Polyaniline doped by a new class of dopants, benzoic acid and substituted benzoic acid: synthesis and characterization

This work reports on a new class of dopants, benzoic acid and substituted benzoic acids such as 2-hydroxybenzoic acid, 2-chlorobenzoic acid, 4-nitrobenzoic acid, 2-methoxybenzoic acid, 3-methylbenzoic acid, 4-methylbenzoic acid, 3-aminobenzoic acid and 4-aminobenzoic acid, for polyaniline. Benzoic acids can be used to dope polyaniline by mixing benzoic acid (or a substituted benzoic acid) with polyaniline in the common solvent 1-methyl-2-pyrrolidone. Properties of benzoic acid doped polyaniline salts are studied using Fourier transform infra-red, X-ray diffraction spectroscopy, scanning electron microscopy, thermogravimetric analysis and conductivity measurements. The conductivity of polyaniline-benzoic acid salt was found to be high (10(-2) S/cm) when compared to polyaniline-substituted benzoic acid salts (10(-3)-10(-5) S/cm). Copyright (c) 2005 John Wiley & Sons, Ltd.