Amine-functionalized ZIF-8 nanoparticles as interlayer for the improvement of the separation performance of organic solvent nanofiltration (OSN) membrane

We successfully fabricated a kind of novel sandwich-like thin-film nanocomposite (TFN) polyamide (PA) membranes via interfacial polymerization (IP) method on polyimide (PI) support surface which was modified by a layer of nanosized amine-modified zeolitic imidazolate framework - 8 (mZIF-8) nanoparticles for organic solvent nanofiltration (OSN). Uniform distribution of the nanoparticles was obtained via directly immersing the PI support membrane in aqueous mZIF-8 suspension prior to the IP. A post-IP cross-linking procedure was conducted to enhance further the solvent resistance of the fabricated TFN OSN membranes. Ultra-smooth (average surface roughness of 13.7 nm) and ultra-thin (average thickness of about 33 nm) skin layer was achieved, together with high Rhodamine B (RDB, 479 Da) rejection (99.1%) and reasonable ethanol permeance (similar to 28 L m(-2) h(-1) MPa-1), as well as nearly unchanged RDB rejection after being submerged in DMF at high temperature (80 degrees C) for 120 h, indicating their very good resistance in very harsh strong polar solvent circumstance and the promising aspect of their industrial application.