A self-cleaning polybenzoxazine/TiO2 surface with superhydrophobicity and superoleophilicity for oil/water separation.

Two important properties-the low surface free energy of polybenzoxazine (PBZ) and the photocatalysis-induced self-cleaning property of titanium dioxide (TiO2) nanoparticles-are combined to develop a promising approach for oil/water separation. They are integrated into a multifunctional superhydrophobic and superoleophilic material, PBZ/TiO2 modified polyester non-woven fabrics (PBZT), through a simple dip coating and subsequent thermal curing method. The resulting PBZT reveals excellent mechanical durability and strong resistance to ultraviolet (UV) irradiation as well as acid and alkali. This durable superhydrophobic and superoleophilic fabric is efficient for separating oil/water mixtures by gravity with high separation efficiency, and it can also purify wastewater that contains soluble dyes, which makes it more effective and promising in treating water pollution. Importantly, PBZT demonstrates an integrated self-cleaning performance on the removal of both oil and particle contamination. It is expected that this simple process can be readily adopted for the design of multifunctional PBZ/TiO2 based materials for oil/water separation.