Molecular Layer Processing of Polyaniline via the Use of Hydrogen Bonding Interactions

Molecular layer-by-layer build-up on a variety of substrates is demonstrated for doped polyaniline (PAn) alternating with non-ionic water soluble polymers. The adsorption is enabled by the strong interchain interactions with PAn, such as hydrogen bonding. Multilayer build-up has been demonstrated with four distinctly different non-ionic water soluble polymers: poly(vinyl pyrrolidone) (PVP), poly(vinyl alcohol) (PVA), poly(acrylamide) (PAAm), and poly(ethylene oxide) (PEO). Thus, non-ionic water soluble polymers containing a wide variety of functional groups such as amide, hydroxyl or ether groups can be used to successfully fabricate multilayer thin films with polyaniline. FTIR spectroscopy measurements show the PAn to be hydrogen bonded in these multilayer films. Conductivities for multilayer films are on the order of 1-4 S/cm for films doped with methane sulfonic acid. Conductivities on the order of 0.1 S/cm can be achieved for a single mixed layer self-assembled from a mixed solution of PAn/PVP or PAn/PAAm.