Polysulfone/Polyamide-SiO2 Composite Membrane with High Permeance for Organic Solvent Nanofiltration

Abstract

To improve the filtration performance and properties of organic solvent nanofiltration (OSN) membranes, we firstly introduce nanoporous silica (SiO2) particles into the polyamide (PA) active layer of polysulfone (PSf) membrane via an interfacial polymerization process. Results from the study revealed that introduction of SiO2 influenced the properties of PSf/PA-SiO2 composite membranes by changing the surface roughness and hydrophilicity. Moreover, results also indicated that nanoporous SiO2 modified membranes showed an improved performance of alcohols solvent permeance. The PSf/PA-SiO2 composite membrane modified by 0.025 wt % of SiO2 reached a permeance of 3.29 L m−2 h−1 bar−1 for methanol and 0.42 L m−2 h−1 bar−1 for ethanol, which were 20.0% and 13.5% higher than the control PSf membrane (permeance of 2.74 L m−2 h−1 bar−1 for methanol and 0.37 L m−2 h−1 bar−1 for ethanol). Conclusively, we demonstrated that the increase of membrane hydrophilicity and roughness were major factors contributing to the improved alcohols solvent permeance of the membranes.