Tunnelling conductivity in conducting polymer composites: a manifestation of chemical interaction

Abstract

Charge transport is studied in conducting composites of polyaniline and cis-1,4-polyisoprene (rubber). Films of different compositions are prepared by the solution route that are easily compressible under low pressure. Electrical conductivity is measured across the film thickness with the applied pressure. The results clearly indicate that conductivity is dominated by quantum tunnelling of charge carriers between conducting particles through an insulating barrier for all compositions. These findings are attributed to a strong chemical interaction between the conducting and non-conducting phases. It is demonstrated that such chemical interaction is a vital phenomenon in controlling charge transport of composites.