Preparation of high flux organic solvent nanofiltration membrane based on polyimide/Noria composite ultrafiltration membrane

Organic solvent nanofiltration (OSN) membrane, a type of thin film composite (TFC) membrane, is widely used in separating organic solvents, but the low permeability of organic solvents is currently challenging to solve. This experiment used cross-linked polyimide (PI) as raw material and Noria as a nanoparticle additive to prepare a composite ultrafiltration membrane through non-solvent-induced phase separation (NIPS). Noria migrated to the composite ultrafiltration membrane surface during NIPS and acted as an interlayer, which can regulate the following interfacial polymerization. Then, the nanofiltration membrane was prepared by interfacial polymerization method using the modified PI membrane as the support layer. The experimental results showed that the hydrophilicity of the PI/Noria composite ultrafiltration membrane was significantly enhanced, in addition to a significant increase in pure water flux to 239 L m(-2)h(-1)bar(-1). The methanol flux of the prepared composite nanofiltration membrane could be up to 5.472 L m(-2)h(-1)bar(-1), which was twice as high as that of the unmodified composite membrane, and the G250 dye retention rate remained at over 99.6%. The nanofiltration performance is excellent and has good prospects for application in OSN.

Automated summary

This experiment used cross-linked polyimide (PI) as raw material and Noria as a nanoparticle additive to prepare a composite ultrafiltration membrane through non-solvent-induced phase separation (NIPS). The nanofiltration membrane was then prepared by interfacial polymerization method. The results showed that the composite membranes had significantly enhanced hydrophilicity, improved pure water and methanol flux, and high dye retention rate, indicating excellent nanofiltration performance suitable for application in organic solvent nanofiltration (OSN).