Stable slippery coating with structure of tubes and pyramids for inhibition of corrosion induced by microbes and seawater

Abstract

Corrosion induced by microorganisms and seawater can accelerate the failure of metals. To inhibit the corrosion process, in this work, an aluminum oxide coating with tubes-pyramids structure and SLIPS (AO-TP-SLIPS) is fabricated by employing a three-step method, which includes anodizing of Al, fluorination modification and lubricant infusion. To this end, the AO-TP-SLIPS coating affords stable mechanical properties and high corrosion-resistance against microorganisms and seawater. The pyramids structure of the AO-TP-SLIPS surface forms a barrier and slows down the consumption of the lubricant in the tubes, which is one of the key reasons for the improved corrosion resistance. The electrochemical measurements show that the AO-TP-SLIPS coating attains a corrosion current density of 3.39 × 10−12 A cm−2 in Pseudomonas aeruginosa broth and 3.17 × 10−13 A cm−2 in seawater. A high corrosion resistance of the AO-TP-SLIPS specimen retains for 36 days in seawater. This work demonstrates that a composite structure with tubes and pyramids can prolong the service life of coatings in an efficient way, which offers a theory basis for applications of SLIPS in marine environment.