The performance of different poly(3,4-ethylenedioxythiophene) (PEDOT) films was compared by electrochemical, spectroelectrochemical, and time-derivative measurements of absorbance versus potential (linear potential-scan voltabsorptometry) for an overall spectroelectrochemical characterization of the electrochromic properties in ionic liquids such as 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMITFSI). The time-derivative signals were monitored at different wavelengths, and information obtained therefrom was complementary to that obtained from conventional cyclic voltammetry. PEDOT films prepared via in situ chemical oxidative polymerization appeared to be much more efficient than electropolymerized and PEDOT-poly(styrenesulfonate) (PSS) reference films, in terms of both contrast ratio and coloration efficiency, which was the case even for PEDOT films deposited on less conductive flexible plastic substrates.

a b s t r a c tSome novel high conductivity-high strength materials were designed in the binary Cu-Mg. They exhibit an excellent balance between strength and electrical properties. The properties and the performance of the designed materials are compared with the main Cu-based alloys and the analysis shows that they perform equally to the best one (Cu-Be). Furthermore, we show that an increase of Mg content modifies the microstructure feature and leads to a strong increase of strength without any significant deterioration of the electrical conductivity. This behavior was attributed to the formation of eutectic islands in which high density of Cu 2 Mg nanoparticles precipitate.

International audienceHybrid organicinorganic nanocomposites of poly(3,4-ethylenedioxythiophene) (PEDOT) and silver or gold {PEDOTmetal (PEDOTM) nano-objects (M = Ag, Au) (particle diameter down to 60 nm)} were prepared by a one-pot oxidative aqueous dispersion polymerization using ammonium persulfate as an oxidant and the corresponding metal salts as co-oxidant (HAuCl4 and AgNO3) in the presence of pyrrole-modified-poly(N-vinylpyrrolidone-co-vinyl alcohol) (PVP-co-PVAL-mod-Py) stabilizer. The hydrophilic character of such a stabilizer enhances the polymer layer through hydrophilic interactions, which leads to a smooth surface with high wetting properties for subsequent electropolymerizations. PEDOTM is more conducting than the commercially available PEDOT:PSS, in which the PSS acts as an insulating agent (electrical conductivities up to 1.25 Scm(-1)). These nanocomposites were used to replace PEDOT:PSS as anchoring layer for further EDOT monomer polymerization, providing an improvement of the electrochromic properties of PEDOT in terms of not only contrast ratio and coloration efficiency but also switching time respons

%, 8.1 at.%, 23.1 at.%) are investigated. The materials exhibit an excellent balance between strength and electrical conductivity properties. An increase of Mg content modifies microstructural features and leads to a strong increase of strength (more than 1000 MPa) without any significant deterioration of the conductivity. This behavior is attributed to the formation of eutectic islands in which high density of Cu 2Mg nanoparticles precipitate during cooling. The Cu-Mg material is a good alternative to the Cu-Be system which has the disadvantage of toxicity. -(GORSSE*, S.; OUVRARD, B.; GOUNE, M.; POULON-QUINTIN, A.; J. Alloys Compd. 633 (2015) 42-47, http://dx.