Aminoazobenzene@Ag modified meshes with large extent photo-response: towards reversible oil/water removal from oil/water mixtures.

Photo-responsive materials with superwetting properties, especially in the azo-based class, have been used in water treatment because of their smart performance on wettability changes. However, their transformation extent in wettability has always troubled researchers. Here, we modified nano-Ag pine needles and aminoazobenzene (AABN) on polydopamine (PDA) pre-treated porous meshes, realizing a large-extent reversible photo-responsive wettability transformation from highly hydrophobic to highly hydrophilic. The contact angle is about 150.0° after being exposed to visible light, and is about 10.0° under 365 nm UV light. Accordingly, the modified mesh can achieve photo-responsive removal between oil and water from oil/water mixtures. This facile and universal approach based on trans-cis isomerization of AABN could be endowed to various commercial conductive meshes. Moreover, the modified meshes exhibit satisfactory removal efficiency, reusability and physical/chemical stability, which are more promising for practical applications such as fuel recycling, remote controlled oil/water separation and astronautical resource regeneration.