Superhydrophobic sand with multifunctionalities by TiO2-incorporated mussel-inspired polydopamine

Abstract

Sand as a kind of natural material exists abundantly in desert has not been effectively utilized because of its superhydrophilicity. In this study, the superhydrophobic sand particles were successfully fabricated by structuring mussel-inspired polydopamine and TiO2 coatings on sand surfaces and subsequent hydrophobic modification with low surface energy material. The water droplets stood on the superhydrophobic sand surfaces with an almost perfect sphere (water contact angle of ~153°), which broke the conventional concept towards the superhydrophilicity of sand. Furthermore, the obtained superhydrophobic sand particles had good water-holding capacity and high thermal stability, which contributed to the storage of water in desert. Meanwhile, the superhydrophobic sand exhibited a multifunctionality including oil/water separation, anti-icing properties and waterproof coating on fiberboards, which widened the application fields of desert sand and provided fast access to sustainable development of environment and natural resource.