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.