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  • C. Debrie, N. Coudert, J. - M. Guigner, T. Nicolai, F. Stoffelbach, O. Colombani, et J. Rieger, « Unimer Exchange Is not Necessary for Morphological Transitions in Polymerization-Induced Self-Assembly », Angewandte Chemie International Edition, vol. 62, nᵒ 8, p. e202215134, 2023.
    Résumé : Polymerization-induced self-assembly (PISA) has established itself as a powerful and straightforward method to produce polymeric nano-objects of various morphologies in (aqueous) solution. Generally, spheres are formed in the early stages of polymerization that may evolve to higher order morphologies (worms or vesicles), as the solvophobic block grows during polymerization. Hitherto, the mechanisms involved in these morphological transitions during PISA are still not well understood. Combining a systematic study of a representative PISA system with rheological measurements, we demonstrate that—unexpectedly—unimer exchange is not necessary to form higher order morphologies during radical RAFT-mediated PISA. Instead, in the investigated aqueous PISA, the monomer present in the polymerization medium is responsible for the morphological transitions, even though it slows down unimer exchange.
    Mots-clés : Block Copolymers, Micelles, PISA, POLYMERES, Rheology, Vesicles.

  • G. Delecourt, L. Plet, Y. L. Guen, O. Tezgel, G. Tresset, P. Midoux, T. Montier, V. Bennevault, et P. Guégan, « Synthesis of Double Hydrophilic Block Copolymers Poly(2-isopropyl-2-oxazoline-b-ethylenimine) and their DNA Transfection Efficiency », Macromolecular Bioscience, vol. 23, nᵒ 1, p. 2200296, 2023.
    Résumé : Gene delivery is now a part of the therapeutic arsenal for vaccination and treatments of inherited or acquired diseases. Polymers represent an opportunity to develop new synthetic vectors for gene transfer, with a prerequisite of improved delivery and reduced toxicity compared to existing polymers. Here, the synthesis in a two-step's procedure of linear poly(ethylenimine-b-2-isopropyl-2-oxazoline) block copolymers with the linear polyethylenimine (lPEI) block of various molar masses is reported; the molar mass of the poly(2-isopropyl-2-oxazoline) (PiPrOx) block has been set to 7 kg mol−1. Plasmid DNA condensation is successfully achieved, and in vitro transfection efficiency of the copolymers is at least comparable to that obtained with the lPEI of same molar mass. lPEI-b-PiPrOx block copolymers are however less cytotoxic than their linear counterparts. PiPrOx can be a good alternative to PEG which is often used in drug delivery systems. The grafting of histidine moieties on the lPEI block of lPEI-b-PiPrOx does not provide any real improvement of the transfection efficiency. A weak DNA condensation is observed, due to increased steric hindrance along the lPEI backbone. The low cytotoxicity of lPEI-b-PiPrOx makes this family a good candidate for future gene delivery developments.
    Mots-clés : gene therapy, oxazoline, PEGylation alternative, PEI, POLYMERES.


  • P. Aoun, A. Hammoud, M. A. Martínez-Aguirre, L. Bouteiller, et M. Raynal, « Asymmetric hydroamination with far fewer chiral species than copper centers achieved by tuning the structure of supramolecular helical catalysts », Catalysis Science & Technology, vol. 12, nᵒ 3, p. 834-842, févr. 2022.
    Résumé : The incorporation of a few chiral monomers (the “sergeants”) in a backbone composed of a majority of achiral monomers (the “soldiers”) is a well-established strategy to control the handedness of helical polymers. However, the implementation of this “sergeants-and-soldiers” effect in asymmetric catalysis is still at its infancy, with only limited examples for which the sergeant amount is actually in lower amount than the (metal) catalytic unit. Herein, supramolecular co-polymers composed of a benzene-1,3,5-tricarboxamide (BTA) phosphine soldier and a catalytically-inactive BTA sergeant were evaluated in the copper-catalysed hydroamination of styrene. Screening of various BTA ligands revealed the marked influence of substituents on the aryl group of the BTA phosphine ligand, the 3,5-bis-CF3-substituted ligand providing the highest rate and enantioselectivity. Thorough optimization of the reaction parameters led to a robust protocol for the generation of the amine product in high yield (82 ± 4%) and moderate e.e. (68 ± 6%). Addition of an achiral BTA additive was found to be beneficial for improving the yield (80–99%), enantioselectivity (up to 81% e.e.) and “sergeants-and-soldiers” effect displayed by the supramolecular helical catalyst. Consequently, an enantio-enriched product (75% e.e.) was afforded with as low as 0.51 mol% of sergeant in the catalytic mixture, i.e. one chiral molecule for 10 copper centers.
    Mots-clés : POLYMERES.

  • F. Bouihi, B. Schmaltz, F. Mathevet, D. Kreher, J. Faure-Vincent, C. Yildirim, A. Elhakmaoui, J. Bouclé, M. Akssira, F. Tran-Van, et M. Abarbri, « D-π-A-Type Pyrazolo[1,5-a]pyrimidine-Based Hole-Transporting Materials for Perovskite Solar Cells: Effect of the Functionalization Position », Materials, vol. 15, nᵒ 22, p. 7992, janv. 2022.
    Résumé : Donor–acceptor (D–A) small molecules are regarded as promising hole-transporting materials for perovskite solar cells (PSCs) due to their tunable optoelectronic properties. This paper reports the design, synthesis and characterization of three novel isomeric D-π-A small molecules PY1, PY2 and PY3. The chemical structures of the molecules consist of a pyrazolo[1,5-a]pyrimidine acceptor core functionalized with one 3,6-bis(4,4′-dimethoxydiphenylamino)carbazole (3,6-CzDMPA) donor moiety via a phenyl π-spacer at the 3, 5 and 7 positions, respectively. The isolated compounds possess suitable energy levels, sufficient thermal stability (Td > 400 °C), molecular glass behavior with Tg values in the range of 127–136 °C slightly higher than that of the reference material Spiro-OMeTAD (126 °C) and acceptable hydrophobicity. Undoped PY1 demonstrates the highest hole mobility (3 × 10−6 cm2 V−1 s−1) compared to PY2 and PY3 (1.3 × 10−6 cm2 V−1 s−1). The whole isomers were incorporated as doped HTMs in planar n-i-p PSCs based on double cation perovskite FA0.85Cs0.15Pb(I0.85Br0.15)3. The non-optimized device fabricated using PY1 exhibited a power conversion efficiency (PCE) of 12.41%, similar to that obtained using the reference, Spiro-OMeTAD, which demonstrated a maximum PCE of 12.58% under the same conditions. The PY2 and PY3 materials demonstrated slightly lower performance in device configuration, with relatively moderate PCEs of 10.21% and 10.82%, respectively, and slight hysteresis behavior (−0.01 and 0.02). The preliminary stability testing of PSCs is also described. The PY1-based device exhibited better stability than the device using Spiro-OMeTAD, which could be related to its slightly superior hydrophobic character preventing water diffusion into the perovskite layer.
    Mots-clés : 3, 5-a]pyrimidine, 6-CzDMPA, D-π-A, hole-transporting materials, perovskite solar cells, POLYMERES, pyrazolo[1.

  • N. A. Burger, G. Meier, L. Bouteiller, B. Loppinet, et D. Vlassopoulos, « Dynamics and Rheology of Supramolecular Assemblies at Elevated Pressures », The Journal of Physical Chemistry B, vol. 126, nᵒ 35, p. 6713-6724, sept. 2022.
    Résumé : A methodology to investigate the linear viscoelastic properties of complex fluids at elevated pressures (up to 120 MPa) is presented. It is based on a dynamic light scattering (DLS) setup coupled with a stainless steel chamber, where the test sample is pressurized by means of an inert gas. The viscoelastic spectra are extracted through passive microrheology. We discuss an application to hydrogen-bonding motif 2,4-bis(2-ethylhexylureido)toluene (EHUT), which self-assembles into supramolecular structures (tubes and filaments) in apolar solvents dodecane and cyclohexane. High levels of pressure (roughly above 20 MPa) are found to slow down the terminal relaxation process; however, the increases in the entanglement plateau modulus and the associated persistence length are not significant. The concentration dependence of the plateau modulus, relaxation times (fast and slow), and correlation length is practically the same for all pressures and exhibits distinct power-law behavior in different regimes. Within the tube phase in dodecane, the relative viscosity increment is weakly enhanced with increasing pressure and reaches a plateau at about 60 MPa. In fact, depending on concentration, the application of pressure in the tube regime may lead to a transition from a viscous (unentangled) to a viscoelastic (partially entangled to well-entangled) solution. For well-entangled, long tubes, the extent of the plateau regime (ratio of high- to low-moduli crossover frequencies) increases with pressure. The collective information from these observations is summarized in a temperature–pressure state diagram. These findings provide ingredients for the formulation of a solid theoretical framework to better understand and exploit the role of pressure in the structure and dynamics of supramolecular polymers.
    Mots-clés : POLYMERES.

  • N. A. Burger, G. Pembouong, L. Bouteiller, D. Vlassopoulos, et B. Loppinet, « Complete Dynamic Phase Diagram of a Supramolecular Polymer », Macromolecules, vol. 55, nᵒ 7, p. 2609-2614, avr. 2022.
    Résumé : We revisit the equilibrium phase diagram of the much-studied model supramolecular polymer, 2,4-bis(2-ethylhexylureido)toluene (EHUT) in nonpolar solvents and provide unambiguous evidence of a much richer behavior, characterized by four distinct regimes. Typically, two types of self-assembled structures are formed: tubes (filaments) at higher (lower) concentrations and lower (higher) temperatures. The tube structure forms viscoelastic solutions that had been characterized by rheology, however, without detailed analysis of the experimental signals. Here, we combine rheology and microrheology to establish the complete dynamic phase diagram of EHUT in dodecane. It still comprises two structures, tubes and filaments, with the transition temperature being almost constant over the examined wide concentration range, as confirmed with the help of complementary differential scanning calorimetry measurements. The tubes are found to exist in three dynamic states with increasing concentration, unentangled, partially entangled, and well entangled, which are separated by isolength lines. We present criteria for unambiguously identifying these phases and discuss their distinct concentration and temperature dependencies. The new, complete phase diagram may serve as a guide for investigating other supramolecular polymers with tunable rheology and, more importantly, providing insights into a universal description of one-dimensional self-assembled structures by linking this class of materials with the classic wormlike surfactant micelles, for which the partially and well-entangled regimes were recently elucidated.
    Mots-clés : POLYMERES.

  • L. Chazot-Franguiadakis, J. Eid, M. Socol, B. Molcrette, P. Guégan, M. Mougel, A. Salvetti, et F. Montel, « Optical Quantification by Nanopores of Viruses, Extracellular Vesic

    les, and Nanoparticles », Nano Letters, vol. 22, nᵒ 9, p. 3651-3658, mai 2022.
    Résumé : Nanopores combined with optical approaches can be used to detect viral particles. In this work, we demonstrate the ability of hydrodynamical driving and optical sensing to identify and quantify viral particles in a biological sample. We have developed a simple and rapid method which requires only fluorescent labeling of the particles and can therefore be applied to a wide range of virus type. The system operates in real time and at the single particle level while providing a low error on concentration (4%) and a low limit of detection of 105 particles/mL for an acquisition time of 60 s with the ability to increase the acquisition time to achieve a lower limit.
    Mots-clés : POLYMERES.

  • N. Illy et E. Mongkhoun, « Thiolactone chemistry, a versatile platform for macromolecular engineering », Polymer Chemistry, vol. 13, nᵒ 32, p. 4592-4614, août 2022.
    Résumé : Thiolactones are often described as latent thiols. They can be ring-opened by hydroxy or amine groups releasing thiols, which can further react with a large variety of functional groups. Based on this one-pot cascade reaction, versatile and powerful tools have been developed for macromolecular engineering. This review covers the different uses of γ-thiobutyrolactones in polymer chemistry either as thiolation agents, as linkers, as ring-opening polymerization monomers, as reactant in stepwise polymerization, as components of initiating systems, or as functional handles for double post-modification reactions.
    Mots-clés : POLYMERES.

  • T. Ishii, K. Miyata, M. Mamada, F. Bencheikh, F. Mathevet, K. Onda, S. Kéna-Cohen, et C. Adachi, « Low-Threshold Exciton-Polariton Condensation via Fast Polariton Relaxation in Organic Microcavities », Advanced Optical Materials, vol. 10, nᵒ 3, p. 2102034, 2022.
    Résumé : In organic microcavities, a macroscopic condensate of exciton-polaritons can be formed at high-exciton polariton densities. The threshold for forming this condensate is proportional to the relaxation rate from initially excited excitons to these polaritons and the lifetime of the lowest energy polariton states. Although the influence of the lower polariton (LP) lifetime on the threshold has been studied, the relationship between the polariton relaxation rate and the threshold has not been fully explored. In this study, a room-temperature polariton condensate is demonstrated at a threshold pump fluence of 9.7 ± 0.1 µJ cm−2, in a microcavity containing 4,4″-bis((E)-4-(3,6-bis(2-ethylhexyl)-(9H-carbazol-9-yl))styryl)-1,1″-biphenyl (BSBCz-EH). By using a semiclassical model to describe the polariton kinetics, it is revealed that this low threshold results from the rapid relaxation rate from the dark exciton reservoir to the set of the LP states forming the condensate, with an effective rate Wep ≈ 2.0 × 10−5 cm3 s−1. These results show that accelerating polariton relaxation is possible and is an important factor for realizing low-threshold polariton condensates.
    Mots-clés : low threshold, microcavities, organic semiconductors, polariton condensate, polariton relaxation, POLYMERES, strong coupling.

  • P. Le Bellec, P. Midoux, H. Cheradame, V. Bennevault, et P. Guégan, « Tuneable thermal properties of PTHF-based copolymers by incorporation of epoxide units », European Polymer Journal, vol. 168, p. 111096, avr. 2022.
    Résumé : In order to decrease the crystallinity of polytetrahydrofuran (PTHF), statistical copolymerizations with 1,2-butylene oxide (BO) and 3,3-dimethyl-1,2-butylene oxide (DMBO) epoxides as comonomer were investigated in a process compatible with an easy scaling up. Difunctionnal poly(tetrahydrofuran-stat-1,2-butylene oxide)s (PTHF-stat-PBO) and poly(tetrahydrofuran-stat-3,3-dimethyl-1,2-butylene oxide)s (PTHF-stat-PDMBO) were synthesized in the range of 0–20 °C using different operating conditions. The reactivity ratios showed a homogeneous distribution of the epoxide units all along the copolymer chains by using BO, while an alternation of several THF and DMBO monomer units sequences was obtained in the DMBO-based copolymers. Still, both copolymerizations fit well with an ideal copolymerization behavior. A slow addition of BO during the propagation step or the introduction of BO or DMBO at the beginning of the polymerization were investigated. Whatever the comonomer used, its insertion in the polymer chain reduced the melting temperature of the copolymers and the impact of the THF polymerization equilibrium on the yields. As a consequence, higher polymerization yields were obtained. A fairly good control of the polymer molar masses was observed, although elimination reactions were highlighted. However, operating conditions were determined to limit the content of the resulting alkene chain ends to about 10%, providing guaranties for further macromolecular architectures developments.
    Mots-clés : 2-Butylene oxide, 2-Butylene oxide3, 3-Dimethyl-1, Cationic ring-opening polymerization, Equilibrium, POLYMERES, Reactivity ratio, Tetrahydrofuran1, Thermal properties.

  • S. Le Luyer, P. Guégan, et N. Illy, « Episulfide Anionic Ring-Opening Polymerization Initiated by Alcohols and Primary Amines in the Presence of γ-Thiolactones », Macromolecules, vol. 55, nᵒ 13, p. 5430-5440, juill. 2022.
    Résumé : Among the sulfur-containing polymers, polythioethers remain very attractive structures due to their high sulfur atom content, making them interesting candidates for various industrial applications, for example, in the fields of energy storage or biomedical applications. Although anionic ring-opening polymerization of episulfides is known since decades, only a limited number of efficient initiating systems enable the synthesis of well-defined polymer chains. In this work, a one-pot, two-step method was developed in order to efficiently initiate the anionic ring-opening polymerization of propylene sulfide with alcohol or amine moieties using the latent thiol functionality of γ-thiolactones. First, the ring opening of γ-thiolactones with alcohols or amines was investigated in the presence of various bases (2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine, 1,8-diazabicyclo[5.4.0]undec-7-ene, 4-dimethylaminopyridine, tBuP1, and tBuP4). Then, the polymerization conditions were optimized, allowing the synthesis of well-defined α,ω-heterotelechelic poly(propylene sulfide)s with controlled molar mass up to 10 kg·mol–1 as evidenced by size-exclusion chromatography, 1H, 13C, and 2D NMR, and matrix-assisted laser desorption and ionization time-of-flight mass spectrometry. Depending on the initiating function (alcohol or amine), the initiator and the polythioether chains are connected either by an ester or by an amide bond. The stability of these bonds was studied under basic conditions.
    Mots-clés : POLYMERES.

  • Q. Sallembien, P. Aoun, S. Blanchard, L. Bouteiller, et M. Raynal, « Interplay between hydrogen bonding and electron transfer in mixed valence assemblies of triarylamine trisamides », Chemistry – A European Journal, p. chem.202203199, nov. 2022.
    Mots-clés : E-POM, POLE 2, POLE 4, POLYMERES.

  • Q. Sallembien, L. Bouteiller, J. Crassous, et M. Raynal, « Possible chemical and physical scenarios towards biological homochirality », Chemical Society Reviews, vol. 51, nᵒ 9, p. 3436-3476, mai 2022.
    Résumé : The single chirality of biological molecules in terrestrial biology raises more questions than certitudes about its origin. The emergence of biological homochirality (BH) and its connection with the appearance of life have elicited a large number of theories related to the generation, amplification and preservation of a chiral bias in molecules of life under prebiotically relevant conditions. However, a global scenario is still lacking. Here, the possibility of inducing a significant chiral bias “from scratch”, i.e. in the absence of pre-existing enantiomerically-enriched chemical species, will be considered first. It includes phenomena that are inherent to the nature of matter itself, such as the infinitesimal energy difference between enantiomers as a result of violation of parity in certain fundamental interactions, and physicochemical processes related to interactions between chiral organic molecules and physical fields, polarized particles, polarized spins and chiral surfaces. The spontaneous emergence of chirality in the absence of detectable chiral physical and chemical sources has recently undergone significant advances thanks to the deracemization of conglomerates through Viedma ripening and asymmetric auto-catalysis with the Soai reaction. All these phenomena are commonly discussed as plausible sources of asymmetry under prebiotic conditions and are potentially accountable for the primeval chiral bias in molecules of life. Then, several scenarios will be discussed that are aimed to reflect the different debates about the emergence of BH: extra-terrestrial or terrestrial origin (where?), nature of the mechanisms leading to the propagation and enhancement of the primeval chiral bias (how?) and temporal sequence between chemical homochirality, BH and life emergence (when?). Intense and ongoing theories regarding the emergence of optically pure molecules at different moments of the evolution process towards life, i.e. at the levels of building blocks of Life, of the instructed or functional polymers, or even later at the stage of more elaborated chemical systems, will be critically discussed. The underlying principles and the experimental evidence will be commented for each scenario with particular attention on those leading to the induction and enhancement of enantiomeric excesses in proteinogenic amino acids, natural sugars, and their intermediates or derivatives. The aim of this review is to propose an updated and timely synopsis in order to stimulate new efforts in this interdisciplinary field.
    Mots-clés : POLYMERES.

  • J. Scelle, H. Vervoitte, L. Bouteiller, L. - M. Chamoreau, M. Sollogoub, G. Vives, et B. Hasenknopf, « Size-dependent compression of threaded alkyldiphosphate in head to head cyclodextrin [3]pseudorotaxanes », Chemical Science, vol. 13, nᵒ 8, p. 2218-2225, févr. 2022.
    Résumé : The encapsulation of guests in a confined space enables unusual conformations and reactivities. In particular, the compression of akyl chains has been obtained by self-assembled molecular capsules but such an effect has not been reported in solution for pseudorotaxane architectures. By exploiting the tendency of cyclodextrin (CD) to form head to head [3]pseudorotaxanes and the hydrogen bonding abilities of phosphate groups, we have studied the effect of the CD dimer cavity on the conformation of threaded α,ω-alkyl-diphosphate axles. The formation of [2]pseudorotaxanes and [3]pseudorotaxanes was investigated by a combination of NMR, ITC and X-ray diffraction techniques. In the solid state, the [3]pseudorotaxane with a C8 axle presents a fully extended conformation with both terminal phosphate groups interacting with hydroxyl groups of the primary rim of CDs. Such hydrogen bonding interactions are also present with the C9 and C10 axles resulting in a compression of the alkyl chain with gauche conformations in the solid state. NMR studies have shown that this effect is maintained in solution resulting in a size-dependent progressive compression of the alkyl chain by the CD [3]pseudorotaxane architecture for C9, C10 and C11 axles.
    Mots-clés : GOBS, POLYMERES.

  • S. Stal, B. Huitorel, T. Coustham, N. Stephant, F. Massuyeau, T. Gacoin, L. Bouteiller, et S. Perruchas, « Photoactive CuI-Cross-Linked Polyurethane Materials », ACS Applied Materials & Interfaces, vol. 14, nᵒ 42, p. 47931-47940, oct. 2022.
    Résumé : Using multinuclear copper iodide complexes as cross-linking agents in a polyurethane matrix, original photoluminescent stimuli-responsive materials were synthesized. The intrinsic photoluminescence properties of the covalently incorporated copper iodide complexes are thus transferred to the materials while retaining the beneficial characteristics of the polymer host. The transparent materials exhibit room-temperature phosphorescence with emission switching properties by displaying luminescence thermochromism and solvatochromism. The luminescence thermochromism is characterized by a change in the wavelength and intensity of the emission with temperature, and the vapochromic effect presents a contrasted response of extinction or exaltation according to the nature of the solvent of exposure. By combining the luminescence characteristics of photoactive copper iodide complexes with the ease of polymer processing, the application of these luminescent materials as phosphors in LED (light-emitting diode) devices was also demonstrated. The present study shows that the use of copper iodide complexes as cross-linkers in polymeric materials is a relevant strategy to design materials with enhanced functionalities in addition to their low cost and sustainable characteristics.
    Mots-clés : POLYMERES.

  • M. Valdez-Hernández, L. N. Acquaroli, J. Vázquez-Castillo, O. González-Pérez, J. C. Heredia-Lozano, A. Castillo-Atoche, L. Sosa-Vargas, et E. Osorio-de-la-Rosa, « Plant/soil-microbial fuel cell operation effects in the biological activity of bioelectrochemical systems », Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, vol. 44, nᵒ 2, p. 2715-2729, juin 2022.
    Résumé : Plant and soil microbial fuel cells (PMFCs and SMFCs, respectively) are bioelectrochemical systems that produce energy using microorganisms as catalysts. This energy can be harvested; however, its impact on biological activity has seldom been explored. To reveal the main characteristics of this impact, we monitored four experimental designs for 20 days under open-sky conditions. The effect of PMFC/SMFC start-up on metabolism was evaluated by photosynthesis of Codiaeum variegatum and heterotrophic soil respiration to determine the short-term effects. To compare the results, a normalized parameter of power density, which considered the PMFC/SMFC configurations, solar irradiance, and soil temperature, was introduced. The highest energy was obtained for the PMFC configuration. The energy harvesting stimulated the photosynthetic rate of C. variegatum up to two times with respect to its normal values, while the heterotrophic soil respiration decreased 30%. Thus, in the PMFC and SMFC start-up operations, the increase in soil temperature due to energy harvesting suggests that soil temperature is the most relevant parameter influencing plant metabolism and energy generation. These results open a new pathway for understanding the bioregulation of plants/soil when subjected to energy harvesting.
    Mots-clés : Codiaeum variegatum photosynthesis, energy harvesting, heterotrophic soil respiration, Plant microbial fuel cells, POLYMERES, soil microbial fuel cell.


  • N. Audureau, F. Coumes, C. Veith, C. Guibert, J. - M. Guigner, F. Stoffelbach, et J. Rieger, « Synthesis and Characterization of Temperature-Responsive N-Cyanomethylacrylamide-Containing Diblock Copolymer Assemblies in Water », Polymers, vol. 13, nᵒ 24, p. 4424, janv. 2021.
    Résumé : We have previously demonstrated that poly(N-cyanomethylacrylamide) (PCMAm) exhibits a typical upper-critical solution temperature (UCST)-type transition, as long as the molar mass of the polymer is limited, which was made possible through the use of reversible addition-fragmentation chain transfer (RAFT) radical polymerization. In this research article, we use for the first time N-cyanomethylacrylamide (CMAm) in a typical aqueous dispersion polymerization conducted in the presence of poly(N,N-dimethylacrylamide) (PDMAm) macroRAFT agents. After assessing that well-defined PDMAm-b-PCMAm diblock copolymers were formed through this aqueous synthesis pathway, we characterized in depth the colloidal stability, morphology and temperature-responsiveness of the dispersions, notably using cryo-transmission electron microscopy (cryo-TEM), dynamic light scattering (DLS), small angle X-ray scattering (SAXS) and turbidimetry. The combined analyses revealed that stable nanometric spheres, worms and vesicles could be prepared when the PDMAm block was sufficiently long. Concerning the thermoresponsiveness, only diblocks with a PCMAm block of a low degree of polymerization (DPn,PCMAm < 100) exhibited a UCST-type dissolution upon heating at low concentration. In contrast, for higher DPn,PCMAm, the diblock copolymer nano-objects did not disassemble. At sufficiently high temperatures, they rather exhibited a temperature-induced secondary aggregation of primary particles. In summary, we demonstrated that various morphologies of nano-objects could be obtained via a typical polymerization-induced self-assembly (PISA) process using PCMAm as the hydrophobic block. We believe that the development of this aqueous synthesis pathway of novel PCMAm-based thermoresponsive polymers will pave the way towards various applications, notably as thermoresponsive coatings and in the biomedical field.
    Mots-clés : amphiphilic block copolymers, micelles, POLYMERES, polymerization-induced self-assembly, RAFT polymerization, self-assembly, synchrotron SAXS, turbidimetry, UCST, vesicles, worms.

  • N. Audureau, C. Veith, F. Coumes, T. P. T. Nguyen, J. Rieger, et F. Stoffelbach, « RAFT-Polymerized N-Cyanomethylacrylamide-Based (Co)polymers Exhibiting Tunable UCST Behavior in Water », Macromolecular Rapid Communications, vol. 42, nᵒ 23, p. 2100556, 2021.
    Résumé : In this present work, the synthesis of a new family of upper critical solution temperature (UCST)-thermoresponsive polymers based on N-cyanomethylacrylamide (CMAm) is reported. It is demonstrated that the thermally initiated reversible addition fragmentation chain transfer (RAFT) polymerization of CMAm conducted in N,N-dimethylformamide (DMF) is well controlled. The homopolymer presents a sharp and reversible UCST-type phase transition in pure water with a very small hysteresis between cooling and heating cycles. It is demonstrated that the cloud point (TCP) of poly(N-cyanomethylacrylamide) (PCMAm) is strongly molar mass dependent and shifts toward lower temperatures in saline water. Moreover, the transition temperature can be tuned over a large temperature range by copolymerization of CMAm with acrylamide or acrylic acid. The latter copolymers are both thermoresponsive and pH responsive. Interestingly, by this strategy sharp and reversible UCST-type transitions close to physiological temperature can be reached, which makes the copolymers extremely interesting candidates for biomedical applications.
    Mots-clés : N-cyanomethylacrylamide, POLYMERES, RAFT polymerization, thermoresponsiveness, UCST-type (co)polymers.

  • V. Ayzac, M. Dirany, M. Raynal, B. Isare, et L. Bouteiller, « Energetics of Competing Chiral Supramolecular Polymers », Chemistry – A European Journal, vol. 27, nᵒ 37, p. 9627-9633, juill. 2021.
    Résumé : Abstract Chirality can have unexpected consequences including on properties other than spectroscopic. We show herein that a racemic mixture of bis-urea stereoisomers forms thermodynamically stable supramolecular polymers that result in a more viscous solution than for the pure stereoisomer. The origin of this macroscopic property was probed by characterizing the structure and stability of the assemblies. Both racemic and non-racemic bis-urea stereoisomers form two competing helical supramolecular polymers in solution: a double and a single helical structure at low and high temperature, respectively. The transition temperature between these assemblies, as probed by spectroscopic and calorimetric analyses, is strongly influenced by the composition (by up to 70?°C). A simple model that accounts for the thermodynamics of this system, indicates that the stereochemical defects (chiral mismatches and helix reversals) affect much more the stability of single helices. Therefore, the heterochiral double helical structure predominates over the single helical structure (whilst the opposite holds for the homochiral structures), which explains the aforementioned higher viscosity of the racemic bis-urea solution. This rationale constitutes a new basis to tune the macroscopic properties of the increasing number of supramolecular polymers reported to exhibit competing chiral nanostructures.
    Mots-clés : bis-urea, helix reversal, net helicity amplification, pathway complexity, POLYMERES, supramolecular polymer.

  • G. Basuyaux, A. Amar, C. Troufflard, A. Boucekkine, R. Métivier, M. Raynal, J. Moussa, L. Bouteiller, et H. Amouri, « Cyclometallated Pt(II) Complexes Containing a Functionalized Bis-Urea Alkynyl Ligand: Probing Aggregation Mediated by Hydrogen Bonds versus Pt⋅⋅⋅Pt and π−π Interactions », European Journal of Inorganic Chemistry, vol. 2021, nᵒ 35, p. 3622-3631, sept. 2021.
    Résumé : Abstract Neutral cyclometallated Pt(II) complexes [(C^Nt?Bu^Nt?Bu)Pt?R] (4?5) containing a bis-urea alkynyl (R) ligand have been prepared and fully characterized. The dichotomous nature of 4?5 makes it difficult to anticipate which interactions (hydrogen bonds, π?π stacking and Pt???Pt) will dominate their assembly process. The aggregation properties of 4?5 were thus probed by multifarious analytical (UV/Vis, FT-IR, NMR, MS, CD, emission) and computational (DFT, TD-DFT) techniques. CD analyses of sergeants-and-soldiers type mixtures between 4 and an enantiopure Pt-free monomer (S,S)-3 reveal that no amplification of supramolecular helicity occurs in this system. In fact, complex 4 acts as competitor or chain capper, likely through hydrogen bonding, of the homochiral assemblies formed by (S,S)-3. In DMSO, 1H NMR and DOSY analyses indicate that 4 and 5 form aggregates. Likewise, the aggregation is promoted by the addition of H2O as suggested by red shift of the lowest energy emission band, which might originate from a 3MMLCT excited state. TD-DFT calculations confirm that self-aggregation occurs through Pt???Pt and π?π interactions yielding head-to-tail aggregates in DMSO and DMSO/H2O mixtures. Our study therefore suggests a (condition dependent) competitive rather than a cooperative mode of action of the different types of interactions present in aggregates of 4?5.
    Mots-clés : Aggregation, ARC, Bisurea, Competitor, Luminescence, POLYMERES, Pt⋅⋅⋅Pt interactions, Sergeants-and-soldiers.

  • A. Benchohra, Y. Li, L. - M. Chamoreau, B. Baptiste, E. Elkaïm, N. Guillou, D. Kreher, et R. Lescouëzec, « The Atypical Hysteresis of [Fe(C6F5Tp)2]: Overlay of Spin-Crossovers and Symmetry-Breaking Phase Transition », Angewandte Chemie, vol. 133, nᵒ 16, p. 8885-8889, 2021.
    Résumé : The [FeII(C6F5Tp)2] spin-crossover complex is an atypical molecular switch, which can be converted upon annealing between two archetypal spin-crossover behaviours: from an extremely gradual spin-crossover to a broad hysteretic spin-transition (of ca. 65 K). The hysteresis shows an uncommon “rounded shape” that is reproducible upon cycling temperature. In depth structural studies reveal a first crystal phase transition, which occurs upon melting and recrystallizing at high temperature. This first irreversible transition is associated with a radical change in the crystal packing. More importantly, the “rounded and broad” hysteretic transition is shown to occur in a non-cooperative SCO system and is associated with the occurrence of a symmetry-breaking phase transition that appears when roughly ca. 50 % of the SCO complexes are switched.
    Mots-clés : ERMMES, POLE 2, POLYMERES.

  • N. A. Burger, A. Mavromanolakis, G. Meier, P. Brocorens, R. Lazzaroni, L. Bouteiller, B. Loppinet, et D. Vlassopoulos, « Stabilization of Supramolecular Polymer Phase at High Pressures », ACS Macro Letters, vol. 10, nᵒ 3, p. 321-326, mars 2021.
    Résumé : We utilize dynamic light scattering (DLS) and passive microrheology to examine the phase behavior of a supramolecular polymer at very high pressures. The monomer, 2,4-bis(2-ethylhexylureido)toluene (EHUT), self-assembles into supramolecular polymeric structures in the nonpolar solvent cyclohexane by means of hydrogen bonding. By varying the concentration and temperature at atmospheric pressure, the formation of the viscoelastic network (at lower temperatures) and predominantly viscous phases, based on self-assembled tube and filament structures, respectively, has been established. The associated changes in the rheological properties have been attributed to a structural thickness transition. Here, we investigate the effects of pressure variation from atmospheric up to 1 kbar at a given concentration. We construct a temperature–pressure diagram that reveals the predominance of the viscoelastic network phase at high pressures. The transition from the viscoelastic network organization of the tubes to a weaker viscous-dominated structure of the filaments is rationalized by using the Clapeyron equation, which yields an associated volume change of about 8 Å3 per EHUT molecule. This change is further explained by means of Molecular Dynamics simulations of the two phases, which show a decrease in the molecular volume at the filament-tube transition, originating from increased intermolecular contacts in the tube with respect to the filament. These findings offer insights into the role of pressure in stabilizing self-assemblies.
    Mots-clés : POLYMERES.

  • T. Choisnet, D. Canevet, M. Sallé, C. Lorthioir, L. Bouteiller, P. Woisel, F. Niepceron, E. Nicol, et O. Colombani, « Colored Janus Nanocylinders Driven by Supramolecular Coassembly of Donor and Acceptor Building Blocks », ACS Nano, vol. 15, nᵒ 2, p. 2569-2577, févr. 2021.
    Résumé : Janus nanocylinders exhibit nanometric dimensions, a high aspect ratio, and two faces with different chemistries (Janus character), making them potentially relevant for applications in optics, magnetism, catalysis, surface nanopatterning, or interface stabilization, but they are also very difficult to prepare by conventional strategies. In the present work, Janus nanocylinders were prepared by supramolecular coassembly in water of two different polymers functionalized with complementary assembling units. The originality of our approach consists in combining charge transfer complexation between electron-rich and electron-poor units with hydrogen bonding to (1) drive the supramolecular formation of one-dimensional structures (cylinders), (2) force the two polymer arms on opposite sides of the cylinders independently of their compatibility, resulting in Janus nanoparticles, and (3) detect coassembly through a color change of the solution upon mixing of the functional polymers.
    Mots-clés : POLYMERES.

  • A. Gainar, T. - L. Lai, C. Oliveras-González, F. Pop, M. Raynal, B. Isare, L. Bouteiller, M. Linares, D. Canevet, N. Avarvari, et M. Sallé, « Tuning the Organogelating and Spectroscopic Properties of a C3-Symmetric Pyrene-Based Gelator through Charge Transfer », Chemistry – A European Journal, vol. 27, nᵒ 7, p. 2410-2420, févr. 2021.
    Résumé : Abstract Two-component organogels and xerogels based on a C3-symmetric pyrene-containing gelator have been deeply characterized through a wide range of techniques. Based on the formation of charge transfer complexes, the gelation phenomenon proved to be highly dependent on the nature of the electron poor dopant. This parameter significantly influenced the corresponding gelation domains, the critical gelation concentrations of acceptor dopants, the gel-to-sol transition temperatures, the microstructures formed in the xerogel state and their spectroscopic properties. In particular, titrations and variable-temperature UV?visible absorption spectroscopy demonstrated the key role of donor?acceptor interactions with a remarkable correlation between the phase transition temperatures and the disappearance of the characteristic charge transfer bands. The assignment of these electronic transitions was confirmed through time-dependent density functional theory (TD-DFT) calculations. Eventually, it was shown that the luminescent properties of these materials can be tuned with the temperature, either in intensity or emission wavelength.
    Mots-clés : charge-transfer complexes, gels, POLYMERES, pyrene, spectroscopic properties, supramolecular polymers.

  • N. Illy, V. Puchelle, S. Le Luyer, et P. Guégan, « Alternating copolymerization of bio-based N-acetylhomocysteine thiolactone and epoxides », European Polymer Journal, vol. 153, p. 110490, juin 2021.
    Résumé : The anionic ring-opening polymerizations (AROP) of bio-based N-acetyl homocysteine thiolactone (NHTL) and different epoxides were carried out using benzyl alcohol and 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine (BEMP) as initiating system. This polymerization is a rare example of AROP in the presence of an acidic moiety (acetamido group). Well-defined alternating poly(ester-alt-sulfide)s are obtained with number-average molar masses Mn ranging from 1.7 to 13.0 kg mol−1 and dispersities as low as 1.14. The presence of one acetamido function in the lateral group on each repeating unit of the copolymers derived from NHTL results in very significant increases (up to 94 °C) of the glass transition temperature Tg compared to similar poly(ester-alt-sulfide) derived from petro-based γ-butyrothiolactone (BTL). These functional poly(NHTL-alt-epoxide)s are valuable structures with numerous potential applications due to the presence in each repeating unit of one cleavable ester group and one redox-sensitive thioether group.
    Mots-clés : Alternating copolymerization, Anionic ring-opening polymerization, Bio-based γ-thiolactone, Epoxide, POLYMERES, Polythioether.

  • T. Ishii, F. Bencheikh, S. Forget, S. Chénais, B. Heinrich, D. Kreher, L. Sosa Vargas, K. Miyata, K. Onda, T. Fujihara, S. Kéna-Cohen, F. Mathevet, et C. Adachi, « Enhanced Light–Matter Interaction and Polariton Relaxation by the Control of Molecular Orientation », Advanced Optical Materials, vol. 9, nᵒ 22, p. 2101048, 2021.
    Résumé : Exciton-polaritons, in which the electronic state of an excited organic molecule and a photonic state are strongly coupled, can form a Bose–Einstein condensate (BEC) at room temperature. However, so far, the reported thresholds of organic polariton BECs under optical excitation are as high as Pth = 11–500 μJ cm–2. One route toward lowering the condensation threshold is to increase the Rabi energy by aligning the molecular transition dipole moments. In this report, it is demonstrated that control of the orientation of a perylene-based discotic dye, which is able to self-organize in mesogenic columnar structures, can significantly enhance exciton–photon interaction and polariton relaxation rate in optical cavities. These results show the importance of the molecular orientation for strong light–matter interactions and provide a promising strategy toward the realization of an organic low threshold polariton BEC system and electrically driven organic polariton BEC.
    Mots-clés : exciton-polaritons, liquid crystals, microcavities, molecular orientation, polariton relaxation, POLYMERES.

  • M. Kim, K. R. Choi, Y. U. Lee, B. Heinrich, S. Y. Ko, F. Mathevet, J. - C. Ribierre, A. D'Aléo, J. W. Wu, et V. Placide, « Natural Hyperbolic Dispersion with Anisotropic Epsilon-Near-Zero and Epsilon-Near-Pole in Squaraine Molecular Film », Advanced Optical Materials, vol. 9, nᵒ 22, p. 2101091, 2021.
    Résumé : Epsilon-near-zero (ENZ) optical material has been employed in a number of novel linear and nonlinear optical applications, owing to the vanishing polarization upon an incident optical wave. In a uniaxial medium possessing hyperbolic energy–momentum dispersion of optical wave, ENZ can take place at ordinary and extraordinary permittivities. Organic thin films presenting a lamellar structure have been reported to exhibit a transverse negative hyperbolic dispersion with ENZ at ordinary permittivity. Here, organic thin film with ENZ at extraordinary permittivity is demonstrated. Newly synthesized polymethine dye (i.e., squaraine indolenine triethyleneglycol molecule) self-organizes to form a layered structure in a pristine film, and both transverse negative and positive hyperbolic dispersions are observed at visible wavelengths. Analysis of tens-nanometer-thick pristine film shows that both ENZ and epsilon-near-pole (ENP) occur at longitudinal as well as transverse component of dielectric permittivity. Optical characterization of squaraine pristine film is presented, and the importance of transverse p

    ositive hyperbolic dispersion in such monolithic thin film is discussed.
    Mots-clés : epsilon-near-pole, epsilon-near-zero, hyperbolic dispersion, POLYMERES, polymethine dye.

  • Y. T. Le Guen, C. Pichon, P. Guégan, K. Pluchon, T. Haute, S. Quemener, J. Ropars, P. Midoux, T. Le Gall, et T. Montier, « DNA nuclear targeting sequences for enhanced non-viral gene transfer: An in vitro and in vivo study », Molecular Therapy - Nucleic Acids, vol. 24, p. 477-486, juin 2021.
    Résumé : An important bottleneck for non-viral gene transfer commonly relates to translocation of nucleic acids into the nuclear compartment of target cells. So-called 3NFs are optimized short nucleotide sequences able to interact with the transcription factor nuclear factor κB (NF-κB), which can enhance the nuclear import of plasmid DNA (pDNA) carrying such motifs. In this work, we first designed a consistent set of six pDNAs featuring a common backbone and only varying in their 3NF sequences. These constructions were then transfected under various experimental settings. In vitro, cationic polymer-assisted pDNA delivery in five human-derived cell lines showed the potential advantage of 3NF carrying pDNA in diverse cellular contexts. In vivo, naked pDNAs were hydrodynamically delivered to muscle hindlimbs in healthy mice; this direct accurate comparative (in the absence of any gene carrier) revealed modest but consistent trends in favor of the pDNAs equipped with 3NF. In summary, the results reported emphasize the implications of various parameters on NF-κB-mediated pDNA nuclear import; under specific conditions, 3NF can provide modest to substantial advantages for pDNA gene transfer, in vitro as well as in vivo. This study thus further underscores the potential of optimized nuclear import for more efficient non-viral gene transfer applications.
    Mots-clés : hydrodynamic limb vein injection, NF-κB, nuclear import, plasmid DNA, POLYMERES, skeletal muscle, transfection.

  • A. Louhichi, C. - A. Charles, S. Arora, L. Bouteiller, D. Vlassopoulos, L. Ramos, et C. Ligoure, « Competition between shear and biaxial extensional viscous dissipation in the expansion dynamics of Newtonian and rheo-thinning liquid sheets », Physics of Fluids, vol. 33, nᵒ 7, p. 073109, juill. 2021.
    Résumé : When a drop of fluid hits a small solid target of comparable size, it expands radially until reaching a maximum diameter and subsequently recedes. In this work, we show that the expansion process of liquid sheets is controlled by a combination of shear (on the target) and biaxial extensional (in the air) deformations. We propose an approach toward a rational description of the phenomenon for Newtonian and viscoelastic fluids by evaluating the viscous dissipation due to shear and extensional deformations, yielding a prediction of the maximum expansion factor of the sheet as a function of the relevant viscosity. For Newtonian systems, biaxial extensional and shear viscous dissipation are of the same order of magnitude. On the contrary, for thinning solutions of supramolecular polymers, shear dissipation is negligible compared to biaxial extensional dissipation and the biaxial thinning extensional viscosity is the appropriate quantity to describe the maximum expansion of the sheets. Moreover, we show that the rate-dependent biaxial extensional viscosities deduced from drop impact experiments are in good quantitative agreement with previous experimental data and theoretical predictions for various viscoelastic liquids.
    Mots-clés : POLYMERES.

  • S. L. Luyer, B. Quienne, M. Bouzaid, P. Guégan, S. Caillol, et N. Illy, « Bio-based poly(ester-alt-thioether)s synthesized by organo-catalyzed ring-opening copolymerizations of eugenol-based epoxides and N-acetyl homocysteine thiolactone », Green Chemistry, vol. 23, nᵒ 19, p. 7743-7750, oct. 2021.
    Résumé : The anionic alternating ring-opening copolymerizations of three bio-based aromatic monomers, eugenol glycidyl ether (EGE), dihydroeugenol glycidyl ether (DEGE) and vanillin glycidyl ether (VGE), were carried out with renewable N-acetyl homocysteine thiolactone (NHTL) using benzyl alcohol and 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine (BEMP) as the initiating system. This polymerization is a rare example of synthesis of linear polyesters using eugenol-based monomers. Alternating poly(ester-alt-thioether)s are obtained with number-average molar masses (Mn) ranging from 1.1 to 10.8 kg mol−1 and dispersities as low as 1.20. The copolymer structures were carefully characterized by 1H, 13C, COSY, HSQC, and 1H–15N NMR. It was found that the alternating copolymers were obtained selectively at different monomer feed ratios. In addition, the use of EGE and VGE monomers allows the preparation of multi-functional poly(ester-alt-thioether)s respectively bearing allyl or aldehyde groups in each repeating unit. The copolymers display only clear glass transition temperatures higher than the ambient temperature. This alternating copolymerization method offers a new chemical pathway for the valorization of bio-based aromatic compounds and expands the scope of renewable polyesters.
    Mots-clés : POLYMERES.

  • M. A. Martínez-Aguirre, Y. Li, N. Vanthuyne, L. Bouteiller, et M. Raynal, « Dissecting the Role of the Sergeants in Supramolecular Helical Catalysts: From Chain Capping to Intercalation », Angewandte Chemie International Edition, vol. 60, nᵒ 8, p. 4183-4191, 2021.
    Résumé : Controlling the properties of supramolecular assemblies requires unveiling the specific interactions between their components. In the present work, the catalytic properties and structure of co-assemblies composed of a benzene-1,3,5-tricarboxamide (BTA) ligand coordinated to copper (the soldier) and seven enantiopure BTAs (the sergeants) have been determined. Whatever the sergeant, the enantioselectivity of the reaction is directly proportional to the optical purity of the supramolecular helices. More strikingly, the role played by the sergeant in the co-assembly process differs significantly: from almost pure intercalator (when it is incorporated in the stacks of the soldier and generates long homochiral helices) to pure chain capper (when it leads to the formation of partly helically biased and short assemblies). The former situation leads to optimal enantioselectivity for the catalytic system under study (58 % ee) while the latter situation leads to very low selectivity (8 % ee). The successful rationalization of this high and unexpected difference is crucial for the development of more efficient catalysts and more elaborate supramolecular systems.
    Mots-clés : helical catalyst, POLYMERES, sergeants-and-soldiers effect, supramolecular catalysis, supramolecular chirality, supramolecular copolymerisation.

  • M. Raynal, Y. Li, C. Troufflard, C. Przybylski, G. Gontard, T. Maistriaux, J. Idé, R. Lazzaroni, L. Bouteiller, et P. Brocorens, « Experimental and computational diagnosis of the fluxional nature of a benzene-1,3,5-tricarboxamide-based hydrogen-bonded dimer », Physical Chemistry Chemical Physics, vol. 23, nᵒ 9, p. 5207-5221, 2021.
    Résumé : High-symmetry (left) and low-symmetry ( e.g. that on the right) conformations of benzene-1,3,5-tricarboxamide dimers derived from glycine alkyl esters are in rapid exchange in solution through amide/ester competition for the binding of the N–H donors. , Precise characterization of the hydrogen bond network present in discrete self-assemblies of benzene-1,3,5-tricarboxamide monomers derived from amino-esters (ester BTAs) is crucial for the construction of elaborated functional co-assemblies. For all ester BTA dimeric structures previously reported, ester carbonyls in the side chain acted as hydrogen bond acceptors, yielding well-defined dimers stabilized by six hydrogen bonds. The ester BTA monomer derived from glycine ( BTA Gly ) shows a markedly different self-assembly behaviour. We report herein a combined experimental and computational investigation aimed at determining the nature of the dimeric species formed by BTA Gly . Two distinct dimeric structures were characterized by single-crystal X-ray diffraction measurements. Likewise, a range of spectroscopic and scattering techniques as well as molecular modelling were employed to diagnose the nature of dynamic dimeric structures in toluene. Our results unambiguously establish that both ester and amide carbonyls are involved in the hydrogen bond network of the discrete dimeric species formed by BTA Gly . The participation of roughly 4.5 ester carbonyls and 1.5 amide carbonyls per dimer as determined by FT-IR spectroscopy implies that several conformations coexist in solution. Moreover, NMR analysis and modelling data reveal rapid interconversion between these different conformers leading to a symmetric structure on the NMR timescale. Rapid hydrogen bond shuffling between conformers having three (three), two (four), one (five) and zero (six) amide carbonyl groups (ester carbonyl groups, respectively) as hydrogen bond acceptors is proposed to explain the magnetic equivalence of the amide N–H on the NMR timescale. When compared to other ester BTA derivatives in which only ester carbonyls act as hydrogen bond acceptors, the fluxional behaviour of the hydrogen-bonded dimers of BTA Gly likely originates from a larger range of energetically favorable conformations accessible through rotation of the BTA side chains.
    Mots-clés : CSOB, POLE 3, POLE 4, POLYMERES.

  • L. Simonin, G. Falco, S. Pensec, F. Dalmas, J. - M. Chenal, F. Ganachaud, A. Marcellan, L. Chazeau, et L. Bouteiller, « Macromolecular Additives to Turn a Thermoplastic Elastomer into a Self-Healing Material », Macromolecules, vol. 54, nᵒ 2, p. 888-895, janv. 2021.
    Résumé : Self-healing allows increasing the service life of materials by overcoming some issues caused by mechanical failures. We propose a new concept to impart room-temperature self-healing properties to thermoplastic elastomers. A macromolecular additive whose interacting units can interfere with the hard segments of the thermoplastic elastomer accelerates chain dynamics and imparts self-healing properties to the composite material with a limited detrimental effect on mechanical properties. By applying this concept to silicone-based elastomers, we have obtained an autonomously self-healing material with a relatively high elastic modulus for this type of elastomers.
    Mots-clés : POLYMERES.

  • X. Zhu, C. Hessin, A. Salamé, L. Sosa‐Vargas, D. Kreher, C. Adachi, A. Proust, P. Mialane, J. Marrot, A. Bouchet, M. Sliwa, S. Méry, B. Heinrich, F. Mathevet, et G. Izzet, « Photoactive Organic/Inorganic Hybrid Materials with Nanosegregated Donor–Acceptor Arrays », Angewandte Chemie International Edition, vol. 60, nᵒ 15, p. 8419-8424, avr. 2021.
    Mots-clés : E-POM, POLE 2, POLE 4, POLYMERES.


  • A. Benchohra, C. Méthivier, J. Landoulsi, D. Kreher, et R. Lescouëzec, « Electrospray ionization: an efficient approach to deposit polymetallic molecular switches onto gold surfaces », Chemical Communications, vol. 56, nᵒ 48, p. 6587-6589, 2020.
    Résumé : Electrospray ionization (EI) deposition is proven efficient in obtaining monolayers of a polymetallic charge transfer complex on gold surfaces. , Electrospray ionization (EI) deposition is proven efficient in obtaining monolayers of a polymetallic charge transfer complex on gold surfaces. The molecule's integrity is monitored by using PM-IRRAS and XPS. This approach broadens the perspective of molecular magnetic switch deposition, which is currently dominated by the thermal evaporation of monometallic spin crossover (SCO) complexes.
    Mots-clés : ERMMES, POLE 2, POLYMERES.

  • F. Coumes, M. Balarezo, J. Rieger, et F. Stoffelbach, « Biobased Amphiphilic Block Copolymers by RAFT-Mediated PISA in Green Solvent », Macromolecular Rapid Communications, vol. 41, nᵒ 9, p. 2000002, 2020.
    Résumé : Biobased amphiphilic diblock copolymers are prepared thanks to the combination of reversible addition–fragmentation transfer (RAFT) polymerization and polymerization-induced self-assembly (PISA) in an eco-friendly solvent mixture. First, the formation of a poly(acrylic acid) macroRAFT agent (PAA-TTC) is performed in water at 70 °C. Then, in a series of experiments, the PAA-TTC macroRAFT agent is used directly, without purification, as both chain transfer agent and stabilizing agent in the RAFT-PISA of menthyl acrylate (MnA) in dispersion in an ethanol/water mixture. The polymerizations of MnA are fast with high final conversions and well-controlled amphiphilic diblock copolymers are synthesized. Stable, sub-micrometric spherical particles composed of the diblock copolymers are formed. The influence of the monomer concentration and the length of the solvophobic block on the diameter of the self-assemblies is studied by means of dynamic light scattering and cryogenic transmission electron-microscopy.
    Mots-clés : amphiphilic copolymers, biobased monomers, dispersion polymerization, PISA, POLE 4, POLYMERES, RAFT.

  • F. D'Agosto, J. Rieger, et M. Lansalot, « RAFT-Mediated Polymerization-Induced Self-Assembly », Angewandte Chemie International Edition, vol. 59, nᵒ 22, p. 8368-8392, 2020.
    Résumé : After a brief history that positions polymerization-induced self-assembly (PISA) in the field of polymer chemistry, this Review will cover the fundamentals of the PISA mechanism. Furthermore, this Review will also give an overview of some of the features and limitations of RAFT-mediated PISA in terms of the choice of the components involved, the nature of the nanoobjects that can be obtained and how the syntheses can be controlled, as well as some potential applications.
    Mots-clés : block copolymers, heterogeneous polymerization, morphology, PISA, POLE 4, POLYMERES, RAFT.

  • Y. T. L. Guen, T. L. Gall, P. Midoux, P. Guégan, S. Braun, et T. Montier, « Gene transfer to skeletal muscle using hydrodynamic limb vein injection: current applications, hurdles and possible optimizations », The Journal of Gene Medicine, vol. 22, nᵒ 2, p. e3150, 2020.
    Résumé : Hydrodynamic limb vein injection is an in vivo locoregional gene delivery method. It consists of administrating a large volume of solution containing nucleic acid constructs in a limb with both blood inflow and outflow temporarily blocked using a tourniquet. The fast, high pressure delivery allows the musculature of the whole limb to be reached. The skeletal muscle is a tissue of choice for a variety of gene transfer applications, including gene therapy for Duchenne muscular dystrophy or other myopathies, as well as for the production of antibodies or other proteins with broad therapeutic effects. Hydrodynamic limb vein delivery has been evaluated with success in a large range of animal models. It has also proven to be safe and well-tolerated in muscular dystrophy patients, thus supporting its translation to the clinic. However, some possible limitations may occur at different steps of the delivery process. Here, we have highlighted the interests, bottlenecks and potential improvements that could further optimize non-viral gene transfer following hydrodynamic limb vein injection.
    Mots-clés : gene transfer, hydrodynamic delivery, locoregional, non-viral gene delivery, optimizations, POLE 4, POLYMERES, skeletal muscle.

  • V. Puchelle, Y. Latreyte, M. Girardot, L. Garnotel, L. Levesque, O. Coutelier, M. Destarac, P. Guégan, et N. Illy, « Functional Poly(ester-alt-sulfide)s Synthesized by Organo-Catalyzed Anionic Ring-Opening Alternating Copolymerization of Oxiranes and γ-Thiobutyrolactones », Macromolecules, vol. 53, nᵒ 13, p. 5188-5198, juill. 2020.
    Résumé : The copolymerization of tert-butyl glycidyl ether (tBuGE), allyl glycidyl ether (AGE), ethoxyethyl glycidyl ether (EEGE) and 1,2-epoxybutane (BO) with γ-thiobutyrolactone was investigated using benzyl alcohol–phosphazene bases as initiating systems. The prepared copolymers display perfect (poly(ester-alt-sulfide)) alternating structures for all epoxide monomers as evidenced by 1H, 13C, and 2D NMR and MALDI–TOF mass spectrometry. A marked influence of the reaction temperature on the occurrence of transesterification side reactions has been evidenced. In particular, at elevated temperature, transesterification reactions led to the formation of alternating macrocycles. The choice of the phosphazene base (tBuP4, tBuP2, or tBuP1) has a strong impact on the system reactivity and on the control of the polymerization. The use of tBuP1 led to very slow polymerization rates. The polymerization is much faster in the presence of tBuP2 even at low temperature. The use of tBuP4 shows an intermediate polymerization rate and enabled a good polymerization control at moderate temperatures. Finally, the synthesis of well-defined polyether-block-poly(ester-alt-sulfide) and the polymerization of a challenging substituted γ-thiolactone were proven to be feasible.
    Mots-clés : POLYMERES.

  • P. - J. Roumanet, N. Jarroux, L. Goujard, J. Le Petit, Y. Raoul, V. Bennevault, et P. Guégan, « Synthesis of Linear Polyesters from Monomers Based on 1,18-(Z)-Octadec-9-enedioic Acid and Their Biodegradability », ACS Sustainable Chemistry & Engineering, vol. 8, nᵒ 45, p. 16853-16860, nov. 2020.
    Résumé : A new family of bio-based linear polyesters from oleic acid was developed by a bulk polymerization process. First, efficient chemical pathways were selected to synthesize three monomer derivatives from 1,18-(Z)-octadec-9-enedioic acid, allowing the synthesis of four polyesters that differ by the number of double bonds along the polymer backbone. After the analysis of the structure of the polymers, their thermal properties and their biodegradability were investigated. It was shown that the melting temperature of the polyesters increased with the decrease in the unsaturation content in the repeat units of the polymers and they have very low glass-transition temperatures. A biodegradation process was also highlighted for poly(1,18-(Z)-octadec-9-enylene 1,18-(Z)-octadec-9-enedioate) and poly(1,18-octadecylene 1,18-octadecanedioate). Based on their thermal features, these biodegradable polyesters can represent an alternative of the synthetic polymers derived from petroleum hydrocarbons, such as low-density polyethylene.
    Mots-clés : POLYMERES.


  • V. Ayzac, Q. Sallembien, M. Raynal, B. Isare, J. Jestin, et L. Bouteiller, « A Competing Hydrogen Bonding Pattern to Yield a Thermo-Thickening Supramolecular Polymer », Angewandte Chemie International Edition, vol. 58, nᵒ 39, p. 13849-13853, 2019.
    Résumé : Introduction of competing interactions in the design of a supramolecular polymer (SP) creates pathway complexity. Ester–bis-ureas contain both a strong bis-urea sticker that is responsible for the build-up of long rod-like objects by hydrogen bonding and ester groups that can interfere with this main pattern in a subtle way. Spectroscopic (FTIR and CD), calorimetric (DSC), and scattering (SANS) techniques show that such ester–bis-ureas self-assemble into three competing rod-like SPs. The previously unreported low-temperature SP is stabilized by hydrogen bonds between the interfering ester groups and the urea moieties. It also features a weak macroscopic alignment of the rods. The other structures form isotropic dispersions of rods stabilized by the more classical urea-urea hydrogen bonding pattern. The transition from the low-temperature structure to the next occurs reversibly by heating and is accompanied by an increase in viscosity, a rare feature for solutions in hydrocarbons.
    Mots-clés : hydrogen bonds, pathway complexity, POLYMERES, self-assembly, supramolecular polymers, urea.

  • N. Illy, V. Corcé, J. Zimbron, V. Molinié, M. Labourel, G. Tresset, J. Degrouard, M. Salmain, et P. Guégan, « pH-Sensitive Poly(ethylene glycol)/Poly(ethoxyethyl glycidyl ether) Block Copolymers: Synthesis, Characterization, Encapsulation, and Delivery of a Hydrophobic Drug », Macromolecular Chemistry and Physics, vol. 220, nᵒ 16, p. 1900210, août 2019.
    Résumé : Abstract Curcumin is a natural polyphenolic compound known for its numerous pharmacological properties. However, its low water solubility and instability at neutral pH are serious drawbacks preventing its use as an oral drug. Well-defined amphiphilic poly(ethylene glycol)-block-poly(ethoxyethyl glycidyl ether) (PEG-b-PEEGE) block copolymers carrying acid-labile acetal groups are synthesized by anionic ring-opening polymerization and investigated as potential pH-sensitive nano-carriers for delivery of curcumin to cancer cells. The nanoparticles, resulting from copolymer self-assembly in aqueous media, are characterized by dynamic light scattering and cryo-transmission electron microscopy. The nanoparticles? stabilities are evaluated in three different phosphate buffers (pH = 7.2, 6.4, and 5.3). The stability decreases at lower pH and a complete disappearance of the nanoparticles is noticed after 4 days at pH 5.3. Curcumin is encapsulated in hydrophobic core of mPEG40-b-PEEGE25 nanoparticles allowing significant enhancements of curcumin solubility in water and lifetime at neutral pH. In vitro curcumin release is studied at different pH by UV-spectroscopy and high-performance liquid chromatography (HPLC). The cytotoxicity of curcumin and curcumin encapsulated in micelles is evaluated by cell viability 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay on MDA-MB-231 human breast cancer cells.
    Mots-clés : amphiphilic polyethers, anionic-ring opening polymerization, CHEMBIO, curcumin encapsulation, pH-sensitive copolymers, POLE 3, POLE 4, POLYMERES, self-assembly.

  • Y. Li, L. Bouteiller, et M. Raynal, « Catalysts Supported by Homochiral Molecular Helices: A New Concept to Implement Asymmetric Amplification in Catalytic Science », ChemCatChem, vol. 11, nᵒ 21, p. 5212-5226, 2019.
    Résumé : Connecting intrinsically achiral catalytic centers to helical polymers provides a new class of asymmetric catalysts whose selectivity exclusively stems from the chiral environment provided by the helical polymer. Chirality amplification phenomena allow to control the handedness and the helical sense excess of these polymers which in turn dictate the stereochemical direction and the extent of enantioinduction, respectively, obtained in the course of the asymmetric reaction. This minireview is focused on such helical catalysts built either on a covalent or a non-covalent scaffold and for which the handedness is controlled by an asymmetric polymerization reaction, by enantiopure monomers or by chiral additives. The selectivity of catalysts based on a dynamic helical backbone can be tuned by changing the solvent or with additives. The fact that the enantiomeric state of such asymmetric catalysts can be switched in a predictable way is particularly emphasized.
    Mots-clés : asymmetric catalysis, chirality amplification, macromolecular helices, POLYMERES, supramolecular helices, switchable catalysis.

  • Y. Li, L. Dubreucq, B. G. Alvarenga, M. Raynal, et L. Bouteiller, « N-Substituted Benzene-1-Urea-3,5-Biscarboxamide (BUBA): Easily Accessible C2-Symmetric Monomers for the Construction of Reversible and Chirally Amplified Helical Assemblies », Chemistry – A European Journal, vol. 25, nᵒ 45, p. 10650-10661, 2019.
    Résumé : Non-C3-symmetric supramolecular helices are gaining interest for the design of hierarchical assemblies, for the compartmentalisation or the self-assembly of polymer chains and for application in asymmetric catalysis. Herein, N-substituted benzene-1-urea-3,5-biscarboxamide (BUBA) monomers, which consist of one urea and two carbon-connected amide functions linked to an aromatic ring, are introduced as an easily accessible class of C2-symmetric supramolecular synthons. In apolar solvents, BUBA monomers assemble into long helical assemblies by means of hydrogen-bonding and aromatic interactions, as assessed by several analytical techniques. To probe the influence of the urea function, BUBA and related benzene-1,3,5-tricarboxamide (BTA) helical polymers have been compared, in terms of their thermodynamics of formation, stability, reversibility and chiral amplification properties. Similar to BTA, BUBA monomers form long helices reversibly through a highly cooperative mechanism and the helicity of their assemblies is governed by chiral amplification effects. However, precise quantification of their properties reveals that BUBA monomers assemble in a more cooperative manner. Also, chiral amplification operates to a higher extent in BUBA helices, as probed by both sergeants-and-soldiers and majority-rules experiments. Compatibility between urea and amide functions also allows the formation of co-assemblies that incorporate both BUBA and BTA monomers. Importantly, a small amount of chiral BUBA monomers in these co-assemblies is sufficient to obtain single-handed helices; thus paving the way towards the development of functional supramolecular helices.
    Mots-clés : chirality, cooperative effects, helical structures, noncovalent interactions, POLYMERES, self-assembly.


  • J. Lyskawa, F. Stoffelbach, D. Fournier, et P. Woisel, « La « Blue Box » : Une molécule hôte pour élaborer des matériaux macromoléculaires (multi)stimulables hauts en couleur », L'Actualité Chimique, nᵒ 430-431, p. 30-36, 2018.

  • M. Raynal et L. Bouteiller, « Polymères supramoléculaires et catalyse asymétrique - L'Actualité Chimique », L'Actualité Chimique, nᵒ 430-431, p. 37-41, 2018.
    Résumé : Dans le but de développer des catalyseurs asymétriques innovants, des sites catalytiques ont été connectés à des polymères supramoléculaires adoptant une configuration hélicoïdale. Les avantages de cette nouvelle classe de catalyseurs sont que leur composition peut être aisément modulée, qu’une quantité minimale de monomères chiraux est utilisée sans diminuer la sélectivité (amplification de chiralité) et que leur sélectivité est contrôlée en temps réel. Toutes ces propriétés, démontrées pour des réactions métallo-catalysées (Rh, Cu), ne sont pas accessibles avec des catalyseurs conventionnels basés sur des liaisons covalentes. L’utilisation de ces catalyseurs supramoléculaires pour la préparation de petites molécules d’intérêt ou de polymères, non accessibles via les méthodes catalytiques conventionnelles, est envisageable.
    Mots-clés : POLE 4, POLYMERES.


  • M. Piot, S. Hupin, H. Lavanant, C. Afonso, L. Bouteiller, A. Proust, et G. Izzet, « Charge Effect on the Formation of Polyoxometalate-Based Supramolecular Polygons Driven by Metal Coordination », Inorganic Chemistry, vol. 56, nᵒ 14, p. 8490-8496, juill. 2017.
    Résumé : The metal-driven self-assembly of a Keggin-based hybrid bearing two remote pyridine units was investigated. The resulting supramolecular species were identified by combination of 2D diffusion NMR spectroscopy (DOSY) and electrospray ionization mass spectrometry (ESI-MS) as a mixture of molecular triangles and squares. This behavior is different from that of the structural analogue Dawson-based hybrid displaying a higher charge, which only led to the formation of molecular triangles. This study highlights the decisive effect of the charge of the POMs in their self-assembly processes that disfavors the formation of large assemblies. An isothermal titration calorimetry (ITC) experiment confirmed the stronger binding in the case of the Keggin hybrids. A correlation between the diffusion coefficient D and the molecular mass M of the POM-based building block and its coordination oligomers was also observed. We show that the diffusion coefficient of these compounds is mainly determined by their occupied volume rather than by their shape.
    Mots-clés : E-POM, POLE 2, POLE 4, POLYMERES.


  • D. Kréher, F. Mathevet, P. Baldeck, C. Ricard, B. V. D. Sanden, et A. - J. Attias, « PH responsive two-photon absorbing functionalized styrylpyridine-based multi-branched dyes », Nonlinear optics, Quantum optics, vol. 46, nᵒ 2, p. 283-297, janv. 2015.
    Résumé : We report on the design, synthesis and optical properties of new two-photon absorbing multi-branched chromophores, based on a pyridine core. Measurements of TPA using the two-photon fluorescence...
    Mots-clés : POLE 4, POLYMERES.

Année non précisée

  • F. A. de Oliveira, L. J. C. Albuquerque, G. Delecourt, V. Bennevault, P. Guégan, et F. C. Giacomelli, « Current Designs of Polymeric Platforms Towards the Delivery of Nucleic Acids Inside the Cells with Focus on Polyethylenimine », Current Gene Therapy, vol. 21, nᵒ 5, p. 431-451, sans date.
    Résumé : Background: Gene delivery is a promising technology for treating diseases linked to abnormal gene expression. Since nucleic acids are the therapeutic entities in such approach, a transfecting vector is required because the macromolecules are not able to efficiently enter the cells by themselves. Viral vectors have been evidenced to be highly effective in this context; however, they suffer from fundamental drawbacks, such as the ability to stimulate immune responses. The development of synthetic vectors has accordingly emerged as an alternative. Objectives: Gene delivery by using non-viral vectors is a multi-step process that poses many challenges, either regarding the extracellular or intracellular media. We explore the delivery pathway and afterwards, we review the main classes of non-viral gene delivery vectors. We further focus on the progresses concerning polyethylenimine-based polymer-nucleic acid polyplexes, which have emerged as one of the most efficient systems for delivering genetic material inside the cells. Discussion: The complexity of the whole transfection pathway, along with a lack of fundamental understanding, particularly regarding the intracellular trafficking of nucleic acids complexed to non-viral vectors, probably justifies the current (beginning of 2021) limited number of formulations that have progressed to clinical trials. Truly, successful medical developments still require a lot of basic research. Conclusion: Advances in macromolecular chemistry and high-resolution imaging techniques will be useful to understand fundamental aspects towards further optimizations and future applications. More investigations concerning the dynamics, thermodynamics and structural parameters of polyplexes would be valuable since they can be connected to the different levels of transfection efficiency hitherto evidenced.
    Mots-clés : POLYMERES.
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