Superwetting cotton textiles for separation of oil/water mixtures

The industrial revolution has led to a frequent leakage of crude oil into marine waters and the contamination of wastewater with various oils and organic liquids. Therefore, the development of multifunctional materials for oil/ water separation is a fast-growing research area for the remediation of oil-polluted water. Separation processes based on advanced superwetting materials have been proposed as a novel and smart nonconventional technology for oily wastewater treatment. This review focuses on the fabrication of superwetting cotton textile materials for water/oil separation. The principles of selective water/oil separation including the wettability models, separation mechanism, and separation modes are highlighted. Two types of superwetting materials are presented including superhydrophobic and superhydrophilic/underwater superoleophobic cotton fabrics for the separation of various immiscible and emulsified oil/water mixtures. The discussion of this review focuses on the fabrication process in terms of (a) modification of surface roughness, and (b) surface energy to achieve the superwetting performance. The performance of the modified superwetting cotton textiles was highlighted in terms of their wetting behaviour, durability, separation efficiency, intrusion pressure, and recyclability. Smart cotton fabrics with controllable and switchable wettability are presented including the pH-responsive, thermo-responsive, photo-responsive, dual-responsive, and Janus membranes. The current assessment methods for the evaluation of mechanical and chemical durability are highlighted. Future studies shall focus on the fabrication of cotton textiles with smart, switchable, and controllable wettability as well as the Janus cotton textiles to maximize the utilization of the amphiphilic nature of cotton fabrics and textiles.

Automated summary

The development of multifunctional materials for oil/water separation is a fast-growing research area to remediate oil-polluted water. Superwetting cotton textile materials are fabricated for water/oil separation. The principles of selective water/oil separation and the fabrication processes for superwetting performance are highlighted. Smart cotton fabrics with controllable and switchable wettability are presented, and methods for evaluating their durability are discussed. Future studies should focus on the fabrication of cotton textiles with smart, switchable, and controllable wettability and the utilization of Janus cotton textiles.