References of "Jérôme, Christine"
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See detailFunctional emulsion-templated porous polymers by macromolecular surfactant anchoring strategies
Mathieu, Kevin ULiege; Jérôme, Christine ULiege; Debuigne, Antoine ULiege

Poster (2017, May 22)

Macroporous polymer monoliths with interconnected structures have attracted considerable interest in the fields of supported catalysis, chromatography, water purification, etc. A popular and ... [more ▼]

Macroporous polymer monoliths with interconnected structures have attracted considerable interest in the fields of supported catalysis, chromatography, water purification, etc. A popular and straightforward synthesis approach for such open-cell polymers is based on the polymerization of high internal phase emulsion (HIPE). Advanced functional polyHIPEs were also produced via different post-modification strategies but the latter often consists in tedious multi-step processes. This communication aims at reporting an efficient one-pot macromolecular surfactant-assisted method for the simultaneous synthesis and chemical functionalization of macroporous polyHIPEs. Briefly, amphiphilic block copolymers prepared by nitroxide-mediated radical polymerization (NMP) or reversible addition-fragmentation chain transfer (RAFT) were used as HIPE stabilizers and grafted at the surface of the walls of polyHIPE during the polymerization process. The impact of the controlled radical polymerization mechanism on the porous structure, openness and functionalization of the monoliths will be discussed. This strategy was also implemented with alkyne-terminated copolymers in order to decorate the surface of the polyHIPE’s cavities with “clickable” moieties which broadens the scope of functional macroporous polymers. [less ▲]

Detailed reference viewed: 56 (3 ULiège)
See detailMerging CO2 transformation and utilization with renewable bio-resources: a step forward to a double vision of sustainable chemistry
Grignard, Bruno ULiege; Poussard, Loïc; Raquez, Jean-Marie et al

Conference (2017, May 22)

Valorizing waste CO2 as a cheap, inexhaustible and renewable C1 feedstock is an early stage technology with strong innovation potential that imposes itself as a strategic driver for developing future low ... [more ▼]

Valorizing waste CO2 as a cheap, inexhaustible and renewable C1 feedstock is an early stage technology with strong innovation potential that imposes itself as a strategic driver for developing future low carbon footprints materials. Beside its use as raw chemical, the “physical” valorization of CO2 in a series of industrial cost-efficient processes will also accelerate the development of a low carbon economy and support the elaboration of a global low carbon vision scheme. The synergistic and paradigm-transforming holistic project we propose perfectly illustrates these concepts by encompassing a “cradle” to “grave” vision, i.e. from the products conception from CO2 and bio-resources to their production and processing through sustainable processes compatible with existing industrial relevant infrastructures. It focuses on the elaboration of sustainable isocyanate-free polyurethane foams with promising thermal insulation properties. By its objectives, this study also proposes an ideal alternative to the conventional synthesis of PUs and a practical answer to the challenge the PU sector is facing due to changes in the REACH regulations limiting the use of isocyanates. The success of the project relies on 3 key steps involving: i) The synthesis of bio- and CO2-sourced cyclic carbonates monomers: Due to the low reactivity of CO2 versus epoxides, addition of catalysts is necessary. To overcome this limitation, we developed a new highly-efficient bicomponent homogeneous organocatalyst that showed unexpected activity for the fast (within a few minutes) and selective addition of CO2 onto model epoxides and epoxidized vegetable oil under solvent-free and mild experimental conditions at the multiKg scale. The use of this powerful dual organocatalyst was further extended to the first organocatalytic coupling of CO2 with less reactive oxetanes to produce hydroxyl telechelic oligocarbonate entering the synthesis of CO2-sourced conventional PUs. - The synthesis of sustainable bio- and CO2- sourced isocyanates-free polyurethanes (NIPU): Sustainable NIPUs were produced by step-growth polymerization between the so-produced bio- and CO2-sourced cyclic carbonates and biosourced amino-telechelic comonomers derived from linseed fatty acids according to a process compatible with existing industrial infrastructures (extrusion). - The foaming of NIPUs: Sustainable foams with thermal insulation were produced by the supercritical CO2 assisted foaming technology. Due to its solubility in polymers, CO2 can replace conventional flammable VOCs and ozone depletion physical blowing agents as hydro- or fluorocarbons exhibiting long atmospheric life-time and/or mean global warming potential 2800 higher than CO2. By finely choosing the CO2 impregnation and the foaming conditions, low density microcellular NIPU foams with a thermal conductivity as low as 0.050 Wm-1K-1 were produced. Our study shows that CO2 is not only sequestered in the material for long-term application, but is also valorized as a blowing agent in the production of sustainable thermally insulating NIPU foams. Such low carbon footprints materials will contribute to energy conservation and savings by reducing CO2 emissions. [less ▲]

Detailed reference viewed: 73 (6 ULiège)
See detailSynthesis of cross-linked P(HEMA) particles in supercritical carbon dioxide for protein delivery
Parilti, Rahmet ULiege; Howdle, Steven M.; Jérôme, Christine ULiege

Poster (2017, May 22)

This project aims to develop a novel one-pot strategy to obtain well-defined cross-linked particles able to carry peptides/proteins in their core, as along with targeting and/or imaging agents on their ... [more ▼]

This project aims to develop a novel one-pot strategy to obtain well-defined cross-linked particles able to carry peptides/proteins in their core, as along with targeting and/or imaging agents on their surface. In addition to this objective, polymerisations will be carried out in supercritical carbon dioxide (scCO2), which confers environmentally benign features to the process. Here, we investigate the feasibility of free radical dispersion polymerizations of 2-hydroxyethyl methacrylate (HEMA) in scCO2. In order to ensure the successful dispersion in scCO2 novel diblock CO2-philic surfactants are employed. These diblock surfactants are formed from two different segments, a CO2-phobic block which has an affinity to the growing particles and a second CO2-philic block that ensures surfactant solubility. [less ▲]

Detailed reference viewed: 39 (4 ULiège)
See detailProtein encapsulation into nanostructured CaCO3 microparticles templated by PEO-b-polyphosphoester using a supercritical CO2 process
Ergül, Zeynep ULiege; Debuigne, Antoine ULiege; Calvignac, Brice et al

Poster (2017, May 22)

The use of calcium carbonate microparticles is becoming more and more attractive in biomedical applications as proteins carriers for their controlled delivery in the body. We investigate the protein ... [more ▼]

The use of calcium carbonate microparticles is becoming more and more attractive in biomedical applications as proteins carriers for their controlled delivery in the body. We investigate the protein encapsulation by in situ precipitation of CaCO3 particles prepared by a process based on supercritical CO2 and using a new type of degradable well-defined double hydrophilic block copolymer composed of poly(ethylene oxide) and polyphosphoester block with an affinity for calcium like poly(phosphotriester)s bearing pendent carboxylic acids on each repeating monomer unit which evidenced an efficient structure for templating the formation of CaCO3 leading to unprecedented small-sized particles. Lysozyme was chosen as a model for therapeutic protein for its availability and ease of detection. It was found that by this green process, loading into the CaCO3 microparticles with a diameter about 2 μm can be obtained as determined by scanning electron microscopy. A protein loading up to 6.5% active lysozyme was measured by a specific bioassay (Micrococcus lysodeikticus). By encapsulating fluorescent-labelled lysozyme (lysozyme-FITC), the confocal microscopy images confirmed its encapsulation and suggested a core–shell distribution of lysozyme into CaCO3. [less ▲]

Detailed reference viewed: 67 (1 ULiège)
See detailFunctional emulsion-templated macroporous polymers via controlled radical polymerization
Mathieu, Kevin ULiege; Jérôme, Christine ULiege; Debuigne, Antoine ULiege

Conference (2017, May 05)

Macroporous polymer monoliths with interconnected structures have attracted considerable interest in the fields of supported catalysis, chromatography, water purification, etc. A popular and ... [more ▼]

Macroporous polymer monoliths with interconnected structures have attracted considerable interest in the fields of supported catalysis, chromatography, water purification, etc. A popular and straightforward synthesis approach for such open-cell polymers is based on the emulsion-templated polymerization. In this strategy, a major phase is dispersed in a minor continuous phase containing monomers, cross-linker, initiator and surfactant. The curing of the continuous phase followed by the removal of the dispersed phase leads to a monolith with voids interconnected by pores. Size and number of the latters are influenced by several parameters and especially by the nature of the surfactant. Consequently, we prepared by controlled radical polymerization a series of well-defined amphiphilic copolymers having different hydrophilic-lipophilic balance (HLB) and chain-ends, used it as stabilizers for the emulsion-templated polymerizations and demonstrated the crucial effect of the macromolecular features as well as the concentration on the foam morphology. Secondly, the physical and the chemical anchoring of the macromolecular surfactants at the surface of the pores were also considered for tuning the surface properties of the porous monoliths in one step. This strategy was also implemented with alkyne-terminated copolymers in order to decorate the surface of the cavities with “clickable” moieties which broadens the scope of functional macroporous polymers. [less ▲]

Detailed reference viewed: 26 (3 ULiège)
See detailSynthesis of hierarchical N-doped porous carbon structure/nanospheres Fe2O3 composites and its application in lithium-ion battery as lithium-ion anodes
Alkarmo, Walid ULiege; Ouhib, Farid ULiege; Aqil, Abdelhafid ULiege et al

Poster (2017, May 04)

Nitrogen-doped porous carbons are of special interest, because their unique physical properties such as high surface area, multidimensional electron transport pathways and good mechanical strength, and ... [more ▼]

Nitrogen-doped porous carbons are of special interest, because their unique physical properties such as high surface area, multidimensional electron transport pathways and good mechanical strength, and are thus very important for applications in the fields of catalysis, environment techniques and energy generation and storage. Moreover, nitrogen-doping can be further amplified in a porous structure that bears a high surface area to increases their materials performance in electrochemical devices, such as double layer capacitors and lithium-ion batteries. In addition, nitrogen-doping can enhance the lithium insertion, between the nitrogen-doped carbon material and lithium. And it can create a large number of defects in the porous configuration and offer more active sites for lithium insertion. Toward this goal, a hierarchically structured macro- and mesoporous N-doped carbon with dispersed Fe2O3 nanoparticles (NDC@Fe2O3) is prepared by thermal treatment of a novel composite composed by PMMA particles decorated by graphene oxide (GO), PPy and iron salts. The NDC@Fe2O3 composite exhibited high surface area with a hierarchical pores structure. Integrated as a lithium ion battery anode, NDC@Fe2O3 exhibited high reversible capacity of 930 mA h/g over 200 cycles. The combination of Fe2O3 nanoparticles with nitrogen-doped porous carbons to form hybrid anode has been an efficient way to maintain the electronic integrity of the whole electrode since the carbon acts as a buffer layer to accommodate the volume variation and to provide multidimensional electron transport pathways during the charge/discharge process. [less ▲]

Detailed reference viewed: 80 (8 ULiège)
See detailDesign of polyphosphoester coplymers as scaffolds for tissue engineering applications
Shah, Urmil ULiege; Ergül, Zeynep ULiege; Jérôme, Christine ULiege

Poster (2017, May 04)

Polymers with repeating phosphoester linkages in the backbone are biodegradable and emerged as a promising class of novel biomaterials. In contrast to polyesters, the pentavalency of the phosphorus atom ... [more ▼]

Polymers with repeating phosphoester linkages in the backbone are biodegradable and emerged as a promising class of novel biomaterials. In contrast to polyesters, the pentavalency of the phosphorus atom offers a large diversity of structures and as a consequence a wide range of properties for these materials. This study aims at taking profit of this easy functionalization to synthesize a series of degradable polymers of precisely tailored properties especially elasticity, hydrophilicity and functionality. We aim at developing a set of degradable materials in which only elasticity is varied keeping unchanged other parameters such as hydrophilicity, which remains quite a challenge. For that purpose, we have synthesized by organocatalyzed ring-opening polymerization,random di- and terpolymers between various cyclic phosphoesters bearing a short side-chain (hydrophilic), a longer side-chain (hydrophobic) and an unsaturated side-chain (butenyl)able to cross-link under UV irradiation. Playing on the composition of these copolymers, the cross-linking density and the hydrophilicity can be tuned quite independently. In the future, these materials will be used as model scaffolds to study the growth and differentiation of stem cells. [less ▲]

Detailed reference viewed: 92 (10 ULiège)
See detailThiol-ene reaction: an efficient tool to design polyphosphoester-based drug delivery systems
Riva, Raphaël ULiege; Vanslambrouck, Stéphanie; Ergül, Zeynep ULiege et al

Poster (2017, May 04)

Thanks to their biocompatibility, biodegradability and their structure similar to natural biomacromolecules, polyphosphoesters (PPE) are appealing polymers for biomedical applications. In contrast to ... [more ▼]

Thanks to their biocompatibility, biodegradability and their structure similar to natural biomacromolecules, polyphosphoesters (PPE) are appealing polymers for biomedical applications. In contrast to polyesters, PPE properties and functionality are easily tuned via the chemical nature of the lateral chains. To enhance the drug loading capacity of PPE-based micelles used as carriers for the delivery of poorly soluble drugs, an efficient strategy to increase the lipophilicity of the PPE block of polyethylene oxide (PEO)-b-PPE amphiphilic copolymers has been investigated. A PEO-b-PPE copolymer bearing pendant vinyl groups along the PPE block was synthesized and then modified by thiol-ene click reaction with thiols bearing either a long linear alkyl chain (dodecyl) or a tocopherol moiety. Ketoconazole was used as model for hydrophobic drugs. Comparison of the loading contents and release profiles with PEO-b-PPE bearing shorter pendant groups is presented evidencing the key role of the structure of the pendant group on the PPE backbone. Finally, the low cytotoxicity of these novel PEO-b-PPE copolymers was also demonstrated. The tocopherol derivative was evidenced as particularly promising for drug delivery systems. [less ▲]

Detailed reference viewed: 53 (2 ULiège)
See detailSynthesis of cross-linked poly(HEMA) microparticles in supercritical carbon dioxide for sustained delivery
Caprasse, Jérémie ULiege; Parilti, Rahmet ULiege; Riva, Raphaël ULiege et al

Poster (2017, May 04)

Microgels are micro-sized polymer networks able to swell or shrink depending on the environment. They find applications in many fields such as for environmental purpose or especially in the biomedical ... [more ▼]

Microgels are micro-sized polymer networks able to swell or shrink depending on the environment. They find applications in many fields such as for environmental purpose or especially in the biomedical field for tissue engineering or controlled drug-delivery applications. Indeed, the use of microgels allows a controlled and sustained release of an encapsulated active ingredient (AI), avoiding Burst release. This work aims at reporting on the solvent-free synthesis of well-defined hydrogel microparticles according to a free radical dispersion polymerization of hydroxyethyl methacrylate (HEMA) in supercritical carbon dioxide (scCO2) which confers environmentally benign features to the process2. For that purpose, a dedicated polymer surfactant has been designed by RAFT polymerization, i.e. poly(ethylene oxide-b-heptadecafluorodecyl acrylate) diblock copolymer with a photocleavable group at the junction of both blocks and used as stabilizer for the HEMA dispersion polymerization in scCO2. The synthesis conditions (stabilizer concentration, temperature and CO2 pressure,…) adapted for the in situ encapsulation of an active ingredient have been studied. Then, the photocleavage of the fluorinated block of the polymer stabilizer allows the further swelling of the polyHEMA particles in water and the sustained release of the encapsulated active ingredient through the microgels. This eco-friendly process allowing the formation of well-defined hydrogel particles, showing a sustain release of their content is quite promising for a high scale microparticles production. Microgels are micro-sized polymer networks able to swell or shrink depending on the environment. They find applications in many fields such as for environmental purpose or especially in the biomedical field for tissue engineering or controlled drug-delivery applications. Indeed, the use of microgels allows a controlled and sustained release of an encapsulated active ingredient (AI), avoiding Burst release. [less ▲]

Detailed reference viewed: 69 (1 ULiège)
See detailHow to exploit bio- and CO2-based isocyanates-free polyurethanes for environmental and biomedical applications?
Gennen, Sandro ULiege; Grignard, Bruno ULiege; Alves, Margot et al

Poster (2017, May 04)

Polyurethane (PU) is one of the most important family of polymers that is largely used in coatings, foams, elastomers, sealants/adhesives in the building, automotive, household and biomedical sectors ... [more ▼]

Polyurethane (PU) is one of the most important family of polymers that is largely used in coatings, foams, elastomers, sealants/adhesives in the building, automotive, household and biomedical sectors. Classically, PU is produced by a step-growth polymerization between di- or polyols and di- or polyisocyanates. However, isocyanates are toxic and produced from even more toxic phosgene. To avoid the use of isocyanates, different synthetic alternatives for PUs have been developed. One of the most studied approaches relies on the step-growth polymerization between di- or polyamines and CO2-sourced di- or polycyclic carbonates, affording poly(β-hydroxyurethane)s (PHUs) that showed improved thermal, chemical and mechanical properties compared to conventional PUs. In this study, we would like to show how PHUs can be exploited to design (bio- and) CO2-based foams for thermal insulation as well as novel reinforced hydrogels for potential biomedical applications. First, we developed a highly efficient binary organocatalyst for the fast and selective synthesis of cyclic carbonates under very mild conditions from CO2 and various epoxides, including bio-based ones. Secondly, these cyclic carbonates were valorised as monomers for the preparation of foams and hydrogels based on PHUs. In this poster, we will describe the preparation and characterization of these PHU foams and hydrogels, and highlight their huge potential as thermal insulating materials (PHU foams) or as biomaterials for shock absorption properties (PHU hydrogels). [less ▲]

Detailed reference viewed: 50 (1 ULiège)
See detailDesign of new reprocessable shape-memory materials
Defize, Thomas ULiege; Riva, Raphaël ULiege; Thomassin, Jean-Michel ULiege et al

Poster (2017, May 04)

Detailed reference viewed: 9 (1 ULiège)
See detailSimple, cheap but highly efficient organo catalysts for the fixation of CO2 on propargylic alcohols
Ngassam Tounzoua, Charlene Gabriela ULiege; Gilbert, Bernard ULiege; Detrembleur, Christophe ULiege et al

Poster (2017, May 04)

In the last years, many efforts have been devoted to the valorisation of CO2 as an abundant and renewable C1 building block for cyclic carbonate synthesis. Many synthetic routes have been proposed to ... [more ▼]

In the last years, many efforts have been devoted to the valorisation of CO2 as an abundant and renewable C1 building block for cyclic carbonate synthesis. Many synthetic routes have been proposed to convert CO2 into five or six-membered cyclic carbonates finding applications as green solvent, electrolytes for Li-ion batteries, intermediates for organic synthesis, monomers for the production of polycarbonates or isocyanate-free synthesis of poly(hydroxyrethane)s, etc. Although the 100% atom economy synthesis of 5-membered cyclic carbonates from CO2 and epoxides/oxetanes has been widely reported in the literature, the carboxylative coupling of CO2 with alkynols remains unexplored. Transition metal-based complexes, organic bases (guanidine, amidine, phosphine), N-heterocyclic carbenes or olefins, and K2CO3 have been proposed as catalysts. However they generally present sufficient activity at high pressure and/or temperature or require a high catalyst loading. Additionally some of them are toxic and/or sensitive to hydrolysis or oxidation. In this work, we designed novel, cheap, easily customizable and highly efficient organocatalysts for the synthesis of cyclic α-methylene carbonates from CO2 and alkynols. Kinetics of the CO2/alkynol coupling reaction were followed by Raman spectroscopy with organocatalysts of different structures, and the best candidate was identified. The main parameters that influenced the system reactivity and selectivity have been identified and will be presented in this poster. [less ▲]

Detailed reference viewed: 47 (6 ULiège)
See detailSynthesis of well-defined polyvinylamine-containing copolymers via organometallic-mediated radical polymerization
Stiernet, Pierre ULiege; Demarteau, Jérémy ULiege; Jérôme, Christine ULiege et al

Poster (2017, May 04)

Polyvinylamine (PVAm) is a useful polymer involved in a large range of applications including paper coating, surface engineering, membrane separation, etc. It is commonly produced via free radical ... [more ▼]

Polyvinylamine (PVAm) is a useful polymer involved in a large range of applications including paper coating, surface engineering, membrane separation, etc. It is commonly produced via free radical polymerization of N-vinylformamide (NVF) or N-vinylacetamide (NVA) followed by hydrolysis of the pendent amides of the resulting polymers. Due to the lack of stabilizing group on the double bond of N-vinylamides, the controlled radical polymerization of these monomers remained a challenge for a long time, preventing the preparation of well-defined PVAms. Recently, our group reported the controlled polymerization of NVA via reversible deactivation of the growing radical chains with cobalt complexes. Moreover, the use of well-defined PVAms as efficient carriers for gene transfection was demonstrated. This communication aims at reporting the synthesis of novel well-defined polyvinylamine-based copolymers. First, we explored the organometallic-mediated radical copolymerization of NVA and vinyl acetate. The optimized polymerization conditions and the comonomer reactivity ratios will be presented. Further conversion of the pendent amides and esters moieties into amino and hydroxy groups, respectively, was also considered for the preparation of unprecedented hydrophilic polyvinylamine-based copolymers. [less ▲]

Detailed reference viewed: 30 (2 ULiège)
See detailPhoto-crosslinkable hydrogel for guided periodontal tissue regeneration
Chichiricco, Pauline Marie ULiege; Riva, Raphaël ULiege; Thomassin, Jean-Michel ULiege et al

Poster (2017, May 04)

Periodontitis is an inflammatory disease resulting from the presence of oral bacteria biofilm in periodontal tissue, which destroys the tooth-supporting attachment apparatus. Untreated inflammation can ... [more ▼]

Periodontitis is an inflammatory disease resulting from the presence of oral bacteria biofilm in periodontal tissue, which destroys the tooth-supporting attachment apparatus. Untreated inflammation can spread to the gum tissue and lead, ultimately, to the loosening of the supporting tooth bone, with the risk that the tooth eventually falls. Guided Tissue Regeneration is a technique based on the application of a barrier membrane designed to prevent colonization of the wound space by epithelial cells from soft tissues. Indeed, these cells, characterized by a faster migration and proliferation rate compared to bone and periodontal ligament cells, could interfere with the regeneration process. In previously work Struillou et al. demonstrated the benefit effect of silated hydroxypropylmethylcellulose (Si HMPC)-based hydrogel can act as an efficient physical barrier in periodontal defect. Typically, this material is able to form a 3D network through the condensation of silanoate groups at physiological pH. However, a decrease of gelation time is necessary to assure the stability in peripheral part of the wound. In this project, we developed an injectable photo-crosslinkable membrane based on methacrylated carboxymethyl chitosan (CMCs) and Si HPMC that can be applied as a viscous solution and cured in situ in presence of a photoinitiator system made of riboflavin and triethanolamine. A visible light lamp (λ 420-480 nm), already used in dentistry, was preferred over a UV lamp. The addition of methacrylated polymer increase the stability of the material and increase the mass loss, in order to improve the bioresorption of the membrane. The chemical grafting of methacrylated carboxymethyl chitosan was characterized by 1H NMR and Infrared Spectroscopy. The gel point of the solution was determined by rheology and remained compatible with a clinical application. Moreover, the biocompatibility of this biomaterials was tested using murine cells using two assay: Neutral Red assay and MTT Cell Proliferation Assay. The in vitro tests validate the chemical synthesis in a biological point of view. The irradiation on cells and the direct contact with hydrogel doesn’t have an impact on cells viability. The capability of this material to act as a physical barrier was also evaluated using human gingival fibroblast. The cells were isolated from human gum explant before being put in contact with the hydrogel. After four days of contact no cells invasion was observed in the hydrogel using confocal microscopy. These preliminary results are quite promising for the development of novel injectable systems for Guided Periodontal Regeneration. In the future work, in vivo assays will be performed in Periodontal defect in a canine model. [less ▲]

Detailed reference viewed: 47 (1 ULiège)
See detailReinforced poly(hydroxyurethane) coatings and high performance adhesive
Panchireddy, Satyannarayana ULiege; Grignard, Bruno ULiege; Thomassin, Jean-Michel ULiege et al

Poster (2017, May 04)

Polyurethane (PU) is one of the most widely used polymeric materials and largely valorised in coating applications as paints or as adhesives. Because toxicity issues of isocyanates and changes in the ... [more ▼]

Polyurethane (PU) is one of the most widely used polymeric materials and largely valorised in coating applications as paints or as adhesives. Because toxicity issues of isocyanates and changes in the environmental and REACH regulations, there is a need today to develop new greener and safer alternatives to produce PU. One of the most promising way relies on the synthesis of polyurethane by a non-isocyanate route (NIPU) by copolymerization between a bicyclic carbonate monomers and a diamine. This study reports on the synthesis of new sustainable NIPU coatings for Al anti-corrosion protection and for metal adhesion. In a first step, (bio- and) CO2-sourced cyclic carbonates will be synthesized by coupling of multifunctional epoxides with CO2 using a new efficient bicomponent organocatalyst. In a second step, various cyclic carbonates/amines formulations were developed and cured in presence of fillers to produce reinforced NIPUs thermosets which anti-corrosion and adhesive properties are evaluated and benchmarked with existing formulations. Some formulations present outstanding adhesions to various substrates. [less ▲]

Detailed reference viewed: 55 (4 ULiège)
See detailAll poly(ionic) liquid-based block copolymers incorporating fluorinated and triethyleneglycol units: direct synthesis in water and investigation as single-ion conductive solids
Ouhib, Farid ULiege; Cordella, Daniela; Aqil, Abdelhafid ULiege et al

Poster (2017, May 04)

Poly(ionic liquid)s (PILs) have attracted a considerable attention as innovative single-ion solid polyelectrolytes (SPEs) in substitution to the more conventional electrolytes for a variety of ... [more ▼]

Poly(ionic liquid)s (PILs) have attracted a considerable attention as innovative single-ion solid polyelectrolytes (SPEs) in substitution to the more conventional electrolytes for a variety of electrochemical devices. Imidazolium-based PILs are amongst the most investigated, because they are easy to synthesize and some of them have shown a good combination between high ionic conductivity, wide chemical and electrochemical stability, and good mechanical properties. Herein, we report the precise synthesis, characterization, and use as single-ion SPE of a novel double PIL-based amphiphilic diblock copolymer (BCP), i.e. where all monomer units are of N-vinyl-imidazolium-type, with triethylene glycol pendant groups in the first block, and a statistical distribution of N-vinyl-3-ethyl- and N-vinyl-3-perfluorooctyl-imidazolium bromides in the second block. BCP synthesis is achieved directly in water by a one-pot process, following the principle of the cobalt-mediated radical polymerization-induced self-assembly (CMR-PISA). A subsequent anion exchange reaction substituting bis(trifluoromethylsulfonyl)imide (Tf2N-) for bromide (Br-) counter-anions leads to the targeted PIL BCPs with two different lengths of the first block. They demonstrate ionic conductivity σDC = 1-3 10-7 S cm-1, as determined by broadband dielectric spectroscopy at 30 °C (under anhydrous conditions), and form free standing films with mechanical properties suited for SPE applications with Young’s modulus of 3.8 MPa and elongation at break of 250 % as determined by stress/strain experiments. [less ▲]

Detailed reference viewed: 76 (3 ULiège)
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See detailPhotosensitive polydimethylsiloxane networks for adjustable-patterned films
Jellali, Rachid; Alexandre, Michaël; Jérôme, Christine ULiege

in Polymer Chemistry (2017), 8(16), 2499-2508

Polydimethylsiloxanes (PDMSs) bearing photoreactive coumarin groups have been synthesized by amida- tion of a coumarin acid chloride derivative with various amine-functionalized PDMSs. Upon exposure to UV ... [more ▼]

Polydimethylsiloxanes (PDMSs) bearing photoreactive coumarin groups have been synthesized by amida- tion of a coumarin acid chloride derivative with various amine-functionalized PDMSs. Upon exposure to UV light having a wavelength of above 300 nm, multifunctional coumarin-PDMSs are transformed into covalent networks via [2 + 2] photocycloaddition of two coumarin moieties forming a cyclobutane ring. Taking advantage of the possible localized irradiation through a photomask, a novel concept to generate patterned PDMS films with various surface topologies was demonstrated. This concept is based on the combination of a low molar mass difunctional PDMS with a multifunctional PDMS of a high molar mass forming a photoreversible network allowing osmotic diffusion of a linear PDMS-coumarin of low mole- cular weight in a loosely crosslinked network. Advantageously, illumination by a light source at 254 nm induces the photocleavage of the cyclobutane cross-links offering some photo-induced reversibility to the PDMS network. These novel photo-responsive networks are interesting for several applications, in photo-adaptable biomedical implants (particularly photo-adjustable intra-ocular lenses), photo-tuneable patterned microsystems (e.g. for microfluidics) and photo-switchable controlled release systems. [less ▲]

Detailed reference viewed: 49 (1 ULiège)
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See detailOrganometallic-mediated radical polymerization of 'less activated monomers': fundamentals, challenges and opportunities
Debuigne, Antoine ULiege; Jérôme, Christine ULiege; Detrembleur, Christophe ULiege

in Polymer (2017), 115

Access to well-defined polymers made of the so-called ‘Less Activated Monomers’ (LAMs) via controlled radical polymerization has long been a challenge due to the lack of radical stabilizing group on the ... [more ▼]

Access to well-defined polymers made of the so-called ‘Less Activated Monomers’ (LAMs) via controlled radical polymerization has long been a challenge due to the lack of radical stabilizing group on the double bond of these monomers. This Feature Article summarizes substantial progress in the organometallic-mediated radical polymerization (OMRP) of this important class of monomers including vinyl esters, olefins, vinyl chloride, vinyl amides, or ionic-liquid vinyl monomers. It aims to provide a clear and comprehensive account of the fundamentals and challenges in the OMRP of LAMs as well as an overview of the resulting macromolecular engineering opportunities. The input of photochemistry, environmentally friendly solvents or flow reactors in OMRP is also presented. Finally, it emphasizes how some well-defined LAMs-based materials contributed to the development of specific applications notably in the fields of biomedicine or energy. [less ▲]

Detailed reference viewed: 78 (13 ULiège)
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See detailDFT investigation of the reaction mechanism for the guanidine catalyzed ring-opening of cyclic carbonates by aromatic and alkyl-amines
Alves, Margot ULiege; Méreau, Raphaël; Grignard, Bruno ULiege et al

in RSC Advances (2017), 7(31), 18993-19001

The guanidine catalysed aminolysis of propylene carbonate has been investigated using the density functional theory (DFT) and highlights that different reaction pathways are involved depending on the ... [more ▼]

The guanidine catalysed aminolysis of propylene carbonate has been investigated using the density functional theory (DFT) and highlights that different reaction pathways are involved depending on the aromatic or aliphatic nature of the amine. The structural ability of 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) to simultaneously give and receive protons was demonstrated by a detailed mechanistic investigation. The bifunctional activity (base/H-bond donor) of TBD significantly reduces the Gibbs energy of the reaction and allows understanding its higher efficiency compared to its methyl counterpart (MTBD). [less ▲]

Detailed reference viewed: 36 (2 ULiège)
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See detailOrganocatalytic coupling of CO2 with a propargylic alcohol: a comprehensive study of the reaction mechanism combining in- situ ATR-IR spectroscopy and DFT calculations
Boyaval, Amélie ULiege; Méreau, Raphaël; Grignard, Bruno ULiege et al

in ChemSusChem (2017), 10(6), 1241-1248

The metal-free coupling of propargylic alcohols with carbon dioxide catalysed by guanidine derivatives was investigated in detail through the combination of online kinetic studies by in-situ ATR-IR ... [more ▼]

The metal-free coupling of propargylic alcohols with carbon dioxide catalysed by guanidine derivatives was investigated in detail through the combination of online kinetic studies by in-situ ATR-IR spectroscopy and DFT calculations. Bicyclic guanidines, namely TBD and MTBD, are effective catalysts for the conversion of 2-methyl-3-butyn-2-ol to α-methylene cyclic carbonate and oxoalkyl acyclic carbonate under mild reaction conditions. The lower selectivity of TBD in comparison with MTBD towards the formation of α-methylene cyclic carbonate was elucidated from DFT calculations and is related to the bifunctional activity (base/H-bond donor) of TBD decreasing the Gibbs free energy of the reaction path for the formation of the acyclic carbonate. Introduction [less ▲]

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