A Durable Superhydrophobic Composite Coating Towards Superior Anticorrosion/Wear Properties

Abstract

Superhydrophobic coatings are attractive as physical barrier layer in various fields. However, the poor durability and unsatisfactory anti-corrosion/wear properties limit their down-to-earth practicality. Here, a durable superhydrophobic coating (PDMS-EP@SiO2-fGO) with good corrosion/wear resistance was prepared by a fluorine-free, facile and low-cost approach. The results of temperature resistance (20~100°C), acid/alkali resistance (pH value of 1~14), sandpaper abrasion (40 m) and tape-peeling (30 cycles) proved the excellent mechanical/chemical stability of PDMS-EP@SiO2-fGO, as shown by a contact angle of more than 156° and a sliding angle of less than 6.3° after experiments. Moreover, PDMS-EP@SiO2-fGO showed the desired protection performance. In 3.5 wt.% NaCl solution, the corrosion current density was decreased by four orders of magnitude. After 7 days of immersion, the lowest-frequency impedance value was 1~2 orders of magnitude higher than that of control groups. Under the reciprocating friction process, the wear rate was reduced by 70.76%. These delightful results were mainly attributable to the synergistic effect of robust air cushion constructed by surface micro/nano structure and the reinforcement/physical barrier effect of well-dispersed amino-functionalized graphene oxide. This work provides a feasible thinking to optimize the superhydrophobic coating and helps its large-scale application.

Keywords: superhydrophobic coating, Functionalized graphene oxide, durability, Corrosion/wear resistance