A Facile and Non-toxic Approach to Develop Superhydrophobic Cotton Fabric Using Octadecylamine and Hexadecyltrimethoxysilane in Aqueous System

Abstract

This study aimed to develop a simple way to design a durable functional superhydrophobic cotton surface by using a self-assembled octadecylamine (ODA) layer to support formation of a micro/nanostructure with hexadecyltrimethoxysilane (HDTMS) in aqueous dispersion. The effect of a molar ratio in the mixture of ODA and HDTMS on superhydrophobicity, surface morphology, chemical composition and wettability were investigated. When the cotton fabric was treated with ODA only, petal-like structures were formed and the surface exhibited a water contact angle (WCA) of 93 ° and shedding angle (SA) of above 90 °. When the fabric was treated with HDTMS only, the surface became more hydrophobic with a WCA of 137 ° and a SA of 18 °. The specimen treated with the solution of ODA/HDTMS mixture, however, micro/nanoscale structures were formed on the surface and represented superhydrophobic properties with a WCA of 161 ° and a SA of 8°. The optimum superhydrophobicity was shown at the 1:3 molar ratio of ODA/HDTMS. After peeling or washing test, WCA slightly decreased and SA increased. Interestingly, the fabric partially damaged by washing or acid/alkali treatment restored its superhydrophobicity after drying at room temperature. Air permeability of the specimen treated at the optimum condition decreased, but the water vapor transmission rate was nearly maintained with only a slight decrease. The contribution of this study is the fabrication of superhydrophobic cotton fabric with durable/self-healing performance and breathability via a one-step water-based dip-coating method allowing to reduce the surface energy and forming micro/nanoscale roughness at the same time in an aqueous system.