Functionalized Superwettable Fabric with Switchable Wettability for Efficient Oily Wastewater Purification, in Situ Chemical Reaction System Separation, and Photocatalysis Degradation

In view of the increasing serious water environmental and human health issues caused by oily wastewater, functional superwetting materials with controllable wettability, high durability, and scale preparation methods are highly desired for efficient oil/water separation. In this respect, a pH-responsive multifunctional fabric with switchable surface wettability, favorable mechanical durability, and self-repairing property has been developed via decorating the modified TiO2 nanoparticles of special surface compositions onto the fabric surface. By virtue of the intelligent surface wettability, the resulted superwettable fabric can be used for controllable separation of multiple oil/water mixtures, particularly the complicated oil/water/oil ternary mixtures, showing excellent separation efficiency and high filtration flux even under extreme pH conditions, which is comparable to most of the commercial and currently reported functionalized membranes. Simultaneously, the negative pressure-driven, continuous, high-speed, and highly efficient in situ purification of large volumes of oily wastewater is successfully achieved based on the resulted superwettable fabric. More importantly, with the as-prepared superwettable fabric as the filtration membrane, the continuous in situ separation of the synthetic oily product from the corresponding chemical reaction systems is well performed without interruption of the reaction, demonstrating outstanding merits of simplifying procedures, saving operation time, and increasing product yield. In addition, it is worth noting that the alkali-treated superhydrophilic fabric presents superior photocatalysis self-cleaning performance for various water-soluble organic pollutants. These unique advantages of the functionalized smart superwettable fabric ensure that it can be competent in multifarious relevant challenging settings, indicating a broad prospect for diverse practical applications, especially the oily wastewater treatment and multiple industrial operation optimizations.