Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailElectrochemical Co-Deposition of Phosphonate-Modified Carbon Nanotubes and Tantalum on Nitinol
Maho, Anthony ULiege; Detriche, Simon; Fonder, Grégory et al

in ChemElectroChem (2014), 1(5), 896--902

Nitinol substrates are coated with thin surface films made of carbon nanotubes (CNTs) and tantalum (Ta), with the aim of fostering their osseointegration aptitudes. Exceptional mechanical and chemical ... [more ▼]

Nitinol substrates are coated with thin surface films made of carbon nanotubes (CNTs) and tantalum (Ta), with the aim of fostering their osseointegration aptitudes. Exceptional mechanical and chemical characteristics of CNTs combined with the resistance to corrosion and strong bioactive properties of tantalum allow for the generation of adherent, protective and functional layers on metallic biomaterial platforms. The composite coatings are elaborated on Nitinol through a two-step electrochemical protocol; firstly, through the electrophoretic deposition of phosphonate-modified CNTs and, secondly, with electrodeposition of Ta. As a preliminary step, phosphonate groups, acting, in addition, as specific Ta-capture entities, are introduced on the CNT sidewalls by means of diazonium derivatives, which imply no hard oxidative treatment. X-ray photoelectron spectroscopy as well as scanning and transmission electronic microscopies are used to analyse the chemical composition, structure and morphology of the different layers. [less ▲]

Detailed reference viewed: 27 (4 ULiège)
Full Text
Peer Reviewed
See detailElectrochemical formation of polypyrrole nanowires
Jérôme, Christine ULiege; Labaye, David; Jérôme, Robert ULiege

in Synthetic Metals (2004), 142(1-3), 207-216

This paper aims at approaching the mechanism of formation of polypyrrole (PPy) nanowires by an all-electrochemical process, which consists in electrografting a poly(alkylacrylate) film onto the surface of ... [more ▼]

This paper aims at approaching the mechanism of formation of polypyrrole (PPy) nanowires by an all-electrochemical process, which consists in electrografting a poly(alkylacrylate) film onto the surface of a cathode, followed by the anodic electropolymerization of pyrrole (Py) at the surface of this organomodified electrode. The experimental conditions for the pyrrole oxidation, including solvent and concentrations of monomer and supporting electrolyte, have been changed with the purpose to tune the characteristic features of the polypyrrole nanowires. The polyacrylate template has also been modified, all other conditions being the same, in an effort to design the shape and size of the wires. The electrochemical behavior of the as-prepared PPy wires has been characterized. [less ▲]

Detailed reference viewed: 54 (2 ULiège)
Full Text
Peer Reviewed
See detailElectrochemical impedance study of the solid electrolyte interphase in MnSn2 based anode for Li-ion batteries
Mahmoud, Abdelfattah ULiege; Chamas, Mohamad; Lippens, Pierre-Emmanuel

in Electrochimica Acta (2015), 184

Abstract This work reports the interfacial properties of nanostructured MnSn2 as anode material for Li-ion batteries in order to explain ageing phenomena. The impedance measurements show variations of the ... [more ▼]

Abstract This work reports the interfacial properties of nanostructured MnSn2 as anode material for Li-ion batteries in order to explain ageing phenomena. The impedance measurements show variations of the solid electrolyte interphase (SEI) resistance during the first cycle that are interpreted from changes in thickness and/or porosity of the SEI film. These changes are mainly due to the degradation of the electrolyte at the beginning of the first discharge and to the de-alloying reaction of Li7Sn2 operating during the first part of the charge that causes strong volume variations. However, a rather stable SEI was obtained during the reformation of MnSn2 in the second part of the charge, which is peculiar to this compound. Finally, capacity fading is related to the continuous growth of the SEI during cycling. [less ▲]

Detailed reference viewed: 11 (0 ULiège)
Full Text
Peer Reviewed
See detailElectrochemical Investigation of Nitinol/Tantalum Hybrid Surfaces Modified by Alkylphosphonic Self-Assembled Monolayers
Maho, Anthony ULiege; Kanoufi, Frédéric; Combellas, Catherine et al

in Electrochimica Acta (2014), 116(0), 78-88

The surface characteristics of bare and modified nickel-titanium samples (NiTi) are investigated by spectroscopic, microscopic and electrochemical techniques. The successful electrodeposition of a ... [more ▼]

The surface characteristics of bare and modified nickel-titanium samples (NiTi) are investigated by spectroscopic, microscopic and electrochemical techniques. The successful electrodeposition of a tantalum coating on NiTi and the effective grafting of 1-dodecylphosphonic acid SAMs on both pristine and Ta-covered NiTi surfaces are evidenced and quantified by XPS and SEM. Cyclic voltammetry performed on the different NiTi-based electrodes highlights their specificities regarding electron transfer to a redox probe present in solution (here ruthenium(III) hexamine). Finally, the samples electrochemical characteristics at a local scale are investigated by scanning electrochemical microscopy (SECM). The impact of the surface modifications on mass transport of the redox probe is analyzed through approach curves in the feedback mode, while the recording of current maps in feedback as well as in substrate-generation/tip-collection modes leads to the qualitative identification of electrochemically-active areas corresponding to precursor pitting corrosion sites. [less ▲]

Detailed reference viewed: 33 (2 ULiège)
Full Text
Peer Reviewed
See detailElectrochemical Mechanism of TiMnSn4 as Anode Material for Li-ion Batteries
Lippens, Pierre-Emmanuel; Jumas, Jean-claude; Olivier-Fourcade, Josette et al

Conference (2017, September 04)

Li-ion batteries are widely used in portable electronic devices, electric vehicles or energy storage systems for intermittent energy sources, due to their high energy density, light weight and long cycle ... [more ▼]

Li-ion batteries are widely used in portable electronic devices, electric vehicles or energy storage systems for intermittent energy sources, due to their high energy density, light weight and long cycle life. However, the performances must be continuously improved, which requires the development of new electrode materials. Carbon is commercially used for the anode but its specific capacity is limited to 372 mAh g-1 due to the electrochemical insertion mechanism involving only 1 Li per 6 C. In order to increase the specific capacity, Sn was considered as electrochemically active element although it is about ten times heavier than C. This is due to the alloying/dealloying mechanism with up to 4.4 Li per Sn, providing a theoretical capacity of 992 mAh g-1. However, the Sn ↔ Li4.4Sn reversible transformations are associated with large volume variations responsible for capacity fading.Tin intermetallic compounds of the form MSnx, where M is a transition metal, were proposed to overcome this problem. The first lithiation transforms the pristine material into Li7Sn2/M nanocomposites where the M nanoparticles are expected to buffer the volume variations [1]. However, the delithiation process is more complex involving a possible back reaction of M with Sn, which could play a crucial role in the cycling stability. Such reaction was observed for Ni3Sn4 [2] and MnSn2 [3] but not for FeSn2 [4]. In addition, TiSnx intermetallics show very poor electrochemical activity [5]. The present work concerns the tin based ternary phase TiMnSn4 as new anode material for Li-ion batteries. This compound is of particular interest because it contains two different transition metals that are expected to react differently with Sn during delithiation, if we consider the previous results obtained for MnSnx and TiSnx. TiMnSn4 was obtained by mechanosynthesis to optimize the microstructure and characterized by different experimental tools and DFT (density functional theory) calculations. We propose an analysis of the reaction mechanism based on operando X-ray diffraction and 119Sn Mössbauer spectroscopy combined with a DFT interpretation of the electrochemical potential curve. References 1) M. Chamas, M.T. Sougrati, C. Reibel, P.E. Lippens, Chem. Mater. 25, 2410 (2013). 2) K.K.D. Ehinon, S. Naille, R. Dedryvère, P.E. Lippens, J.C. Jumas, D. Gonbeau, Chem. Mater. 20, 5388 (2008). 3) A. Mahmoud, M. Chamas, J.C. Jumas, B. Philippe, R. Dedryvère, D. Gonbeau, I. Saadoune, P.E. Lippens, J. Power Sources 244, 246 (2013). 4) M. Chamas, P.E. Lippens, J.C. Jumas, K. Boukerma, R. Dedryvère, D. Gonbeau, J. Hassoun, S. Panero, B. Scrosati, J. Power Sources 196, 7011 (2011). 5) A. Ladam, L. Aldon, P.E. Lippens, J. Olivier-Fourcade, J.C. Jumas, C. Cenac-Morthe, Hyperfine Interact. 237, 51 (2016). [less ▲]

Detailed reference viewed: 27 (7 ULiège)
Full Text
Peer Reviewed
See detailElectrochemical performances and mechanisms of MnSn2 as anode material for Li-ion batteries
Mahmoud, Abdelfattah ULiege; Chamas, Mohamad; Jumas, Jean-Claude et al

in Journal of Power Sources (2013), 244

Abstract A synthesis method consisting of a mechanical ball milling activation process followed by a sintering heating treatment is proposed to obtain MnSn2 as anode material for Li-ion batteries. This ... [more ▼]

Abstract A synthesis method consisting of a mechanical ball milling activation process followed by a sintering heating treatment is proposed to obtain MnSn2 as anode material for Li-ion batteries. This two-step approach strongly reduces the amount of βSn impurities and provides a better material morphology. This improves the electrochemical performances, even at high C-rate, as shown from the comparison between electrode materials obtained with and without this preliminary activation process. The electrochemical reactions have been followed at the atomic scale by in situ 119Sn Mössbauer spectroscopy. The first discharge is a restructuring step that transforms the pristine material into Mn/Li7Sn2 nanocomposite which should be considered as the real starting material for cycling. The delithiation of this nanocomposite is characterized by two plateaus of potential attributed to the de-alloying of Li7Sn2 followed by the back reaction of Mn with poorly lithiated LixSn alloys, respectively. The composition and the stability of the solid electrolyte interphase were characterized by X-ray photoelectron spectroscopy. [less ▲]

Detailed reference viewed: 14 (0 ULiège)
Full Text
Peer Reviewed
See detailElectrochemical strategies for the strengthening of polymer – metal interfaces
Baute, Noëlle; Jérôme, Christine ULiege; Martinot, Lucien et al

in European Journal of Inorganic Chemistry (2001), 2001(5), 1097-1107

Polymers have been widely used for the protection of metals against corrosion and for improving the performance of structural adhesive joints. In this contribution, the weakness and short-term durability ... [more ▼]

Polymers have been widely used for the protection of metals against corrosion and for improving the performance of structural adhesive joints. In this contribution, the weakness and short-term durability of these polymer-metal interactions and some common approaches for alleviating this problem are briefly reviewed. Among the existing techniques, electrochemical processes offer the advantage of controlled interfacial reactions. Promising results have been reported by Strat-mann et al. and Le´cayon et al., who have emphasized the interest and opportunity to create strong chemical bonds between the organic coating and the metallic substrate. Their work is discussed in this review, along with results recently obtained in our group [less ▲]

Detailed reference viewed: 54 (7 ULiège)
Full Text
Peer Reviewed
See detailElectrochemical study of the uranium exchange by polypyrrole-based resins
Jérôme, Christine ULiege; Martinot, Lucien; Jérôme, Robert ULiege

in Journal of Applied Polymer Science (1999), 74(14), 3473-3484

Electrochemical control of the binding of uranium ions by redox active polypyrrole resins was studied. The experimental conditions for this binding were optimized with respect to the uranium ions to be ... [more ▼]

Electrochemical control of the binding of uranium ions by redox active polypyrrole resins was studied. The experimental conditions for this binding were optimized with respect to the uranium ions to be fixed, the resin, and the solution. [less ▲]

Detailed reference viewed: 38 (3 ULiège)
Full Text
Peer Reviewed
See detailElectrochemical study of two tris-O-substituted calix[4]arenes: 25,27-dipropoxy-26-hydroxy-28-benzoyloxycalix[4]arene(partial cone) and 25,27-dibenzyl-26-hydroxy-28-benzoyloxy-calix[4]-arene (partial cone). Electro synthesis of the corresponding calix[4]arene-monoquinones
Louati, Alain; Spraula, Julien; Gabelica, Valérie ULiege et al

in Electrochemistry Communications (2006), 8(5), 761-766

The anodic oxidation of 25,27-dipropoxy-26-hydroxy-28-benzoyloxycalix[4]arene 1 and 25,27-dibenzyl-26-hydroxy-28-benzoyloxycalix[4]arene 2 in dichloromethane was investigated by electrochemical and ... [more ▼]

The anodic oxidation of 25,27-dipropoxy-26-hydroxy-28-benzoyloxycalix[4]arene 1 and 25,27-dibenzyl-26-hydroxy-28-benzoyloxycalix[4]arene 2 in dichloromethane was investigated by electrochemical and spectroclectrochemical techniques. For both, the overall reaction is a two-electron oxidation of the phenolic group according to an ECE mechanism resulting in the ultimate formation of an observable phenoxylium cation. After reaction of the latter with traces of water and subsequent internal electron transfer, the corresponding calix[4]-monoquinones are formed. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

Detailed reference viewed: 106 (5 ULiège)
Full Text
Peer Reviewed
See detailElectrochemical study of uranium exchange on a polypyrrole resin
Jérôme, Christine ULiege; Martinot, Lucien; Jérôme, Robert ULiege

in Journal of Radioanalytical & Nuclear Chemistry (1999), 240(3), 969-972

The ability to electrochemically control the binding of uranium ions by redox active polypyrrole resins has been studied. The optimization of the conditions for the fixation of uranium has been defined ... [more ▼]

The ability to electrochemically control the binding of uranium ions by redox active polypyrrole resins has been studied. The optimization of the conditions for the fixation of uranium has been defined while taking in account the nature of the fixed species, the nature of the resin and the nature of the solutions. [less ▲]

Detailed reference viewed: 27 (1 ULiège)
Full Text
Peer Reviewed
See detailElectrochemical synthesis and characterization of the electronic structure of new conjugated polymers from dithienylene vinylene derivatives
Jérôme, Christine ULiege; Maertens, Christophe; Mertens, Marc et al

in Synthetic Metals (1996), 83(2), 103-109

Highly conjugated thiophene derivatives, based on thienylene vinylene and thienylene vinylene phenylene units, have been synthesized in order to examine: (i) the effect of such regular conjugated monomer ... [more ▼]

Highly conjugated thiophene derivatives, based on thienylene vinylene and thienylene vinylene phenylene units, have been synthesized in order to examine: (i) the effect of such regular conjugated monomer structures on polymer formation; and (ii) the optical and electrochemical properties of the corresponding macromolecules. The all-trans monomers have been prepared by a Wittig reaction. The polymers have then been synthesized electrochemically. The polymers are electrochromic and can be reversibly doped both oxidatively and reductively. Their electrochemical behavior and optical properties have been analyzed on the basis of a series of quantum-chemical calculations. [less ▲]

Detailed reference viewed: 45 (3 ULiège)
Full Text
Peer Reviewed
See detailElectrochemical synthesis of conjugated polymer wires and nanotubules
Jérôme, Christine ULiege; Demoustier-Champagne, Sophie; Legras, Roger et al

in Chemistry : A European Journal (2000), 6(17), 3089-3093

Two electrochemical methods designed for the synthesis of polypyrrole (PPy) wires and nanotubules are the topic of this paper. The concept that allows the morphology of PPy to be controlled is discussed ... [more ▼]

Two electrochemical methods designed for the synthesis of polypyrrole (PPy) wires and nanotubules are the topic of this paper. The concept that allows the morphology of PPy to be controlled is discussed for each method, and the performances of the two complementary techniques are compared in terms of dimension, shape and conductivity of PPy. [less ▲]

Detailed reference viewed: 20 (4 ULiège)
Full Text
Peer Reviewed
See detailElectrochemical synthesis of new electroactive polymers from dithienylene-vinylene derivatives
Jérôme, Christine ULiege; Maertens, Christophe; Mertens, Marc et al

in Synthetic Metals (1997, January), 84(1-3), 163-164

Highly conjugated thiophene derivatives, based on thienylene-vinylene and thieneylene-vinylene-phenylene units, have been synthesized in order to examine: (i) the effect of such regular conjugated monomer ... [more ▼]

Highly conjugated thiophene derivatives, based on thienylene-vinylene and thieneylene-vinylene-phenylene units, have been synthesized in order to examine: (i) the effect of such regular conjugated monomer structures on the polymerization; (ii) the optical and electrochemical properties of the corresponding conjugated polymers. The all-trans monomers have been prepared by a Wittig reaction and the polymers have then been synthesized electrochemically. The polymers are electrochromic and can be reversibly doped both oxidatively and reductively. Their electrochemical behavior and optical properties have been analysed on the basis of quantum-chemical calculations. [less ▲]

Detailed reference viewed: 46 (1 ULiège)
Full Text
Peer Reviewed
See detailElectrochemical synthesis of polypyrrole nanowires
Jérôme, Christine ULiege; Jérôme, Robert ULiege

in Angewandte Chemie (International ed. in English) (1998), 37(18), 2488-2490

Through a hole in a poly(ethyl acrylate) (PEA) layer that is electrochemically grafted to the surface of a vitreous carbon electrode-that is the route that must be taken by a growing polypyrrole nanowire ... [more ▼]

Through a hole in a poly(ethyl acrylate) (PEA) layer that is electrochemically grafted to the surface of a vitreous carbon electrode-that is the route that must be taken by a growing polypyrrole nanowire in the electropolymerization of pyrrole. Chain growth is controlled by diffusion of the monomer through the DMF-swollen PEA layer, which acts as a template for the formation of nanowires (shown in the picture) with diameters of 400-1000 nm and lengths of up to 300 m. [less ▲]

Detailed reference viewed: 33 (1 ULiège)
Full Text
Peer Reviewed
See detailElectrochemically Driven Sequential Machines: An Implementation of Copper Rotaxanes
Periyasamy, Ganga ULiege; Collin, Jacques ULiege; Sauvage, Jacques ULiege et al

in Chemistry : A European Journal (2009), 15(6), 1310-1313

Detailed reference viewed: 15 (2 ULiège)
Full Text
Peer Reviewed
See detailElectrochemically synthesized polypyrrole nanotubules : effects of different experimental conditions
Demoustier-Champagne, Sophie; Ferain, Etienne; Jérôme, Christine ULiege et al

in European Polymer Journal (1998), 34(12), 1767-1774

Nanotubules of polypyrrole (PPy) were electrochemically synthesized using the pores of nanoporous polycarbonate (PC) particle track-etched membranes (PTM) as templates. The influence of some conditions of ... [more ▼]

Nanotubules of polypyrrole (PPy) were electrochemically synthesized using the pores of nanoporous polycarbonate (PC) particle track-etched membranes (PTM) as templates. The influence of some conditions of electrosynthesis (electrochemical method, monomer concentration, electrolyte concentration and nature) on the kinetics of pyrrole electropolymerization and on the morphology of the obtained nanomaterials has been investigated. In particular, the empirical kinetics of the electrochemical generation of polypyrrole-perchlorate (PPy-ClO4) from aqueous solution, at 0.8 V (vs SCE) was followed by electrical charges measurement. The orders with respect to pyrrole and LiClO4 are 0.34 and 0.70 respectively. The electrogeneration of polypyrrole-polystyrenesulfonate (PPy-PSS) was also followed and shows that an increase of the electrolyte concentration increases the polymerization rate at constant potential. Finally, the morphology of PPy nanotubules doped with LiClO4 and NaPSS has been studied by high resolution emission SEM and by TEM. [less ▲]

Detailed reference viewed: 104 (2 ULiège)
Full Text
See detailElectrochemistry as a correlation tool candidate with catalytic activities in ruthenium(II)-catalysed atom transfer radical polymerisation ?
Richel, Aurore ULiege; Tutusaus, Oscar; Viñas, Clara et al

in Polymer Preprints (2005), 46(2), 227-228

Detailed reference viewed: 22 (5 ULiège)
Full Text
Peer Reviewed
See detailElectrochemistry as a correlation tool with the catalytic activities in [RuCl2(p-cymene)(PAr3)]-catalysed Kharasch additions
Richel, Aurore ULiege; Demonceau, Albert ULiege; Noels, Alfred ULiege

in Tetrahedron Letters (2006), 47

[RuCl2(p-cymene)] complexes containing triarylphosphine ligands with various substituents at the para position were used to catalyse the atom transfer radical addition of carbon tetrachloride to various ... [more ▼]

[RuCl2(p-cymene)] complexes containing triarylphosphine ligands with various substituents at the para position were used to catalyse the atom transfer radical addition of carbon tetrachloride to various olefins, and their catalytic activities were nicely correlated with their electrochemical parameters. [less ▲]

Detailed reference viewed: 24 (2 ULiège)