Fabrication of durable super-repellent surfaces on cotton fabric with liquids of varying surface tension: Low surface energy and high roughness

In this study, we have developed super-repellent surface on cotton fabric via a facile and eco-friendly strategy using zirconia particles with water-soluble siloxane emulsion. The coated fabric using zirconia-siloxane (ZS) coating showed super-repellency of liquids with surface tension >47.7 mN/m, like water, mixtures of isopropyl alcohol with deionized water (2% and 5%, v/v), and ethylene glycol with contact angle of 158(omicron), 155(omicron), 153(omicron) and 152(omicron), respectively. Furthermore, the coated fabric displays low sliding angle, <10(omicron), with these liquids. The super-repellency of the coated fabric is attributed due to its lower surface energy (<1.0 mJ m(-2)). The produced coating exhibited excellent durability and retained its super-repelling properties under harsh environment conditions like acidic, alkaline, salty, ultraviolet irradiation, mechanical abrasion and repeated tear test with an adhesive tape. In addition, in a mixture of water and oil (having surface tension <30 mN/m), the developed coated fabric exhibited dual nature viz., superhy-drophobicity and superoleophilicity, maintaining the super-repellency with water even they are wetted with oily liquids. The materials with ability to repel water in the presence of oily pollutants are very useful in application related to sea water. Thus as-prepared coated fabric, with dual functionality, is a promising material for many applications including anti-wetting, self-cleaning, support for aquatic floating devices and as a filtration material for rapid and continuous oil-water separation. (C) 2017 Elsevier B.V. All rights reserved.