Developing high-performance H 2 /CH 4 separation membranes is of great potential for H 2 production in the petroleum industry. Incorporating nanofillers into a polymer matrix to form mixed matrix membranes (MMMs) can elevate selectivity and permeability, but poor polymer-filler interfacial compatibility and filler aggregation are formidable problems. Targeting this, we propose a novel approach by incorporating a metal–organic framework (MOF) gel, ZIF-8 gel, as the versatile filler to a high free volume polymer PIM-1 and investigate the H 2 /CH 4 separation capabilities of the MMMs. Benefiting from the gel network morphology of ZIF-8, they were dispersed evenly in the PIM-1 matrix. The interconnected gel network structure of ZIF-8 gel helped to construct continuous gas transport pathways in the polymer. As a result, the H 2 /CH 4 separation performance was notably improved, demonstrating a substantial increase in H 2 permeability by 78.9% (exceeding 6800 Barrer) and a 38.0% enhancement in H 2 /CH 4 selectivity at a ZIF-8 gel loading of 31.0 wt%. These improvements surpassed the upper bound established in 2008. The Maxwell and Lewis-Nielsen models were developed to clarify gas transport mechanisms across membranes, and the experimental data of ZIF-8 gel/PIM-1 was well-matched with the calculated results of the Lewis-Nielsen models. Adopting MOF gel as fillers may pave a new approach to design high-performance MMMs with interconnected transport pathways.
The urgent need for efficient CO 2 capture technologies to mitigate climate change has driven the advancement of membrane-based separation systems. We report a mixed matrix membrane design through the in-situ growth of a ZIF-8 gel network within a Pebax-1657 matrix. By tuning the solvent ratio and concentration of modulator, ZIF-8 gel rather than particles are formed within the polymer, establishing a three-dimensional interconnected MOF network that ensures homogeneous filler dispersion and creates continuous gas transport nanochannels. The optimized membrane achieves a remarkable CO 2 permeability of 183.9 Barrer and a CO 2 /N 2 selectivity of 73.3, surpassing the 2008 Robeson upper bound. These values represent 190.4 % and 34.9 % enhancements in permeability and selectivity, compared to the pristine polymer. The membrane also demonstrates robust operational stability and maintains > 95 % of its initial performance over 60 days. This work offers a promising solution to creating continuous channels in CO 2 separation membranes.
危险品化学品经营许可证（带存储）