Facile membrane preparation from colloidally stable metal-organic framework-polymer nanoparticles

Abstract

UiO-MOFs are based on zirconium cluster and carboxylic acid linkers. They have excellent chemical and thermal stability, tolerance to linkers of different length and functionalities, making them good candidates for a broad range of applications. However, difficulties of processing the polycrystalline powder of MOFs limit their application. Here, we report for the first time the synthesis of the UiO-66 in the presence of a well-defined poly (methacrylic acid)-b-poly (methyl methacrylate) (PMAA-b-PMMA) nanoparticles (NPs) prepared via Reversible Addition−Fragmentation Chain-transfer Polymerization controlled Polymerization Induced Self-Assembly (RAFT-PISA). The PMAA-b-PMMA NPs with multi carboxylic acid groups on their surface, well defined in shape and size, act as multivalent connecting agent for the synthesis of the UiO-66. The resulting colloidally stable UiO-polymer NPs are crystalline, porous, and with an improved processability as was demonstrated by the preparation of a thin film nanocomposite (TFN) membrane. This membrane was applied in the filtration of Nickel (II) phthalocyanine-tetrasulfonic acid tetrasodium salt aqueous solution obtaining a water permeability circa 20 L m−2 h−1 bar−1 with a rejection of more than 90%. This unprecedented facile synthesis approach could be universally applied to other MOFs, expanding their application in different fields due to their enhanced processability.