Dehydroxylation-assisted self-crosslinking of MXene-based pervaporation membranes for treating high-salinity water

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) 2023, 119(0), , pp.506-515
• Main Authors: Fareed, Hasan, Jang, Kyunghoon, Lee, Woojin, Kim, In S., Han, Seunghee
• Format: Article
• Language: English
• Subjects: Brine treatment; Desalination; MXene; Pervaporation; Self-crosslinking; Swelling; 화학공학
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2022.11.074

[Display omitted] •MXene-based membranes were synthesized and crosslinked via thermal treatment.•Optimum temperature was 140 °C for efficient crosslinking with ideal thickness.•M140 generated a permeation flux of 70 kg m-2h−1 for a 10 % NaCl solution at 70 °C. In this study, an additive-free self-crosslinking technique was optimized to prepare pervaporation desalination membranes for brine treatment. MXene-coated membranes that were about 100 nm thick were synthesized using the facile vacuum filtration technique. The MXene nanosheets were then crosslinked at different temperatures from 25 °C to 180 °C, inspired by weight loss through thermogravimetric analysis. The MXene membrane self-crosslinked at 140 ℃ (M140) proved to be the optimal membrane in terms of the permselectivity of brine with a stable d-spacing of 1.43 nm in distilled water and 1.48 nm in a 10 wt% NaCl solution. Fourier-transformed infrared spectroscopy and X-ray photoelectron spectroscopy revealed TiOTi bond formation induced by reverse hydrolysis of MXene, leading to increased surface roughness and decreased swelling tendency. M140 generated a permeation flux of 70 kg m-2h−1 with salt rejection up to 99.9 % for 100 g/L of NaCl solution at a feed temperature of 70 °C. Furthermore, M140, tested with simulated brine for a 48 h operation test, showed successful suppression of salt transport on the permeate side, while maintaining ∼ 50 kg m-2h−1 flux and 99.9 % salt rejection. M140 is recommended for pervaporation desalination, where a high salinity feed is expected.