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-an d easily transferrable LB monolayers were formed at the air-water inte rface by mixing polyaniline in its emeraldine-base form (PANb) with tw o processing aids. In the first case a conventional surface-active mol ecule (stearic acid (StA)) was used to promote monolayer formation. In the second case a novel polyion (PI) complex of sulfonated polyanilin e 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 ma cromolecule. 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 polyanil ine LB films were rendered conductive by doping with HCI. The high lev el of conductivity, in the range 0.5-1 S cm-1, exhibited by both syste ms indicated that the addition of a processing aid, comprising less th an 25 mol% in each system, did not compromise the overall conductivity of the films.