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  • A. Ali Mohamed, S. Salhi, S. Abid, R. El Gharbi, et A. Fradet, « Quasi-alternating polyesteramides from ε-caprolactone and α-amino acids », Journal of Applied Polymer Science, vol. 133, nᵒ 46, p. n/a-n/a.
    Résumé : Glycine-ɛ-caprolactone-based and α-alanine-ɛ-caprolactone-based polyesteramides with a strong tendency to form alternating sequences (degree of randomness = 1.64 and 1.31) were synthesized by melt polycondensation of intermediate hydroxy- and ethyl ester-terminated amides. These intermediates were synthesized by the reaction of equimolar amounts of ɛ-caprolactone and glycine or L-α-alanine ethyl esters in mild conditions. The structure and microstructure of these polyesteramides are discussed on the basis of an in-depth nuclear magnetic resonance study. Both polyesteramides are semi-crystalline, but the glycine-based one presents the highest melting enthalpy. This polyesteramide also exhibits higher Young's modulus and stress at break than its α- and β-alanine counterparts. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44220.
    Mots-clés : biopolymers and renewable polymers, POLE 4, Polyesteramides, polyesters, POLYMERES, α-amino acids.

  • K. Belal, S. Poitras-Jolicoeur, J. Lyskawa, G. Pembouong, G. Cooke, P. Woisel, et F. Stoffelbach, « A triple carboxylic acid-functionalized RAFT agent platform for the elaboration of well-defined telechelic 3-arm star PDMAc », vol. 52, nᵒ 9, p. 1847-1850.
    Résumé : This communication describes the synthesis of a triple acid-functionalized RAFT agent and its use to prepare well-defined 3-arm star polymers of N,N-dimethylacrylamide (DMAc). A simple esterification reaction allowed the convenient integration of three electron-rich naphthalene recognition units on the RAFT agent platform and subsequently the elaboration of a naphthalene end-decorated telechelic 3-arm star PDMAc. This functionalized star polymer was further exploited to build a hydrogel with a complementary homoditopic host unit featuring tetracationic macrocycle cyclobis(paraquat-p-phenylene) units.
    Mots-clés : POLE 4, POLYMERES.

  • K. Belal, F. Stoffelbach, J. Lyskawa, M. Fumagalli, D. Hourdet, A. Marcellan, L. De Smet, V. R. de la Rosa, G. Cooke, R. Hoogenboom, et P. Woisel, « Recognition-mediated hydrogel swelling controlled by interaction with a negative thermoresponsive LCST polymer », Angewandte Chemie (International Edition), vol. 55, nᵒ 45, p. 13974-13978.
    Résumé : Most polymeric thermoresponsive hydrogels contract upon heating beyond the lower critical solution temperature (LCST) of the polymers used. Herein, we report a supramolecular hydrogel system that shows the opposite temperature dependence. When the non-thermosesponsive hydrogel NaphtGel, containing dialkoxynaphthalene guest molecules, becomes complexed with the tetra cationic macrocyclic host CBPQT4+, swelling occurred as a result of host–guest complex formation leading to charge repulsion between the host units, as well as an osmotic contribution of chloride counter-ions embedded in the network. The immersion of NaphtGel in a solution of poly(N-isopropylacrylamide) with tetrathiafulvalene (TTF) end groups complexed with CBPQT4+ induced positive thermoresponsive behaviour. The LCST-induced dethreading of the polymer-based pseudorotaxane upon heating led to transfer of the CBPQT4+ host and a concomitant swelling of NaphtGel. Subsequent cooling led to reformation of the TTF-based host–guest complexes in solution and contraction of the hydrogel.
    Mots-clés : POLE 4, POLYMERES.

  • V. Besse, N. Illy, G. David, S. Caillol, et B. Boutevin, « A Chitosan Derivative Containing Both Carboxylic Acid and Quaternary Ammonium Moieties for the Synthesis of Cyclic Carbonates », ChemSusChem, vol. 9, nᵒ 16, p. 2167-2173.
    Résumé : Chitosan, a renewable feedstock, is modified and used as a catalytic support in the presence of potassium iodide. The system is highly efficient towards the incorporation of carbon dioxide (CO2) into epoxides. It demonstrates very good thermal stability and is recyclable more than five times without loss of activity. The optimal reaction conditions were determined using allylglycidyl ether as a model and extended to a wide range of other epoxides. Cyclic carbonates were obtained with very high yield in a few hours under mild conditions (2–7 bar≈0.2–0.7 MPa, 80 °C) and no solvent.
    Mots-clés : chitosan, cyclic carbonates, epoxides, heterogeneous catalysis, POLE 4, POLYMERES, supported catalyst.

  • X. Callies, C. Fonteneau, S. Pensec, L. Bouteiller, G. Ducouret, et C. Creton, « Adhesion and non-linear rheology of adhesives with supramolecular crosslinking points », vol. 12, nᵒ 34, p. 7174-7185.
    Résumé : Soft supramolecular materials are promising for the design of innovative and highly tunable adhesives. These materials are composed of polymer chains functionalized by strongly interacting moieties, sometimes called “stickers”. In order to systematically investigate the effect of the presence of associative groups on the debonding properties of a supramolecular adhesive, a series of supramolecular model systems has been characterized by probe-tack tests. These model materials, composed of linear and low dispersity poly(butylacrylate) chains functionalized in the middle by a single tri-urea sticker, are able to self-associate by six hydrogen bonds and range in molecular weight (Mn) between 5 and 85 kg mol−1. The linear rheology and the nanostructure of the same materials (called “PnBA3U”) were the object of a previous study. At room temperature, the association of polymers via hydrogen bonds induces the formation of rod-like aggregates structured into bundles for Mn < 40 kg mol−1 and the behavior of a soft elastic material was observed (G′ ≪ G′′ and G′ ∼ ω0). For higher Mn materials, the filaments were randomly oriented and the polymers displayed a crossover towards viscous behavior although terminal relaxation was not reached in the experimental frequency window. All these materials show, however, similar adhesive properties characterized by a cohesive mode of failure and low debonding energies (Wadh < 40 J m−2 for a debonding speed of 100 μm s−1). The debonding mechanisms observed during the adhesion tests have been investigated in detail with an Image tools analysis developed by our group. The measure of the projected area covered by cavities growing in the adhesive layer during debonding can be used to estimate the true stress in the walls of the cavities and thus to characterize the in situ large strain deformation of the thin layer during the adhesion test itself. This analysis revealed in particular that the PnBA3U materials with Mn < 40 kg mol−1 soften very markedly at large deformation like yield stress fluids, explaining the low adhesion energies measured for these viscoelastic gels.
    Mots-clés : POLE 4, POLYMERES.

  • S. Catrouillet, L. Bouteiller, O. Boyron, C. Lorthioir, E. Nicol, S. Pensec, et O. Colombani, « Patchy Supramolecular Bottle-Brushes Formed by Solution Self-Assembly of Bis(urea)s and Tris(urea)s Decorated by Two Incompatible Polymer Arms », Langmuir, vol. 32, nᵒ 35, p. 8900-8908.
    Résumé : In an attempt to design urea-based Janus nanocylinders through a supramolecular approach, nonsymmetrical bis(urea)s and tris(urea)s decorated by two incompatible polymer arms, namely, poly(styrene) (PS) and poly(isobutylene) (PIB), were synthesized using rather straightforward organic and polymer chemistry techniques. Light scattering experiments revealed that these molecules self-assembled in cyclohexane by cooperative hydrogen bonds. The extent of self-assembly was limited for the bis(urea)s. On the contrary, reasonably anisotropic 1D structures (small nanocylinders) could be obtained with the tris(urea)s (Nagg ∼ 50) which developed six cooperative hydrogen bonds per molecule. 1H transverse relaxation measurements and NOESY NMR experiments in cyclohexane revealed that perfect Janus nanocylinders with one face consisting of only PS and the other of PIB were not obtained. Nevertheless, phase segregation between the PS and PIB chains occurred to a large extent, resulting in patchy cylinders containing well separated domains of PIB and PS chains. Reasons for this behavior were proposed, paving the way to improve the proposed strategy toward true urea-based supramolecular Janus nanocylinders.
    Mots-clés : POLE 4, POLYMERES.

  • M. C. Chong, G. Reecht, H. Bulou, A. Boeglin, F. Scheurer, F. Mathevet, et G. Schull, « Narrow-Line Single-Molecule Transducer between Electronic Circuits and Surface Plasmons », Physical Review Letters, vol. 116, nᵒ 3, p. 036802.
    Résumé : A molecular wire containing an emitting molecular center is controllably suspended between the plasmonic electrodes of a cryogenic scanning tunneling microscope. Passing current through this circuit generates an ultranarrow-line emission at an energy of ≈1.5 eV which is assigned to the fluorescence of the molecular center. Control over the linewidth is obtained by progressively detaching the emitting unit from the surface. The recorded spectra also reveal several vibronic peaks of low intensities that can be viewed as a fingerprint of the emitter. Surface plasmons localized at the tip-sample interface are shown to play a major role in both excitation and emission of the molecular excitons.
    Mots-clés : POLE 4, POLYMERES.

  • A. Desmarchelier, X. Caumes, M. Raynal, A. Vidal-Ferran, P. W. N. M. van Leeuwen, et L. Bouteiller, « Correlation between the Selectivity and the Structure of an Asymmetric Catalyst Built on a Chirally Amplified Supramolecular Helical Scaffold », Journal of the American Chemical Society, vol. 138, nᵒ 14, p. 4908-4916.
    Résumé : For the first time, supramolecular helical rods composed of an achiral metal complex and a complementary enantiopure monomer provided a good level of enantioinduction in asymmetric catalysis. Mixtures containing an achiral ligand monomer (BTAPPh2, 2 mol %) and an enantiopure ligand-free comonomer (ester BTA, 2.5 mol %), both possessing a complementary benzene-1,3,5-tricarboxamide (BTA) central unit, were investigated in combination with [Rh(cod)2]BArF (1 mol %) in the asymmetric hydrogenation of dimethyl itaconate. Notably, efficient chirality transfer occurs within the hydrogen-bonded coassemblies formed by BTA Ile and the intrinsically achiral catalytic rhodium catalyst, providing the hydrogenation product with up to 85% ee. The effect of the relative content of BTA Ile as compared to the ligand was investigated. The amount of chiral comonomer can be decreased down to one-fourth of that of the ligand without deteriorating the enantioselectivity of the reaction, while the enantioselectivity decreases for mixtures containing high amounts of BTA Ile. The nonlinear relationship between the amount of chiral comonomer and the enantioselectivity indicates that chirality amplification effects are at work in this catalytic system. Also, right-handed helical rods are formed upon co-assembly of the achiral rhodium complex of BTAPPh2 and the enantiopure comonomer BTA Ile as confirmed by various spectroscopic and scattering techniques. Remarkably, the major enantiomer and the selectivity of the catalytic reaction are related to the handedness and the net helicity of the coassemblies, respectively. Further development of this class of catalysts built on chirally amplified helical scaffolds should contribute to the design of asymmetric catalysts operating with low amounts of chiral entities.
    Mots-clés : POLE 4, POLYMERES.

  • M. Dréan, P. Guégan, C. Detrembleur, C. Jérôme, J. Rieger, et A. Debuigne, « Controlled Synthesis of Poly(vinylamine)-Based Copolymers by Organometallic-Mediated Radical Polymerization », Macromolecules, vol. 49, nᵒ 13, p. 4817-4827.
    Résumé : Living/controlled polymerization methods have enabled the synthesis of numerous (co)polymers with defined compositions and architectures. However, the precision design of poly(vinylamine)-based copolymers remains challenging despite their extensive use in various fields of applications and the clear benefits to finely tune their properties. Here, we report on a two-step strategy for the synthesis of tailor-made poly(vinylamine) derivatives through the organometallic-mediated radical (co)polymerization (OMRP) of N-vinylacetamide and/or N-methylvinylacetamide followed by acid hydrolysis of the acetamide groups. A series of well-defined homopolymers as well as statistical and block copolymers with pendant primary and/or secondary amines having controlled molar masses, compositions, and low dispersities were produced accordingly. The reactivity ratios of the comonomers as well as the composition drift along the chain were determined in order to have a precise idea of the polymer structures. These advances represent a significant step toward an efficient platform for synthesis of this important class of amino group-containing (co)polymers.
    Mots-clés : POLE 4, POLYMERES.

  • L. Duarte, S. Nag, M. Castro, E. Zaborova, M. Ménand, M. Sollogoub, V. Bennevault, J. - F. Feller, et P. Guégan, « Chemical Sensors Based on New Polyamides Biobased on (Z) Octadec-9-Enedioic Acid and β-Cyclodextrin », Macromolecular Chemistry and Physics, vol. 217, nᵒ 14, p. 1620-1628.

  • J. Dubarle-Offner, J. Moussa, H. Amouri, B. Jouvelet, L. Bouteiller, et M. Raynal, « Induced Circular Dichroism in Phosphine Gold(I) Aryl Acetylide Urea Complexes through Hydrogen-Bonded Chiral Co-Assemblies », Chemistry – A European Journal, vol. 22, nᵒ 12, p. 3985-3990.
    Résumé : Phosphine gold(I) aryl acetylide complexes equipped with a central bis(urea) moiety form 1D hydrogen-bonded polymeric assemblies in solution that do not display any optical activity. Chiral co-assemblies are formed by simple addition of an enantiopure (metal-free) complementary monomer. Although exhibiting an intrinsically achiral linear geometry, the gold(I) aryl acetylide fragment is located in the chiral environment displayed by the hydrogen-bonded co-assemblies, as demonstrated by induced circular dichroism (ICD).
    Mots-clés : ARC, gold complexes, induced circular dichroism, POLE 1, POLE 4, POLYMERES, sergeants and soldiers, supramolecular chirality, supramolecular polymers.

  • A. Giustiniani, P. Guégan, M. Marchand, C. Poulard, et W. Drenckhan, « Generation of Silicone Poly-HIPEs with Controlled Pore Sizes via Reactive Emulsion Stabilization », Macromolecular Rapid Communications, vol. 37, nᵒ 18, p. 1527-1532.

  • L. Goujard, P. - J. Roumanet, B. Barea, Y. Raoul, F. Ziarelli, J. L. Petit, N. Jarroux, E. Ferré, et P. Guégan, « Evaluation of the Effect of Chemical or Enzymatic Synthesis Methods on Biodegradability of Polyesters », Journal of Polymers and the Environment, vol. 24, nᵒ 1, p. 64-71.
    Résumé : This work compares the biodegradability of polyesters produced by an esterification reaction between glycerol and oleic di-acid (D 18:1) issued from green chemical pathways, via either classical thermo-chemical methods, or an enzymatic method using the immobilized lipase of Candida antartica B (Novozym 435). An elastomeric polymer synthesized by enzymatic catalysis is more biodegradable than an elastomeric thermo-chemical polyester synthesized by a standard chemical procedure. This difference lies in percentage of the dendritic motifs, in values of the degree of substitution, and certainly in cross-links inducing an hyper-branched structure less accessible to the lipolytic enzymes in a waste treatment plant. However, when the elastomeric polymer synthesized by enzymatic catalysis is processed at high temperature as required for certain industrial applications, it presents an identical rate of biodegradation than the chemical polyester. The advantages of the thermo-chemical methods are greater speed and lower cost. Enzymatic synthesis appears be suited to producing polyesters, devoid of metallic catalysts, which must be used without processing at high temperature to keep a high biodegradability.
    Mots-clés : POLE 4, POLYMERES.

  • C. Grazon, J. Rieger, P. Beaunier, R. Méallet-Renault, et G. Clavier, « Fluorescent core–shell nanoparticles and nanocapsules using comb-like macromolecular RAFT agents: synthesis and functionalization thereof », vol. 7, nᵒ 25, p. 4272-4283.
    Résumé : Fluorescent nanoparticles and nanocapsules (FNPs) were synthesized via a one-pot RAFT miniemulsion process copolymerizing BODIPY-methacrylate and styrene in water. Ultra-bright sub-100 nm core–shell nanoparticles could be obtained with BODIPY covalently linked in the core, and possessing various shells. The nature and architecture of the particle shells could be tuned by using different macromolecular RAFT (macro-RAFT) agents in the miniemulsion polymerization process. The macro-RAFT agents were composed of poly(ethylene oxide) acrylate (PEOA) and/or acrylic acid (AA), owing to their biocompatibility and functionality respectively, in different proportions. Interestingly, with comb-like macro-RAFT agents comprising a high number of PEOA, nanocapsules were formed, while with linear macro-RAFT agents or with those exhibiting a high number of AA, full core–shell nanoparticles were obtained. For all the structures the control over the polymerization, the size, morphology, and zeta-potential as well as the photophysical properties were measured and compared with FNPs exhibiting a linear PEO-b-PAA block copolymer shell structure (C. Grazon, J. Rieger, R. Méallet-Renault, G. Clavier and B. Charleux, Macromol. Rapid Commun., 2011, 32, 699). Regardless of the shell structures, the brightness of the formed nanoparticles was estimated to be 100–1000 times higher than that of quantum dots. Ultimately, the shell of the different FNPs was functionalized with a second fluorophore via the AA's carboxyl groups. Thus, water-soluble ultra-bright FNPs with two fluorophores in distinct environments (water and in polystyrene) were obtained. They should have great potential for bioimaging applications.
    Mots-clés : POLE 4, POLYMERES.

  • C. T. Howells, K. Marbou, H. Kim, K. J. Lee, B. Heinrich, S. J. Kim, A. Nakao, T. Aoyama, S. Furukawa, J. - H. Kim, E. Kim, F. Mathevet, S. Mery, I. D. W. Samuel, A. A. Ghaferi, M. S. Dahlem, M. Uchiyama, S. Y. Kim, J. W. Wu, J. - C. Ribierre, C. Adachi, D. - W. Kim, et P. André, « Enhanced organic solar cells efficiency through electronic and electro-optic effects resulting from charge transfers in polymer hole transport blends », vol. 4, nᵒ 11, p. 4252-4263.
    Résumé : We demonstrate that blending fluorinated molecules in PEDOT:PSS hole transport layers (HTL) induces charge transfers which impact on both charge extraction and photogeneration within organic photovoltaic (OPV) devices. OPVs fabricated with modified HTL and two photoactive polymer blends led systematically to power conversion efficiencies (PCE) increases, with PTB7:PC70BM blend exhibiting PCE of ∼8.3%, i.e. ∼15% increase compared to pristine HTL devices. A reduced device-to-device characteristics variations was also noticed when fluorinated additives were used to modify the PEDOT:PSS. Shading lights onto the effect of HTL fluorination, we show that the morphology of the polymer:PCBM blends remains surprisingly unaffected by the fluorinated HTL surface energy but that, instead, the OPVs are impacted not only by the HTL electronic properties (work function, dipole layer, open circuit voltage, charge transfer dynamic) but also by alteration of the complex refractive indices (photogeneration, short circuit current density, external quantum efficiencies, electro-optic modelling). Both mechanisms find their origin in fluorination induced charge transfers. This work points towards fluorination as a promising strategy toward combining both external quantum efficiency modulation and power conversion efficiency enhancement in OPVs. Charge transfers could also be used more broadly to tune the optical constants and electric field distribution, as well as to reduce interfacial charge recombinations within OPVs.
    Mots-clés : POLE 4, POLYMERES.

  • B. Isare, S. Pensec, M. Raynal, et L. Bouteiller, « Bisurea-based supramolecular polymers: From structure to properties1 », Comptes Rendus Chimie, vol. 19, nᵒ 1–2, p. 148-156.
    Résumé : This review focuses on the synthesis, self-assembled structure and properties of bisurea-based supramolecular polymers. The straightforward synthetic accessibility of the bisurea synthon has allowed the systematic description of the relationship between the molecular structure and supramolecular assembly. Remarkably, these systems self-assemble at equilibrium into two competing supramolecular structures. Therefore, the assembly of low molar mass bisureas can lead to stimuli responsive viscoelastic gels as well as to systems which are able to report on weak intermolecular interactions. When deposited on surfaces, these hydrogen-bonded chains of molecules form well-organized monolayers in spite of defects from the substrate. Moreover, polymers with improved rheological or adhesive properties can be designed by grafting bisurea stickers.
    Mots-clés : Gels, monolayers, nanostructures, nanotubes, POLE 4, POLYMERES, polymers, Self-assembly, Supramolecular chemistry, Thermodynamics.

  • J. Lazko, T. Sénéchal, A. Bouchut, Y. Paint, L. Dangreau, A. Fradet, M. Tessier, J. M. Raquez, et P. Dubois, « Acid-free extraction of cellulose type I nanocrystals using Brønsted acid-type ionic liquids », Nanocomposites, vol. 2, nᵒ 2, p. 65-75.
    Résumé : Extraction of cellulose type I nanocrystals from cotton fibers was straightforwardly carried out using exclusively Brønsted acid-type ionic liquids (ILs) via a two-step swelling/hydrolysis route, the switch between these two stages being induced by water addition. Since the whole process was achieved in a single reaction medium predominantly based on 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) and 1-(4-sulfobutyl)-3-methylimidazolium hydrogen sulfate ([SBMIM]HSO4), the process parameters were investigated in order to ensure a perfect compatibility and sequencing towards the two-step route proposed here. The impacts on nanoparticle morphology, crystallinity evolution, and cellulose type I to type II denaturation were observed under field-emission gun scanning electron microscopy and corroborated by X-ray diffraction characterizations. ILs recovery and reuse were also demonstrated, opening up new prospects of conception of multi-cycle, environmentally and economically sustainable processes.
    Mots-clés : Cellulose nanocrystals, hydrolysis, Ionic liquids, POLE 4, POLYMERES, Recycling, Swelling.

  • K. J. Lee, J. H. Woo, E. Kim, Y. Xiao, X. Su, L. M. Mazur, A. - J. Attias, F. Fages, O. Cregut, A. Barsella, F. Mathevet, L. Mager, J. W. Wu, A. D'Aléo, et J. - C. Ribierre, « Electronic energy and electron transfer processes in photoexcited donor–acceptor dyad and triad molecular systems based on triphenylene and perylene diimide units », vol. 18, nᵒ 11, p. 7875-7887.
    Résumé : We investigate the photophysical properties of organic donor–acceptor dyad and triad molecular systems based on triphenylene and perylene diimide units linked by a non-conjugated flexible bridge in solution using complementary optical spectroscopy techniques. When these molecules are diluted in dichloromethane solution, energy transfer from the triphenylene to the perylene diimide excited moieties is evidenced by time-resolved fluorescence measurements resulting in a quenching of the emission from the triphenylene moieties. Simultaneously, another quenching process that affects the emission from both donor and acceptor units is observed. Solution ultrafast transient absorption measurements provide evidence of photo-induced charge transfer from either the donor or the acceptor depending upon the excitation. Overall, the analysis of the detailed time-resolved spectroscopic measurements carried out in the dyad and triad systems as well as in the triphenylene and perylene diimide units alone provides useful information both to better understand the relations between energy and charge transfer processes with molecular structures, and for the design of future functional dyad and triad architectures based on donor and acceptor moieties for organic optoelectronic applications.
    Mots-clés : POLE 4, POLYMERES.

  • K. J. Lee, J. H. Woo, Y. Xiao, E. Kim, L. M. Mazur, D. Kreher, A. - J. Attias, K. Matczyszyn, M. Samoc, B. Heinrich, S. Méry, F. Fages, L. Mager, A. D'Aléo, J. W. Wu, F. Mathevet, P. André, et J. - C. Ribierre, « Structure–charge transfer property relationship in self-assembled discotic liquid-crystalline donor–acceptor dyad and triad thin films », vol. 6, nᵒ 63, p. 57811-57819.
    Résumé : The photophysical properties of donor–acceptor (D–A) and donor–acceptor–donor (D–A–D) liquid crystalline dyads and triads based on two different discotic mesogens are examined in thin films by steady-state optical spectroscopy and subpicosecond transient absorption measurements. In these systems, triphenylene and perylene bisimide units are covalently linked by flexible decyloxy chain(s) and act as an electron donor (D) and acceptor (A), respectively. These discotic liquid-crystalline systems form well-separated D and A π-stacked columnar structures in thin films. The absorption spectra of the films indicate an aggregation of the perylene bisimide and triphenylene moieties along the columns. Steady-state photoluminescence measurements show a strong fluorescence quenching that is mainly attributed to a photo-induced charge transfer process taking place between the triphenylene and perylene bisimide units. Subpicosecond transient absorption measurements show that the photoinduced charge transfer (CT) states in the dyad and triad films are formed within 0.3 ps and recombine on a 150–360 ps time scale. In addition, a correlation between the dynamics of the charge recombination process and the spacing distances between D and A units can be established in the dyad and triad films. This study provides important information on the relationship between molecular packing and the charge transfer properties in such self-organized D and A columnar nanostructures.
    Mots-clés : POLE 4, POLYMERES.

  • N. Mansour, K. Hriz, N. Jaballah, D. Kreher, et M. Majdoub, « Synthesis, characterization, optical and electrical properties of bis(phenylvinyl)anthracene-based polymers », Optical Materials, vol. 58, p. 296-305.
    Résumé : A series of bis(phenylvinyl)anthracene-based polymers containing different lengths of polar ethylene glycol groups in the main chain (P1–3) were efficiently synthesized by Wittig polycondensation. These polymers are fully soluble in volatile solvents, which helped a lot to obtain high quality films. Moreover, these semi-conducting materials exhibited semi-crystalline morphology with relatively high glass transition temperature. In this article, the UV–visible absorption and fluorescence properties of P1–3 were studied consequently both in solution and as thin solid film: tan absorption-onset at 433 nm was observed and all these bis(phenylvinyl)anthracene-based polymers (P1–3) show a blue emission in solution, fluorescence quantum efficiencies being respectively 52% for P1, 75% for P2 and 67% for P3. In addition, the HOMO/LUMO energy levels were evaluated by cyclic voltammetry measurements and indicate a p-type semi-conducting materials. Finally

    , the electrical properties of P1–3 were investigated by recording current-tension characteristics and these experimental results were modeled by the current space-charge-limited (SCLC) mechanism.
    Mots-clés : Anthracene, Optical properties, Organic thin layer, POLE 4, polymer synthesis, POLYMERES, Semi-conducting polymer, Space-charge limited current (SCLC).

  • B. Rasolonjatovo, B. Pitard, T. Haudebourg, V. Bennevault, et P. Guégan, « Synthesis of tetraarm star block copolymer based on polytetrahydrofuran and poly(2-methyl-2-oxazoline) for gene delivery applications », European Polymer Journal.
    Résumé : New star shaped block copolymers were synthesized according to a core first strategy, with a hydrophobic polytetrahydrofuran (PTHF) central block and a poly(2-methyl-2-oxazoline) (PMeOx) external block. First, the cationic polymerization of THF was initiated from a tetrafunctional triflate ester synthesized in situ. The chain ends were functionalized by quenching the polymerization with an excess of MeOx, that allowed for the MeOx polymerization under microwave in a subsequent step. Demonstration of the expected structures was carried out at each step of the polymerization. The controlled molar mass of the star copolymers was kept below 5000 g mol−1 in order to mimick the structure of the efficient poloxamines for gene transfer applications. Formulations containing various concentrations of star block copolymers were intramuscularly injected in mice. Efficient gene transfer was measured at formulations with very low concentration of copolymer compared to reference standard containing Lutrol®.
    Mots-clés : CROP, Gene therapy, POLE 4, Poly(2-methyl-2-oxazoline), POLYMERES.

  • E. Ressouche, S. Pensec, B. Isare, G. Ducouret, et L. Bouteiller, « Rational Design of Urea-Based Two-Component Organogelators », ACS Macro Letters, vol. 5, nᵒ 2, p. 244-247.
    Résumé : Low molecular weight gelators are versatile and responsive gel-forming systems. However, it is still a challenge to develop a new organogelator for a precise application, i.e., to gel a predetermined liquid. We propose a simple concept of a two-component gelling system that can be rationally adapted to gel liquids ranging in polarity from silicone oil to acetonitrile.
    Mots-clés : POLE 4, POLYMERES.

  • E. Velasquez, J. Rieger, F. Stoffelbach, F. D'Agosto, M. Lansalot, P. - E. Dufils, et J. Vinas, « Surfactant-free poly(vinylidene chloride) latexes via one-pot RAFT-mediated aqueous polymerization », Polymer.

  • Y. Xiao, X. Su, L. Sosa-Vargas, E. Lacaze, B. Heinrich, B. Donnio, D. Kreher, F. Mathevet, et A. - J. Attias, « Chemical engineering of donor–acceptor liquid crystalline dyads and triads for the controlled nanostructuration of organic semiconductors », vol. 18, nᵒ 25, p. 4787-4798.
    Résumé : Multi-segregated columnar structures provide a geometrically ideal scheme for ambipolar organic semiconductors, but are not easy to design. A set of novel materials with dyad and triad architectures based on 2 different discotic cores is reported and the conditions of emergence of such complex structures are investigated. The designed molecules associate together electron-donor triphenylene cores (D) and perylene or naphthalene diimides as acceptor moieties (A), both entities being linked via alkyl chain spacers. The evaluation in solution of their HOMO/LUMO energy levels by cyclic voltammetry demonstrates the preservation of the individual features of the D and A units. Their thermal and self-organization behaviors were studied by polarized-light optical microscopy, differential scanning calorimetry, temperature-dependent small-angle X-ray scattering and dilatometry, which permitted detailed investigation of the self-organization behaviour. These D–A compounds turned out to spontaneously self-organize into columnar mesophases at room temperature, with the D and A moieties segregated into either alternated stacks within mixed columns or in distinct columns, the latter providing an ideal configuration for 1D hole and electron transport pathways. In view of potential applications of the triad/dyad template, thin films of these self-organized materials were also probed by atomic force microscopy and grazing incidence X-ray scattering.
    Mots-clés : POLE 4, POLYMERES.

  • S. Y, G. C, C. G, R. J, A. Jf, S. B, et M. - R. R, « Rapid and accurate detection of Escherichia coli growth by fluorescent pH-sensitive organic nanoparticles for high-throughput screening applications. », Biosensors & bioelectronics, vol. 75, p. 320-327.
    Résumé : Abstract: Rapid detection of bacterial growth is an important issue in the food industry and for medical research. Here we present a novel kind of...
    Mots-clés : POLE 4, POLYMERES.

  • H. Zrida, K. Hriz, N. Jaballah, H. Hrichi, D. Kreher, et M. Majdoub, « New soluble anthracene-based polymer for opto-electronic applications », Journal of Materials Science, vol. 51, nᵒ 2, p. 680-693.
    Résumé : A new anthracene-based polymer containing the isosorbide group in the side chain (PPVIs-An) has been synthesized via Wittig reaction. The polymer is soluble in common organic solvents and shows good film-forming abilities. The macromolecular structure was characterized by NMR and FT-IR spectroscopies. This organic material was investigated by differential scanning calorimetry and thermogravimetric analysis and showed an amorphous behavior with a Tg of 48 °C. The surface property of the PPVIs-An film was analyzed by contact angle and by atomic force microscopy. The optical properties of this organic semi-conductor were investigated by UV–Visible absorption and photoluminescence spectroscopies. The polymer exhibits a blue fluorescence in dilute solution and a green emission in thin film. The introduction of the polar isosorbide groups shown to improve the PL intensity, and a quantum yield of 72 % was obtained. The absence of π–π interaction between the chromophore units in polymer thin layer at fundamental electronic state was observed, due to the presence of steric repulsions between anthracene and isosorbide groups. The HOMO–LUMO energy levels were determined by cyclic voltammetry. An ITO/PPVIs-An/Al single-layer device was elaborated and investigated using current–voltage measurements which show a turn-on voltage of 5.3 V. The conduction mechanism seems to be a space-charge-limited current with exponential trap distribution at high applied bias voltage. The electrical transport properties of this device were studied as a function of frequency (100 Hz–10 MHz) and applied bias in impedance spectroscopy analyses.
    Mots-clés : POLE 4, POLYMERES.


  • B. Ben Salem, K. Hriz, N. Jaballah, D. Kreher, et M. Majdoub, « New semi-conducting poly(phenylene vinylene-alt-anthrylene vinylene)s: Synthesis, characterization and photophysical properties », Optical Materials, vol. 50, p. 114-122.
    Résumé : An anthracene-based semi-conducting polymer (P1) and its cyano-analogue (P2) were synthesized via the Wittig and Knoevenagel polycondensations. The polymers were soluble in common organic solvents and have number-average molecular weights of 13,750 and 6430 g mol-1 for P1 and P2, respectively. The DSC analyzes show a good thermal stability and an amorphous morphology in solid state for these organic materials. The optical properties of the polymers were investigated by UV-visible absorption and fluorescence spectroscopies. The HOMO and LUMO levels were estimated using cyclic voltammetry analysis. The effect of cyano group on the photophysical properties of poly(phenylene vinylene-alt-anthrylene vinylene)s was investigated. The results demonstrate an enhancement in the ionization potential and a significant improvement of the fluorescence yield due to introduction of such groups into the π-conjugated system. Single-layer diodes based on these organic semiconductors have been fabricated and showed relatively low turn-on voltages.
    Mots-clés : Anthracene, Optical properties, POLE 4, polymer synthesis, POLYMERES, Semi-conducting polymer, thin films.

  • V. Bennevault, C. Huin, P. Guégan, K. Evgeniya, X. - P. Qiu, et F. M. Winnik, « Temperature sensitive supramolecular self assembly of per-6-PEO-β-cyclodextrin and α,ω-di-(adamantylethyl)poly(N-isopropylacrylamide) in water », vol. 11, nᵒ 32, p. 6432-6443.
    Résumé : The host/guest interactions in water of a star polymer consisting of a β-cyclodextrin (β-CD) core bearing six poly(ethylene oxide) arms linked to the C6 positions of β-CD (β-CD-PEO7, Mn 5000 g mol−1) and α,ω-di-(adamantylethyl)poly(N-isopropylacrylamide) (Ad-PNIPAM-12K, Mn 12000 g mol−1) were studied by 1D and 2D 1H and 13C NMR spectroscopy, isothermal calorimetry (ITC), and light scattering (LS). In cold water (T < 26 °C) supramolecular “dumbbell” assemblies, consisting of PNIPAM chains with β-CD/Ad inclusion complexes at each end, formed via β-CD-insertion of the terminal Ads through the β-CD secondary face. Light scattering, microcalorimetry (DSC), and DOSY NMR studies indicated that mixed aqueous solutions of β-CD-PEO7 and Ad-PNIPAM-12K undergo a reversible heat-induced phase transition at ∼32 °C, accompanied by a release of a fraction of the Ad-bound β-CD-PEO7 into bulk solution and the formation of aggregated Ad-PNIPAM-12K stabilized by a β-CD-PEO7 shell.
    Mots-clés : POLE 4, POLYMERES.

  • F. Bonnet, F. Stoffelbach, G. Fontaine, et S. Bourbigot, « Continuous cyclo-polymerisation of L-lactide by reactive extrusion using atoxic metal-based catalysts: easy access to well-defined polylactide macrocycles », Rsc Advances, vol. 5, nᵒ 40, p. 31303-31310.
    Résumé : The bulk polymerisation of L-lactide was assessed using the alkaline-earth and lanthanide borohydride complexes Mg(BH4)(2) (1), Ca(BH4)(2)(THF)(2) (2) and Ln(BH4)(3)(THF)(3) with Ln = Nd (3), Sm (4) and La (5). All five catalysts display good activities, with up to 77% conversion in 20 min with 5. Lanthanide-based catalysts 3, 4 and 5, which were found to lead to the highest conversions, were tested in reactive extrusion polymerisation conditions in a twin-screw micro-extruder. High activities were also observed in theses experimental conditions, affording up to 73% conversion in only 20 min with lanthanum-based catalyst 5. More interestingly, the polylactides formed display a macrocyclic structure with molecular weights up to 30 000 g mol(-1) along with relatively narrow dispersities (1.23-1.79). The macrocycles are formed via intramolecular transesterification reactions taking place during the ring opening polymerisation. Furthermore, the reactive extrusion polymerisations operate at a temperature as low as 130 degrees C, this monomer usually being polymerized at 185 degrees C. This is the first example of a cyclic polyester obtained directly via a continuous process.
    Mots-clés : borohydride complexes, cyclic esters, epsilon-Caprolactone, initiators, lanthanide borohydrides, POLE 4, POLYMERES, polymers, rac-lactide, ring-opening polymerization, twin-screw extruder, zwitterionic polymerization.

  • J. Bonnet, G. Suissa, M. Raynal, et L. Bouteiller, « Organogel formation rationalized by Hansen solubility parameters: influence of gelator structure », Soft Matter, vol. 11, nᵒ 11, p. 2308-2312.
    Résumé : Some organic compounds form gels in liquids by forming a network of anisotropic fibres. Based on extensive solubility tests of four gelators of similar structures, and on Hansen solubility parameter formalism, we have probed the quantitative effect of a structural variation of the gelator structure on its gel formation ability. Increasing the length of an alkyl group of the gelator obviously reduces its polarity, which leads to a gradual shift of its solubility sphere towards lower δp and δh values. At the same time, its gelation sphere is shifted – to a much stronger extent – towards larger δp and δh values.
    Mots-clés : amide, crystallization, gel properties, insights, mass organic gelators, mixtures, POLE 4, POLYMERES, solvent.

  • X. Callies, C. Fonteneau, C. Véchambre, S. Pensec, J. - M. Chenal, L. Chazeau, L. Bouteiller, G. Ducouret, et C. Creton, « Linear rheology of bis-urea functionalized supramolecular poly(butylacrylate)s: Part I – weak stickers », Polymer, vol. 69, p. 233-240.
    Résumé : We investigated the linear viscoelastic properties in the melt of a series of nearly monodisperse poly(n-butyl acrylate) (PnBA) chains center-functionalized with a bis-urea sticker group, able to self-associate by quadruple hydrogen bonding. All materials are viscoelastic liquids at 40 °C and their Newtonian viscosity varies from 100 to 5000 Pa s. However we show clearly that the viscosity changes non monotonously going through a minimum for a molecular weight (Mn) of 20 kg/mol and a sticker density of 1.1 wt%. We found two regimes: For Mn < 20 kg/mol, the viscosity increases with decreasing Mn, the linear viscoelastic properties change dramatically with temperature, forming a viscoelastic gel at 0 °C and flowing at 40 °C and the strength of the stickers association controls the size of molecular aggregates. However for Mn > 20 kg/mol, the viscosity increases with Mn, the rheology is controlled by the polymer dynamics and the stickers simply increase the terminal relaxation time relative to unfunctionalized PnBA of the same Mn, as expected from sticky reptation theory. Despite clear evidence of sticker–sticker interactions by FTIR, none of the materials self-assemble at 20 °C into structures with a long range order detectable by SAXS.
    Mots-clés : POLE 4, POLYMERES, Reptation, Rheology, Supramolecular.

  • X. Callies, C. Véchambre, C. Fonteneau, S. Pensec, J. - M. Chenal, L. Chazeau, L. Bouteiller, G. Ducouret, et C. Creton, « Linear Rheology of Supramolecular Polymers Center-Functionalized with Strong Stickers », Macromolecules, vol. 48, nᵒ 19, p. 7320-7326.
    Résumé : We investigate the linear viscoelastic properties of a series of low polydispersity poly(n-butyl) acrylate chains center-functionalized with a triurea interacting moiety, able to self-associate by six hydrogen bonds. Depending on the molecular weight (Mn) of the side chains, the polymers can self-associate and form supramolecular structures in the melt state. For Mn < 40 kg/mol, the polymers form large bundles of parallel rods which relax stress as large colloidal objects. For Mn ≥ 40 kg/mol, the self-assembly of stickers form smaller and randomly oriented rods and the viscoelastic properties are mainly governed by the side chains relaxations, as observed for weak stickers. However, in both regimes, the side chains relax at short time scales, and then, the relaxation of fibrillar aggregates follow (by scission or diffusion process) at long time scales. The weak correlation between both relaxation modes makes the tuning of the linear viscoelastic properties relatively easy by varying independently the length of the side chains and the associating strength of the sticker. The good control of the molecular dynamics via the chemical structure makes the supramolecular center-functionalized polymers extremely interesting for materials applications where dissipative rheological behaviors are targeted over large frequencies ranges, such as vibration damping or adhesive applications.
    Mots-clés : POLE 4, POLYMERES.

  • S. Catrouillet, L. Bouteiller, E. Nicol, T. Nicolai, S. Pensec, B. Jacquette, M. Le Bohec, et O. Colombani, « Self-Assembly and Critical Solubility Temperature of Supramolecular Polystyrene Bottle-Brushes in Cyclohexane », Macromolecules, vol. 48, nᵒ 5, p. 1364-1370.
    Résumé : The formation of polystyrene (PS) supramolecular bottle-brushes by self-assembly in cyclohexane of hydrogen-bonding tris(urea) units decorated by PS chains was investigated using light and neutron scattering. Atom transfer radical polymerization (ATRP) was used to control the length of the PS side-chains and allowed the straightforward synthesis of the targeted tris(urea)s. It was shown that their extent of self-assembly strongly depended on the degree of polymerization and chemical nature of the polymer side chains, in contrast with what was previously observed with cyclic oligopeptides, another type of self-assembling units. With sufficiently short PS side-chains, anisotropic supramolecular bottle-brushes could be obtained. Their critical solubility temperature, T-c, was measured in cyclohexane, proving experimentally for the first time that densely grafted PS bottle-brushes exhibit a much lower T-c than linear PS or even star-shaped PS of similar molecular weight.
    Mots-clés : 4-arm star polystyrene, branched polymer, cloud-point curves, coil block-copolymers, cyclic peptide templates, light-scattering, phase-separation, POLE 4, POLYMERES, shape-persistent macrocycles, theta temperature, transfer radical polymerization.

  • L. Dentzer, C. Bray, S. Noinville, N. Illy, et P. Guégan, « Phosphazene-Promoted Metal-Free Ring-Opening Polymerization of 1,2-Epoxybutane Initiated by Secondary Amides », Macromolecules, vol. 48, nᵒ 21, p. 7755-7764.
    Résumé : The in situ generation of an anionic initiator X– obtained by the deprotonation of various secondary amides with tBuP4 phosphazene base was tested as possible way to initiate the polymerization of 1,2-epoxybutane. The initiation efficiency of different amide-containing molecules was investigated. Particular attention was given to the detection of eventual transfer or side reactions, especially due to nucleophilic attacks on the initiator moiety at the α-chain end. In all cases, the initiation of the polymerization by the amidate anion was effective. And in most cases, the polymerization proceeded in a controlled manner to afford amide end-capped poly(butylene oxide) with narrow molar mass distribution and expected molar masses.
    Mots-clés : POLE 4, POLYMERES.

  • A. Desmarchelier, M. Raynal, P. Brocorens, N. Vanthuyne, et L. Bouteiller, « Revisiting the assembly of amino ester-based benzene-1,3,5-tricarboxamides: chiral rods in solution », Chemical Communications, vol. 51, nᵒ 34, p. 7397-7400.
    Résumé : Some benzene-1,3,5-tricarboxamide (BTA) monomers derived from (L) α-amino esters self-assemble into long rods at millimolar concentrations, and display a strong chiral amplification effect. These rods are in competition with dimeric species.
    Mots-clés : amplification, asymmetric catalysis, dynamic supramolecular polymer, helical polymers, molecules, POLE 4, POLYMERES, principle, solvent, stacking, switch.

  • M. Dirany, V. Ayzac, B. Isare, M. Raynal, et L. Bouteiller, « Structural Control of Bisurea-Based Supramolecular Polymers: Influence of an Ester Moiety », Langmuir, vol. 31, nᵒ 42, p. 11443-11451.
    Résumé : A few examples of monomers are known that self-assemble into various high molar mass structures in solution. Controlling the morphology of the resulting supramolecular polymers is a highly desirable goal for many applications. Herein, we compare the self-assembling properties of newly prepared ester bisurea monomers with those of previously investigated alkyl bisurea monomers. The ester functionality decreases the hydrogen bonding strength of the bisurea monomers but does not prevent the formation of long assemblies in nonpolar solvents: gels are formed at millimolar concentration. Surprisingly, ester bisureas self-assemble at room temperature into rod-like urea-bonded supramolecular polymers that are different from the ones formed by alkyl bisureas. The rods formed by ester bisurea supramolecular polymers are compact (instead of tubular in the case of alkyl bisureas) and display two monomers in the cross-section (instead of three in the case of alkyl bisureas). The stability of the structures formed by ester bisureas can be easily tuned by changing the nature of the substituent in the α-position of the urea functions and/or the nature of the alkyl side chains.
    Mots-clés : POLE 4, POLYMERES.

  • M. Dréan, P. Guégan, C. Jérôme, J. Rieger, et A. Debuigne, « Far beyond primary poly(vinylamine)s through free radical copolymerization and amide hydrolysis », vol. 7, nᵒ 1, p. 69-78.
    Résumé : Due to their affinity for many supports, their pH responsiveness, metal binding capacity and polyelectrolyte complexation, poly(vinylamine) derivatives have attracted attention for many applications including coatings, water purification, or gas membrane separation. Nevertheless, most of them possess only pendant primary amines despite the possible benefits of incorporating different amino groups along the chain. In this work, a straightforward and scalable synthesis route towards polymers bearing primary and secondary amines, as well as imidazole groups, is reported. The general strategy relies on the radical copolymerization of different vinylamides and vinyl imidazoles followed by the hydrolysis of the resulting poly(vinylamide) derivatives. Binary and ternary free radical copolymerizations of N-vinylacetamide (NVA), N-methyl vinylacetamide (NMVA) and 1-vinylimidazole (VIm) were investigated and the reactivity ratios for each copolymerization system were determined. Thanks to these values a series of statistical copolymers with predictable composition and low deviation over the chain distribution could then be synthesized. Finally, the acidic hydrolysis of the acetamide functions towards the corresponding amine was performed and optimized. Copolymers containing various pendant amino groups and with low dispersity in the chain composition could be obtained, which opens new perspectives for the above mentioned applications.
    Mots-clés : POLE 4, POLYMERES.

  • P. Du, D. Bléger, F. Charra, V. Bouchiat, D. Kreher, F. Mathevet, et A. - J. Attias, « A versatile strategy towards non-covalent functionalization of graphene by surface-confined supramolecular self-assembly of Janus tectons », Beilstein Journal of Nanotechnology, vol. 6, nᵒ 1, p. 632-639.
    Résumé : A versatile strategy towards non-covalent functionalization of graphene by surface-confined supramolecular self-assembly of Janus tectons
    Mots-clés : POLE 4, POLYMERES.

  • P. Du, D. Kreher, F. Mathevet, P. Maldivi, F. Charra, et A. - J. Attias, « Surface-Confined Supramolecular Self-Assembly of Molecular Nanocranes for Chemically Lifting and Positioning C60 above a Conducting Substrate », ChemPhysChem, vol. 16, nᵒ 18, p. 3774-3778.
    Résumé : 2D supramolecular self-assembly is a good way to form well-defined nanostructures on various substrates. One of the current challenges is to extend this approach to 3D functional building blocks. Here, we address this issue by providing a strategy for the controlled lifting and positioning of functional units above a graphitic substrate. This is the first time that multistory cyclophane-based 3D tectons incorporating C60 units have been designed and synthesized. Molecular modelling provides a description of the 3D geometries and evidences the flexible character of the building blocks. Despite this later feature, the supramolecular self-assembly of Janus tectons on HOPG yields well-ordered adlayers incorporating C60 arrays at well-defined mean distances from the surface. As our approach is not limited to C60, the results reported here open-up possibilities for applications where the topological and electronic interactions between the substrate and the functional unit are of prime importance.
    Mots-clés : cyclophanes, Fullerenes, molecular modeling, POLE 4, POLYMERES, scanning probe microscopy, Self-assembly.

  • 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 », ResearchGate, vol. 46, nᵒ 2, p. 283-297.
    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.

  • J. Lesage de La Haye, J. - M. Guigner, E. Marceau, L. Ruhlmann, B. Hasenknopf, E. Lacôte, et J. Rieger, « Amphiphilic Polyoxometalates for the Controlled Synthesis of Hybrid Polystyrene Particles with Surface Reactivity », Chemistry – A European Journal, vol. 21, nᵒ 7, p. 2948-2953.
    Résumé : Amphiphilic organo-polyoxometalates (POMs) used in the radical emulsion polymerization of styrene allowed the preparation in aqueous medium of stable 50–100 nm polystyrene–POM composite latexes. Thanks to the presence of a trithiocarbonate group in the POM amphiphile, POMs could be covalently linked to the polymer particle surface. The chemical and catalytic integrity of the POMs was confirmed, and the POM-mediated surface photoactivity of the latexes was demonstrated by the spatially controlled nucleation of silver nanoparticles at the periphery of the composites.
    Mots-clés : amphiphiles, emulsion polymerization, GOBS, hybrid materials, photocatalysis, POLE 3, POLE 4, POLYMERES, Polyoxometalates.

  • L. Mbotchak, C. Le Morvan, K. L. Duong, B. Rousseau, M. Tessier, et A. Fradet, « Purification, Structural Characterization, and Modification of Organosolv Wheat Straw Lignin », Journal of Agricultural and Food Chemistry, vol. 63, nᵒ 12, p. 5178-5188.
    Résumé : Biolignin, a wheat straw lignin produced by acetic acid/formic acid/water hydrolysis, was characterized by P-13 and C-13-H-1 2D NMR spectroscopy and by size-exclusion chromatography. Biolignin is a mixture of lbw molar ins compounds (M-n = 1660 g/mol), made up of S, G, and H units and of coumaric and ferulic acid units. beta-5 and beta-O-4 interunit linkages are partially acylated in the gamma-position by acetate and p-coumarate groups. Deacylated samples with a low content of contaminants were obtained by combining alkaline hydrolysis and solvent extraction. The high phenolic OH content found by P-31 NMR reflects the presence of condensed aromatic units, such as 5-5 units. Reaction of purified lignin with ethanol and ethane-1,2-diol yielded esterified lignins much more soluble than Biolignin in common organic solvents. During this reaction, the secondary OH beta-O-4 linkages was simultaneously etherified. Phenol hydrox

    yethylation by 2-chloroethanol yielded samples containing only aliphatic hydroxyl groups.
    Mots-clés : accurate, acids, composites, engineering plastics, ester, esterification, etherification, foams, NMR, oxypropylation, plants, POLE 4, POLYMERES, polyurethanes, wheat straw lignin, wood.

  • F. Nzulu, S. Telitel, F. Stoffelbach, B. Graff, F. Morlet-Savary, J. Lalevée, L. Fensterbank, J. - P. Goddard, et C. Ollivier, « A dinuclear gold(I) complex as a novel photoredox catalyst for light-induced atom transfer radical polymerization », Polym. Chem., vol. 6, nᵒ 25, p. 4605-4611.

  • J. Potier, S. Menuel, J. Lyskawa, D. Fournier, F. Stoffelbach, E. Monflier, P. Woisel, et F. Hapiot, « Thermoresponsive self-assembled cyclodextrin-end-decorated PNIPAM for aqueous catalysis », Chemical Communications, vol. 51, nᵒ 12, p. 2328-2330.
    Résumé : The catalytic performance of thermoresponsive poly(N-isopropylacrylamide) ( PNIPAM) functionalized at the terminal position with randomly methylated beta-cyclodextrin was demonstrated by the aqueous Rh-catalysed hydroformylation of higher olefins.
    Mots-clés : 2-phase hydroformylation, biphasic hydroformylation, complexes, higher alkenes, higher olefins, Ligands, organometallic catalysis, phase-transfer agents, Pickering emulsions, POLE 4, POLYMERES, water.

  • B. Rasolonjatovo, J. - P. Gomez, W. Meme, C. Goncalves, C. Huin, V. Bennevault-Celton, T. Le Gall, T. Montier, P. Lehn, H. Cheradame, P. Midoux, et P. Guegan, « Poly(2-methyl-2-oxazoline)-b-poly(tetrahydrofuran)-b-poly(2-methyl-2-oxa zoline) Amphiphilic Triblock Copolymers: Synthesis, Physicochemical Characterizations, and Hydrosolubilizing Properties », Biomacromolecules, vol. 16, nᵒ 3, p. 748-756.
    Résumé : Block copolymers assembled into micelles have gained a lot of attention to improve drug delivery. The recent drawbacks of the poly(ethylene oxide) blocks (PEO) contained in amphiphilic pluronics derivatives made of a central poly(propylene oxide) block surrounded by two PEO blocks were recently revealed, opening the way to the design of new amphiphilic block copolymers able to self-assemble in water and to entrap molecules of interest. Here, a family of p(methyloxazoline)-b-p(tetrahydrofuran)-b-p(methyloxazoline) triblock copolymers (called TBCP) is synthesized using cationic ring opening polymerization. Studies of micelle formation using dynamic light scattering, isothermal titration calorimetry (ITC), NMR diffusion-ordered spectroscopy (DOSY), and fluorescence experiments lead us to draw a relationship between copolymer structure and the physicochemical properties of the block copolymers (critical micellar concentration (CMC), Nagg, core diameter, shell thickness, etc.). The packing parameter of the block copolymers indicates the formation of a core-corona structure. Hydrosolubilizing properties of TBCPs were exemplified with curcumin selected as a highly insoluble drug model. Curcumin, a natural polyphenolic compound, has shown a large spectrum of biological and pharmacological activity, including anti-inflammatory, antimicrobial, antioxidant, and anticarcinogenic activities. An optimized formulation process reveals that the aggregation number is the parameter affecting drug encapsulation. Patch clamp experiments carried out to study the interaction of TBCP with the cell membrane demonstrate their permeation property suitable to promote the cellular internalization of curcumin.
    Mots-clés : aqueous-solutions, block-copolymers, drug-delivery, nanoparticles, oxide), pluronic micelles, POLE 4, poly(ethylene glycol), POLYMERES, polymeric micelles, solubilization, turmeric curcuma-longa.

  • R. Shokri, O. Guskova, A. Jamal, K. Jahanshahi, B. Isare, L. Bouteiller, L. Simon, J. - U. Sommer, et G. Reiter, « Consequences of a Single Double Bond within a Side Group on the Ordering of Supramolecular Polymers », The Journal of Physical Chemistry C, vol. 119, nᵒ 39, p. 22596-22603.
    Résumé : By combining atomic force microscopy experiments and full-atomistic computer simulations, we compared the two-dimensional ordering dynamics of two variants of supramolecular polymers of bis-urea molecules which differed only by a single cis-double bond in their side groups. At early stages of ordering, the double bonds favored kinks at the level of individual molecules, which induced transient steric constraints hindering the spontaneous formation of long supramolecular polymers. In addition, due to these kinks, molecule?substrate interactions were disturbed. At later stages, however, due to a progressively increasing number of established directional hydrogen bonds between molecules, the self-assembly process improved and thereby increased the length of the supramolecular polymers. Large domains of micrometer-long and aligned supramolecular polymers were formed, epitaxially guided by the graphite substrate and having a constant width consistent with the length of the molecule. Thus, introducing flexible (kinked) side chains can reduce the nucleation probability and slow the growth of supramolecular polymers due to incommensurablility with the crystalline substrate. Such an elementary control of nucleation and growth via the introduction of a single double bond represents a powerful pathway for the formation of large ordered domains of aligned one-dimensional supramolecular polymers.
    Mots-clés : POLE 4, POLYMERES.

  • J. Swiergiel, L. Bouteiller, et J. Jadżyn, « Hierarchical Structure of Supramolecular Polymers Formed by N,N′-Di(2-ethylhexyl)urea in Solutions », The Journal of Physical Chemistry B, vol. 119, nᵒ 40, p. 12947-12953.
    Résumé : Supramolecular chain polymers formed by N,N?-di(2-ethylhexyl)urea (EHU) dissolved at low concentrations (up to 0.1 mole fraction) in heptane were investigated with the use of the dielectric spectroscopy. The experimental data show an exceptional ability of the chains for the antiparallel self-aggregation due to dipole?dipole interactions, leading to an anomalous dependence of the static permittivity of EHU + heptane solutions on temperature and concentration of the urea. The primary molecular assembly into polymeric chains is therefore followed by a secondary bundling of the chains which facilitates a longitudinal translation of the chains. That peculiarity and an asymmetry of the alkyl substituent in the EHU molecule making the system a mixture of diastereoisomers of unfavorable packing of the side group, are the most probable molecular mechanisms which prevent the crystallization of EHU?the only known liquid urea derivative.
    Mots-clés : POLE 4, POLYMERES.

  • J. Świergiel, L. Bouteiller, et J. Jadżyn, « Electrical conductivity studies for hydrogen-bonded supramolecular polymer formed by dialkylurea in non-polar solvent », Electrochimica Acta, vol. 170, p. 321-327.
    Résumé : The electrical features of the supramolecular hydrogen-bonded polymers formed by N,N′-di(2-ethylhexyl)urea (EHU) in non-polar medium were investigated with the use of the impedance spectroscopy. It was found that the thermal activation energy of the direct current electrical conductivity is independent of the medium viscosity in a large range of EHU mole fraction (0.3 &lt; x ≤ 1), in full analogy to behavior of the activation energy of the dipolar relaxation time of the entities resulting from the thermally stimulating breaking of the hydrogen bonds chains. Besides, in that urea concentration range one observes the correlation between the relaxation times of the charge carriers translation and the dipolar entities rotation. The presented data point out for the participation of the protons, released in the acts of the hydrogen bonds breaking, in the electrical conductivity of the studied supramolecular system.
    Mots-clés : Hydrogen bonding, Impedance spectroscopy, N,N′-di(2-ethylhexyl)urea, POLE 4, POLYMERES, Proton conductivity, Supramolecular polymer.

  • S. Teka, K. Hriz, N. Jaballah, D. Kreher, F. Mathevet, N. Jarroux, et M. Majdoub, « New semi-conducting rotaxane based on β-cyclodextrin and anthracene moieties », Materials Science in Semiconductor Processing, vol. 34, p. 189-197.
    Résumé : A new rotaxane (BPAAn/β-CD), consisting of an anthracene-based semi-conducting material (BPAAn) encapsulated into β-cyclodextrin (β-CD), has been synthesized via the Williamson reaction in solvent-free conditions. The supramolecular structure of the compound was confirmed by NMR and FT-IR spectroscopies. The optical and morphological properties of this organic material were investigated by UV–visible absorption, photoluminescence spectroscopy and atomic force microscopy. BPAAn/β-CD film has an optical gap of 2.9 eV and exhibits green photoluminescence. An optical gap of 2.9 eV was estimated from the absorption edge of the rotaxane thin film. The BPAAn/β-CD exhibits a blue photoluminescence in dilute solution; whereas, a green emission was observed in the solid state, due to the π–π interaction in the anthracene moieties. The rotaxane shows a significantly enhanced PL quantum yield and improved film quality in comparison with the free BPAAn. The HOMO and LUMO levels were estimated using cyclic voltammetry analysis, and show enhanced electron affinity of the BPAAn in its complexed form. A single-layer device with the configuration [ITO/rotaxane/Aluminum] has been elaborated and showed low turn-on voltage of 5 V.
    Mots-clés : photoluminescence, POLE 4, POLYMERES, Rotaxane, Semi-conducting material, Thin film morphology., β-Cyclodextin.

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