ZIF-8 based dual scale superhydrophobic membrane for membrane distillation

• Published in: Desalination 2023-03, Vol.550, p.116373, Article 116373
• Main Authors: Cao, Han, Mao, Yanpeng, Wang, Wenlong, Jin, Yang, Gao, Yibo, Zhang, Miaomiao, Zhao, Xiqiang, Sun, Jing, Song, Zhanlong
• Format: Article
• Language: English
• Subjects: Dual scale superhydrophobic membrane; Membrane distillation; micro-nano roughness; Size control; ZIF-8
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/j.desal.2023.116373

Hydrophobicity is one of the key factors in determining the permeate flux of membrane distillation. To obtain a high-performance membrane for membrane distillation, a novel preparation method of a superhydrophobic membrane with dual scale hierarchical rough structure was proposed by controlling the particle size of ZIF-8. Nano and micro scale ZIF-8 particles were synthesized by exploring the particle size regulation rules and then deposited on PTFE substrates through the spray method after hydrophobic modification by POTS. The prepared ZIF-8 crystal and modified membrane were analyzed by DLS, SEM-EDS, XRD, AFM, and WCA. The water contact angle of the superhydrophobic surface under optimized experimental conditions reached 165.5°. Furthermore, membrane distillation experiments results of superhydrophobic membrane showed excellent permeate flux than commercial PTFE membrane. This research provides a promising strategy to prepare a superhydrophobic membrane and expands the possibility of MOF as a superhydrophobic coating. [Display omitted] •Continuous modulation of ZIF-8 size between nano scale and micro scale.•Loading of dual scale ZIF-8 improved the roughness and hydrophobicity of the substrate.•The modified membrane exhibits high flux even when treating 15 wt% NaCl solution at 50 °C.