PREPARATION OF ELECTRONICALLY CONDUCTING ULTRA-THIN POLYMER-FILMS

Admicellar polymerization uses adsorbed surfactant aggregates to conce ntrate monomeric species at the solution-solid interface and to locali ze the polymer-forming reaction over a surface. The process has been a dapted for the deposition of polypyrrole thin films on mica substrates . Amphiphiles adsorb from aqueous solution onto mica substrates and fo rm self-assembled arrays. These arrays have been characterized by atom ic force microscopy (AFM). Polypyrrole films prepared by polymerizatio n in the self-assembled arrays (PSAA) were characterized and compared with samples made by polymerization in the absence of self-assembled a rrays (surface nucleation, PSN). Images and measurements by AFM indica te that PSAA films over mica surfaces tend to be much smoother than PS N layers at the same condition. The ultrathin PSAA (130 nm) can be fab ricated simply, controlled by changing the ratio between water, surfac tant, and pyrrole concentration under ambient conditions. Although thi nner, PSAA films have more stable and higher conductivity than the PSN films. The relationship between film morphology and electronic proper ties has been discussed.