Superhydrophilic and underwater superoleophobic polylactide/cellulose diacetate composite nanofibrous membranes for effective oil-in-water emulsions separation

Electrospun polylactide (PLA) fibrous membranes, characterized by good biodegradability and high porosity, demonstrate significant potential for oily wastewater treatment. However, the inherent hydrophobicity of PLA poses a significant challenge in separating oil-in-water emulsions. Herein, a facile and effective strategy was proposed to fabricate a PLA based nanofibrous membrane for oil-in-water emulsions separation. By combining the electrospinning and nonsolvent-induced phase separation technologies, hydrophilic cellulose diacetate (CDA) networks were in-situ constructed throughout the entire body of PLA fibrous membrane, resulting in a unique hierarchical porous structure. As a result, the obtained PLA/CDA composite nanofibrous membrane exhibited intriguing superhydrophilicity and underwater superoleophobicity, as well as gratifying separation performances for various oil-in-water emulsions solely under the driving force of gravity. Furthermore, the PLA/CDA composite nanofibrous membrane could be easily reused and will not bring out significant environmental concerns after extended use and disposal. We anticipate that this work could pave a way for the development of environmentally friendly membranes for oily wastewater treatment.