Nanostructured superhydrophobic lyocell fabrics with asymmetric moisture absorbency: Moisture managing properties

This study investigated moisture management properties of a single-faced superhydrophobic fabric. A single-faced superhydrophobic lyocell fabric, where one face of the surface is superhydrophobic and the opposite face is hydrophilic, was produced by a two-step plasma process on one side of the fabric: (1) the addition of nano-scale roughness by 5 minutes of O2 plasma etching; (2) subsequent 30 seconds of plasma enhanced chemical vapor deposition with hexamethyldisiloxane to lower the surface energy of lyocell fibers. As a result, the superhydrophobic lyocell fabric exhibited water repellency with a static water contact angle greater than 161° on the treated surface, allowing water absorption from the untreated face. The nanometer depth of the superhydrophobic layer in the hydrophilic textile affected water absorption capacity, drying rate, vertical wicking rate, and moisture management properties. The air permeability and water vapor transmission rate of the superhydrophobic treated lyocell fabric were hardly changed. The superhydrophobic properties were maintained after a gentle wash cycle, although the level of superhydrophobicity was reduced, especially when it was washed with detergent. This superhydrophobic and moisture managing textile would be relevant for an application that requires a water repellent property on one face and water absorbing property on the opposite face, such as medical operation gowns, wound dressings, and hygienic products.