No abstract

A facile strategy to boost anticorrosion potency of graphene oxide/silica hybrid sol-gel coating is developed through fully exploiting the capabilities of graphene oxide (GO). Together with a barrier to corrosives and crack inhibitor, GO was further explored herein as a regulator to regulate the gelation process and provide robust coating films with stratified microstructures and ultimately extended diffusion paths. The sol-gel coating with stratified microstructure achieved on AA5052 aluminum alloy surface afforded greatly enhanced corrosion protection capability as assessed by electrochemical measurements and immersion tests. The corrosion current density of the sample of a hybrid GO sol-gel film was about 30 times less than that of sample of pure sol-gel film sample. The regulation mechanism of GO during the film formation process and the anticorrosive protection properties of the film were discussed.

The purpose of this work is to study the effect of nanofibrous SiO2 on the corrosion protection performance of the sol-gel film coated on AA5052 aluminum alloy. The structure and surface morphology of the hybrid film ware evaluated by Transmission electron microscope (TEM) and Scanning electron microscopy (SEM), the result highlighted that the surface of composite films appears uniform and the nanofibrous SiO2 was evenly dispersed in the film. By analyzing the results of infrared spectroscopy, the addition of nanofibrous SiO2 enhanced the cross-linking of the sol-gel film. The electrochemical behavior of coated samples was determined by electrochemical test. The corrosion protection performance of the sol-gel film had a great improvement with addition of nanofibrous SiO2, the optimal additive concentration was 1 mg/ml at which the hybrid film showed the best corrosion protective performance in 3.5% NaCl solution. From the result of potentiodynamic polarization, the corrosion rate of sample coated with the sol-gel film with 1 mg/ml nanofibrous SiO2 was about 6 times slower than pure sol-gel film coated sample.