Facile fabrication and evaluation of self-healing Zn-Al layered double hydroxide superhydrophobic coating on aluminum alloy

Abstract

The preparation of superhydrophobic coating on the surface of aluminum alloy can effectively improve its performance in the harsh environment. In this work, a superhydrophobic coating with water contact angle (WCA) up to 157.5\u2009±\u20090.5° and sliding angle less than 3° is prepared on aluminum alloy 6061 substrate by simple and environment-friendly hydrothermal reaction and stearic acid modification. The in situ growth coating is composed of Zn-Al layered double hydroxide and the morphology of the coating was a micro–nano composite structure with micro-sheet and nano-needle. The stearic acid is combined with the coating by physical adsorption and chemical bonding. The superhydrophobic coating imparts the properties of low adhesion, self-cleaning, and anti-corrosion to the aluminum alloy substrate, and it also has good high-temperature stability, acid and alkali resistance, mechanical stability and time durableness. The superhydrophobic coating can spontaneously recover 7 times after damaged by oxygen plasma etching. The outstanding comprehensive performance of the coating makes it a promising application for protection of aluminum alloy.