Durable fluorine-free superhydrophobic polyethersulfone (PES) composite coating with uniquely weathering stability, anti-corrosion and wear-resistance

Abstract

A superhydrophobic fluorine-free polyethersulfone (PES)-based coating has been fabricated by a scale-up spraying technique. The structure of the prepared coating is constructed by polyimide (PI) particles, functionalized carbon nanofiber (CNF) and room temperature vulcanized silicone rubber (RTVSR). Attributing to the above composite components and micro-structure, the superhydrophoicity is successfully realized without extra addition of fluorine substance, reaching a high water contact angle (WCA) of 156.1 ± 1.1° and a low slide angle (SA) of 4.8 ± 0.7°. The wear life of our prepared superhydrophobic coating is over 4.5 and 2 times higher than that of the pure PES coating and the superhydrophobic SiC coating, respectively. Embracing broad engineering application prospects. Moreover, the anti-corrosion property of composite coating can be significantly enhanced with low corrosion current density of 2.04 × 10−9A/cm2 and high protection efficiency of 99.998% even after 10 days immersion in corrosive medium, which takes advantage of the defect free coating surface and air cushion captured at the solid-liquid interface based on the well-designed structure, thereby preventing the infiltration of corrosive ions. In addition, the prepared coating also manifests prominent superhydrophobic stability under the conditions of snow melting test (10 cycles), outdoor exposure (120 days) and strong UV irradiation (45 days). Studies indicated that the incorporation of PI particles, CNF and RTVSR have essential effects on the unique properties of the prepared superhydrophobic coating.