Constructing robust superhydrophobic interface with self-assembled Cu6Sn5 arrays and application in copper corrosion inhibition

The superhydrophobic scallop-like Cu6Sn5 micro/nano structure were successfully constructed on pure copper substrate by heat-induced Cu/Sn interfacial metallurgical reaction and simple chemical modification process. The microstructure, chemical composition and corrosion resistance of as-prepared samples were characterized by field emission scanning electron microscopy and X-ray photoelectron spectroscopy, etc. The results show that the averaged shear resistance strength between micro Cu6Sn5 and Cu substrate is higher than 40 MPa. After modified with myristic acid and Cu2+, copper myristate with low surface energy is formed on the armor Cu6Sn5 surface. The wetting angle of water droplets on as-modified surface is higher than 150° and its rolling angle is 7.2°. Compared with pure copper, the self corrosion current density of the samples modified by copper myristate in 3.5%NaCl(mass fraction) solution is about 1/10 of that of the samples before modification,showing better corrosion resistance. Based on the metallurgical bonding mechanism between intermetallic compounds and metal matrix, the armor formation strategy of metal materials in micro-scale by heat-induced interfacial reaction is proposed, which can successfully solve the open and key scientific problem of low mechanical stability for artificial superhydrophobic interface.