Nanocoated amphiphobic membrane for flux enhancement and comprehensive anti-fouling performance in direct contact membrane distillation

Membrane distillation, which can utilize low grade energy, has attracted significant attention recently. However, membrane fouling is a big issue impeding its development and industrialization. Hence, it is essential to prepare amphiphobic membrane for comprehensive anti-fouling performance. Herein, a facile and biomimetic method is explored to design amphiphobic surface with special structure and controllable wettability . Commercial polyvinylidene fluoride (PVDF) was primarily functionalized with polydopamine (PDA) coatings and then nanoscale roughness was introduced on the membrane surface, followed by the fluorination of 1H,1H,2H,2H-perfluorodecanethiol. It is revealed that the amphiphobic property can be accurately controlled by controlling the dosage of Ag + . When the concentration of Ag + is 300 mM, the water and oil contact angle of the optimal membrane can achieve 167.6 ± 0.27° and 136.9 ± 0.4°, respectively, while the water sliding angle is only 3 ± 0.1°, which demonstrates prominent superhydrophobicity and oleophobicity. Furthermore, the amphiphobic membrane exhibits excellent chemical and thermal stability under harsh conditions as well as outstanding comprehensive anti-fouling capacity with higher flux and excellent salt rejection in the long-term direct contact membrane distillation (DCMD) experiments, which shows promising potentials for application in the field of membrane distillation.