Poly(vinyl alcohol) nanofiber incorporated graphene oxide/gelatin composite aerogels modified by chemical vapor deposition with superwetting character for efficient separation of oil and water

Superhydrophobic/superoleophilic nanofibrous aerogel is a good candidate for oil/water separation because of its superwetting character, highly open structure and tunable porosity. However, developing a facile and green strategy to fabricate nanofibrous aerogel with specific wettability remains challenging. Herein, poly(vinyl alcohol) (PVA) nanofiber incorporated graphene oxide (GO)/gelatin composite aerogels were prepared, and the obtained aerogels were modified with methyltrimethoxysilane (MTMS) by chemical vapor deposition. The entire fabrication process was completed without usage of organic solvents. When exposed to different oils and organic solvents, the as-prepared nanofibrous aerogels showed exceptional absorption capacity. Due to high elasticity of the aerogels, it was possible to recover oils by mechanical squeezing. In addition, it was found that oils could be selectively absorbed from oil/water mixtures by the composite aerogels with superhydrophobicity and superoleophilicity to realize effective separation of oil and water. Importantly, surfactant-stabilized water-in-oil emulsions could also be separated by the composite aerogels without external pressure. Furthermore, the aerogels could be used to continuously collect oil pollutants from oil/water mixtures with a simple pumping device. The current work offered an environmentally friendly method for creating superwetting nanofibrous aerogels for wastewater treatment.