Facile, robust and large-scale fabrication method of mechanically durable superhydrophobic PDMS/aerogel coating on fibrous substrates

Abstract

A simple method was developed for the large-scale fabrication of mechanically durable superhydrophobic surfaces with roughness on the microscale. The method is applicable for a large number of fibrous substrates with different pore sizes. With this method, it is possible to prepare polymeric fibrous substrates with a water droplet (5 μL) roll-off angle of less than 5°. The method developed is based on dip-coating of fibrous substrates in polydimethylsiloxane (PDMS)/toluene solution, followed by the electrostatic spray of aerogel microparticles on the samples. Depending on the PDMS solution concentration, it is possible to obtain a superhydrophobic surface with dual-scale roughness on the microscale. In this article, preparation and characterization of surfaces with electrostatic powder spray on the common fibrous cellulose substrates are provided. Fibrous surfaces obtained were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy and static water contact angle measurement. Effects of PDMS/toluene solution concentration on the surface morphology and wettability behavior of surfaces were investigated. We demonstrate the mechanical durability of the surface using high-pressure air flow.