Work

Superwettable Carbon Fiber Membranes Functionalized with Cu-TiO2: High-Performance Oil–Water Separation and Sustainable Reusability

Year: 2025

Type: article

Abstract: Oily wastewater poses severe ecological and health threats, but conventional separation technologies have limitations like low efficiency or high energy consumption. Herein, two superwettable carbon fiber (CF)-based membranes were fabricated for efficient oil–water separation. Using CF (low cost, excellent mechanical stability) as the substrate, Cu-TiO2@CF (superhydrophilic/underwater superoleophobic, renewable) was prepared via a deep ultraviolet (DUV)-assisted sol–gel method, and OTMS/Cu-TiO2@CF (superhydrophobic/superoleophilic) was obtained by modifying Cu-TiO2@CF with octadecyltrimethoxysilane (OTMS) via hydrothermal synthesis. Characterization showed Cu-TiO2 coatings uniformly covered CF, with strong substrate bonding. Both membranes exhibited outstanding performance: Cu-TiO2@CF achieved water fluxes of up to 79,839.6 L·m−2·h−1 and >97.3% separation efficiency for four oil–water mixtures; OTMS/Cu-TiO2@CF had a maximum oil flux of 86,593.4 L·m−2·h−1 and >98.1% efficiency. Cu-TiO2@CF regenerated via 10 min UV irradiation (restoring underwater oil contact angle to 153°), while OTMS/Cu-TiO2@CF achieved recovery through the process of UV irradiation followed by OTMS re-modification. Both membranes maintained stable performance over 100 cycles, demonstrating considerable potential for engineering applications.

Source: Coatings

DOI: 10.3390/coatings15111273