近日，课题组硕士生论文“Post-modification of UiO-66-NH₂ enhances the interfacial interaction of mixed matrix membranes for Efficient CO₂/N₂ separation”被ACS Applied Polymer Materials（2023中科院SCI二区， IF=4.4）

Abstract

MOFs-filled mixed matrix membranes have great potential to overcome the trade-off effects of traditional gas separation membranes. However, achieving good interfacial compatibility and adequate dispersion of MOF is not straightforward. Several studies have confirmed the improvement in gas separation performance of MMMs by optimizing the interface between a polymer matrix and inorganic filler, e.g. UiO-66 functionalized with -NH₂ group. However, they still have limitations of decreasing the active surface area or a multistep operation process which is different from case to case and less of universality. In this study, we introduce flexible polymer chains through the covalent grafting method. UiO-66-NH₂ was easily modified with Trimesoyl chloride (UiO-66-TMC) and polyethylene glycol (UiO-66-PEG), which was utilized as fillers to construct Polyimide (PI) based mixed matrix membranes (MMMs). The rich interactions between modified UiO-66-NH₂ and the PI matrix contribute to the efficient CO₂/N₂ separation. At 25°C and 0.1 MPa, UiO-66-TMC/PI MMMs exhibited a CO₂/N₂ selectivity of 55.3, and a CO₂ permeability of 616.17 Barrer, and those are 56.7 and 686 Barrer for UiO-66-PEG200/PI MMMs. Both of them exceed the 2008 Robeson upper bound. The ether bonds in PEG exhibit strong interactions with CO₂ molecules and improve CO₂ dissolution selectivity. Meanwhile, the introduction of organic ingredients realized good dispersion and interfacial compatibility within the PI matrix.This work lays the groundwork for further fabricating highly selective CO₂ separation materials with specific microscopic interface structures and properties.