Preparation of Langmuir−Blodgett Films of Soluble Polypyrrole

Stable monolayers of soluble parent polypyrrole (Ppy) and mixed monolayers of cadmium stearate and Ppy were studied for the first time using surface pressure and surface potential isotherms. Ppy was obtained by chemical polymerization of the pyrrole monomer in the presence of dodecylbenzene sulfonic acid and characterized by ultraviolet−visible (UV−vis), Fourier transform infrared (FTIR), and elemental analysis techniques. Pure Ppy monolayers could only be transferred if optimized experimental conditions were employed, but mixed monolayers could be easily transferred in the form of Y-type Langmuir−Blodgett (LB) films, with a uniform layer-by-layer transfer according to UV−vis results. The FTIR spectrum indicated the presence of cadmium stearate along with Ppy. X-ray diffraction patterns showed the presence of cadmium stearate domains. The transferred LB films were characterized by electrical conductivity, cyclic voltammetry, and surface potential measurements.