Nanofiltration Performance of Poly( p -xylylene) Nanofilms with Imidazole Side Chains.

Herein, we report the nanofiltration performance of poly( p -xylylene) thin films with imidazole side chains that were deposited onto commercial polyethersulfone ultrafiltration membranes using a chemical vapor deposition process. The resulting thin films with a few tens of nanometers exhibited water permeation under a pressure difference of 0.5 MPa and selectively rejected water-soluble organic dyes based on their molecular sizes. Additionally, thin flaky ZIF-L crystals (Zn(mim) 2 ·(Hmim) 1/2 ·(H 2 O) 3/2 ) (Hmim = 2-methylimidazole) formed on the surface of imidazole-containing poly( p -xylylene) films, and the composite films demonstrated the ability to adsorb methylene blue molecules within the cavities of ZIF-L.