A robust superhydrophobic PVDF composite coating with wear/corrosion-resistance properties

A robust wear/corrosion-resistant superhydrophobic polyvinylidene fluoride (PVDF)/fluorinated ethylene propylene (FEP)/carbon nanofibers (CNFs) composite coating with a water contact angle (WCA) of 164 +/- 1.5 degrees and a slide angle of 5 +/- 0.2 degrees has been fabricated through the combination of chemical etching and spraying technique. The WCA of the coating still maintains 141 +/- 1.2 degrees after 10,000 times rubbing due to the designed internal nano/micro-structure and the slide angle increases from 5 +/- 0.2 degrees to 20 +/- 0.5 degrees. The prepared coating also demonstrates excellent corrosion-resistance property under strongly acidic or alkaline conditions for 15 days. The wear-resistance of the superhydrophobic coating is approximately 5 times higher than the pure PVDF coating and commercial fluorocarbon coating. These excellent mechanical properties are attributed to the new groups of C=C and C-C by dehydrofluorination of PVDF and the new beta-phase of PVDF by recrystallization of the alpha-phase. Furthermore, the enhanced adhesive ability of the coating corresponds with Grade 1 according to GB/T9286, mainly because that the interaction force among PVDF macromolecules can be intensified by chemical cross-linking and the hydroxyl groups formed on the surface of the aluminum plate by etching. It is believed that this robust multifunctional superhydrophobic coating may have the potential values in large-scale application. (C) 2015 Elsevier B.V. All rights reserved.