Polyamide composite nanofiltration membrane modified by nanoporous TiO2 interlayer for enhanced water permeability

The traditional polyamide composite nanofiltration membrane has high selectivity. However, low water permeability is an important problem to be solved. Herein, the conventional polyamide composite nanofiltration (TFC) membrane was modified with nanoporous TiO2 (nTiO2) interlayer through vacuum-assisted strategy for enhanced water permeability. By tuning the nTiO2 nanoparticles loading, the nTiO2 modified TFC membrane with crumpled structure was fabricated. Besides, the thickness of polyamide layer was reduced due to the hydrophilicity and porosity of nTiO2. Because of the larger effec-tive filtration area and thinner polyamide layer, the modified membrane had a permeability of 12.8 L m-2 h-1 bar-1 (increased by 20.8% than that of TFC membrane) and a rejection of 98.2% when fil-tering Na2SO4 aqueous solution. This work provided a solution for enhanced water permeability and extended the application of TiO2 in the modification of polyamide composite nanofiltration membrane. CO 2022 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Automated summary

In this study, the water permeability of the traditional polyamide composite nanofiltration membrane was enhanced by modifying it with a nanoporous TiO2 interlayer through a vacuum-assisted strategy. The modified membrane, with a crumpled structure, was fabricated by tuning the loading of nTiO2 nanoparticles. The hydrophilicity and porosity of the nTiO2 interlayer led to a reduction in the thickness of the polyamide layer. The modified membrane exhibited increased permeability and rejection rate, providing a solution for enhancing water permeability and extending the application of TiO2 in the modification of polyamide composite nanofiltration membranes.