Dimple Morphology Formation on Non-woven Fabric by Fluorinated Polymers for Tunable Surface Wettability

Abstract

In this paper, we report the synthesis of two fluorinated block-copolymers, namely, poly(TFEMA-co-BMA) (PFB) and poly(HFIMA-co-BMA) (PHFB) using radical polymerization. We studied their ability to function as water-repellent surface coatings using non-woven fabric as substrate by forming dimple morphology on the fabric surface. The compositions of PFB and PHFB were determined using 1 H NMR, gel permeation chromatography (GPC), and IR spectroscopy analyses. The dimple morphology was obtained from the fluorinated polymer on non-woven fabric by drop coating in a high-humidity environment, through self-organization. Initially, water droplets were assembled on the coating solution and dried by evaporation of different solvents such as methylene chloride and chloroform. Eventually, a template of dimple morphology was formed on the non-woven fabric. The morphology can be easily tuned, for example, by choice of organic solvent, concentration, and humidity (flow rate of water vapor). The dimple morphology was observed using scanning electron microscopy (SEM). The diameters of the dimples, PFB and PHFB, were roughly 0.63 µm and 2.5 µm, respectively. The wettability on the surface was characterized using static contact angle measurements.