CNRS Macromolecular Chemistry and Physics Laboratory

Nancy, France

CNRS Macromolecular Chemistry and Physics Laboratory

Nancy, France

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Collin D.,Charles Sadron Institute | Covis R.,Charles Sadron Institute | Allix F.,CNRS Macromolecular Chemistry and Physics Laboratory | Jamart-Gregoire B.,CNRS Macromolecular Chemistry and Physics Laboratory | Martinoty P.,Charles Sadron Institute
Soft Matter | Year: 2013

The liquid to organogel transition of solutions containing new organogelator molecules of the amino-acid type is studied using rheological and differential scanning calorimetry (DSC) techniques. This paper describes the formation of the organogel as a function of the temperature for various concentrations of the organogelator molecules, and the mechanical properties of the organogel as a function of concentration, frequency, thermal history and aging. We show that the organogel is not a physical gel, but a jammed suspension. The viscoelastic behavior at different extents of the jamming can be scaled onto a single master curve describing the growth of a solid network in a background fluid. The formation of the solid network exhibits a critical-like behavior that is reminiscent of elasticity percolation. Four characteristic temperatures have been identified: the temperature at which the clusters begin to form, the transition temperature between the liquid and the organogel, the onset temperature of the percolation-like behavior of the solid component of the system and the temperature at which the solid component has a pure elastic response. The comparison between the rheological measurements and the DSC measurements shows that the rheological measurements detect the fluid-to-organogel transition, whereas DSC detects the molecular associations in the material, which are at the origin of the formation of the clusters. The two temperatures differ significantly from each other and their difference gives the temperature range where the clusters are crowding. This study demonstrates for the first time that an organogel is not a physical gel, as it is currently believed, but a jammed suspension. © 2013 The Royal Society of Chemistry.


Boyer C.,University of New South Wales | Whittaker M.R.,University of New South Wales | Nouvel C.,University of New South Wales | Nouvel C.,CNRS Macromolecular Chemistry and Physics Laboratory | Davis T.P.,University of New South Wales
Macromolecules | Year: 2010

This paper describes a new approach for the synthesis of hollow functional polymer nanocapsules, which exploits gold nanoparticles as sacrificial templates. Two different functional diblock polymers have been coassembled on the gold nanoparticles prior to gold removal. The block polymers (made by RAFT polymerization) consisted of a biocompatible polymer segment, either (poly(oligoethylene glycol) acrylate, P(OEG-A), or poly(hydroxylpropylacrylamide), P(HPMA) and a cross-linkable segment comprised of an alternating copolymer of styrene (Sty) and maleic anhydride (MA), (Sty-alt-MA). The block copolymers were assembled onto the GNP surfaces using a grafting "onto" methodology exploiting the high affinity of the RAFT end-groups for the gold surface. The anhydride group was utilized to cross-link the polymer layer. Finally, the gold cores were removed using aqua regia without affecting the integrity of the polymers chains or the nanocapsules. All reaction and assembly steps were characterized by employing a range of techniques, such, as TEM, XPS, ATR-FTIR, DLS, and UV-visible spectroscopy. © 2010 American Chemical Society.


Covis R.,CNRS Macromolecular Chemistry and Physics Laboratory | Desbrieres J.,University of Pau and Pays de l'Adour | Marie E.,CNRS Macromolecular Chemistry and Physics Laboratory | Durand A.,CNRS Macromolecular Chemistry and Physics Laboratory
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2014

Biodegradable polymeric emulsifiers were prepared by covalent attachment of aliphatic hydrocarbon groups onto dextran macromolecules (a bacterial nonionic polysaccharide), varying the number of attached hydrocarbon tails. Submicronic oil-in-water emulsions were prepared by sonication using previous polymeric stabilizers with oil volume fractions between 10 and 50% and two oils (hexadecane and nujol). An optimal range of dextran hydrophobic modification was evidenced conciliating a strong anchoring of polymer to oil/water interface and sufficient steric repulsions between droplets. These results were correlated to dilational rheology of air/water interfaces covered by amphiphilic dextrans. The storage stability of these emulsions was of several weeks. © 2013 Elsevier B.V.


Dupayage L.,CNRS Macromolecular Chemistry and Physics Laboratory | Nouvel C.,CNRS Macromolecular Chemistry and Physics Laboratory | Six J.-L.,CNRS Macromolecular Chemistry and Physics Laboratory
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2011

The synthesis of amphiphilic dextran-g-poly(methyl methacrylate) glycopolymers (Dex-g-PMMA) is studied using "grafting from" concept and atom transfer radical polymerization. Two strategies have been examined to control the macromolecular parameters of such glycopolymers. One is involving four steps including a protection/deprotection approach and the second one only two steps. The introduction of initiators group onto a protected acetylated dextran (and directly onto dextran) was achieved resulting in protected DexAcBr (and in unprotected DexBr). These two types of polysaccharidic macroinitiators differ in term of solubility (hydrophilic DexBr vs. hydrophobic DexAcBr) and of position of the initiators groups on the glucosidic units (which are the sites of the future grafts). When evaluated as macroinitiators for ATRP of MMA, control was achieved in both cases but DexBr gave much faster polymerization and lower average grafting efficiency compared with DexAcBr or model initiator. Advantages and drawbacks of both pathways have finally been discussed. Copyright © 2010 Wiley Periodicals, Inc.


Moussodia R.-O.,CNRS Macromolecular Chemistry and Physics Laboratory | Acherar S.,CNRS Macromolecular Chemistry and Physics Laboratory | Bordessa A.,CNRS Macromolecular Chemistry and Physics Laboratory | Vanderesse R.,CNRS Macromolecular Chemistry and Physics Laboratory | Jamart-Gregoire B.,CNRS Macromolecular Chemistry and Physics Laboratory
Tetrahedron | Year: 2012

Different α-hydrazinoesters with high optical purity have been obtained in large scale via an S N2 protocol. A coupling reaction with a natural amino acid leads to the corresponding dimers, which have been oligomerized in order to obtain the 1:1 [α/α-N α- hydrazino]mer series. Conformational studies show that these mixed oligomers are self-organized in solution via a succession of γ-turn and hydrazinoturn whatever the absolute configuration of the chiral carbons. © 2012 Elsevier Ltd. All rights reserved.


Legrand B.,CNRS Macromolecular Chemistry and Physics Laboratory | Andre C.,Max Mousseron Institute of Biomolecules | Wenger E.,University of Lorraine | Didierjean C.,University of Lorraine | And 4 more authors.
Angewandte Chemie - International Edition | Year: 2012

BAC for more: A constrained bicyclic building block with urea linkages is an efficient combination for the formation of a highly rigid helical system. This type of bicyclic amino carbamoyl (BAC) foldamer was studied both in solution (see scheme) and in the solid state. A robust H-bond (dotted line) network was found between the carbonyl oxygen atoms (red) and the amino groups (dark blue) within the helix. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Duval C.,CNRS Macromolecular Chemistry and Physics Laboratory | Nouvel C.,CNRS Macromolecular Chemistry and Physics Laboratory | Six J.-L.,CNRS Macromolecular Chemistry and Physics Laboratory
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2014

Poly(d,l-lactide-co-glycolide) (PLGA) copolyesters are commonly used in biomedical applications. Researches were carried out on nontoxic or low-toxic catalysts that are enough efficient to provide short polymerization times, adequate microstructure chains and similar properties than the commercial PLGA materials. In this study, PLGA were synthesized by ring-opening copolymerization (ROP) using three different catalysts. Stannous octoate is the first catalyst we used, as it is very efficient, even its toxicity is still on debate. Two others low-toxic catalysts [zinc lactate and bismuth subsalicylate (BiSS)] were also evaluated. The comparison of these ROP was realized in terms of kinetics and control of the polymerization. Then, the influence of the catalyst on the PLGA microstructure chains is reported. Finally, abiotic hydrolytic degradation rate is studied. Results described in this article show that BiSS is one very attractive catalyst to produce low toxic PLGA for biomedical applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1130-1138 Three catalysts (SnOct2, ZnLac2, and BiSS) are compared to produce poly(D,L-lactide-co-glycolide) (PLGA). The linear evolution of Ln([M]0/[M]t) versus time is observed until 95% in the case of bismuth subsalicylate ring-opening (co)polymerization (BiSS-ROP). 13C NMR reveals that PLGA with "short block" microstructures are obtained, and, more precisely, that SnOct2 and BiSS lead to a similar microstructure. Finally, the hydrolytic degradation profile of PLGA depends on their chemical composition, and on the microstructure and catalyst used. Copyright © 2014 Wiley Periodicals, Inc.


Sadtler V.,University of Lorraine | Rondon-Gonzalez M.,University of Lorraine | Acrement A.,University of Lorraine | Choplin L.,University of Lorraine | Marie E.,CNRS Macromolecular Chemistry and Physics Laboratory
Macromolecular Rapid Communications | Year: 2010

This study reports the first PEO-coated polymer nanoparticles synthesis by miniemulsion polymerization of nano-emulsions prepared by the low-energy emulsification method called EIP. The surfactant used was Brij 98, a PEO based non ionic commercial surfactant. The partial phase diagram of the system water/Brij 98/styrene was first determined. The Emulsion Inversion Point technique was then used on the water/Brij 98/styrene system to the formation of styrene-in-water nano-emulsions. After miniemulsion polymerization, particle sizes as low as 36 nm were obtained. To the best of our knowledge, this method had not been used for polymerizable system up to now. (Figure Presented) © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Allix F.,CNRS Macromolecular Chemistry and Physics Laboratory | Curcio P.,CNRS Macromolecular Chemistry and Physics Laboratory | Pham Q.N.,CNRS Macromolecular Chemistry and Physics Laboratory | Pickaert G.,CNRS Macromolecular Chemistry and Physics Laboratory | Jamart-Gregoire B.,CNRS Macromolecular Chemistry and Physics Laboratory
Langmuir | Year: 2010

A comparative IR and NMR study of two low-molecular-weight organogels (LMWGs) based on aminoacid derivatives let us point out the hierarchy of the gelation assembly process. Different association states of corresponding organogelator molecules can be observed leading to the supramolecular organization of gel. A first hydrogen bond network of gelators leads to the formation of "head-to-tail" stacking-up, which can be assembled afterward one to the other by π-π stacking interactions. These small supramolecular aggregates (incipient precursor) are still visible in NMR spectra, and they represent, for example, 36% of the total amount of gelator in the case of the L-phenylalanine derivative (gelator 1) at 1 wt % in toluene. Finally, in the last step, the incipient precursor tends to form the expected 3D fibrillar network responsible for the gelation phenomenon. Temperature- dependent IR and NMR experiments allowed us to identify these different states clearly. © 2010 American Chemical Society.


Moulay S.,CNRS Macromolecular Chemistry and Physics Laboratory
Progress in Polymer Science (Oxford) | Year: 2010

Poly(vinyl chloride) (PVC) has continued to be a research topic in polymer science since its discovery in the early 19th century. Its internal structural defects, which stem from its direct manufacture (via free radical polymerization), heighten its peculiarities, including its thermal instability. Apart from the addition of organic and inorganic thermal stabilizers, improved chemistry in the formation of PVC has been proposed to alleviate some of its intrinsic limiting properties. This chemistry, mainly via the chemical transformations of this polymeric material, has been broadened by widespread ongoing research. The so-called anomalous or labile chlorine atoms, that is, the tertiary and allylic chlorines, and the normal secondary ones coupled with a varying content of carbon-carbon double bonds, have been subjected to numerous chemical modifications. The latter were undertaken not only for routine chemical reactions, but also for the sake of enhancing the properties, understanding PVC-related phenomena, and the use of PVC in specific applications. The different reactions on PVC, basically dechlorination, involved nucleophilic and radical substitutions, elimination or dehydrochlorination, and grafting polymerizations via cationic and free radical pathways (old processes or new ones, ATRP and LCRP). Leading and attractive applications of the chemically modified PVCs were ion-selective electrode membranes, membrane sensors, and biomedical devices. In this paper, an account of many of the chemical modifications of PVC based on reports over the last decade is delineated, along with related applications. These modifications are presented according to the bond formed (CPVC-X) between the PVC carbon CPVC and the atom X (X = N, O, S, Hal) of the modifying molecule. © 2009 Elsevier Ltd. All rights reserved.

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