References of "Jérôme, Christine"
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See detailOrganocatalyzed ring-opening polymerization of cyclic phosphate monomers
Clement, Benoît ULg; Vanslambrouck, Stéphanie ULg; Koole, Leo H. et al

Conference (2013, November 19)

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See detail« Product-oriented engineering » applied to the development of porous scaffolds for tissue engineering.
de Bien, Charlotte ULg; Ounally, Thameur; Collard, Valérie ULg et al

Poster (2013, November 15)

Ce travail vise à appliquer une approche « génie-orienté produit » à la fabrication de matrices poreuses synthétiques (scaffolds) susceptibles d’être utilisées en ingénierie tissulaire [1]. Parmi les ... [more ▼]

Ce travail vise à appliquer une approche « génie-orienté produit » à la fabrication de matrices poreuses synthétiques (scaffolds) susceptibles d’être utilisées en ingénierie tissulaire [1]. Parmi les différents polymères biosourcés et biodégradables déjà utilisés pour la fabrication de scaffolds, l’acide polylactique (PLA) a été choisi [2]. Des matrices poreuses ont été obtenues par un procédé de moussage par lyophilisation puis leur microstructure 2D/3D a été caractérisée par microtomographie à rayons X avant d’être mise en lien avec les conditions d’élaboration testées [3]. La diminution de la porosité ainsi que l’augmentation de l’épaisseur des parois avec l’augmentation de rapport polymère/solvant ont été confirmées. [less ▲]

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See detailHigh-quality thin graphene films from fast electrochemical exfoliation
Aqil, Abdelhafid ULg; Ouhib, Farid ULg; Detrembleur, Christophe ULg et al

Poster (2013, November)

Many methods have been developed in the last few decades to obtain high-quality graphene thin sheets. They are based on very different physicochemical processes. Here we demonstrate a novel one step and ... [more ▼]

Many methods have been developed in the last few decades to obtain high-quality graphene thin sheets. They are based on very different physicochemical processes. Here we demonstrate a novel one step and simple electrografting acrylate monomer method to exfoliate highly oriented pyrolytic graphite (HOPG) into thin nanoplatelets and even down to the single graphene sheet level. Among the high research activity in the area of surface modification, electrografting is a very powerful method which has received comparatively little attention. This is surprising because this technique has many attractive features for modification of conducting or semi-conducting surfaces. The main interest of the electrografting process is to solve the recurrent problem of the organic/substrates interface weakness. The electrografting warranties a robust polymer/substrates interface and offers the possibility to tailor the functionality of the grafted polymer film opening the door to a wide range of demanding technological applications. The graphene sheets obtained through electrografting process give a stable suspension in dimethyl formamide (DMF), and they can self-precipitate on the surface of substrates after adding water as an antisolvent due to their strong surface hydrophobicity. Interestingly, the continuous films obtained exhibit ultratransparency (∼98% transmittance), and the lateral size of the exfoliated graphene sheets observed by AFM ~1nm. Raman and TEM characterizations corroborate that the graphene sheets exfoliated by our electrochemical method preserve the intrinsic structure of grapheme and give preferentially monolayered graphene sheets. The electrochemical behaviour of the acrylate monomer grafted graphene sheets was evaluated in lithium-half cells with no addition of conductive additive or binder. The PAN grafted graphene dispersed in DMF was coated on Cu foil and dried in a vacuum oven at 55°C for 12h. After 200 cycles, the reversible capacity was still kept at 300mAh/g at the current density of 50mA/g. These results indicate that the prepared high quality graphene sheets possess good electrochemical performances for lithium storage. This work provides an efficient approach to obtain high-quality, cost-effective, and scalable production of “graphene ink”, which may pave a way toward future applications in lithium- ion batteries. [less ▲]

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See detailCross-linkable polythiophene diblock copolymers: toward high thermally stable organic solar cells
Ouhib, Farid ULg; Tomassetti, Mirco ULg; Manca, Jean et al

Conference (2013, November)

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See detailNovel and simple electrografting monomer method to exfoliate HOPG for lithium-ion batteries
Aqil, Abdelhafid ULg; Ouhib, Farid ULg; Jérôme, Christine ULg et al

Conference (2013, October 28)

Many methods have been developed in the last few decades to obtain high-quality graphene thin sheets. They are based on very different physicochemical processes. Here we demonstrate a novel one step and ... [more ▼]

Many methods have been developed in the last few decades to obtain high-quality graphene thin sheets. They are based on very different physicochemical processes. Here we demonstrate a novel one step and simple electrografting acrylate monomer method to exfoliate highly oriented pyrolytic graphite (HOPG) into thin nanoplatelets and even down to the single graphene sheet level. Among the high research activity in the area of surface modification, electrografting is a very powerful method which has received comparatively little attention. This is surprising because this technique has many attractive features for modification of conducting or semi-conducting surfaces. The main interest of the electrografting process is to solve the recurrent problem of the organic/substrates interface weakness. The electrografting warranties a robust polymer/substrates interface and offers the possibility to tailor the functionality of the grafted polymer film opening the door to a wide range of demanding technological applications. The graphene sheets obtained through electrografting process give a stable suspension in dimethyl formamide (DMF), and they can self-precipitate on the surface of substrates after adding water as an antisolvent due to their strong surface hydrophobicity. Interestingly, the continuous films obtained exhibit ultratransparency (∼98% transmittance), and the lateral size of the exfoliated graphene sheets observed by AFM ~1nm. Raman and TEM characterizations corroborate that the graphene sheets exfoliated by our electrochemical method preserve the intrinsic structure of grapheme and give preferentially monolayered graphene sheets. The electrochemical behaviour of the acrylate monomer grafted graphene sheets was evaluated in lithium-half cells with no addition of conductive additive or binder. The PAN grafted graphene dispersed in DMF was coated on Cu foil and dried in a vacuum oven at 55°C for 12h. After 200 cycles, the reversible capacity was still kept at 300mAh/g at the current density of 50mA/g. These results indicate that the prepared high quality graphene sheets possess good electrochemical performances for lithium storage. This work provides an efficient approach to obtain high-quality, cost-effective, and scalable production of “graphene ink”, which may pave a way toward future applications in lithium- ion batteries. [less ▲]

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See detailMonocatenary, branched, double-headed and bolaform surface active carbohydrate esters via photochemical thiol-ene/-yne reactions
Boyère, Cédric ULg; Broze, Guy ULg; Blecker, Christophe ULg et al

in Carbohydrate Research (2013), 380

An original and versatile method for the synthesis of a range of novel mannose-based surfactants was developed via metal-free photo-induced thiol-ene/-yne “click” reactions. This light-mediated ... [more ▼]

An original and versatile method for the synthesis of a range of novel mannose-based surfactants was developed via metal-free photo-induced thiol-ene/-yne “click” reactions. This light-mediated hydrothiolation reaction involving a thiolated mannose was successfully applied to terminal and internal alkenes, dienes and alkynes, leading to monocatenary, branched, double-headed and bolaform amphiphilic carbohydrate esters,respectively. A surface activity study showed that these new compounds possess valuable properties and display specific behavior at the air-water interface. It also demonstrated the greater flexibility of the thioether moiety in the spacer of the surfactants produced via a thiol-ene reaction in comparison withthe triazole heterocyclic rings in similar glucose-based surfactants synthesized elsewhere by the alkyne-azide 1,3-dipolar addition. [less ▲]

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See detailLe « génie orienté produit » appliqué à l’élaboration de matrices poreuses pour l’ingénierie tissulaire.
de Bien, Charlotte ULg; Ounally, Thameur ULg; Collard, Valérie ULg et al

in Récents Progrès en Génie des Procédés (2013, October 08)

Ce travail vise à appliquer une approche « génie-orienté produit » à la fabrication de matrices poreuses synthétiques (scaffolds) susceptibles d’être utilisées en ingénierie tissulaire. Parmi les ... [more ▼]

Ce travail vise à appliquer une approche « génie-orienté produit » à la fabrication de matrices poreuses synthétiques (scaffolds) susceptibles d’être utilisées en ingénierie tissulaire. Parmi les différents polymères biosourcés et biodégradables déjà utilisés pour la fabrication de scaffolds, l’acide polylactique (PLA) a été choisi. Des matrices poreuses ont été obtenues par un procédé de moussage par lyophilisation puis leur microstructure 2D/3D a été caractérisée par microtomographie à rayons X avant d’être mise en lien avec les conditions d’élaboration testées. La diminution de la porosité ainsi que l’augmentation de l’épaisseur des parois avec l’augmentation de rapport polymère/solvant ont été confirmées. [less ▲]

Detailed reference viewed: 87 (44 ULg)
See detailDesign of novel polyphosphoesters (co)polymers for improving a drug delivery system based on calcium carbonate particles
Ergül, Zeynep ULg; Boury, Frank; Debuigne, Antoine ULg et al

Poster (2013, October)

Biomedical applications, especially drug delivery systems, often require biodegradable and biocompatible materials that permit safe retention as well as controlled delivery of a drug. CaCO3 particles are ... [more ▼]

Biomedical applications, especially drug delivery systems, often require biodegradable and biocompatible materials that permit safe retention as well as controlled delivery of a drug. CaCO3 particles are safe and biodegradable drug carriers that have excellent properties such as low density, high specific surface areas and porosity for drugs microencapsulation. The encapsulation of a model protein within CaCO3 particles has been successfully investigated by Boury and coworkers but the release profiles still need to be improved. In this project, we would like to slow down the kinetics of protein release. One strategy consists in loading the CaCO3 particles with degradable micelles containing the protein/drug in their core. In this perspective, we have developed a novel class of degradable polyphosphoesters (PPE) (co)polymers able to self-assemble into micelles. Note that the degradation products of PPEs, like phosphates, associated with calcium from the inorganic carrier could favor some reconstruction processes like bone regeneration. Pendant carboxylic acid functions were introduced along the backbone of the copolymers in order to increase their affinity for calcium and facilitate their incorporation in the CaCO3 particles. First, an alkynyl-functionalized phospholane monomer, i.e. butynyl phosphate (BYP), was prepared by condensation of 2-chloro-2-oxo-1,3,2-dioxaphospholane and 3-butyn-1-ol (43 % yield), according to a reported procedure. Then, a series of well-defined (Ɖ < 1.2) alkyne-containing PBYP (co)polymers were synthesized by ring opening polymerization using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and thiourea (TU) as catalysts[5] (see scheme below). The structures of the PPE (co)polymers were characterized by 1H NMR, 31P NMR and size exclusion chromatography (SEC). Next, carboxylic acid functions were introduced along the PPE backbone by click-type thiol-yne addition of mercaptopropionic acid onto the pendant alkynes. The degradability of the PPEs was investigated at different pH. In the future, the self-assembly behavior of the PPE-based copolymers will be studied as well as their drug loading capacity and ability to accumulate within the CaCO3 particles. In addition, the acid-bearing PPE-based copolymers will be tested as templating agents for the synthesis of CaCO3 particles. [less ▲]

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See detailDrug delivery systems based on amphiphilic polyphosphate-copolymers
Vanslambrouck, Stéphanie ULg; Clement, Benoît ULg; Riva, Raphaël ULg et al

Poster (2013, September 18)

Thanks to their biocompatibility, biodegradability and their structure similar to natural biomacromoleculesn such as nucleic acids, polyphosphates (PPhos) are of prime interest as biomaterials. In ... [more ▼]

Thanks to their biocompatibility, biodegradability and their structure similar to natural biomacromoleculesn such as nucleic acids, polyphosphates (PPhos) are of prime interest as biomaterials. In contrast to poly--caprolactone and polylactides, PPhos properties and functionality are easily tuned via the nature of the pendant group of the starting cyclic monomer. For example, by varying the length of the alkyl chain the hydrophobicity of the PPhos can be adjusted. In this work, an efficient organo-catalytic system was developed to synthesize a series of amphiphilic diblock copolymers, i.e. poly(ethylene oxide)-b-polyphosphate (PEO-b-PPhos) by ring-opening polymerization of cyclic phosphates. This novel approach prevents metallic residues to polute the final product, and which is highly desirable when biomedical applications are foreseen. For drug delivery application, the micellization of these novel diblock copolymers in aqueous media was investigated, as well as, encapsulation of an hydrophobic drug. Data on, the influence of the polyphosphate nature of the polymer on drug loading will be presented. [less ▲]

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See detailUse of response surface methodology for the optimization of the lipase-catalyzed synthesis of mannosyl myristate in pure ionic liquid
Galonde, Nadine ULg; Brostaux, Yves ULg; Richard, Gaetan ULg et al

in Process Biochemistry (2013), 48(11), 1914-1920

The purpose of the present study is to find the conditions allowing to reach the highest 24 h-yield(24 h- ) for the synthesis of mannosyl myristate catalyzed by the immobilized lipase B from Candida ... [more ▼]

The purpose of the present study is to find the conditions allowing to reach the highest 24 h-yield(24 h- ) for the synthesis of mannosyl myristate catalyzed by the immobilized lipase B from Candida antarctica (Novozym®435) in the ionic liquid (IL) [Bmpyrr][TFO] (1-butyl-1-methylpyrrolidinium tri-fluoromethanesulfonate). A full factorial design (FFD) was used in order to study the influence of three variables (temperature, mannose/vinyl myristate ratio and total substrate quantity) on the 24 h- . This design led to a model based on a second order polynomial response function. The resulting predicted con-tour plots have shown that the highest 24 h- should be obtained with high temperatures, low sugar/vinylester molar ratio and intermediate total substrate quantities (mmol). The model has been successfully verified and experimentally confirmed at the optimal conditions of 80◦C, substrate molar ratio of 1/10and total substrate quantity of 0.26 mmol leading to the highest predicted 24 h- of 72.2%. [less ▲]

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See detailCarbon nanotubes/polypropylene nanocomposites foams for EMI shielding applications
Tran, Minh Phuong ULg; Detrembleur, Christophe ULg; Thomassin, Jean-Michel ULg et al

Conference (2013, September 12)

In order to reduce the undesired effect of the electromagnetic interference, the developing of the materials with high capacity of electromagnetic interference (EMI) shielding has attracted a great ... [more ▼]

In order to reduce the undesired effect of the electromagnetic interference, the developing of the materials with high capacity of electromagnetic interference (EMI) shielding has attracted a great attention to scientific and industrial communities during last two decades.Indeed, polymer carbon nanotubes (CNTs) nanocomposites foams are addressed due to their high electrical conductivity and a great potential applications in electrostatic dissipation (ESD) and in electromagnetic interferences (EMI) shielding. However, the shortcoming of the addition of CNTs is that it usually leads to an increase of permittivity which results in enhancing undesirably the electromagnetic reflectivity due to the mismatch between the wave impedances for the signal propagating into air and into the absorbing material, respectively. To solve this problem, the introduction of air into these nanocomposites by the formation of foam will be favorable in order to reduce the permittivity of conductive composites. A good understanding of the influence of the foam structural parameters on the electrical properties of the foam will ultimately enable the optimum design of these materials for the targeted applications. A wide range of poly (propylene)/CNTs nanocomposites foams were synthesized using the supercritical CO2 technology. Different foaming parameters, such as the temperature, impregnation pressure will be controlled to modify the foam structure. Nanocomposite foams show higher electrical conductivity than non-foamed nanocomposites at the same volume content of CNTs. Effects of foam morphology such as cell density, pore size, volume expansion, and cell-wall thickness on electrical conductivity were comprehensively assessed. Similarly to our previous study on PMMA foam nanocomposites, the electrical conductivity of foams show higher value when the volume expansion is increased and when the average pore size is decreased. The preliminary EMI performances have highlighted that PP/CNTs foams containing 0.1 vol%CNTs are able to absorb about 90% of the incident radiation in the 25 to 40 GHz frequency range. [less ▲]

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See detailMorphology and electrical conductivity of poly(propylene)/multi-walled carbon nanotubes nanocomposites foams compatibilized by poly(propylene) -graft-maleic anhydride (PP-g-MA)
Tran, Minh Phuong ULg; Detrembleur, Christophe ULg; Alexandre, Michaël et al

Poster (2013, September 09)

The agglomerate of carbon nanotubes (CNTs) in poly(propylene) (PP) matrix often results in low electrical conductivity and poor mechanical properties. In order to improve the dispersion of CNTs, different ... [more ▼]

The agglomerate of carbon nanotubes (CNTs) in poly(propylene) (PP) matrix often results in low electrical conductivity and poor mechanical properties. In order to improve the dispersion of CNTs, different amounts of compatibilizer based on poly(propylene-graft-maleic anhydride) (PP-g-MA) were added in the PP matrix. Carbon nanotubes materbatches pre-dispersed at a high loading in the compatibilizer were used to create the samples used in this study. The nanocomposites of PP/PP-g-MA/CNTs were then foamed in supercritical carbon diozide (scCO2) followed by analysis of the foam morphology and the electrical conductivity. The presence of PPgMA did not significantly change the foam morphology, which exhibits good homogeneity and highly uniform closed-cells with penta-heptagonal cell-form. The expansion volume of the foams is not adversely affected by the addition of the compatibilizer; very high expansion volume (around 15 - 25 times) was achieved. The most interesting point is that the PP-PPgMA - 4wt%CNTs foams show a significantly higher electrical conductivity than the uncompatibilized PP-4wt%CNTs at the same volume percent content of CNTs [less ▲]

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See detailSynthesis of poly(vinyl acetate)-based nanogels via cobalt-mediated radical polymerization (CMRP)
Weiss-Maurin, Mathilde ULg; Jérôme, Christine ULg; Taton, Daniel et al

Poster (2013, September 05)

Cobalt-Mediated Radical Polymerization (CMRP) is one of the most efficient techniques to form sequenced copolymers between monomers of very different reactivities(e.g. vinyl acetate and acrylonitrile ... [more ▼]

Cobalt-Mediated Radical Polymerization (CMRP) is one of the most efficient techniques to form sequenced copolymers between monomers of very different reactivities(e.g. vinyl acetate and acrylonitrile). CMRP is used here to synthesize nanogels of poly(vinyl acetate) using different concentrations of cross-linking agent (divinyl adipate). The aim is to determine the structure of the nanogels, in order to use them for the preparation of star-like and/or core-shell structures. [less ▲]

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See detail"Product-oriented engineering" applied to the development of porous scaffolds for tissue engineering.
de Bien, Charlotte ULg; Ounally, Thameur ULg; Collard, Valérie ULg et al

in Procedia Engineering (2013, September 02)

This work applies a “product-oriented engineering” approach to the development of porous scaffolds for tissue engineering. Polylactic acid scaffolds were obtained by a freeze-drying process. Their 2D/3D ... [more ▼]

This work applies a “product-oriented engineering” approach to the development of porous scaffolds for tissue engineering. Polylactic acid scaffolds were obtained by a freeze-drying process. Their 2D/3D microstructure was characterized by X-ray microtomography and related to the operating conditions used. Two types of scaffold end-use properties were characterized in relation to their microstructure: the mechanical and the transport properties. Scaffold young's modulus was computed from data measured on tension-compression devices. To evaluate the permeability, Darcy’s experiments were carried out. The obtained results allowed highlighting the quantitative relationships existing between elaboration conditions, microstructure and end use properties of the fabricated PLA scaffolds. [less ▲]

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See detailTunable self-assembled nanogels composed of well-defined thermoresponsive hyaluronic acid-polymer conjugates
Jing, Jing; Alaimo, David ULg; De Vlieghere, Elly et al

in Journal of Materials Chemistry B (2013), 1(32), 3883-3887

Here we report that grafting temperature-responsive polymers onto hyaluronic acid allows temperature-induced self-assembly into nanogels with tunable size. These nanogels can be easily loaded with ... [more ▼]

Here we report that grafting temperature-responsive polymers onto hyaluronic acid allows temperature-induced self-assembly into nanogels with tunable size. These nanogels can be easily loaded with hydrophobic molecules and hold potential for anti-cancer drug delivery towards human ovarian cancer cells. [less ▲]

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See detailTailor made amphiphilic copolymers for the design of smart drug delivery systems
Riva, Raphaël ULg; Cajot, Sébastien; Jérôme, Christine ULg

Conference (2013, August 21)

Detailed reference viewed: 43 (6 ULg)