ZIF-8 based dual scale superhydrophobic membrane for membrane distillation

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.