Electrospun cellulose nanofibers membranes with photothermal/pH-induced switchable wettability for oil-water separation and elimination of bacteria

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 518; p. 164394
• Main Authors: Fang, Xubo, Du, Yuhan, Nawaz, Haq, Li, Xin, Yan, Ning, Zheng, Wenqiu, Li, Deqiang, Xu, Feng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.08.2025
• Subjects: Antibacterial; Electrospun cellulose nanofibers membranes; Oil-water separation; Photothermal/pH-responsive; Switchable wettability; Oil-water separation; Electrospun cellulose nanofibers membranes; Antibacterial; Photothermal/pH-responsive; Switchable wettability
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2025.164394

Considering the substantial annual global discharge of oily wastewater, there exists a crucial requirement to develop smart membranes that possess environmentally sustainable attributes, tunable wettability, and potent antibacterial properties, enabling efficient and controlled separation of oil/water mixtures. Here, a photothermal/pH-responsive electrospun cellulose nanofibers (ECF-P-Fe3O4-N) membrane endowed with wettability modulation and bacterial elimination capabilities was successfully prepared. The advancement in the fabrication method stemmed from the ingenious integration of three key strategies: the interpenetrating network formation between cellulose and the thermosensitive polymer, the co-precipitation embedding of photothermal medium (Fe3O4 NPs), and the chemical grafting of aminosilane. The resultant ECF-P-Fe3O4-N membrane exhibited fast and reversible wettability transitions between high hydrophilicity (under acid or high-temperature stimulation) and hydrophobicity (under alkali or low-temperature stimulation), achieving on-demand separation of diverse immiscible oil-water mixtures and surfactant-stabilized emulsions. The maximum separation flux for oil-water emulsions attained a value of 225.6 L m−2 h−1, accompanied by a separation efficiency surpassing 98.53 %. It also possessed strong elimination of bacteria, satisfying for the long-lasting contact usage. This work holds significant implications in designing smart membranes for remotely controlling the oil-water separation. The photothermal/pH-responsive electrospun cellulose nanofibers membranes, capable of wettability regulation and bacterial elimination, were successfully fabricated through the integration of three strategies: the formation of interpenetrating networks, the co-precipitation embedding of Fe3O4 NPs, and the chemical grafting of aminosilane. The resultant ECF-P-Fe3O4-N membrane exhibited rapid and reversible wettability transitions, thereby enabling high-efficiency separation of oil-water mixtures and emulsions. [Display omitted] •A smart electrospun cellulose nanofibers membrane was successfully prepared.•Reversible transitions of hydro-phil/phobia facilitate on-demand oil-water separation.•The membrane achieves a maximum flux of 225.6 L m−2 h−1 with >98.53 % efficiency.•It is highly antibacterial and suitable for prolonged contact use.