Mireille Fouletier

Electrochemical method for characterization of graphite-aluminium chloride intercalation compounds

Abstract The electrochemical behaviour of different graphites in molten lithium chloroaluminate electrolyte was studied using the potentiodynamic method. The oxidation currents observed at potentials below chlorine evolution are related to the oxidation of graphite during aluminium chloride intercalation.

Determination of the surface properties of a coke grist and its oxidised derivative

The surface properties of a slightly oxidized coke sample were compared to those of the non-oxidized coke using a series of analytical methods: acidimetry for the evaluation of the oxygenated surface group content, electron spectroscopy, determination of H-bonding ability, zeta potential measurements and inverse gas chromatography (IGC). Some methods show no difference between the two coke samples, but IGC pointed to major changes especially when considering adsorption enthalpies and the entropies of a series of selected molecular probes.

Electrochemical Doping of Polycyanoacetylene, A New Conducting Polymer

Abstract Polycyanoacetylene was prepared by dehydrochlorination of poly-α-chloroacrylonitrile at low temperature. Thin films were simply obtained by spreading a DMF solution onto a stainless steel substrate. Transmission electron microscopy revealed a highly crystalline structure. Two different morphologies were observed : large isolated single crystals and numerous small crystals dispersed in the precursor matrix. The electrochemical behaviour of polycyanoacetylene was studied using a (-CH=C(CN)-) /(PEO)8LICIO4/Li cell. Cyclic voltammetry indicated a very reversible behaviour. Lithium intercalation/deintercalation occurred at ca 2.6 V vs Li/Li+. This high value compared to polyacetylene may be attributed to the electron withdrawing effect of the cyano- group. These properties make polycyanoacetylene suitable for use as a positive electrode in batteries.

Chemically modified PTFE-carbon as a solid state oxygen sensor electrode material

Abstract Transition metal complexes such as [Fe, (pyridin2) n ] 2+ have been synthesized and grafted on PTFE carbon. In aqueous electrolyte, these materials display catalytic properties for the oxygen evolution/reduction electrode reaction. The behaviour of a chemically modified PTFE carbon electrode in a PbSnF 4 electrolyte oxygen sensor in the 10 −3 atm o 2 −1 atm range at 100°C and 160°C is reported.