A facile approach to superhydrophobic coating from direct polymerization of “super glue”

Abstract

Superhydrophobic surfaces, which have amazing abilities such as self-cleaning and drag reduction, have aroused great interest in both academic studies and industrial fields in the past decade. Although many methods and techniques to fabricate superhydrophobic surfaces have been investigated, most of the coatings have a lack of adherence which hinders the practical usage. Herein, we introduce a superhydrophobic coating developed from ethyl α-cyanoacrylate (ECA), which is a kind of widely used glue with tenacious adhesion to various substrates. A liquid film of ECA monomers was coated on a substrate and put in an environment of ammonia vapor and high humidity at room temperature. The polymerization concurrently started at the top of the film triggered by ammonia and at the bottom initiated by the substrate. A layer of PECA microfibers was formed at the surface first, and then vapor phase polymerization of the volatilized ECA monomers was conducted on the as-formed microfibers generating twisted and coiled micro/nanofibers. After the monomers were all consumed, a PECA coating with three layers were generated: one layer of micro/nanofibers on top, one layer of microfibers in the middle and one layer of bulk PECA at the bottom. The polymeric coating obtained a CA as high as 158° and SA of 4° due to the micro/nanofiber-structured surface and a good adhesion to the substrate.