Two-Dimensional Polyaniline Thin Film Electrodeposited on a Self-Assembled Monolayer

Abstract

A two-dimensional conducting polyaniline (PAN) monolayer has been formed on an electrically insulating monolayer. The approach is based on the electrochemical polymerization of surface-confined anilinium ions that were electrostatically attached to a negatively charged self-assembled monolayer of ω-mercaptodecanesulfonate (MDS), HS(CH2)10SO3-, on a gold surface. The formation and characterization of the two-dimensional film and the MDS monolayer have been examined by cyclic voltammetry, Fourier transform IR spectroscopy, X-ray photoelectron spectroscopy, wettability, and scanning electrochemical microscope. The formation of a capacitor-like assembly, in which electron transfer was blocked between PAN and the gold surface, was accomplished by electrochemically incorporating hexadecanethiol (C16) into the MDS monolayer. The PAN monolayer exhibits properties similar to those of a thin polymer film.