One step synthesis of highly ordered free standing flexible polypyrrole-silver nanocomposite films at air-water interface by photopolymerization

Free standing polypyrrole-silver nanocomposite films were prepared by interfacial photopolymerization of pyrrole (in DCM) using AgNO3 (aqueous) as photosensitizer. During the photopolymerization process, film formation starts first at the DCM-water interface and later at the air-water interface. The films prepared at the air-water interface are thin (<1 mu m), flexible, having a very low content of uniformly distributed metallic Ag nanoparticles and exhibiting high electrical conductivity similar to 14.8 S cm(-)1. The thick films (similar to 200 mu m) prepared at the DCM-water interface are porous, mechanically weak, contain a very high amount of Ag micro and nanoparticles and exhibit two orders of magnitude lower conductivity similar to 0.1 S cm(-1). High conductivity of PPy-Ag films formed at the air-water interface is attributed to controlled polymerization due to the limited availability of pyrrole and Ag+ ions at this interface.