Silicone and nano-diamond modified graphene oxide anticorrosive coating

Abstract

Graphene oxide (GO) has abundant oxygen-containing functional groups, making it easy to undergo covalent and non-covalent modifications, coupled with its excellent physical barrier ability, which shows great prospects in improving the corrosion resistance of coatings. Unfortunately, GO has a strong van der Waals force and π-π interactions, which make it prone to self-aggregation, and at the same time, in the process of preparing the coating due to the volatilization of solvents, it is easy to produce micropores and other defects, which will not be conducive to the long-term corrosion resistance of the coating. Therefore, this work used silicone as a “bridge” to modify GO with nanodiamond, and then a composite coating with excellent anticorrosion properties was prepared with vinyl ester resin under heating conditions. This work not only effectively solved the dispersion and interface interaction of GO in the resin, but also the diluent in this process could fully participate in the polymerization reaction, effectively avoiding the volatilization of volatile gases. The results showed that the conductivity of the modified GO reached the level of the insulating material (9.6 × 10−9 S/cm, 30 MPa pressure). Electrochemical tests showed that the |Z|0.01Hz value of the coating was as high as 1.00 × 109 Ω cm2 after soaking in 3.5 wt% brine for 120 days, which was three orders of magnitude higher than the control group. Compared to the control group, the protective efficiency of the coating remained at 97.8 %. This was mainly related to the synergistic anticorrosion effect of GO and nano-diamond. In short, this work provided a new research approach for the preparation of long-lasting anticorrosion coatings using zero-dimensional and two-dimensional materials.