Twofold bioinspiration of TiO2-PDA hybrid fabrics with desirable robustness and remarkable polar/nonpolar liquid separation performance

Abstract

The fundamental relationship between microstructure, constituent, processing and performances of separating materials is really a vital issue. Traditional preparation methods for separation membranes are complex, time-consuming and easy to be fouled. Also, the durability of conventional coatings on membrane is poor. By combination of bioinspiration from mussel adhesive and fish scales’ underwater superoleophobicity, we propose a general route to prepare organic-inorganic hybrid coatings, while no complex apparatus is needed. Specifically, based on the biomimetic adhesion of polydopamine (PDA), we used it as a binder to adhere TiO2 nanoparticles and built rough microstructure on fabric. In this way, we obtained TiO2-PDA treated fabric with special wettability. These TiO2-PDA treated samples owned superamphiphilicity in air, underwater superoleophobicity (underwater oil contact angles (OCAs) > 150°), underoil superhydrophobicity (underoil water contact angles (WCAs)> 150°), excellent multiresistance; and can separate polar/nonpolar liquid mixture effectively. It also owned superaerophobicity underwater (underwater bubble contact angles (BCAs) > 150°). The proposed TiO2-PDA coatings are highly expected to be employed for real situation of water pollution remediation, self-cleaning, oil extraction and harsh chemical engineering issues.