Anticorrosive oligoaniline-containing electroactive siliceous hybrid materials

Abstract

In this work, a novel electroactive silsesquioxane precursor, N-(3-triethoxysilylpropylureido) aniline tetramer (TESPAT), was synthesized via one-step coupling reaction between phenyl-capped aniline tetramer (AT) and 3-(triethoxysilyl)propyl isocyanate (TESPIC) under mild conditions. The chemical structure and electroactivity of the resulting silsesquioxane precursor were investigated by FTIR, NMR, UV-vis spectra, and cyclic voltammetry. Subsequently, the sol–gel reactions of TESPAT with triethoxymethylsilane (TEMS) at various compositions were carried out to achieve new electroactive siliceous hybrid materials with good thermal stability. Furthermore, polarization curves and electrochemical impedance spectroscopic (EIS) measurements indicated that the obtained hybrid materials exhibit remarkably enhanced corrosion protection on Q235 electrodes as compared to pure silica coating. The significantly improved anticorrosion performance is attributed to the redox catalytic capabilities of the AT units in the hybrid materials.