Nanovoid-Enhanced Thin-Film Composite Reverse Osmosis Membranes Using ZIF-67 Nanoparticles as a Sacrificial Template

In this work, nanovoid-enhanced thin-film composite (TFC) membranes have been successfully fabricated using ZIF-67 nanoparticles as the sacrificial template. By incorporating different amounts of ZIF-67 during interfacial polymerization, the resultant TFC membranes can have different degrees of nanovoids after selfdegradation of ZIF-67 in water, consequently influencing their physiochemical properties and separation performance. Nanovoid structures endow the membranes with additional passages for water molecules. Thus, all the newly developed TFC membranes exhibit better separation performance for brackish water reverse osmosis (BWRO) desalination than the pristine TFC membrane. The membrane made from 0.1 wt % ZIF-67 shows a water permeance of 2.94 LMH bar(-1) and a salt rejection of 99.28% when being tested under BWRO at 20 bar. This water permeance is 53% higher than that of the pristine TFC membrane with the salt rejection well maintained.

Automated summary

Nanovoid-enhanced TFC membranes fabricated using ZIF-67 nanoparticles as sacrificial templates demonstrated better separation performance for BWRO desalination. The incorporation of ZIF-67 in different amounts resulted in membranes with varying nanovoid structures, influencing their physiochemical properties and separation performance. The membrane made from 0.1 wt % ZIF-67 exhibited significantly improved water permeance and salt rejection compared to the pristine TFC membrane.