In-situ deposited thin films of polypyrrole: conformational changes induced by variation of dopant and substrate surface

Thin films of polypyrrole (PPY) were deposited in-situ from aqueous polymerizing solutions of pyrrole onto the surface of various substrates. A relationship between the structure of the dopant ion, conductivity, and optical absorption in the near IR was observed. The changes in conductivity and spectra are related to molecular conformational changes of polypyrrole. Conductivity and adhesion could be optimized by tuning the hydrophobicity of substrate surface. Thickness and morphology of deposited films were determined by Atomic Force Microscopy (AFM) [1]. AFM images showed that the films consist of fused globular particles.