Langmuir-Blodgett thin films of electrically conductive surface-active polypyrroles

Abstract Electrically conductive polypyrroles have been synthesized at the air-water interface of a Langmuir-Blodgett film balance by spreading mixtures of pyrrole monomer and a surface-active pyrrole derivative (3-octadecyl pyrrole or 3-octadecanoyl pyrrole) onto a subphase containing ferric chloride. The thickness and conductivity of the resultant polymers were found to depend strongly on the mole ratio of surface-active pyrrole to pyrrole monomer used in the dispersing solvent. By varying this mole ratio, it is possible to create films ranging from monolayer to multilayer thicknesses. The most highly conducting films were produced with mole ratios of pyrrole to substituted pyrrole approaching 5000:1. Multilayers of these films were fabricated successfully by both the horizontal and the vertical lifting methods. The electrical and optical properties of these new films are discussed.