Durably superhydrophobic textile based on fly ash coating for oil/water separation and selective oil removal from water

Abstract

Fly ash as an industrial solid waste can pose great risks to the environment. In the present study, superhydrophobic cotton textile for oil/water separation was developed based on the formation of fly ash coating and subsequent hydrophobization. The hierarchical fly ash coating immobilized exhibited superhydrophobicity with a water contact angle of 152°. The as-prepared textile can effectively separate a series of oil/water mixtures with high separation efficiency up to 97.3%. Furthermore, the obtained textile can be used under acidic, alkaline, salty, and ultraviolet irradiation conditions. After sixteen cycles of oil/water separation, the textiles still maintained stable superhydrophobicity and high separation efficiency. Owning to good environmental friendliness, low cost, high separation efficiency, and excellent durability and recyclability, the as-prepared textile may be a promising candidate for the separation of oil/water mixtures.