Thin Nanocomposite Films of Polyaniline/Au Nanoparticles by the Langmuir-Blodgett Technique

The Langinuir-Blodgett (LB) method was used to deposit multilayers of polyaniline (PANI)- and mercaptoethanesulfonate (MES)-stabilized Au nanoparticles, The electrostatic interaction between the negatively charged nanoparticles in the subphase and the positively charged PANI at the air-water interface assisted the deposition of the nanocomposite film onto a solid support. These PANI/Au-NPs films were characterized using cyclic voltammetry, copper under potential deposition, scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. We found that the nanocomposite layers were uniform and reproducible. The density of Au-NPs in the monolayer depended oil the acidity of the subphase as well as oil the nanoparticles concentration. Moreover, the Au-NPs extrude above the PANI and therefore could be used as nanoelectrodes for the underpotential deposition (UPD) of copper.