Polyaniline salt films after deprotonation: structural differences from pristine emeraldine base

Abstract

Polyaniline salt films, obtained either by acid treatment of emeraldine base films or by direct casting of polyaniline salts in N-methylpyrrolidinone solutions, are subjected to deprotonation and reprotonation. Spectroscopic evidence suggest than an increase in the oxidation state and/or a decrease in the conjugation of the polymer occur when the salt films are deprotonated. The treatment of the as-cast base film by acids with large anions such as dodecylbenzenesulphonic acid or sulphosalicylic acid results in an insignificant amount of protonation in the bulk of the film. In contrast, the as-cast polyaniline salt film after deprotonation readily undergoes reprotonation by these acids. © 1994.