Mixed matrix membranes embedded with Janus mesoporous silica nanoparticles for highly efficient water treatment

Abstract

A periodic mesoporous organosilica (PMO) Janus nanoparticle (PMO-SO3H&SiO2-NR) was gently synthesized and mixed with polyethersulfone (PES) to fabricate a series of mixed matrix membranes via the phase inversion method. The Janus structure of PMO-SO3H&SiO2-NR nanoparticle enabled the hydrophilic –SO3H and hydrophobic hexadecyl (-NR) to be separately distributed on the PMO cores and SiO2 branches, and hence Janus PMO-SO3H&SiO2-NR nanoparticle was endowed with good hydrophilicity and excellent compatibility with PES membrane matrix. As a result, the mixed matrix membranes presented improved bulk porosity, surface mean pore size, hydrophilicity and permeability. Particularly, the pure water flux of the mixed matrix membrane with 5 wt% porous Janus PMO-SO3H&SiO2-NR nanoparticles (M5) was as high as 330 l・m–2・h–1 that was 2.2 times that of the pristine PES ultrafiltration (UF) membrane (M0) while its rejection for bovine serum albumin (BSA) remained above 98.0%. Besides, after multi-cycles UF experiment with BSA as model contaminant, M5 retained a high flux recovery rate, permeation flux and rejection, suggesting its outstanding overall performance. Porous Janus PMO-SO3H&SiO2-NR nanoparticle is the first time to be used as an effective additive to prepare mixed matrix membrane, providing a new approach to achieve highly efficient water treatment of UF membranes.

Keywords

• polymer membranes
• porous janus nanoparticle
• ultrafiltration
• hydrophilicity
• compatibility