Polyaniline monolayer self-assembled on hydroxyl-terminated surfaces

A monolayer of conducting polymer, polyaniline (PAN), was assembled on hydroxyl-terminated surfaces, such as quartz, glass, indium-tin oxide, and native oxide on Si. The approach for assembling two-dimensional monolayers of PAN is based on a chemical or electrochemical surface polymerization of electrostatically bound anilinium. The latter was bound to the negatively charged sulfonate group of mercaptoethanesulfonate that was previously coupled by an S_N2 reaction to an iodopropyl self-assembled monolayer. The consecutive assembling steps were followed by X-ray photoelectron spectroscopy, UV-vis-NIR spectroscopy, variable angle spectroscopic ellipsometry, contact angle, and atomic force microscopy measurements. The characteristic electronic properties of the PAN monolayers were studied by UV-vis-NIR spectroscopy and cyclic voltametry.