Robust and Durable Superhydrophobic Polythiophene/SiO2 Coated Cotton Fabric for Versatile Oil-Water Separation

With the development of industrialization, environmental pollution problems (e.g., oily water discharge and oil spill accidents) are becoming increasingly severe. The efficient and economic treatments for oily sewage are urgently needed and remain a huge challenge. Here, a robust and durable superhydrophobic material with the contact angle above 160 degrees is prepared by coating SiO2 particles/polythiophene on cotton fabrics through a sol-gel process and an oxidation coupling polymerization. The polythiophene/SiO2 coated cotton fabric displays excellent resistance to ultraviolet irradiation, high and low temperatures, acid and salt solution immersion, organic solvent immersion, and good mechanical abrasion durability, antidirt and antifrost properties. The modified fabric is successfully applied as a filter to separate oil-water mixtures by gravity with high separation efficiency and excellent reusability. Moreover, superhydrophobic absorbers can be easily prepared from common 3D porous materials such as a sponge wrapped with the modified fabric for the effective collection of oil. Both immiscible oil-water mixtures and emulsions (oil-in-water and water-in-oil) can be separated even under harsh conditions (acidic solution or artificial seawater). This work provides a facile and selectable solution to treat oily sewage and leads to new ways of efficient oil-water separation.