Preparation of robust, customizable Janus membrane with hydrogel-like coating via interfacial free radical polymerization for membrane distillation
Janus membranes exhibit notable benefits in enhancing the anti-fouling ability during membrane distillation (MD). However, the bonding stability between the hydrophilic layer and the hydrophobic matrix is a worrying concern. In this work, we developed an interfacial free radical polymerization (IFRP) method by segregating photoinitiator and polyethylene glycol diacrylate (PEGDA) monomers into the oil and water phases, respectively. This approach facilitated a crosslinking reaction initiated at the oil–water interface, leading to the formation of a discontinuous or continuous hydrogel-like coating on one side of the PVDF membrane within a 30-second light-induced reaction. The PEGDA gel filled the membrane pores rather than growing outward along its surface, thus creating a “physical interlocking” effect and significantly enhancing their bonding stability. Anti-fouling and anti-wetting experiments were conducted under harsh conditions, including hypersaline solution of 20 wt%, high oil-content saline emulsion and humic acid/CaCl 2 mixed brine. Results demonstrated stable water vapor flux and salt rejection. By increasing the molecular weight of PEGDA monomers, a dense gel layer can be conveniently obtained, which can withstand high-concentration surfactant. This proposed IFRP method offers strong customizability, enabling the efficient production of either porous or dense hydrophilic layers to adapt to various salt solutions.
危险品化学品经营许可证（带存储）