MOLECULAR-LEVEL PROCESSING OF CONJUGATED POLYMERS .4. LAYER-BY-LAYER MANIPULATION OF POLYANILINE VIA HYDROGEN-BONDING INTERACTIONS

The molecular-level layer-by-layer processing of polyaniline with a va riety of different nonionic water soluble polymers has been demonstrat ed. This new type of layer-by-layer adsorption process is driven by hy drogen-bonding interactions and has been accomplished with poly(vinylp yrrolidone), poly(vinyl alcohol), poly(acrylamide), and poly(ethylene oxide). FTIR spectroscopy measurements confirm a high level of hydroge n bonding between polyaniline and the nonionic polymer in the multilay er films. The effects of solution pH and polymer molecular weight on t he deposition process were investigated. Comparisons with polyaniline films assembled via an electrostatic mechanism with sulfonated polysty rene indicate that the nonionic polymers adsorb onto polyaniline with a greater density of loops and tails and form highly interpenetrated b ilayers with a high polyaniline content. The conductivities of these s elf-assembled multilayer films were found to be on the order of 1-4 S/ cm for films doped with methane sulfonic acid. It was also demonstrate d that the deposition process could be carried out with mixed solution s of polyaniline and a nonionic polymer.