Corrosion protection by hydrophobic silica particle-polydimethylsiloxane composite coatings

In this study, the time-dependent corrosion protection ability of 10-15 mu m thin polydimethylsiloxane-nanoparticle composite coatings was evaluated using mainly open circuit potential and electrochemical impedance spectroscopy measurements. The best result was obtained for the coating containing 20 wt% hydrophobic silica nanoparticles, where it was possible to achieve protection for almost 80 days in 3 wt% NaCl solution. The protective properties offered by this coating are suggested to be due to a synergistic effect of the hydrophobicity of the polydimethylsiloxane matrix and the prolonged diffusion path caused by addition of hydrophobic silica particles. (C) 2015 Elsevier Ltd. All rights reserved.