Conductivity and morphology of polyaniline and polypyrrole prepared in the presence of organic dyes

Polyaniline was prepared by the oxidation of aniline hydrochloride or aniline with ammonium peroxydisulfate in the presence of 37 anionic or cationic organic dyes. Similar preparation of polypyrrole used iron(III) chloride as an oxidant. The goal of the study is to evaluate the effect of dyes on the conductivity of both polymers and their morphology at nanoscale. The preparation of polyaniline using aniline hydrochloride as a monomer was unaffected by the dyes presence, its conductivity was of the order of units S cm(-1) and morphology was globular. The similar oxidation of aniline has led to the products with reduced conductivity and unresolved morphology. On the other hand, the presence of dyes had significant impact on the conductivity of polypyrrole, and all tested dyes improved the conductivity, for example methyl red from 1 S cm(-1) to 42 S cm(-1). Most of the samples were globular, but several dyes, such as Acid Blue 25, acriflavine, methyl orange, methylene blue, neutral red, phenosafranin or safranin stimulated the growth of one-dimensional morphologies, polypyrrole nanofibers or nanotubes.