Fabrication of Ultra-Water-Repellent Polymeric Substrates by a Two-Step Plasma Process

Abstract

The wettability of a solid surface is governed by two factors, that is, its surface morphology and composition. Ultra water-repellent polymeric substrates [poly(ethylene naphthalate) and polystyrene] have been fabricated while retaining their transparency by a two-step plasma process combining oxygen plasma etching and plasma-enhanced chemical vapor deposition (PECVD). In order to avoid optical scattering, appropriate nanotextures were prepared on the polymeric substrates through the oxygen plasma etching. Subsequently, a hydrophobic layer was coated on the nanotextured surfaces by PECVD using an organosilane source. The modified surfaces were certainly ultra-water-repellent, showing water contact angles greater than 150°.