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

Abstract

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 μm), flexible, having a very low content of uniformly distributed metallic Ag nanoparticles and exhibiting high electrical conductivity ∼14.8 S cm−1. The thick films (∼200 μm) 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 ∼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.