Polyaniline monolayer self-assembled on hydroxyl-terminated surfaces

A monolayer of conducting polymer, polyaniline (PAN), was assembled on hydr oxyl-terminated surfaces, such as quartz, glass, indium-tin oxide, and nati ve oxide on Si. The approach for assembling two-dimensional monolayers of P AN is based on a chemical or electrochemical surface polymerization of elec trostatically bound anilinium. The latter was bound to the negatively charg ed sulfonate group of mercaptoethanesulfonate that was previously coupled b y an S(N)2 reaction to an iodopropyl self-assembled monolayer. The consecut ive assembling steps were followed by X-ray photoelectron spectroscopy, W-v is-NIR spectroscopy, variable angle spectroscopic ellipsometry, contact ang le, and atomic force microscopy measurements. The characteristic electronic properties of the PAN monolayers were studied by W-vis-NIR spectroscopy an d cyclic voltametry.