Fluorine free TiO2/cyanate ester coated cotton fabric with low surface free energy and rough surface for durable oil-water separation

Low cost superhydrophobic cotton fabric was developed using TiO2/cyanate ester coating for the first time. The TiO2/cyanate ester coated cotton fabric displayed superhydrophobic behaviour with water contact angle of 158 degrees, sliding contact angle of 8 degrees and surface free energy of 18.0 mN/m(2). Besides, the TiO2/cyanate ester coated cotton fabric also possesses excellent laundry durability as well as stability against acid, alkali salt solutions and mechanical abrasion. Consequently, the TiO2/cyanate ester coated cotton also delivered superior oil-water separation efficiency with different types of oil/water mixtures that includes engine oil/water, waste engine oil/water, petrol/water and diesel/water. The TiO2/cyanate ester coated cotton fabric shows separation efficiency as high as 98% with flux value of 7200 L/m(2)h for petrol/water mixture. Further, both cyanate ester and TiO2/cyanate ester coated cotton fabric delivers ultra-high UV-resistant ability with Ultraviolet Protection Factor value as high as 500 + . Hence, it is anticipated that the present approach of using cyanate ester can be widely explored further to construct multifunctional fabrics towards excellent self-cleaning as well as oil/water separation with UV and chemical robustness.