MOLECULAR-LEVEL PROCESSING OF CONJUGATED POLYMERS .3. LAYER-BY-LAYER MANIPULATION OF POLYANILINE VIA ELECTROSTATIC INTERACTIONS

Multilayer thin films comprised of sequentially adsorbed layers of par tially doped polyaniline and a polyanion, sulfonated polystyrene, were fabricated via the use of a simple layer-by-layer molecular-level pro cessing scheme. Using this simple multilayer polymer adsorption proces s, uniform thin films of polyaniline in the 40-600 Angstrom thickness range were readily fabricated onto a variety of different substrates. Doping of these films with strong acids such as HCl aad methane sulfon ic acid results in electrically conductive thin films with conductivit ies comparable to those obtained with spin cast films (0.5-1.0 S/cm). The adsorption process used to fabricate the films was found to be dri ven primarily by the electrostatic attractions developed between the p artially doped chains of polyaniline (polycation) and the negatively c harged chains of the polyanion.