The molecular-level layer-by-layer processing of polyaniline with a variety of different nonionic water soluble polymers has been demonstrated. This new type of layer-by-layer adsorption process is driven by hydrogen-bonding interactions and has been accomplished with poly(vinylpyrrolidone), poly(vinyl alcohol), poly(acrylamide), and poly(ethylene oxide). FTIR spectroscopy measurements confirm a high level of hydrogen bonding between polyaniline and the nonionic polymer in the multilayer films. The effects of solution pH and polymer molecular weight on the deposition process were investigated. Comparisons with polyaniline films assembled via an electrostatic mechanism with sulfonated polystyrene indicate that the nonionic polymers adsorb onto polyaniline with a greater density of loops and tails and form highly interpenetrated bilayers with a high polyaniline content. The conductivities of these self-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 demonstrated that the deposition process could be carried out with mixed solutions of polyaniline and a nonionic polymer.

Multilayer thin films comprised of sequentially adsorbed layers of partially doped polyaniline and a polyanion, sulfonated polystyrene, were fabricated via the use of a simple layer-by-layer molecular-level processing scheme. Using this simple multilayer polymer adsorption process, uniform thin films of polyaniline in the 40−600 Å thickness range were readily fabricated onto a variety of different substrates. Doping of these films with strong acids such as HCl and methane sulfonic acid results in electrically conductive thin films with conductivities 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 driven primarily by the electrostatic attractions developed between the partially doped chains of polyaniline (polycation) and the negatively charged chains of the polyanion.

Neutron reflectivity has been used to study the organization of self-assembled multilayers of sulfonated polyaniline and polyallylamine. Films were prepared by the sequential adsorption of polycations and polyanions from dilute aqueous solutions. Scattering contrast was achieved by selective deuteration of the blocks of bilayers at varying intervals along the film. The multilayer structure was found to be preserved over 40 bilayer depositions, but with an internal organization which decays monotonically away from the substrate. These results suggest that the observed interfacial widths are primarily due to the accumulation of defects as the bilayers are deposited.

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Several diacetylenic lecithins form tubular microstructures (tubules) when their liposomes are cooled through the chain-melting transition. Recently, the tubules have been metal plated by an electroless technique. This paper reports on the interaction of permalloy coated tubules with electromagnetic radiation. At 10 vol % loading of tubules in an epoxy matrix has a real dielectric constant ε′≊50 at a frequency of 9.5 GHz. Simple electrodynamics accounts well for the observed results. Far higher values of ε′ may be achievable with longer tubules and with improved metal coatings.