Superhydrophilic membrane coupled with hydroxide ion-assisted bubbles for efficient separation of surfactant-stabilized oil/water emulsions

Hui Li; Shaopeng Gan; Chuan Yue; Zechen Yan; Qingzhong Xue; Jianqiang Zhang; Tao Yan; Hongbo Zeng

doi:10.1016/j.jhazmat.2024.136397

Superhydrophilic membrane coupled with hydroxide ion-assisted bubbles for efficient separation of surfactant-stabilized oil/water emulsions

J Hazard Mater. 2024 Nov 4:485:136397. doi: 10.1016/j.jhazmat.2024.136397. Online ahead of print.

Authors

Hui Li¹, Shaopeng Gan², Chuan Yue², Zechen Yan², Qingzhong Xue², Jianqiang Zhang³, Tao Yan⁴, Hongbo Zeng⁵

Affiliations

¹ Jiangsu Provincial Engineering Research Center for Biomedical Materials and Advanced Medical Devices, Faculty of Mechanical and Material Engineering, Huaiyin Institute of Technology, 1 Meicheng Rd., Huaian 223003, China; State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, Qingdao 266580, Shandong, PR China.
² State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, Qingdao 266580, Shandong, PR China.
³ State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum, Qingdao 266580, Shandong, PR China. Electronic address: zhangjianqiang@upc.edu.cn.
⁴ Department of Hepatobiliary Surgery, PLA Rocket Force Characteristic Medical Center, Beijing 100088, China. Electronic address: yata1977@126.com.
⁵ Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.

PMID: 39667147
DOI: 10.1016/j.jhazmat.2024.136397

Abstract

Developing a feasible and efficient membrane for the purification of surfactant-stabilized emulsions is urgently needed but impeded by the issues of membrane fouling and the inherent trade-off between separation efficiency and permeation flux. A superhydrophilic conductive membrane was developed by coating MXene/carbon nanotubes layer and polydopamine-hydrogel molecular layer, which as cathode integrates feasible hydroxide ion-assisted bubbles on its surface by electrolysis of water. These bubbles are more effective than conventional ones in removing surfactant-stabilized oil droplets because the hydroxide ions significantly promote the aggregation of oil droplets and bubbles by reducing their Debye length. In this way, the oil droplets even the small-sized ones assisted by these bubbles are quickly detached from the membrane surface, avoiding the oil accumulation and penetration, significantly mitigating the membrane fouling and trade-off challenges. Therefore, the membrane has outstanding separation efficiency (99.57 %), permeation flux (2065 L m^-1 h^-1 bar^-1), antifouling ability and durability in surfactant-stabilized oil/water emulsion separation. Besides, this membrane coupled with hydroxide ion-assisted bubbles is easily manageable and eco-friendly, which provides a promising solution and valuable insights for efficient emulsion separation and wastewater remediation.

Keywords: Antifouling; Bubble; Hydroxide ion; Membrane; Oil/water emulsion.