SOLID-STATE POLYMERIZATION OF PYRROLE WITHIN A LANGMUIR-BLODGETT-FILMOF FERRIC STEARATE

Ultrathin, highly conductive films have been formed by inducing the po lymerization of pyrrole within the structure of a Langmuir-Blodgett fi lm. The synthesis proceeded through the sequential exposure of a ferri c stearate multilayer to hydrogen chloride gas and pyrrole vapor. Both steps resulted in significant chemical and structural changes. The fi rst reaction converted the multilayer to stearic acid and hydrated fer ric chloride and resulted in the partial disordering of the LB organiz ation. In the second step, the oxidizing ferric chloride polymerized t he pyrrole monomer and doped the resultant polypyrrole polymer. The fi lm thickness doubled, and conductivities as high as 10 S/cm were attai ned after polymer aggregates were created in the multilayer. Infrared and ultraviolet-visible spectra indicated that the newly formed polyme r chains showed little or no preferential orientation within the LB ma trix. Electrical measurements confirmed that the polypyrrole phase sep arates into microdomains.