Anti-corrosive and scale inhibiting polymer-based functional coating with internal and external regulation of TiO₂ whiskers

A novel multi-functional carrier of mesoporous titanium dioxide whiskers (TiO₂(w)) modified by ethylenediamine tetra (methylene phosphonic acid) (EDTMPA) and imidazoline was devised in epoxy coating to improve the anti-corrosion and scale inhibition properties of metal surface. Rigorous characterization using analytical techniques showed that a mesoporous structure was developed on the TiO₂(w). EDTMPA and imidazoline were successfully grafted on the outer and inner surfaces of mesoporous TiO₂(w) to synthesize iETiO₂(w). The results demonstrated that the corrosion resistance of the final iETiO₂(w) epoxy coating is 40 times higher than that of the conventional unmodified OTiO₂(w) epoxy coating. The enhanced corrosion resistance of the iETiO₂(w) functional coating is due to the chelation of the scaling cations by EDTMPA and electron sharing between imidazoline and Fe. Scale formation on the iETiO₂(w) coating is 35 times lower than that on the unmodified OTiO₂(w) epoxy coating. In addition, EDTMPA and imidazoline act synergistically in promoting the barrier property of mesoporous TiO₂(w) in epoxy coating. It is believed that this novel, simple, and inexpensive route for fabricating functional surface protective coatings on various metallic materials will have a wide range of practical applications.