Electrochemical preparation of conductive poly( N-alkylaniline)s with long N-alkyl chains using appropriate dopant anions and organic solvents

Abstract

To prepare conductive polymers more soluble in organic solvents and more stable to over-oxidation than polyaniline, some N-alkylanilines were electropolymerized. Several polymerizing solutions with different kinds of anions (SO 4 2− and ClO 4 −) and organic solvents (acetonitrile and dimethyl sulfoxide) were employed. The anions and organic solvents were selected on the basis of the lipophilicity relationship among the poly( N-alkylaniline)s, the dopant anions and the organic solvents. The bell-shaped dependence of the conductivity on the N-alkyl chain length of the poly( N-alkylaniline)s was first observed for the poly( N-alkylaniline)s prepared from acetonitrile solution, and the highest conductivity of 1.0×10 −3 S cm −1 was obtained for SO 4 2−doped poly( N- n-heptylaniline). The dependence of the conductivity on the alkyl chain length of poly( N-alkylaniline)s was explained by the lipophilic affinity of the organic solvents for the poly( N-alkylaniline)s.