In Situ crystallization to zinc aluminate films with controlled surface microstructure and anticorrosion performance

Spinel-type zinc aluminate (ZnAl2O4) thin films with controlled surface microstructure on aluminum substrates were fabricated via a facile and effective in situ crystallization method without using any templates or surfactants. The surface microstructure of ZnAl2O4 films could be significantly controlled by varying the experimental conditions including concentration of reactants, crystallization temperature, and crystallization time. After surface modification, the specific topography of ZnAl2O4 films was beneficial to obtain surface hydrophobic or superhydrophobic properties. More importantly, compared to nanoparticle- and nanosword-assembled ZnAl2O4 films, nanorod-assembled ZnAl2O4 film provided a more effective barrier to aggressive species for aluminum substrates in a wide range of pH values; very low corrosion current density of the order of similar to 10-19 A cm-12 could be achieved. A new contribution to the development of advanced coating system with ZnAl2O4 film materials that can be used in practical application for corrosion protection of aluminum materials is provided. (c) 2011 American Institute of Chemical Engineers AIChE J, 2012