Bioinspired and hydrophobic alkyl-silanized protective polymer coating for Mg alloy

The modification of silica coating surfaces by trimethylsilylation has contributed to enhanced hydrophobicity ( θ w o > 90° ) against fluid permeation and corrosion in NaCl. These alkyl-silanized coatings were deployed to protect Mg alloy after reinforcing their internal structures with nanosilica powder. The reduced wetness of coating surfaces is attributed to their chemically-modified surface morphology, and this has been compared to the reticulate leaf structures of lotus plant. The optimum amount of silylating additive (hexamethyldisilazane) required to prepare a hydrophobic coating with minimum water adhesion has been established. Barrier performance of coatings were examined by electrochemical and surface analyses in 5 wt% NaCl. The corrosion resistance of these coatings is a result of the direct contribution of their bulk stability and surface hydrophobicity, and this is expressed in terms of the variation of electrochemical parameters with exposure time. These coatings may have emerging industrial applications, including a future in metal surface treatments and anticorrosion paints. • Trimethylsilylation of silica coatings enhances their surface hydrophobicity. • Silanized coatings are deployed to protect Mg alloy. • Reduced coating wetness is linked with trimethylsilylated surface morphology. • Barrier strength of coatings is examined in chloride media. • Corrosion resistance relates to bulk stability/surface hydrophobicity of coatings.