MOLECULAR RECOGNITION EFFECTS IN POLYANILINE

Polyaniline (PANI) is known to dissolve in strong acids, such as sulph onic acids. PANI, in its electrically conductive form, is generally re garded to be poorly soluble in low-acidic solvents and to be infusible , closely resembling fully aromatic rigid rod polymers. We show that ' 'less'' acidic solvents and plasticizers can be found based on phenyl- phenyl interactions in combination with hydrogen bonding. The requirem ent is that the interactions are strong enough and, importantly, steri cally match the complementary moieties of the sulphonic acid doped PAN I. Dihydroxybenzenes and bisphenols are examples of such low-acidic co mpounds. This type of molecular recognition allows solution and melt p rocessibility of PANI doped by generic sulphonic acid, such as methane sulphonic acid or alkylbenzenesulphonic acid. Molecular recognition is also offered as an explanation for the previously observed high solub ility of camphorsulphonic acid (CSA) doped PANI in phenols.