Effect of sol–gel catalyst on the microstructure of silica-based xerogel films for eco-friendly anticorrosion films

In this study, the sol–gel process is used to prepared silica xerogels using various basic and acidic (ammonium hydroxide, hydrochloric acid, nitric acid, acetic acid) catalysts with the same precursor (Tetraethyl orthosilicate – TEOS) and solvent (ethanol) and applied on carbon steel by using dip-coating technique. Optical Microscopy and Scanning electron microscopy (SEM) and energy dispersive X-ray (EDS) is used to analyze the microstructure of xerogels. Hydrolysis and condensation of sol-gel are the main mechanisms to control size, distribution of particles and It is found that the type of catalysts which used in synthesis of xerogels affect the cracks and uniformity of films were related to the microstructure of silica xerogels, which depends on the catalysts used in the sol–gel process, then, the cracks and uniformity of films were investigated by mentioned analysis. The cracks of coated films were decreased by using acetic acid and hydrochloric acid which showed more uniformity than the other films which synthesis by different catalysts, and confirmed suitability for anticorrosive coating applications to protect metal alloys against corrosion.

کلیدواژه ها:

: Sol-gel ، Xerogel ، Eco-friendly coatings ، Protection coatings