Complete alignment of polyaniline monolayers on muscovite mica: epitaxial effects of a lattice-matched substrate

Abstract

Totally aligned monolayers of the conducting polymer, polyaniline, have been deposited ‘epitaxially’ on a lattice-matched ‘Moscovite’ mica substrate using an in-situ deposition method in aqueous solution. The polyaniline molecules have a repeat unit that is an excellent match to the mica surface oxygen spacing. Images of the monolayers, recorded by atomic force microscopy, show that the polyaniline molecules align parallel to each other on the mica and that the interchain alignment appears to be strongly influenced by nitrogen atoms on adjacent polyaniline molecules that line up to form highly ordered rows of nitrogen atoms between chains. These results suggest the possibility of growing multilayer crystalline films which would be expected to have significantly higher conductivity compared with the more typical disordered polyaniline thin films. Ordered films could also promote and enhance the performance of a large variety of electronic devices where conducting polymers are the active material.