Effect of solvents and co-solvents on the processibility of polyaniline: I. solubility and conductivity studies

Abstract Fully protonated polyaniline (ratio H+/PhN = 0.5) can be dissolved in organic solvents only in the case when the PANI-(acid)0.5 complex is solvated by at least an additional 0.5 mole of solvating agent per PANI unit (PhN). For solvents with strong hydrogen bonding ability, this solvating ligand can be the solvent itself. Alternatively, either an extra amount of protonic acid or some neutral surfacant-type compounds (with a strong hydrogen bonding group on one side and an organic tail compatible with solvent on the other side) can be used. Depending on the choice of solvent and co-solvent, the electrical conductivity of films cast from the corresponding solution can be much higher or lower than that of the initial PANI powder. The solvating ligand can be removed after processing without significant reduction of the conductivity of resulting polyaniline films.