Hydrogel Assisted Interfacial Polymerization for Advanced Nanofiltration Membranes
With the rapid growth of world population and water contamination, nanofiltration membranes with extraordinary permeance and high salt rejection are eminently desirable for addressing global water scarcity. Here, an innovative approach to design thin film composite (TFC) membranes with ultrahigh permeance via hydrogel assisted interfacial polymerization was reported. The hydrogel containing piperazine (PIP) monomers serving an aqueous phase in interfacial polymerization enables a homogeneous interfacial polymerization, reduces the diffusion rate of PIP monomers, and provides mechanical strength to the thin polyamide (PA) selective layer. As a result, the synthesized advanced TFC membranes have ultrahigh high permeance of 52.8 L m-2 h-1 bar-1 and 62.9 L m-2 h-1 bar-1 while maintaining a satisfactorily high rejection of 96.4 % and 93.5% for Na2SO4, demonstrating a desalination performance superior to PA TFC nanofiltration membranes reported so far. Moreover, the mechanism behind the exceptional high permeance is delineated by exploring theoretically hydrogel assisted interfacial polymerization through simulation. Most importantly, the fabrication process of Hydrogel-TFC membranes is simple, enabling a cost-efficient and scalable manufacturing.