Compositing fluid infused in superhydrophobic Cu(OH)2 nanoneedle matrix to inhibit abiotic and microbiologically induced corrosion of Cu in seawater environment

Abstract Although superhydrophobicity (SHP) and liquid infused surface (LIS) bio-inspired by the lotus leaf and pitcher plant have afforded high corrosion inhibition to metals, they still have the drawbacks such as short term duration and drainage in water phase. In this report, using a facile electrochemical anodization approach, Cu(OH)2 nanoneedle matrix is built onto Cu substrate. The surface modification with dodecanethiol enables superhydrophobicity wettability. Oil and hydrophobic ZnO nanoparticle obtained by modification with dodecanethiol realize compositing liquid infused surface (CLIS) on Cu surface. For superhydrophobic Cu(OH)2 layer, its corrosion inhibition to Cu is limited. However, when Cu metal is covered with compositing fluid, the corrosion inhibition capability to abiotic and biotic corrosion induced by sulfate reducing bacteria has been remarkably enhanced. After immersion in seawater for 20 days, Z0.01Hz of CLIS Cu is still as high as 1.30 × 109 Ω·cm2, confirming the higher protection efficiency than SHP and LIS coverage. For biotic corrosion inhibition, after soaking for 10 days in sulfate reducing bacteria suspension, Z0.01 Hz of CLIS Cu still remains 1.25 × 105 Ω·cm2, which is much higher than SHP Cu and LIS Cu. Hydrophobic nanoparticles work as the additional absorption matrix to further anchor oil phase, so that drainage will be avoided. The duration of the coating is enhanced. Therefore, CLIS layer has afforded a versatile route to protect Cu from both seawater corrosion and microbiologically induced corrosion.