POLYPYRROLE ELECTRODES, CHARGE TRANSFER TO AQUEOUS AND SOLID POLYMER ELECTROLYTES

Nous avons étudié l'interface entre le polypyrrole conducteur et des polymères électrolytes solides ou aqueux. Le polypyrrole est poreux pour le solvant et les ions de l'électrolyte mais pas pour des polymères électrolytes solides. Les deux types d'interfaces montrent sans ambiguité que la porosité, et donc la surface spécifique réelle, est responsable du rapide taux de transfert de charge vers les ions en solution qui est observé.We have studied interfaces between conducting polypyrrole and aqueous and solid polymer electrolytes. Polypyrrole is porous to solvent and electrolyte ions but not to solid polymer electrolytes. Contrasting the two interfaces shows unambiguously that the porosity, and consequently large actual surface area, is responsible for the observed rapid rate of charge transfer to ionic species in solution

Design, Synthesis, Characterization and Use of Random Conjugated Copolymers for Optoelectronic Applications

Part 19: Electronics - IIInternational audienceWe report the synthesis and the optoelectronic characterization of a new family of random conjugated copolymers based on 9, 9-bisalkylfluorene, thiophene and benzothiadiazole monomers unit synthesized by a palladium-catalyzed Suzuki cross-coupling reaction. The photophysical, thermal, electrochemical properties were investigated. The electronic structures of the copolymers were simulated via quantum chemical calculations. Bulk heterojunction solar cells based on these copolymers blended with fullerene, exhibited power conversion efficiency as high as 1% under illumination of 97 mWcm− 2. One of the synthesized copolymers has been successfully tested as active layer in simple light-emitting diode, working in the green spectral region and exhibiting promising optical and electrical properties. This study suggests that these random copolymers are versatile and are promising in a wide range of optoelectronic devices

Polypyrrole-based conducting polymers and interactions with biological tissues

Polypyrrole (PPy) is a conjugated polymer that displays particular electronic properties including conductivity. In biomedical applications, it is usually electrochemically generated with the incorporation of any anionic species including also negatively charged biological macromolecules such as proteins and polysaccharides to give composite materials. In biomedical research, it has mainly been assessed for its role as a reporting interface in biosensors. However, there is an increasing literature on the application of PPy as a potentially electrically addressable tissue/cell support substrate. Here, we review studies that have considered such PPy based conducting polymers in direct contact with biological tissues and conclude that due to its versatile functional properties, it could contribute to a new generation of biomaterials