72 results on '"Michel Schappacher"'
Search Results
52. Synthesis of (poly(chloroethyl vinyl ether)-g-polystyrene)comb-b-(poly(chloropyran ethoxy vinyl ether)-g-polyisoprene)comb copolymers and study of hyper-branched micelle formation in dilute solutions
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Redouane Borsali, Michel Schappacher, David Lanson, Alain Deffieux, Laboratoire de Chimie des polymères organiques (LCPO), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Institut de Chimie du CNRS (INC), Team 1 LCPO : Polymerization Catalyses & Engineering, Laboratoire de Chimie des Polymères Organiques (LCPO), and Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)
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Polymers and Plastics ,TRANSFER RADICAL POLYMERIZATION ,Ether ,02 engineering and technology ,ATRP ,010402 general chemistry ,COIL BLOCK-COPOLYMERS ,01 natural sciences ,Micelle ,Styrene ,Inorganic Chemistry ,chemistry.chemical_compound ,AGGREGATION BEHAVIOR ,Polymer chemistry ,Materials Chemistry ,Copolymer ,medicine ,BRUSH AMPHIPHILIC COPOLYMERS ,CYLINDRICAL BRUSHES ,Organic Chemistry ,ANIONIC-POLYMERIZATION ,Vinyl ether ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Solvent ,[CHIM.POLY]Chemical Sciences/Polymers ,chemistry ,GRAFT-COPOLYMERS ,Alkoxy group ,Polystyrene ,MOLECULAR BRUSHES ,POLYMERS ,0210 nano-technology ,medicine.drug - Abstract
International audience; Poly(styrene)comb-b-poly(isoprene)comb copolymers having a heterofunctional polyvinyl ether diblock backbone were synthesized by the grafting onto method. Their synthesis involves in a first step the selective coupling reaction of polystyryllithium chains onto the reactive chloroether functions of a poly(chloroethyl vinyl ether) first block while the second block poly(pyranethoxy vinyl ether) remains unchanged, yielding Poly(styrene)comb with a poly(pyranethoxy vinyl ether) tail. In a second step, living polyisoprenyllithium chains are grafted onto the second block previously modified to introduce reactive chlorobutyl functions. The obtained high molar masses PScomb-b-PIcomb copolymers exhibit a low polydispersity and a controlled number of branches. Their characteristics and behavior were further studied as isolated objects using imaging technique such as atomic force microscopy and using light scattering in a good solvent for PS and PI moieties, and in a selective solvent of PIcomb blocks. The PScomb-b-PIcomb copolymers adopt a cylindrical conformation in good solvent and self-assemble in micelles by association of the combPS blocks in heptane.
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- 2007
53. Application of living ionic polymerizations to the design of AB-type comb-like copolymers of various topologies and organizations
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Fumi Ariura, David Lanson, Michel Schappacher, Redouane Borsali, Alain Deffieux, RICHARD, Dominique, Laboratoire de Chimie des polymères organiques (LCPO), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Institut de Chimie du CNRS (INC), Team 1 LCPO : Polymerization Catalyses & Engineering, Laboratoire de Chimie des Polymères Organiques (LCPO), and Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)
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[CHIM.POLY] Chemical Sciences/Polymers ,Materials science ,topology ,Polymers and Plastics ,General Chemical Engineering ,Nanochemistry ,Ionic bonding ,Ether ,02 engineering and technology ,polystyrene ,010402 general chemistry ,Living cationic polymerization ,01 natural sciences ,polyisoprene ,chemistry.chemical_compound ,comb-like copolymers ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Living anionic polymerization ,Organic Chemistry ,fungi ,Cationic polymerization ,organization ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,[CHIM.POLY]Chemical Sciences/Polymers ,chemistry ,living anionic polymerization ,Polystyrene ,0210 nano-technology - Abstract
ISSN: 1598-5032; International audience; Living anionic and cationic polymerizations have been combined to prepare various types of comb-like copolymers composed of polystyrene (PS) and polyisoprene (PI) blocks, with a precisely controlled architecture. According to the relative placement of these elementary building blocks, combs with randomly distributed PS and PI or with poly(styrene-b-isoprene) diblock branches (I & II, respectively) can be prepared. The reaction procedure initially includes the synthesis of a poly(chloroethylvinyl ether) using living cationic polymerization, which is used as the reactive backbone to successively graft PS-Li+ and PI-Li+ or PI-b-PS-Li+ to obtain structures (I) or (II). The synthesis of Janus-type PS-comb-b-PI-combs (III) initially involves the synthesis of a diblock backbone using living cationic polymerization, which bears two distinct reactive functions having either a protected or activated form. Living PS-Li+ and PI-Li+ are then grafted, in two separate steps, onto each of the reactive functions of the backbone, respectively.
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- 2007
54. Water-soluble dendrigrafts bearing saccharidic moieties: elaboration and application to enzyme linked OligoSorbent Assay (ELOSA) diagnostic tests
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Marie-Therese Charreyre, Michel Schappacher, Julien Bernard, Thierry Delair, Roberto Lazzaroni, Marie-Helene Charles, Alain Deffieux, Philippe Viville, Laboratoire de Chimie des polymères organiques (LCPO), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Institut de Chimie du CNRS (INC), Team 1 LCPO : Polymerization Catalyses & Engineering, Laboratoire de Chimie des Polymères Organiques (LCPO), Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC), Laboratory for Chemistry of Novel Materials, Université de Mons (UMons), Systèmes Macromoléculaires et Physiopathologie Humaine (SMPH), and BIOMERIEUX-Centre National de la Recherche Scientifique (CNRS)
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Dendrimers ,Vinyl Compounds ,Stereochemistry ,Biomedical Engineering ,Pharmaceutical Science ,saccharidic functions ,Molecular Probe Techniques ,Bioengineering ,Ether ,02 engineering and technology ,010402 general chemistry ,diagnostic functionalization ,01 natural sciences ,chemistry.chemical_compound ,medicine ,nucleic acid probes ,Pharmacology ,chemistry.chemical_classification ,dendrigrafts ,oligonucleotides ,Chemistry ,Oligonucleotide ,Organic Chemistry ,Galactose ,Water ,Polymer ,Vinyl ether ,021001 nanoscience & nanotechnology ,Combinatorial chemistry ,0104 chemical sciences ,[CHIM.POLY]Chemical Sciences/Polymers ,Polymerization ,Solubility ,Covalent bond ,immobilization ,Polystyrenes ,0210 nano-technology ,Oligonucleotide Probes ,DNA ,Biotechnology ,medicine.drug ,Conjugate ,Ethers - Abstract
International audience; The synthesis of a series of water-soluble galactopyranose-functionalized polystyrene-polyvinyl ether dendrigrafts and their characterization (in solution and thin solid deposits) have been achieved. The presence of external galactopyranose groups on dendritic polymers has been exploited to prepare dendrigraft-oligonucleotide conjugates using a simple one-step coupling procedure with amino-ended oligonucleotides (ODNs). Several parameters such as the peripherical density of hydrophilic branches, the polymerization degree of polystyrene or poly(hydroxyethyl vinyl ether) blocks, and the number of galactopyranose groups were tuned. A capture test with short labeled complementary ODNs (25 bases) confirmed the presence of covalently bound ODNs on various kinds of dendrigrafts. The ability of the dendritic polymers to enhance the sensitivity of enzyme-linked oligosorbent assay (ELOSA) diagnostic tests (detection of hepatitis B virus, DNA target of 2400 bases) was then evaluated, especially the influence of the macromolecular architecture and the impact of the structural parameters. The dendrigraft-ODN conjugate with the lower saccharide external density was found to lead to a very significant amplification of the fluorescence signal, corresponding to a limit of sensitivity of 10(9) DNA copies per milliliter (instead of 10(11) DNA copies per milliliter without using dendrigrafts). Conversely, the dendrigrafts exhibiting a very high number of branches and galactopyranose groups at their periphery were not able to induce a better sensitivity due to steric hindrance generated by the peripheral congestion on these polymers.
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- 2006
55. Micellar aggregation in blends of linear and cyclic poly(styrene-b-isoprene) diblock copolymers
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Redouane Borsali, Nadia Ouarti, Jean-Luc Putaux, Roberto Lazzaroni, Michel Schappacher, Alain Deffieux, Edson Minatti, Pascal Viville, Univ Mons, Belgique, Serv Chim Mat Nouveaux, Université de Mons (UMons), Univ Fed Santa Catarina, Dept Quim, Univ Fed Santa Catarina, Laboratoire de Chimie des polymères organiques (LCPO), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Institut de Chimie du CNRS (INC), Team 1 LCPO : Polymerization Catalyses & Engineering, Laboratoire de Chimie des Polymères Organiques (LCPO), Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC), Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Team 3 LCPO : Polymer Self-Assembly & Life Sciences, and Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)
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SELECTIVE SOLVENTS ,WORMLIKE MICELLES ,Materials science ,HOMOPOLYMER BLENDS ,ORDERED STRUCTURE ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Micelle ,Styrene ,chemistry.chemical_compound ,EXCLUDED-VOLUME INTERACTIONS ,PHASE-EQUILIBRIA ,Dynamic light scattering ,BLOCK-COPOLYMER ,Polymer chemistry ,Electrochemistry ,Copolymer ,General Materials Science ,Thermal stability ,ComputingMilieux_MISCELLANEOUS ,Spectroscopy ,SMALL-ANGLE NEUTRON ,Molar mass ,Surfaces and Interfaces ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,LIGHT-SCATTERING ,0104 chemical sciences ,[CHIM.POLY]Chemical Sciences/Polymers ,chemistry ,Chemical engineering ,Transmission electron microscopy ,Volume fraction ,0210 nano-technology ,FORMING COPOLYMERS - Abstract
International audience; The morphology of micelles formed from blends of linear and cyclic poly(styrene-b-isoprene) (PS-b-PI) block copolymers has been investigated in solution using dynamic light scattering (DLS) and in thin solid deposits by atomic force microscopy (AFM) and transmission electron microscopy under cryogenic conditions (cryo-TEM). Micelles of the pure cyclic PS290-b-PI110 copolymers are wormlike cylindrical objects built by unidirectional aggregation of 33 nm wide sunflower micelles, while the linear block copolymer having the same volume fraction and molar mass forms spherical micelles 40 nm in diameter. The DLS, AFM, and cryo-TEM results consistently show that the addition of the linear copolymer (even for amounts as low as 5% w/w) to the cyclic copolymer rather favors the formation of spherical micelles at the expense of the cylindrical aggregates. Those results clearly show that the linear block copolymer chains can be used to stabilize the thermodynamically unstable elementary sunflower micelle. The thermal stability of the micelles (from the pure copolymers and from the blends) has been examined in solid deposits with in situ AFM measurements. Coalescence starts at about 70 degrees C, and the surface roughness shows a two-step decrease toward a fully homogeneous and flat structure.
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- 2005
56. Synthesis and properties of PS-PEO core-shell amphiphilic dendrigrafts
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Pascal Viville, Julien Bernard, Alain Deffieux, Roberto Lazzaroni, Michel Schappacher, Laboratoire de Chimie des polymères organiques (LCPO), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Institut de Chimie du CNRS (INC), Univ Mons, Belgique, Serv Chim Mat Nouveaux, Université de Mons (UMons), Team 1 LCPO : Polymerization Catalyses & Engineering, Laboratoire de Chimie des Polymères Organiques (LCPO), and Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)
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Materials science ,Polymers and Plastics ,02 engineering and technology ,macromolecular substances ,Degree of polymerization ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,Dynamic light scattering ,Amphiphile ,Polymer chemistry ,Materials Chemistry ,Hydroxymethyl ,chemistry.chemical_classification ,Ethylene oxide ,Organic Chemistry ,technology, industry, and agriculture ,Polymer ,021001 nanoscience & nanotechnology ,Grafting ,0104 chemical sciences ,core-shell ,[CHIM.POLY]Chemical Sciences/Polymers ,chemistry ,PEO ,Polystyrene ,dendrigraft ,0210 nano-technology - Abstract
International audience; Water-soluble amphiphilic dendrigrafts constituted of a hydrophobic polystyrene core and a hydrophilic poly(ethylene oxide) shell have been prepared via a 'grafting onto' procedure from polystyrene dendrigraft precursors. The introduction of the surrounding hydrophilic shell was achieved through cyclic trans-acetalization between omega-acetal functionalized branches of the polystyrene precursor and PEO grafts bearing a alpha-bis(hydroxymethyl) chain end (A(2)-PEO). Yields of grafting are strongly affected by the increase of the degree of polymerization of the reactive PEO grafts (respectively, 100, 87, and 38% with A(2)-PEO20, A(2)-PEO100 and A(2)-PEO150). However, paradoxically, only the use of A(2)-PEO100 or A(2)-PEO150 as reactive grafts affords water-soluble dendrigrafts due to higher PEO weight content (respectively, 41 and 36%). The dimensions and the shape of the PScore-PEOshell Polymers were investigated in solution (THF and water) by dynamic light scattering and in the dry state by TEM and AFM.
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- 2005
57. Control of the morphology of linear and cyclic PS-b-PI block copolymer micelles via PS addition
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Edson Minatti, and Alain Deffieux, Michel Schappacher, Nadia Ouarti, Pascal Viville, Roberto Lazzaroni, Redouane Borsali, Univ Mons, Belgique, Serv Chim Mat Nouveaux, Université de Mons (UMons), Univ Fed Santa Catarina, Dept Quim, Univ Fed Santa Catarina, Laboratoire de Chimie des polymères organiques (LCPO), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Institut de Chimie du CNRS (INC), Team 1 LCPO : Polymerization Catalyses & Engineering, Laboratoire de Chimie des Polymères Organiques (LCPO), Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC), and Team 3 LCPO : Polymer Self-Assembly & Life Sciences
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WORMLIKE MICELLES ,Materials science ,ACID) ,02 engineering and technology ,Degree of polymerization ,010402 general chemistry ,01 natural sciences ,Micelle ,ANGLE NEUTRON-SCATTERING ,PHASE-BEHAVIOR ,VESICLES ,chemistry.chemical_compound ,Dynamic light scattering ,Polymer chemistry ,Electrochemistry ,Copolymer ,DILUTE-SOLUTION ,General Materials Science ,SURFACTANTS ,DRUG-DELIVERY ,Spectroscopy ,Heptane ,Surfaces and Interfaces ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,DIBLOCK COPOLYMERS ,[CHIM.POLY]Chemical Sciences/Polymers ,chemistry ,Polymerization ,Chemical engineering ,Polystyrene ,Self-assembly ,0210 nano-technology ,MULTIPLE MORPHOLOGIES - Abstract
International audience; We have studied the effect of polystyrene (PS) homopolymer addition on the morphology of self-assembled block copolymer micelles made from linear or cyclic poly(styrene-b-isoprene), PS-b-PI, in a selective solvent for the PI block (heptane). Both copolymers have the same composition: the degree of polymerization is 290 for the PS block, and 110 for the PI block, and we focused on the influence of the addition of small amounts of PS homopolymer on the micellar morphology. For the copolymer concentrations considered, the linear copolymer self-organizes into spherical micelles while the cyclic copolymer forms cylindrical micelles. PS and PI chains constitute the core and the corona of these micelles, respectively, due to the different affinity of the blocks for heptane. Consequently, the PS homopolymer added is "solubilized" into the micellar core. Dynamic light scattering (DLS) data combined with atomic force microscopy (AFM) results show that the addition of PS homopolymer induces a drastic change in the micellar organization. Indeed, a morphological transition, from spheres to cylinders for the linear copolymer, and from cylinders to vesicles for the cyclic copolymer, is observed. These results highlight the fact that a small incorporation of PS homopolymer is clearly sufficient to modify the morphology (size and shape) of the micelles. This approach could be a key parameter for the design/control of micelles for specific applications in nanotechnology.
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- 2005
58. Vesicles made of PS-PI cyclic diblock copolymers: in situ freeze-drying cryo-TEM and dynamic light scattering experiments
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Christelle Lefebvre, Jean-Luc Putaux, Michel Schappacher, Alain Deffieux, Edson Minatti, Redouane Borsali, Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Univ Fed Santa Catarina, Dept Quim, Univ Fed Santa Catarina, Laboratoire de Chimie des polymères organiques (LCPO), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Université Sciences et Technologies - Bordeaux 1-Institut de Chimie du CNRS (INC), Team 3 LCPO : Polymer Self-Assembly & Life Sciences, Laboratoire de Chimie des Polymères Organiques (LCPO), Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Polytechnique de Bordeaux-Ecole Nationale Supérieure de Chimie, de Biologie et de Physique (ENSCBP)-Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC), and Team 1 LCPO : Polymerization Catalyses & Engineering
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SELECTIVE SOLVENTS ,Materials science ,CONCENTRATED-SOLUTIONS ,ACID) BLOCK-COPOLYMERS ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Micelle ,ANGLE NEUTRON-SCATTERING ,AQUEOUS-SOLUTION ,Dynamic light scattering ,Polymer chemistry ,Copolymer ,DILUTE-SOLUTION ,Physical and Theoretical Chemistry ,POLYSTYRENE-BLOCK-POLY(ETHYLENE PROPYLENE) COPOLYMER ,DRUG-DELIVERY ,Molar mass ,Aqueous solution ,TRANSMISSION ELECTRON-MICROSCOPY ,Vesicle ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,[CHIM.POLY]Chemical Sciences/Polymers ,Chemical engineering ,Transmission electron microscopy ,Volume fraction ,0210 nano-technology ,MULTIPLE MORPHOLOGIES - Abstract
International audience; We have studied the morphology of self-assembled micelles made of linear and cyclic poly(styrene-b-isoprene) PS-b-PI block copolymers dispersed in selective solvents of the PI block (n-heptane, n-decane). Up to a copolymer concentration of 5 mg mL(-1), the micelles made from linear block copolymer chains adopt a spherical shape. Those arising from cyclic copolymer chains having exactly the same molar mass and volume fraction self-assemble into (i) planar sun. ower-shaped particles at low concentration (c < 0.1 mg mL(-1)), (ii) giant wormlike micelles at intermediate concentration (0.1 mg mL(-1) < c < 2 mg mL(-1)) and (iii) vesicles at higher concentration (2 mg mL(-1) < c < 5 mg mL(-1)). Those results were obtained using dynamic light scattering and in situ freeze-drying cryo-transmission electron microscopy. In this contribution, we discuss the effects of concentration and temperature on the morphology of the self-assembled particles made from both linear and cyclic PS-PI copolymers, and highlight the surprising vesicle formation in cyclic block copolymer solutions.
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- 2005
59. From sunflower-like assemblies toward giant wormlike micelles
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Redouane Borsali, Pascal Viville, Edson Minatti, Roberto Lazzaroni, Theyencheri Narayanan, Alain Deffieux, Michel Schappacher, Jean-Luc Putaux, Centre de Recherches sur les Macromolécules Végétales (CERMAV), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)
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Molar mass ,Morphology (linguistics) ,Materials science ,Vesicle ,Dispersity ,02 engineering and technology ,Surfaces and Interfaces ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Micelle ,0104 chemical sciences ,Solvent ,Chemical engineering ,Polymer chemistry ,Electrochemistry ,Copolymer ,General Materials Science ,Lamellar structure ,0210 nano-technology ,Spectroscopy ,ComputingMilieux_MISCELLANEOUS - Abstract
One of the most interesting and fascinating solution properties of block copolymers is their ability to self-assemble into micelles, lamellar aggregates, and vesicles. Such organized structures have made diblock copolymers of great importance in nanotechnology applications.1-11 For instance, the spontaneously formed vesicles in water are potentially useful as vehicles for delivering drugs and as biomimetic models of biological cells. We show here for the first time that the cyclization of a linear copolymer chain induces a remarkable change in the micellar morphology. This result is highlighted in the case of linear and cyclic polystyrene−polyisoprene (PS−PI) diblock copolymers having exactly the same molar weight and dispersed in a selective solvent for PI. The micelles arising from linear diblock copolymers exhibit a monodisperse spherical shape (50 nm in diameter) whereas those formed from cyclic copolymers are long (>1 μm) cylindrical (wormlike) objects resulting from the unidirectional self-assembly ...
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- 2003
60. Synthesis and characterization of water-soluble amphipatic polystyrene-based dendrigrafts
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Pascal Viville, Roberto Lazzaroni, Alain Deffieux, Jean-Luc Putaux, Michel Schappacher, Centre de Recherches sur les Macromolécules Végétales (CERMAV), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), and Carret, Michèle
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chemistry.chemical_classification ,Polymers and Plastics ,Organic Chemistry ,Cationic polymerization ,Ether ,Polymer ,Vinyl ether ,Living cationic polymerization ,Inorganic Chemistry ,chemistry.chemical_compound ,Anionic addition polymerization ,chemistry ,Polymer chemistry ,Materials Chemistry ,Copolymer ,medicine ,Polystyrene ,ComputingMilieux_MISCELLANEOUS ,medicine.drug - Abstract
New water-soluble amphipatic hyperbranched organic polymers composed of a hydrophobic polystyrene core and a hydrophilic shell have been synthesized and characterized. An arborescent polystyrene core is first synthesized by the “graft-on-graft” technique based on the iterative grafting of end-functional polystyryllithium chains onto reactive poly(chloroethyl vinyl) ether backbones. Chain-extension of the external branches of the hyperbranched polystyrene is then achieved by living cationic polymerization of protected hydrophilic vinyl ethers. This yields polystyrene dendrigrafts surrounded by a dense poly(vinyl ether) shell that is made hydrophilic by deprotection of hydroxyl functions of vinyl ether units. The obtained nanometer-sized macromolecular structures are fully soluble in aqueous media and present unimodal and narrow size distribution with an average diameter of about 100 nm. The dimensions and shape of the individual macromolecules before and after the deprotection step were further investigate...
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- 2003
61. Recent Advances in the Design of Branched Polymeric Architectures
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Alain Deffieux, Michel Schappacher, Daniel Taton, Yves Gnanou, and Valérie Héroguez
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chemistry.chemical_classification ,chemistry.chemical_compound ,Materials science ,Monomer ,Molar mass ,Polymer science ,chemistry ,Polymerization ,Atom-transfer radical-polymerization ,Intrinsic viscosity ,Copolymer ,Polymer - Abstract
In recent years it has become clear that the future of polymer chemistry and of the polymer industry lies more in improving existing polymers rather than discovering new monomers. Thus, the focus has now turned towards the synthesis of either novel or better controlled architectures through “living” polymerization mechanisms.
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- 2002
62. Functional Polymers with Various Macrocyclic Chain Architectures and Well-Defined Dimensions
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Laurence Rique-Lurbet, Michel Schappacher, and Alain Deffieux
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Valinomycin ,chemistry.chemical_compound ,Membrane ,chemistry ,Amphiphile ,Molecule ,Biological membrane ,Functional polymers ,Ring (chemistry) ,Combinatorial chemistry ,Ion channel - Abstract
Natural macrocycles represent a broad class of medium to large size molecules which actively contribute to numerous biological and chemical processes. Their cyclic architecture, generally associated to a special arrangement of comonomer units allow them to play very specific and sophisticated roles in complex reaction pathways. For example, Valinomycin shown in Figure 1 possesses inner/outer amphiphilic ring chain properties which makes it able to complex organic alkali salts. It may be regarded as one of the natural forerunners of large size crown ethers. Amphotericin, Figure 2a, presents an amphiphilic diblock-type cyclic architecture. The latter allows the formation of ion channels across biological membranes through which salts can be transported. Via this function Amphotericin can manifest antibiotic properties. Other large size macrocycles with a distinct diblock-type amphiphilic structure are also found in living systems. The one shown in Figure 2b, is a constituent of the lipidic membrane of bacteria which grow in very hard conditions (pH=2, 85°C), thus suggesting that cell wall stability can be reinforced by cyclic molecular architecture.
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- 1995
63. Comb Copolymers with Polystyrene and Polyisoprene Branches: Effect of Block Topology on Film Morphology.
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David Lanson, Fumi Ariura, Michel Schappacher, Redouane Borsali, and Alain Deffieux
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- 2009
- Full Text
- View/download PDF
64. Precise Synthesis and Characterization of Fourth-Generation Dendrimer-like Star-Branched Poly(methyl methacrylate)s and Block Copolymers by Iterative Methodology Based on Living Anionic Polymerization.
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Akira Hirao, Takumi Watanabe, Koji Ishizu, Moonhor Ree, Sangwoo Jin, Kyeong Sik Jin, Alain Deffieux, Michel Schappacher, and Stéphane Carlotti
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- 2009
- Full Text
- View/download PDF
65. Poly(styrene)comb-b-Poly(ethylene oxide)comb Copolymers: Synthesis and AFM Investigation of Intra- and Supramolecular Organization as Thin Deposits.
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David Lanson, Michel Schappacher, Redouane Borsali, and Alain Deffieux
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- *
DISINFECTION & disinfectants , *EPOXY compounds , *ETHYLENE oxide , *COPOLYMERS - Abstract
PScomb-block-PEOcomb copolymers having a poly(chloroethyl vinyl ether)-b-poly(hydroxy ethyl vinyl ether) backbone with polystyrene chains on one side and poly(ethylene oxide) chains on the other, i.e. (PCEVE-g-PS)-b-(POHEVE-g-PEO), were synthesized. The strategy is based on grafting of polystyryllithium onto the reactive chloro functions of the poly(chloroethyl vinyl ether) first block and on grafting polyethylene oxide from the hydroxyl functions of the second block. This procedure allows the preparation of densely grafted amphiphilic diblocklike, Janus-type, comblike copolymers with high molar masses and narrow polydispersity.The characteristics and dimensions of isolated (PCEVE-g-PS)-b-(POHEVE-g-PEO) macromolecules were studied by light scattering in THF, a good solvent of both PS and PEO branches, as well as using AFM imaging of highly diluted deposits. Unimolecular rodlike nano-objects with distinct PS and PEO domains were observed, in agreement with their diblocklike structure. In relation with their amphiphilic nature, the combs can self-assemble in different morphologies. When graphite deposits are made from more concentrated methylene dichloride solutions, the PScomb-b-PEOcomb copolymers self-assemble directly on the substrate, forming flowerlike molecular aggregates interconnected by their PEO moieties. When deposits are made from a selective solvent (methanol) of the PEO comb block, hyperbranched micelles formed in the solution retain their structure on the solid substrate, yielding well-defined spherical objects. [ABSTRACT FROM AUTHOR]
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- 2007
- Full Text
- View/download PDF
66. Synthesis of (Poly(chloroethyl vinyl ether)-g-polystyrene)comb-b-(poly(chloropyran ethoxy vinyl ether)-g-polyisoprene)comb Copolymers and Study of Hyper-Branched Micelle Formation in Dilute Solutions.
- Author
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David Lanson, Michel Schappacher, Redouane Borsali, and Alain Deffieux
- Subjects
- *
ORGANIC compounds , *ETHERS , *VINYL ethers , *COPOLYMERS - Abstract
Poly(styrene)comb-b-poly(isoprene)comb copolymers having a heterofunctional polyvinyl ether diblock backbone were synthesized by the grafting onto method. Their synthesis involves in a first step the selective coupling reaction of polystyryllithium chains onto the reactive chloroether functions of a poly(chloroethyl vinyl ether) first block while the second block poly(pyranethoxy vinyl ether) remains unchanged, yielding Poly(styrene)comb with a poly(pyranethoxy vinyl ether) tail. In a second step, living polyisoprenyllithium chains are grafted onto the second block previously modified to introduce reactive chlorobutyl functions. The obtained high molar masses PScomb-b-PIcomb copolymers exhibit a low polydispersity and a controlled number of branches. Their characteristics and behavior were further studied as isolated objects using imaging technique such as atomic force microscopy and using light scattering in a good solvent for PS and PI moieties, and in a selective solvent of PIcomb blocks. The PScomb-b-PIcomb copolymers adopt a cylindrical conformation in good solvent and self-assemble in micelles by association of the combPS blocks in heptane. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
67. Vesicles made of PS-PI cyclic diblock copolymers: In situ freeze-drying cryo-TEM and dynamic light scattering experiments .
- Author
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Jean-Luc Putaux, Edson Minatti, Christelle Lefebvre, Redouane Borsali, Michel Schappacher, and Alain Deffieux
- Published
- 2004
68. Synthesis, structure, and spectroscopic properties of five-coordinate mercaptoiron(II) porphyrins. Models for the reduced state of cytochrome P450
- Author
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Louis Ricard, E. Bill, Michel Schappacher, Raymond Weiss, R. Montiel-Montoya, Jean-Claude Fischer, and Alfred X. Trautwein
- Subjects
Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,biology ,Chemistry ,X-ray crystallography ,Analytical chemistry ,biology.protein ,Cytochrome P450 ,Crystal structure ,State (functional analysis) ,Physical and Theoretical Chemistry ,Porphyrin - Published
- 1989
69. Models for the reduced states of cytochrome P-450 and chloroperoxidase. Structures of a pentacoordinate high-spin iron(II) mercaptide mesoporphyrin derivative and its carbonyl adduct
- Author
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Michel Schappacher, Christine Caron, Georges Riviere, Andre Mitschler, Louis Ricard, and Raymond Weiss
- Subjects
Cytochrome ,biology ,General Chemistry ,Photochemistry ,Biochemistry ,Catalysis ,Adduct ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,chemistry ,Polymer chemistry ,biology.protein ,Spin (physics) ,Derivative (chemistry) - Published
- 1979
70. Low-valent molybdenum porphyrin derivatives: synthesis and structure of a .pi.-bonded diphenylacetylene adduct of molybdenum(II) (meso-tetra-p-tolylporphyrin)
- Author
-
Michel Schappacher, Jocelyne Colin, Raymond Weiss, Louis Ricard, and André De Cian
- Subjects
biology ,chemistry.chemical_element ,General Chemistry ,biology.organism_classification ,Photochemistry ,Biochemistry ,Porphyrin ,Catalysis ,Adduct ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,chemistry ,Molybdenum ,Polymer chemistry ,Tetra ,Diphenylacetylene - Published
- 1981
71. Low-valent molybdenum porphyrin derivatives: synthesis and X-ray crystal structures of dinitrosyl- and methanol(nitrosyl)-meso-tetra-p-tolylporphyrinatomolydenum(II) benzene solvates
- Author
-
Bernard Chevrier, Raymond Weiss, Michel Schappacher, and Tharcis Diebold
- Subjects
biology ,Inorganic chemistry ,X-ray ,chemistry.chemical_element ,Crystal structure ,biology.organism_classification ,Porphyrin ,Medicinal chemistry ,chemistry.chemical_compound ,chemistry ,Molybdenum ,Molecular Medicine ,Tetra ,Methanol ,Benzene - Abstract
Reduction by zinc amalgam of dichloromolybdenum meso-tetra-p-tolylporphyrin [Mo(ttp)Cl2] under NO leads to two low-valent nitrosyl molybdenum porphyrin derivatives Mo(ttp)(NO)2·C6H6 and Mo(NO)(MeOH)·2C6H6; the molecular structures of both compounds were established by X-ray diffraction.
- Published
- 1979
72. Additions and Corrections - Low-Valent Molybdenum Porphyrin Derivatives: Synthesis and Structure of a π-Bonded Adduct of Molbdenum(II) (meso-Tetra-p-tolylporphyrin)
- Author
-
Louis Ricard, Michel Schappacher, Jocelyne Colin, Raymond Weiss, and André De Cian
- Subjects
biology ,Chemistry ,chemistry.chemical_element ,General Chemistry ,Photochemistry ,biology.organism_classification ,Biochemistry ,Porphyrin ,Catalysis ,Adduct ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Molybdenum ,Polymer chemistry ,Tetra - Published
- 1983
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