Spectroscopic, microscopic, and surface analysis of alkanethiol- and fluoroalkanethiol-modified conducting polymer thin films

Electrochemically grown films of polyaniline, polypyrrole, polythiophene, a nd poly(ethylenedioxythiophene) were treated with alkane- and fluoroalkanet hiols for 1-24 h. The resulting films showed surface energies and polaritie s similar to glass slides coated with monolayers of the corresponding alkyl - and fluoroalkylsilanes. Treatment of the polyaniline, polypyrrole, and, t o a lesser extent, poly(ethylenedioxythiophene) films resulted in covalent bonding of the thiol to the polymer backbone as evidenced by X-ray photoele ctron, energy-dispersive X-ray, and electronic spectroscopies. Polypyrrole and poly(ethylenedioxythiophene) films showed reduced electroactivity upon treatment, while the derivatized polyaniline could be returned to a conduct ing state. Polythiophene primarily oxidized the thiols to soluble products, leaving the polymer backbone unaffected.