chem. Chem. Phys.* **2014**, *16* (48), 26672–26683. https://doi.org/10.1039/C4CP03791J.

(45) Krupka, O.; Hudhomme, P. Recent Advances in Applications of Fluorescent Perylenediimide and Perylenemonoimide Dyes in Bioimaging, Photothermal and Photodynamic Therapy. *Int. J. Mol. Sci.* **2023**, *24* (7), 6308. https://doi.org/10.3390/ijms24076308.
(46) Wang, X.; Zeng, T.; Nourrein, M.; et al. Concentration-Dependent Self-Assembly Structures of an Amphiphilic Perylene Diimide with Tri(Ethylene Glycol) Substituents at Bay Positions. *RSC Adv.* **2017**, *7* (42), 26074–26081. https://doi.org/10.1039/C7RA04296E.

(47) Baram, J.; Shirman, E.; Ben-Shitrit, N.; Ustinov, A.; Weissman, H.; Pinkas, I.; Wolf, S. G.; Rybtchinski, B. Control over Self-Assembly through Reversible Charging of the Aromatic Building Blocks in Photofunctional Supramolecular Fibers. *J. Am. Chem. Soc.* **2008**, *130* (45), 14966–14967. https://doi.org/10.1021/ja807027w.

(48) Krieg, E.; Shirman, E.; Weissman, H.; et al. Supramolecular Gel Based on a Perylene Diimide Dye: Multiple Stimuli Responsiveness, Robustness, and Photofunction. *J. Am. Chem. Soc.* **2009**, *131* (40), 14365–14373. https://doi.org/10.1021/ja903938g.

(49) Tidhar, Y.; Weissman, H.; Wolf, S. G.; Gulino, A.; Rybtchinski, B. Pathway-Dependent Self-Assembly of Perylene Diimide/Peptide Conjugates in Aqueous Medium. *Chem. – Eur. J.* **2011**, *17* (22), 6068–6075. https://doi.org/10.1002/chem.201003419.

(50) Shahar, C.; Baram, J.; Tidhar, Y.; et al. Self-Assembly of Light-Harvesting Crystalline Nanosheets in Aqueous Media. *ACS Nano* **2013**, *7* (4), 3547–3556. https://doi.org/10.1021/nn400484y.

(51) Krieg, E.; Weissman, H.; Shimoni, E.; Bar On (Ustinov), A.; Rybtchinski, B. Understanding the Effect of Fluorocarbons in Aqueous Supramolecular Polymerization: Ultrastrong Noncovalent Binding and Cooperativity. *J. Am. Chem. Soc.* **2014**, *136* (26), 9443–9452. https://doi.org/10.1021/ja503906p.

(52) On (Ustinov), A. B.; Tidhar, Y.; Pinkas, I.; Weissman, H.; Rybtchinski, B. Supramolecular Nanofibers Self-Assembled from Foldamers: Structure Control through Preassembly. *Isr. J. Chem.* **2014**, *54* (5–6), 748–758. https://doi.org/10.1002/ijch.201400016.

(53) Baram, J.; Weissman, H.; Tidhar, Y.; Pinkas, I.; Rybtchinski, B. Hydrophobic Self-Assembly Affords Robust Noncovalent Polymer Isomers. *Angew. Chem. Int. Ed.* **2014**, *53* (16), 4123–4126. https://doi.org/10.1002/anie.201310571.

(54) Berruée, S.; Guigner, J.-M.; Bizien, T.; Bouteiller, L.; Sosa Vargas, L.; Rieger, J. Spontaneous Formation of Polymeric Nanoribbons in Water Driven by $\pi-\pi$ Interactions. *Angew. Chem. Int. Ed.* **2025**, *64* (1), e202413627. https://doi.org/10.1002/anie.202413627.

(55) Ulrich, H. F.; Gruschwitz, F. V.; Klein, T.; et al. Influence of Polymer Side Chain Size and Backbone Length on the Self-Assembly of Supramolecular Polymer Bottlebrushes. *Chem. – Eur. J.* **2024**, *30* (26), e202400160. https://doi.org/10.1002/chem.202400160.

(56) Nowak-Król, A.; Würthner, F. Progress in the Synthesis of Perylene Bisimide Dyes. *Org. Chem. Front.* **2019**, *6* (8), 1272–1318. https://doi.org/10.1039/C8QO01368C.

(57) Catrouillet, S.; Fonteneau, C.; Bouteiller, L.; et al. Competition Between Steric Hindrance and Hydrogen Bonding in the Formation of Supramolecular Bottle Brush Polymers. *Macromolecules* **2013**, *46* (19), 7911–7919. https://doi.org/10.1021/ma401167n.

(58) Mellot, G.; Guigner, J.-M.; Jestin, J.; Bouteiller, L.; Stoffelbach, F.; Rieger, J. Bisurea-Functionalized RAFT Agent: A Straightforward and Versatile Tool toward the Preparation of Supramolecular Cylindrical Nanostructures in Water. *Macromolecules* **2018**, *51* (24), 10214–10222. https://doi.org/10.1021/acs.macromol.8b02156.

(59) Ghosh, S.; Li, X.-Q.; Stepanenko, V.; Würthner, F. Control of H- and J-Type $\pi$ Stacking by Peripheral Alkyl Chains and Self-Sorting Phenomena in Perylene Bisimide Homodimer and Heteroaggregates. *Chem. – Eur. J.* **2008**, *14* (36), 11343–11357. https://doi.org/10.1002/chem.200801454.
(60) Hestand, N. J.; Spano, F. C. Expanded Theory of H- and J-Molecular Aggregates: The Effects of Vibronic Coupling and Intermolecular Charge Transfer. *Chem. Rev.* **2018**, *118* (15), 7069–7163. https://doi.org/10.1021/acs.chemrev.7b00581.

(61) Yoo, H.; Yang, J.; Yousef, A.; Wasielewski, M. R.; Kim, D. Excimer Formation Dynamics of Intramolecular π-Stacked Perylenediimides Probed by Single-Molecule Fluorescence Spectroscopy. *J. Am. Chem. Soc.* **2010**, *132* (11), 3939–3944. https://doi.org/10.1021/ja910724x.

(62) Li, J.; Zhao, S.; Bai, L.; Liu, X.; Shang, L. Ratiometric Fluorescence Aptasensor for Lysozyme Based on the Controllable Excimer Formation of Perylene Probe. *Talanta* **2025**, *286*, 127521. https://doi.org/10.1016/j.talanta.2025.127521.

(63) Somerharju, P. Pyrene-Labeled Lipids as Tools in Membrane Biophysics and Cell Biology. *Chem. Phys. Lipids* **2002**, *116* (1), 57–74. https://doi.org/10.1016/S0009-3084(02)00020-8.

(64) Wang, Y.; Chen, J.; Chen, Y.; Li, W.; Yu, C. Polymer-Induced Perylene Probe Excimer Formation and Selective Sensing of DNA Methyltransferase Activity through the Monomer–Excimer Transition. *Anal. Chem.* **2014**, *86* (9), 4371–4378. https://doi.org/10.1021/ac500195u.
**Supporting Information**

Supporting Information is available from the Wiley Online Library or from the author.

**Direct assembly of micrometer-long polymeric cylinders in water via supramolecular sticker engineering**

Sébastien Berruée, Jean-Michel Guigner, Cécile Huin, Jan Patrick Calupitan, Laurent Bouteiller, Lydia Sosa Vargas*, Jutta Rieger*

**Engineering order at the nanoscale:** Tailored design of PDI- and TEG-functionalized poly(N,N-dimethylacrylamide) enables direct assembly of micrometer-long nanocylinders in water. TEG prevents clustering, while the polymer chain length governs the morphology. Heating or aging increases the length of the H-aggregates formed, increasing the viscosity. This scalable approach offers precise control for sustainable nanomaterials without the use of organic solvents.

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