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See detailElectrografting method for forming and regulating a strong adherent nanostructured polymer coating
Jérôme, Robert ULg; Jérôme, Christine ULg; Serwas, Harry ULg et al

Patent (2008)

Electrografting method for forming and regulating a strongly adherent nanostructured polymer coating onto an electro-conductive surface profile characterized in that the surface profile is regulated by ... [more ▼]

Electrografting method for forming and regulating a strongly adherent nanostructured polymer coating onto an electro-conductive surface profile characterized in that the surface profile is regulated by electrodeposition of nanometre- and/or micrometre-scale nuclei onto the surface profile prior to or simultaneously to the formation of the polymer coating. [less ▲]

Detailed reference viewed: 22 (3 ULg)
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See detailElectrografting method for forming and regulating a strong adherent nanostructured polymer coating
Voccia, Samuel; Serwas, Harry ULg; Jérôme, Christine ULg et al

Patent (2009)

Electrografting method for forming and regulating a strongly adherent nanostructured polymer coating onto an electro-conductive surface profile characterized in that the surface profile is regulated by ... [more ▼]

Electrografting method for forming and regulating a strongly adherent nanostructured polymer coating onto an electro-conductive surface profile characterized in that the surface profile is regulated by electrodeposition of nanometre- and/or micrometre-scale nuclei onto the surface profile prior to or simultaneously to the formation of the polymer coating. [less ▲]

Detailed reference viewed: 33 (8 ULg)
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See detailElectrografting of acrylic and methacrylic monomers onto metals: influence of the relative polarity and donor-acceptor properties of the monomer and the solvent
Baute, Noëlle; Teyssié, Philippe; Martinot, Lucien et al

in European Journal of Inorganic Chemistry (1998), 1998(11), 1711-1720

The possibility of grafting a series of alkyl polyacrylates and polymethacrylates onto a nickel cathode by electropoly-merization of the parent monomers has been investigated and has emphasized the ... [more ▼]

The possibility of grafting a series of alkyl polyacrylates and polymethacrylates onto a nickel cathode by electropoly-merization of the parent monomers has been investigated and has emphasized the critical importance of the solvent used. Indeed, the intensity of the inhibition peak, which is the electrochemical mark of the cathode passivation as result of the polymer grafting, clearly depends on both the polarity and the donor-acceptor properties of the solvent. The Gutmann concept is used to account for these experimental results. An increase in the donicity of the solvent used for the electrochemical medium has allowed, for the very first time, several polyacrylates and polymethacrylates [such as poly(ethyl acrylate), poly(methyl methacrylate), and poly(2-trimethylsilyloxyethyl methacrylate)] to be electrografted onto Ni. This observation is consistent with a competition process between the monomer and the solvent for being adsorbed on the cathode and amassing in its very close vicinity. The outcome of this competition is controlled by the relative polarity (in case of low donicity) and the relative donor-acceptor properties (when the difference is high enough) of the monomer/solvent pair, and by the monomer concentration (in case of weak competition). A semiquantitative relationship has also been observed between the monomer ability to be electrografted and the electron-accepting character of the vinyl β-carbon atom as measured by 13C NMR. [less ▲]

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See detailElectrografting of conducting polymers onoto ITO surfaces
Labaye, David Emmanuel; Jérôme, Christine ULg; Demoustier-Champagne, Sophie et al

Poster (2001, May 16)

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See detailElectrografting of Poly(ethylene glycol) Acrylate : A One-Step Strategy for the Synthesis of Protein-Repellent Surfaces
Gabriel, Sabine ULg; Dubruel, Peter; Schacht, Etienne et al

in Angewandte Chemie (International ed. in English) (2005), 44(34), 5505-5509

Electrografting of acrylate end-capped poly(ethylene glycol) (PEG) is an important technique for the one-step coating of electroconductive substrates by an adherent hydrophilic coating (see figure). This ... [more ▼]

Electrografting of acrylate end-capped poly(ethylene glycol) (PEG) is an important technique for the one-step coating of electroconductive substrates by an adherent hydrophilic coating (see figure). This technique is very efficient for the production of new protein-repellent surfaces. [less ▲]

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See detailElectrografting of poly(ethylene glycol) acrylate: a novel one-step strategy for protein repellent surfaces
Gabriel, Sabine ULg; Dubruel, P.; Schacht, Etienne et al

Conference (2005, June 01)

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See detailElectrografting of polymers onto AFM tips: A novel approach for chemical force microscopy and force spectroscopy
Jérôme, Christine ULg; Willet, Nicolas ULg; Jérôme, Robert ULg et al

in Chemphyschem : A European Journal of Chemical Physics and Physical Chemistry (2004), 5(1), 147-149

Polymer-modified AFM tips have been prepared through an easily implemented and versatile electrochemical method (see graphic). The authors describe the electropolymerization process of acrylic-based ... [more ▼]

Polymer-modified AFM tips have been prepared through an easily implemented and versatile electrochemical method (see graphic). The authors describe the electropolymerization process of acrylic-based monomers onto gold-coated tips (see graphic) and show force curves obtained during approach-retraction cycles between the modified tips and a bare silicon surface. This direct chemical grafting creates new possibilities for single-molecule force spectroscopy. [less ▲]

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See detailElectrografting of polythiophenes on zinc oxide nanorods for photovoltaic cells
Demarteau, Jérémy ULg; Ouhib, Farid ULg; Henrist, Catherine ULg et al

Poster (2014, May 20)

As the rarefaction of fossil energies, photovoltaic cells are certainly amongst the most important energy sources for the future. Our work concentrated on hybrid photovoltaic cells that are based on ... [more ▼]

As the rarefaction of fossil energies, photovoltaic cells are certainly amongst the most important energy sources for the future. Our work concentrated on hybrid photovoltaic cells that are based on organic (polythiophene) and inorganic components (ZnO nanorods). The technology that maximizes the contact area between the two semi-conductor n and p while maintaining two separate components is the interdigital configuration. As the inorganic part, perfectly well aligned zinc oxide (ZnO) 1D nanostructures have been synthesized by hydrothermal growth on ZnO-seeded FTO substrates. SEM, AFM and XRD characterizations evidence patterned well- aligned nanorods with high c-axis, their roughness of surface and the length of their nanostructure. Concerning the organic component, we synthetize polythiophenes based diblock copolymer with high degree of regioregularity and predetermined molecular weight using Grignard Methatis (GRIM) process. Diblock polythiophene based copolymers are of interest because of the possibility of generating multifunctional materials (by associating the specific properties of each block), including their ability for self-assembly into well-defined nanostructures (fibrils or micelles) with controllable dimensions. Poly(3-hexylthiophene) (P3HT) composes the first block and the second block is either a polythiophene bearing an acrylate group on each monomer unit (PAcET), or a polythiophene bearing both acrylate and poly(ethylene glycol) side chains (P(AcET-co-PEGET)). Typically, the acrylates are used to fixe in a covalent way the copolymer to ZnO nanorods, while the PEG grafts are necessary for the solubilisation of the copolymer in the electrografting medium. 1H NMR and DLS characterizations allow us to find the backbone and the micellar structure of the copolymer. Cathodic polarization (electrografting) of ZnO nanorods induces electropolymerization of acrylate groups, leading to an adherent organized film of poly(thiophene)-based micelles. During the illumination tests, we obtained a typical response of a photovoltaic despite the low yields. This promising synthetic route opens exciting perspectives for the production and the electrochemical functionalization of different lengths of ZnO nanowires, which seems to be promising candidate for hybrids photovoltaic cells. [less ▲]

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See detailElectrografting of preformed aliphatic polyesters onto metallic surfaces
Lou, Xudong; Jérôme, Christine ULg; Detrembleur, Christophe ULg et al

in Langmuir (2002), 18(7), 2785-2788

Preformed aliphatic polyesters bearing pendent acrylate groups, poly(4-acryloyloxy-epsilon-caprolactone)co-epsilon-caprolactone) [poly(ACL-co-epsilonCL)], were grafted onto metallic surfaces by a cathodic ... [more ▼]

Preformed aliphatic polyesters bearing pendent acrylate groups, poly(4-acryloyloxy-epsilon-caprolactone)co-epsilon-caprolactone) [poly(ACL-co-epsilonCL)], were grafted onto metallic surfaces by a cathodic electrochemical process. Content of acrylates must exceed a lower limit for them to be adsorbed on the cathode with the proper orientation and for the grafting to be successful. The strongly adhering films were analyzed by IR reflection-absorption spectroscopy and scanning electron microscopy. As a result of the known miscibility of poly-e-caprolactone with poly(vinyl chloride) (PVC), the pregrafting of poly(ACL-co-epsilonCL) imparts strong adhesion to PVC topcoats. [less ▲]

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See detailElectrografting of thermo-responsive polymer film on conductive substrate
Gabriel, Sabine ULg; Stach, M.; Zhang, T. et al

Poster (2006, May 18)

Detailed reference viewed: 25 (1 ULg)
See detailElectrografting of thermo-responsive polymer films on conducting surfaces
Gabriel, Sabine; Stach, M.; Confortini, O. et al

Poster (2008, November 28)

Detailed reference viewed: 26 (2 ULg)
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See detailElectrografting of thin polymer films: Three strategies for the tailoring of functional adherent coatings
Voccia, Samuel; Gabriel, Sabine ULg; Serwas, Harry et al

in Progress in Organic Coatings (2006), 55(2), 175-181

Cathodic electrografting is an efficient technique to impart adhesion to poly(meth)acrylate coatings onto inorganic conducting surfaces. Although this technique was restricted for many years to very few ... [more ▼]

Cathodic electrografting is an efficient technique to impart adhesion to poly(meth)acrylate coatings onto inorganic conducting surfaces. Although this technique was restricted for many years to very few monomers ((meth)acrylonitrile and (meth)acrylates) and to deposition of very thin polymer films, recent developments have overcome these limitations. First of all, classical controlled/living polymerization techniques have been combined with cathodic electrografting as a powerful strategy for tuning thickness, properties and reactivity of the chemisorbed organic films. Secondly, thanks to the successful electrografting of a new reactive monomer bearing an activated ester, electrografted surfaces are now available for further derivatization by a wide variety of nucleophiles. Finally, the electrografting process has been extended to the direct electrografting of reactive polymers, i.e. preformed polymers beating pendant acrylic functions, which opens the way to the grafting of, e.g., polycondensates. [less ▲]

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See detailElectrografting on nanoparticles: A new way toward polymer stabilized nanoparticle suspensions
Serwas, Harry ULg

Doctoral thesis (2012)

Abstract: Nowadays, nanomaterials keep sparking interest tremendously because of the unique properties materials exhibit at the nanoscale. However, the stabilization of nanoparticles against aggregation ... [more ▼]

Abstract: Nowadays, nanomaterials keep sparking interest tremendously because of the unique properties materials exhibit at the nanoscale. However, the stabilization of nanoparticles against aggregation is a prerequisite to exploit their remarkable properties, since they are very prone to aggregation. Moreover, even if many synthetic methods have been reported to prepare nanoparticles, achieving an efficient and convenient stabilization, without an alteration of the properties nanoparticles remains a challenge up to now. Therefore, a novel approach toward polymer stabilized metal based nanoparticles was developed using sonoelectrochemistry combined to electrografting to form a protective polymer layer in-situ directly on the generated particles. Nanopaticles prepared using this new approach were characterized. The influence of major experimental parameters on the characteristics of the produced polymer coated particles was also studied. [less ▲]

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See detailElectrografting onto ITO substrates of poly(thiophene)-based micelles decorated by acrylate groups
Ouhib, Farid ULg; Desbief, Simon; Lazzaroni, Roberto et al

in Polymer Chemistry (2013), 4(15), 4151-4161

We report on a simple process for the chemisorption of poly(thiophene)-based block copolymers onto ITO substrates. Two poly(thiophene) block copolymers functionalized by acrylates on the second block are ... [more ▼]

We report on a simple process for the chemisorption of poly(thiophene)-based block copolymers onto ITO substrates. Two poly(thiophene) block copolymers functionalized by acrylates on the second block are prepared by the Grignard Metathesis (GRIM) process. The first block is composed of poly(3-hexylthiophene) (P3HT) and the second block is either a polythiophene bearing an acrylate group on each monomer unit (PAcET), or a polythiophene bearing both acrylate and poly(ethylene glycol) side chains (P(AcET-co-PEGET)). After characterizing their macromolecular parameters and optical properties, we investigate their ability to self-assemble into micelles in DMF solutions. This solvent is required for the electrografting procedure that is used for strongly anchoring the polymer to ITO. These micelles are expected to be formed by a P3HT core and a PAcET or P(AcET-co-PEGET) shell. When PEG side chains are present in the second block, the copolymer nicely self-assembles into micelles decorated by acrylates. Cathodic polarization of ITO induces chemisorption and polymerization of acrylate groups, leading to an adherent organized film of poly(thiophene)-based micelles. The optical absorption spectra show that the electrografted polymer chains have a degree of π-electron conjugation similar to that of crystalline P3HT films. In the absence of the PEG chains, the copolymer does not organize into micelles, due to the low stabilizing ability of the second block in DMF. [less ▲]

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See detailElectroinitiated polymerization
Jérôme, Christine ULg

in Matyjaszewski, Krzysztof; Möller, Martin (Eds.) Polymer Science: a comprehensive reference ; volume 4: Ring-Opening Polymerization and Special Polymerization Processes (2012)

Electroinitiated polymerization, a method particularly relevant in coating technology, offers the unique opportunity of imparting permanent functionality/reactivity to a variety of surfaces, provided that ... [more ▼]

Electroinitiated polymerization, a method particularly relevant in coating technology, offers the unique opportunity of imparting permanent functionality/reactivity to a variety of surfaces, provided that the solid substrate is (semi)conducting. By focusing on the electroinitiation of acrylic monomers, basic concepts and some tools dedicated to the analysis of this peculiar polymerization process are discussed in this chapter. The important role of this polymerization method in the field of conjugated polymers is also highlighted. Finally, this chapter concludes with the opportunities and future challenges of this technology. [less ▲]

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See detailELECTROKINETIC CHARACTERIZATION OF IMMOBILIZED ASPERGILLUS-NIGER BETA GALACTOSIDASE
Paquot, Michel ULg; LESAGE, V.

in Belgian Journal of Food Chemistry and Biotechnology (1986), 41(6), 161-165

Microcrystalline cellulose was activated with diphenylmethane 4,4-diisocyanate and triethylamine and was used to immobilize beta-galactosidase (beta-Gal) at 4 or 20C and pH 3.6 or 4.6. The activation ... [more ▼]

Microcrystalline cellulose was activated with diphenylmethane 4,4-diisocyanate and triethylamine and was used to immobilize beta-galactosidase (beta-Gal) at 4 or 20C and pH 3.6 or 4.6. The activation procedure modified the electrokinetic characteristics of the carrier, making the zeta potential less negative; at pH below 4.5 the zeta potential became positive. Immobilization of beta-Gal shifted the isoelectric point to acid pH. Conditions to produce the highest residual beta-Gal activity were pH 4.6 and temp. of 4C. Addition of 1250 p.p.m. NaCl, CaCl2 or Ca(NO3)2 at the optimum pH decreased beta-Gal activity, effects being greater for the immobilized enzyme than for free enzyme. Optimum pH after immobilization was increased by approx. one unit by Ca salts, while Na had no effect. Ca(NO3)2 caused a shift of zeta potential to more positive values and the isoelectric point of the immobilized enzyme to alkaline pH. Na had less influence on zeta potential but at 50 p.p.m. did displace the isoelectric point. [less ▲]

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See detailElectrokinetic Model Refinement Via a Perturbation Finite-Element Method—From 2-D to 3-D
Ferreira da Luz, Mauricio V.; Dular, Patrick ULg; V Sabariego, Ruth ULg et al

in IEEE Transactions on Magnetics (2010), 46(8), 2839-2842

A method for increasing the contact area of a grounding system with the earth is the installation of counterpoise wires. Counterpoise wires improve the reliability of overhead power transmission lines ... [more ▼]

A method for increasing the contact area of a grounding system with the earth is the installation of counterpoise wires. Counterpoise wires improve the reliability of overhead power transmission lines. They are conductors buried in the ground parallel to or at an angle to the line conductors. This paper presents an electrokinetic model refinement via a perturbation finite-element method to calculate the grounding resistance of counterpoise wires. The perturbation method is herein developed for refining the electric field distribution in soil starting from simplified models, based on electric field distributions from 2-D models, that evolve towards a 3-D accurate model. The analysis of the distribution of the electric field and of the electric potential around the tower footing allows accurately determining the tower footing resistance. The comparisons between the grounding resistance simulated and calculated analytically of a counterpoise wire are presented. [less ▲]

Detailed reference viewed: 64 (1 ULg)