FABRICATION OF ELECTRICALLY CONDUCTIVE LANGMUIR-BLODGETT MULTILAYER FILMS OF POLYANILINE

Two new methods of fabricating multilayer Langmuir-Blodgett (LB) thin films of electrically conductive polyaniline were developed. Stable-and easily transferrable LB monolayers were formed at the air-water interface by mixing polyaniline in its emeraldine-base form (PANb) with two processing aids. In the first case a conventional surface-active molecule (stearic acid (StA)) was used to promote monolayer formation. In the second case a novel polyion (PI) complex of sulfonated polyaniline and stearylamine was utilized. Although uniform Y-type LB films were fabricated from both systems, the quality and behavior of these films were observed to be greatly influenced by the type of intermolecular interaction developed between the processing aid and the conductive macromolecule. Films fabricated from the PANb-StA mixture were found to be phase separated with domains of polyaniline and stearic acid, while those from the PANb-PI blend were found to be miscible. Both polyaniline LB films were rendered conductive by doping with HCI. The high level of conductivity, in the range 0.5-1 S cm-1, exhibited by both systems indicated that the addition of a processing aid, comprising less than 25 mol% in each system, did not compromise the overall conductivity of the films.