pH-Induced Switchable Superwettability of Efficient Antibacterial Fabrics for Durable Selective Oil/Water Separation

The superhydrophobic antibacterial fabrics with intelligent switchable wettability were fabricated by the cross-link reaction among pH-responsive antibacterial copolymer tethered hydroxyl groups, methylol-contained poly(ureaformaldehyde) nanoparticles (PUF NPs), and hexamethylene diisocyanate. It was found that the surface concentration of N⁺ were heavily influenced by acid solutions, resulting in the rapid wettability conversion from superhydrophobicity/superoleophilicity to superhydrophilicity/underwater superoleophobicity in a remarkably short time. The above responsiveness feature of coated cotton fabric contributes a prominent selective oil/water separation property, and the separation efficiency invariably remained at greater than 95% even after 20 reuse cycles, which exhibited brilliant durability. More importantly, the coated cotton fabric possessed excellent self-cleaning performance after contamination by oil and held high bactericidal rate (more than 80%) regardless of pH treatment, and thus could abate the surface biological pollution caused by bacteria proliferation. The attractive properties of the prepared smart superwetting materials shows great promise for potential application in oil/water separation from an environmental-protection perspective.