Processability of Electrically Conductive Polyaniline Due to Molecular Recognition

Publisher Summary This chapter focuses on the processability of electrically conductive polyaniline (PANI) by molecular recognition. The electrically conductive emeraldine-salt form of PANI has long been regarded as infusible and poorly soluble because of the aromatic structure, the interchain hydrogen bonding, and the charge delocalization effects. The phenyl rings of PANI are considered as potential sites of phenl–phenyl interaction with a periodicity of around 6 A. At the same periodicity, there are hydrogen bonding sites as well consisting of amines and sulfonates due to protonating sulfonic acids. The first requirement for low acidic solvents is that the solvent has to comprise phenyl rings and sufficiently strong hydrogen-bonding-functional-groups at the same periodicity. Second, for PANI protonated by generic sulfonic acids such as p-dodecyl benzene sulfonic acid (DBSA), methyl benzene sulfonic acid (TSA), or methane sulfonic acid, an additional requirement is that at least one hydrogen bond and at least one phenyl–phenyl interaction should be made. In the special case where the counter ion itself allows a suitable hydrogen bonding, such as camphor-lo-sulfnic acid (CSA), the critical number of the interactions is reduced to two.