References of "Fustin, Charles-André"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailDouble thermo-responsive hydrogels from poly(vinylcaprolactam) containing diblock and triblock copolymers
Thomassin, Jean-Michel ULg; Mathieu, Kevin ULg; Kermagoret, Anthony ULg et al

in Polymer Chemistry (2015), 6(10), 1856-1864

The thermally-induced gelation and gel properties of concentrated aqueous solutions of double thermoresponsive poly(N-vinylamide)-based di- and triblock copolymers are studied by rheology. The copolymers ... [more ▼]

The thermally-induced gelation and gel properties of concentrated aqueous solutions of double thermoresponsive poly(N-vinylamide)-based di- and triblock copolymers are studied by rheology. The copolymers under investigation, prepared by cobalt-mediated radical polymerization and coupling reactions, are composed of poly(vinylcaprolactam) (PNVCL) blocks and of a statistical poly(vinylcaprolactam-stat-vinylpyrrolidone) segment with a cloud point temperature (TCP) higher than that of PNVCL. Heating the di- and triblock solutions beyond the first phase transition temperature favors gel formation while heating above the second TCP leads to opaque gels without macroscopic demixing. Moduli of the triblock hydrogels are systematically higher than those of the corresponding diblocks, even above the second transition. Rheological data suggest distinct micellar structures for each copolymer architecture: densely packed micelles of diblocks and 3-D networks of bridged micelles for triblocks. Strain sweep experiments also emphasize the positive effect of the micelle bridging on the elasticity and stability of the hydrogels. The formation and properties of the obtained gels are also shown to depend on the copolymer concentration, block length, and composition. Addition of salt also allows us to tune the phase transition temperatures of these double thermoresponsive hydrogels. [less ▲]

Detailed reference viewed: 36 (10 ULg)
Full Text
Peer Reviewed
See detailSelf-assembly of a triblock terpolymer mediated by hydrogen-bonded complexes
Guerlain, Claire; Piogé, Sandie; Detrembleur, Christophe ULg et al

in Journal of Polymer Science. Part A, Polymer Chemistry (2015), 53(3), 459-467

A poly(methyl methacrylate)-block-poly(4-vinylpyridine)-block-polystyrene (PMMA-b-P4VP-b-PS) triblock terpolymer is synthesized by ATRP to study its self-assembly with PAA in organic solvents. The self ... [more ▼]

A poly(methyl methacrylate)-block-poly(4-vinylpyridine)-block-polystyrene (PMMA-b-P4VP-b-PS) triblock terpolymer is synthesized by ATRP to study its self-assembly with PAA in organic solvents. The self-assembly behavior of this system is compared with the one of a mixture of two diblocks, namely polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) and poly(methyl methacrylate)-block-poly(methacrylic acid) (PMMA-b-PMAA). For both systems, formation of hydrogen-bonded complexes between the P4VP and PMAA or PAA blocks occurs. These complexes become insoluble in the solvent used and micelles with a P4VP/P(M)AA complexes core surrounded by PS and PMMA coronal chains are obtained in both cases. These micelles are analyzed by DLS and TEM. Spherical micelles are formed for both systems but the hydrodynamic radii obtained for the two types of micelles are different. Indeed, the micelles formed by the PMMA-b-P4VP-b-PS + PAA system are smaller than those observed for the PS-b-P4VP + PMMA-b-PMAA system. Finally, the effect of the molar ratio of the P4VP/PMAA complexing blocks is investigated. [less ▲]

Detailed reference viewed: 14 (1 ULg)
Full Text
Peer Reviewed
See detailStimuli-responsive behavior of micelles prepared from a poly(vinyl alcohol)-block-poly(acrylic acid)-block-poly(4-vinylpyridine) triblock terpolymer
Poggi, Elio; Guerlain, Claire; Debuigne, Antoine ULg et al

in European Polymer Journal (2015), 62

A poly(vinyl alcohol)-block-poly(acrylic acid)-block-poly(4-vinylpyridine) triblock terpolymer (PVOH-b-PAA-b-P4VP) is prepared by hydrolyzing a poly(vinyl acetate)-block-poly(acrylonitrile)-block-poly(4 ... [more ▼]

A poly(vinyl alcohol)-block-poly(acrylic acid)-block-poly(4-vinylpyridine) triblock terpolymer (PVOH-b-PAA-b-P4VP) is prepared by hydrolyzing a poly(vinyl acetate)-block-poly(acrylonitrile)-block-poly(4-vinylpyridine) precursor (PVAc-b-PAN-b-P4VP) synthesized by a combination of cobalt-mediated radical polymerization (CMRP) and nitroxide mediated polymerization (NMP). The PVOH-b-PAA-b-P4VP terpolymer is further micellized in water and the accordingly obtained micellar structures are characterized by a combination of dynamic light scattering (DLS) and cryo-transmission electron microscopy (cryo-TEM) as a function of pH. Well-defined micelles are observed in the whole pH range except for pH values below 4.5 where non-aggregated chains (unimers) are present. The formation of micelles can be rationalized by the formation of insoluble PAA/P4VP inter-polyelectrolyte complexes in the 4.5–6 pH range while hydrophobic P4VP cores are observed at pH values above 6. Finally, the effect of the addition of different salts on the micellar characteristic features is investigated. [less ▲]

Detailed reference viewed: 21 (3 ULg)
Full Text
Peer Reviewed
See detailDouble thermoresponsive di- and triblock copolymers based on N-vinylcaprolactam and N-vinylpyrrolidone: synthesis and comparative study of solution behaviour
Kermagoret, Anthony ULg; Mathieu, Kevin ULg; Thomassin, Jean-Michel ULg et al

in Polymer Chemistry (2014), 5(22), 6534-6544

Poly(N-vinylcaprolactam) (PNVCL) and poly(N-vinylpyrrolidone) (PNVP) are water soluble polymers of interest especially in the biomedical field. Moreover, PNVCL is characterized by a lower critical ... [more ▼]

Poly(N-vinylcaprolactam) (PNVCL) and poly(N-vinylpyrrolidone) (PNVP) are water soluble polymers of interest especially in the biomedical field. Moreover, PNVCL is characterized by a lower critical solution temperature close to 36 °C in water, which makes it useful for the design of thermoresponsive systems. In this context, we used the cobalt-mediated radical polymerization (CMRP) and reaction coupling (CMRC) for synthesizing a series of well-defined NVCL and NVP-based copolymers, including statistical copolymers as well as double thermoresponsive diblocks and triblocks. Dynamic light scattering and turbidimetry analyses highlighted the crucial impact of the copolymer composition and architecture on the cloud point temperature (TCP) of each segment and also their influence on the multistep assembly behaviour of block copolymers. Addition of NaCl enabled us to adjust the inter-TCP range of the di- and triblock in which selective precipitation of one block and self-assembly of the copolymer were favoured. Overall, data presented here provide a basis for the synthesis of a broad range of NVCL/NVP based copolymer architectures with a tunable thermal response in water. [less ▲]

Detailed reference viewed: 29 (7 ULg)
Full Text
Peer Reviewed
See detailProbing the mobility of catenane rings in single molecules
Van Quaethem, Anne; Lussis, Perrine; Leigh, David A. et al

in Chemical Science (2014), 5

Detailed reference viewed: 10 (0 ULg)
Full Text
See detailMetallo-supramolecular micellar gels: a structural study
Mugemana, Clément; Joset, Arnaud ULg; Guillet, Pierre et al

Poster (2013, July 10)

Detailed reference viewed: 48 (6 ULg)
Full Text
See detailDesign of well-defined N-vinylamides based copolymers via organometalllic-mediated radical polymerization
Debuigne, Antoine ULg; Kermagoret, Anthony ULg; Fustin, Charles-André et al

Conference (2013, June 19)

Detailed reference viewed: 23 (4 ULg)
Full Text
See detailMetallo-supramolecular micellar gels: a structural study
Mugemana, Clément; Joset, Arnaud ULg; Guillet, Pierre et al

Conference (2013, May 17)

Detailed reference viewed: 15 (1 ULg)
Full Text
Peer Reviewed
See detailOne-pot controlled synthesis of double thermoresponsive N-vinylcaprolactam-based copolymers with tunable LCSTs
Kermagoret, Anthony ULg; Fustin, Charles-André; Bourguignon, Maxime et al

in Polymer Chemistry (2013), 4(8), 2575-2583

N-Vinylcaprolactam (NVCL) was copolymerized statistically for the first time in a controlled manner with hydrophilic N-vinylamide or hydrophobic vinylester monomers in order to precisely tune up and down ... [more ▼]

N-Vinylcaprolactam (NVCL) was copolymerized statistically for the first time in a controlled manner with hydrophilic N-vinylamide or hydrophobic vinylester monomers in order to precisely tune up and down the lower critical solution temperature (LCST) of the resulting copolymers. The incorporation of these segments in complex architectures was also considered. Several narrowly distributed NVCL-based copolymers were prepared by cobalt-mediated radical polymerization (CMRP) using the bis-(acetylacetonato)cobalt(II) complex as a controlling agent and N-methyl-N-vinylacetamide (NMVA), N-vinylacetamide (NVA), vinyl acetate (VAc) or vinyl pivalate (VPi) as comonomers. PNVCL-containing block copolymers having two discrete LCSTs were also synthesized following a one-pot strategy based on the sequential CMRP of NVCL followed by the copolymerization of NMVA with the residual NVCL. Upon gradual heating of aqueous solutions of such double thermoresponsive copolymers, we noticed a transition from free chains to micelles before full dehydration and collapse of the block copolymers. These advances represent a significant step towards the development of a platform based on thermoresponsive PNVCL copolymers with a single phase separation or multistep assembly behaviors. [less ▲]

Detailed reference viewed: 60 (18 ULg)
Full Text
See detailSynthesis in scCO2 of nano-hydrogels for proteins delivery
Alaimo, David ULg; Grignard, Bruno ULg; Fustin, Charles-André et al

Conference (2012, November 14)

Detailed reference viewed: 26 (5 ULg)
Full Text
Peer Reviewed
See detailNanoporous thin films from ionically connected diblock copolymers
Yu, Haizhou; Stoffelbach, François; Detrembleur, Christophe ULg et al

in European Polymer Journal (2012), 48(5), 940-944

An ionically connected polystyrene-block-poly(ethylene oxide) diblock copolymer (PS−+PEO) has been prepared by blending a PEO block functionalized by a dimethylamino group at one extremity with a sulfonic ... [more ▼]

An ionically connected polystyrene-block-poly(ethylene oxide) diblock copolymer (PS−+PEO) has been prepared by blending a PEO block functionalized by a dimethylamino group at one extremity with a sulfonic acid terminated PS block. Proton transfer occurs from the sulfonic acid to the dimethylamino group, resulting in the formation of an ion pair acting as a junction between the two polymer blocks. This copolymer was further used to prepare thin films with a cylindrical morphology consisting of PEO cylinders embedded in a PS matrix and oriented perpendicularly to the film surface. Nanoporous thin films with sulfonate groups on the pore walls have been finally obtained after solvent extraction of the PEO microphases. The presence of those sulfonate groups was evidenced by grafting a positively charged fluorescent dye on the pore walls. [less ▲]

Detailed reference viewed: 19 (3 ULg)
Full Text
Peer Reviewed
See detailOrganometallic-mediated radical polymerization: unusual route toward (quasi-) diblock graft copolymers starting from a mixture of monomers of opposed reactivity
Hurtgen, Marie ULg; Debuigne, Antoine ULg; Fustin, Charles-André et al

in Macromolecules (2011), 44(12), 4623-4631

Graft copolymers have been prepared by one-step organometallic-mediated radical polymerization (OMRP) for the first time. Poly(ethylene glycol) acrylate (PEGA) was copolymerized with vinyl acetate (VAc ... [more ▼]

Graft copolymers have been prepared by one-step organometallic-mediated radical polymerization (OMRP) for the first time. Poly(ethylene glycol) acrylate (PEGA) was copolymerized with vinyl acetate (VAc) to yield well-defined P(PEGA-grad-VAc) gradient graft copolymers using bis(acetylacetonato)cobalt(II) as the control agent. The influence of experimental parameters such as the PEGA/VAc molar ratio, the nature of the initiator, and the temperature on the control of the copolymerization was discussed. The use of an excess of cobalt complex appeared as a key parameter to maintain a good level of control when higher contents of acrylate were used in the comonomer feed. The reactivity ratios were estimated and revealed that PEGA was added around 30 times faster than VAc, which gave access to a gradient P(PEGA-grad-VAc) copolymer or to a P(PEGA-grad-VAc)-b-PVAc diblock copolymer when the VAc polymerization was pursued after the full consumption of PEGA. The amphiphilic character of the copolymers makes them prone to self-assemble into micelles in water, as evidenced by dynamic light scattering. [less ▲]

Detailed reference viewed: 59 (12 ULg)
See detailNovel graft copolymers by organometallic-mediated radical polymerization of a conjugated with a non-conjugated monomer
Hurtgen, Marie ULg; Debuigne, Antoine ULg; Fustin, Charles-André et al

Scientific conference (2011, February 24)

Detailed reference viewed: 22 (2 ULg)
Full Text
See detailCobalt-mediated radical copolymerization of conjugated and non-conjugated monomers
Hurtgen, Marie ULg; Debuigne, Antoine ULg; Fustin, Charles-André et al

in Polymer Preprints (2011), 52(2), 626-627

Detailed reference viewed: 21 (7 ULg)
Full Text
Peer Reviewed
See detailA single synthetic small molecule that generates force against a load
Lussis, Perrine ULg; Svaldo Lanero, Tiziana ULg; Bertocco, Andrea et al

in Nature Nanotechnology (2011), 6

Some biomolecules are able to generate directional forces by rectifying random thermal motions. This allows these molecular machines to perform mechanical tasks such as intracellular cargo transport or ... [more ▼]

Some biomolecules are able to generate directional forces by rectifying random thermal motions. This allows these molecular machines to perform mechanical tasks such as intracellular cargo transport or muscle contraction in plants and animals. Although some artificial molecular machines have been synthesized and used collectively to perform mechanical tasks, so far there have been no direct measurements of mechanical processes at the single-molecule level. Here we report measurements of the mechanical work performed by a synthetic molecule less than 5 nm long. We show that biased Brownian motion of the sub-molecular components in a hydro- gen-bonded [2]rotaxane—a molecular ring threaded onto a molecular axle—can be harnessed to generate significant directional forces. We used the cantilever of an atomic force microscope to apply a mechanical load to the ring during single-molecule pulling–relaxing cycles. The ring was pulled along the axle, away from the thermodynamically favoured binding site, and was then found to travel back to this site against an external load of 30 pN. Using fluctuation theorems, we were able to relate measurements of the work done at the level of individual rotaxane molecules to the free-energy change as previously determined from ensemble measurements. The results show that individual rotaxanes can generate directional forces of similar magnitude to those generated by natural molecular machines. [less ▲]

Detailed reference viewed: 132 (39 ULg)
See detailBiomimetic coatings with robust antibacterial properties
Jérôme, Christine ULg; Cécius, Michaël; Faure, Emilie ULg et al

Conference (2010, July 01)

Detailed reference viewed: 26 (4 ULg)