Morphological changes in electrochemically deposited poly(3,4-ethylenedioxythiophene) films during overoxidation

Electrochemical and morphological properties of thin poly(3,4-ethylenedioxy-thiophene) (PEDOT) films deposited on gold were investigated in aqueous sulfuric acid solutions. X-ray diffraction and electron microscopy were used for monitoring the morphological changes and structure evolution caused by overoxidation. The diffraction peaks of PEDOT became sharper and more intensive during the subsequent oxidation cycles. This indicates that besides the degradation of the PEDOT film, its crystallinity was gradually improved with increasing the number of oxidation cycles. These changes may result in the appearance of novel properties that may be advantageous for specific applications

New electrochemical procedure for obtaining surface enhanced Raman scattering active polythiophene films on platinum

A new electrochemical procedure for obtaining Surface Enhanced Raman Scattering (SERS) spectra of silver islands polybithiophene composite films is described. During the electropolymerization process which consists to use silver dodecylsulfate micellar aqueous solution mixed with bithiophene and LiClO4, silver cations are reduced, thus giving metallic silver particles embedded within the polybithiophene (PbT) film. Both doped and undoped PbT species display SERS spectra with exaltation factors varying between 40 and 200 with respect to the film prepared in sodium dodecylsulfate. Vibrational characterization of both doped and undoped species show that the amount of the polymer structural defects are more important in the oxidized species than in the reduced ones. This general method allows to synthesize various polymeric films displaying SERS effect and appears very promising for the structural study of these materials

Dépôt sur métaux oxydables de films de poly[3,4-éthylènedioxythiophène] électrosynthétisés en milieu aqueux micellaire

L'électropolymérisation du 3,4-éthylène dioxythiophène (EDT) a été réalisée en mode galvanostatique sur électrode de Fe et d'Al en milieu aqueux micellaire dodécylsulfate de sodium (SDS) en présence de phtalate de sodium comme sel électrolytique. Des films de PEDT électroactifs, homogènes et adhérents sont obtenus sur Fe et Al. Le rendement faradique γ d'électropolymérisatio