Construction of a novel painting system using electrodeposited SiO2 film as the pretreatment layer

The present work reports a novel painting system for mild steels using electrodeposited silica (E-SiO2) film as the pretreatment layer. The electrodeposition is based on basic catalysis of sol–gel processes (hydrolysis and condensation reactions) of tetraethoxysilane by applying a negative potential. The highly porous E-SiO2 layer obtained ensures good adhesion to the topcoat. The painting system constructed on E-SiO2 pretreatment layer is superior in its corrosion performance to traditional phosphating process. It is believed that such environmentally friendly and low-cost pretreatment layer can be used to fabricate highly corrosion resistant painting system for a variety of structural metal substrates.

► Electrodeposited SiO2 film is used as pretreatment layer for painting system. ► The new painting system exhibits good corrosion performance. ► Such type pre-treated layer shows wide applicability on various metals.