Fabrication and performance study of a superhydrophobic anti-scaling and anti-corrosion coating

In this work, we designed and fabricated an anti-scaling and anti-corrosion superhydrophobic 1H,1H,2H,2H-perfluorodecyl triethoxysilane (PFDS)/ethylenediamine tetraacetic acid (EDTA)/anodized copper oxide (ACO) coating at the surface of a copper alloy. The water contact angle of PFDS/EDTA/ACO coating reaches 164.53°, showing superhydrophobicity, which will reduce the contact between scale crystals, corrosive medium and substrates, and help to inhibit scaling deposition and corrosion. Results show during the CaCO3 deposition test, EDTA molecules, EDTA-Zn2+ and EDTA-Cu2+ chelates stored in the micro-structure of superhydrophobic PFDS/EDTA/ACO coating are released to the interface and help to improve scaling prevention. After soaking for 48 h, the CaCO3 scaling mass of PFDS/EDTA/ACO coating was only 27.0 % that of ACO coating, and the corrosive protection efficiency of the superhydrophobic PFDS/EDTA/ACO coating was improved by 3.4 times that of ACO coating. Studies indicated that the anti-scaling and anti-corrosion of the superhydrophobic PFDS/EDTA/ACO coating contributes to the cooperation of superhydrophobic air film and the potential storage and dynamic release of EDTA, as well as the passivation layer formed on the substrate.