Effects of electrochemical synthesis conditions on poly(o-methoxyaniline) thin films formation

This article investigates how preparation conditions, such as monomer concentration and anodic charge, influence poly(o-methoxyaniline) (POMA) thin film electrochemical synthesis by cyclic voltammetry. Electrochemical Quartz Crystal Microbalance monitoring of mass increase during POMA electrosynthesis helped to establish a relationship between polymeric film mass and anodic charge as a function of monomer concentration and the number of polymerization cycles. POMA film electrosynthesis carried out at monomer concentrations above 0.5 mol L-1 demands a larger number of cycles to reach 69 mC cm(-2), an indication of lower growth rate. Scanning Electron Microscopy revealed that the POMA film first surface layer is more compact and has uniform granular morphology with spherical grains of different sizes. This produces agglomerates that are distributed in the first layer. A lower quantity of these agglomerates appear in POMA films synthesized at monomer concentrations higher than 0.5 mol L-1 probably as a result of degradation reactions. This study provides useful information about POMA films, which can be used as substrate for Pt catalyst particles during methanol electrooxidation. (C) 2018 Elsevier B.V. All rights reserved.