Etude de la cinétique de désorganisation de monocouches condensées à l'interface électrochimique

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Etude de la cinétique de désorganisation de monocouches condensées à l'interface électrochimique

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Ordered organic adlayers at electrode surface

The adsorption of organic molecules at the electrochemical interface can result in the formation of highly ordered monolayers that are easily detected by the presence of two-dimensional (2D) phase transitions. This review is mainly concerned with the role played by the electrode substrate in the ordering and the disordering of 2D organic films made of nonelectroactive molecules. The current status of our knowledge is summarized by reporting recent experimental results obtained at various single-crystal electrodes and by emphasizing some fundamental advances made earlier at the mercury electrode. In particular, the kinetics of the adlayer ordering and disordering are discussed in some detail.SCOPUS: ch.binfo:eu-repo/semantics/publishe

Mild steel corrosion in chloride environment: Effect of surface preparation and influence of inorganic inhibitors

The aim of the present work is to study the effect of surface mild steel preparation on its electrochemical behaviour in neutral chloride solution without and with an inorganic inhibitor. Various surface preparations are examined: alkaline degreasing, acid pickling and polishing. Open circuit potential measurements and potentiodynamic polarisations are used as corrosion monitoring techniques. The effect of chloride concentration is evaluated. The ability of inorganic inhibitors (Na2MoO4, NaNO2, Na 2WO4 and Na2VO3) to stabilise the passive state of steel in chloride containing solutions is assessed by electrochemical and surface analysis techniques. The results reveal that, among the four inhibitors studied, the sodium molybdate is the best environmentally friendly corrosion inorganic inhibitor for steel. © 2013 Institute of Materials, Minerals and Mining.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Cyanide-free silver electrochemical deposition on copper and nickel

Uracil was used as complexing agent to developp cyanide-free processes for silver deposition on copper and nickel substrates. We have highlighted that the molar ratio Ur/Ag+ between uracil and silver ions concentrations and the pH are crucial in the formulation of a stable and efficient bath and were found to be equal to 4 and 13.7 respectively. Silver was deposited in a single step on copper according to a three-dimensional nucleation mechanism while silver plating of nickel substrates was found to require an additionnal silver strike step. We worked out a choline chloride – oxalic acid DES-based silver solution which allowed to obtain bright, adherent and ductile silver coatings on Ni.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Preventing Biofouling in Steam Condensers: the MATChING Approach

<p>The Poster describes the activities that will be performed in the frame of the EU MATChING project for the reduction of biofouling phenomen in steam condenser through the use of advanced materials and coatings</p

Performance Analysis Based on Thermal Aging Tests of Sol-Gel and Polymer Insulated Wires by Enameling and Extrusion Technology

International audienceThis research activity aims to evaluate electrical insulation system (EIS) intended for electrical machine winding wires. The evaluation is based on mechanical, thermal, and electrical properties tests following international standards for enameled wires. Dielectric parameters such as dissipation factor, partial discharge inception voltage (PDIV), parallel capacitance, and parallel resistance behavior of different insulator configurations on twisted-pair samples are observed during thermal aging tests. Those configurations are formed of different combinations of dielectric layers based on conventional polymers (polyester-imide (PEI), polyamide-imide (PAI), polyimide (PI)) used as coating wires. A study using two mineral varnishes (silica-based) obtained by the sol-gel process integrated on these classical enamels an outer layer of extrusion of thermoplastic polymer with and without mineral fillers. Given the high consummation of energy and the use of unsustainable materials involving the production of wires, the principal interest of this work is to exploit new configurations of coating wire produced, with less environmental impact than conventional ones. This work investigates the impact of filled resins on the performance of insulating samples and the influence of the use of sol-gel solutions (mineral varnishes) on the insulated wire to increase the thermal class