Interfacial nanoarchitectonics for ZIF-8 membranes with enhanced gas separation

Metal-organic framework (MOF) membranes are potentially useful in gas separation applications. Conventional methods of MOF membrane preparation require multiple steps and high-pressure conditions. In this study, a reliable one-step interfacial synthesis method under atmospheric pressure has been developed to prepare zeolitic imidazolate framework-8 (ZIF-8) membranes supported on porous alpha-Al2O3 disks. To obtain optimal ZIF-8 membranes, three reaction parameters were investigated, namely, reaction temperature, reaction time, and concentration of the organic linker (i.e., 2-methylimidazole). The growth of ZIF-8 membranes under various parameters was evaluated by field-emission scanning electron microscopy, and the optimal synthesis conditions were determined (i.e., 80 degrees C for 12 h in 50 mM of 2-methylimidazole). The as-synthesized ZIF-8 membranes were then applied to CO2/N-2 gas separation, which exhibited a maximum separation factor of 5.49 and CO2 gas permeance of 0.47 x 10(-7) mol.m(-2).s(-1).Pa--(1).

Automated summary

In this study, a reliable one-step interfacial synthesis method was developed to prepare ZIF-8 membranes supported on porous alpha-Al2O3 disks for gas separation applications. The optimal synthesis conditions were determined through evaluating the growth of ZIF-8 membranes under various parameters. The as-synthesized ZIF-8 membranes exhibited high separation factor and CO2 gas permeance in CO2/N2 gas separation experiments.