High-performance thin-film nanocomposite (TFN) forward osmosis (FO) membranes incorporated with porous hydrophobic-core/ hydrophilic-shell nanoparticles

The current article discusses some unprecedented information about the improvement in forward osmosis (FO) performance of polyethersulfone/polyamide (PES/PA) membranes, mainly focused on water flux and selectivity along with resistance to fouling phenomenon; which itself is brought in by the introduction of pre-modified zeolitic imidazolate framework-8 MOF nanoparticles. An investigation has been conducted on ZIF-8 nanoparticles surface with hydrophilicity feature to evaluate their potential for utilization in active polyamide layer of FO membranes for the first time, free from any decrease in water flux value (when hydrophobic ZIF-8 is exploited solely) and selectivity (when mSiO2 with unselective channels is employed). Correspondingly, to fulfill the desired goal, MOF nanocrystals were coated with a thin mSiO2 shell at first, so they can be modified in the next step by GPTMS and ultimately aspartic acid. Feasibility of applied strategy (using hydrophobic-core/hydrophileshell nanofillers) in FO membranes' desalination performance was assessed after incorporating ZIF-8@mSiO2GPTMS-Asp nanoparticles of various concentrations in the polyamide rejection layer throughout the interfacial polymerization (IP) process. The obtained results divulge that the optimal membrane (TFN400) has the highest water flux and selectivity as well as superior resistance to BSA and SA foulant.

Automated summary

This article discusses the improvement in forward osmosis performance of PES/PA membranes by using pre-modified zeolitic imidazolate framework-8 MOF nanoparticles, which enhance water flux and selectivity while resisting fouling. Through coating MOF nanocrystals with a mSiO2 shell and modifying them with GPTMS and aspartic acid, the optimal membrane (TFN400) achieved high water flux, selectivity, and resistance to fouling.