Anodic electrodeposition of highly oriented zirconium phosphate and polyaniline-intercalated zirconium phosphate films

Films of highly oriented alpha-zirconium phosphate and polyaniline- intercalated zirconium phosphate with controllable thickness in the micrometer range were grown anodically on Pt electrodes. To optimize the electrodeposition conditions, the exfoliation of alpha-zirconium phosphate by tetrabutylammonium (TBA) salts was investigated in several nonaqueous solvents. Acetonitrile was found to be the best solvent for making crack-free, oriented films because of its high vapor pressure, low viscosity, and relatively high permittivity. With TBA salts of neutral or weakly acidic anions (TBACl, TBABr, TBAI, TBA(HSO4), or TBA(H2PO4)), full exfoliation did not occur and alpha-zirconium phosphate and/or polyaniline were deposited as rough films. With basic anions (TBAF or TBAOH), dense, adherent films were obtained. X-ray diffraction patterns of the films showed that they were highly oriented along the stacking axis. The thickness could be controlled, up to about 40 Am, by limiting the time of the electrodeposition reaction. At monomer concentrations below 1.0 x 10(-2) mol/dm(3), the emeraldine form of the intercalated polymer was obtained. Electrodeposition thus provides a thick film alternative to layer-by-layer assembly for intercalation compounds of alpha-zirconium phosphate with a conducting polymer.