Secondary doping phenomena of conductive polyaniline composite

摘要

FURTHER development of the "doping" concept in the area of conductive polymers is based on the following facts: polyaniline (PAn) doped by camphorsulfonic acid (CSA) and cast from m-cresol solution has a conductivity 10~3 times higher than that cast from chloroform solution. The first metallic behavior of PAn cast from m-cresol was observed, i. e. conductivity decreases with the increase of temperature from 178 K to room temperature and σ_(178K)/σ_((RT)) = 1.1. Recent works of Heeger and MacDiarmidgroups indicated that m-cresol can extend the coiled chains of PAn-CSA and cause the polaron to change from localized into delocal-ized. The conductivity of PAn-CSA film cast from chloroform solution can also be improved by exposure to m-cresol vapor orcoating with m-cresol.