Ning Li,Chao Ma,Dudu Li,Peng Li,Mao Ye,Ziyue Wang,Zhihua Qiao,Chongli Zhong
Mixed matrix membranes (MMMs), combining the advantages of polymer membranes and porous materials, processing the potential to realize large-scale gas separation applications. However, the interfacial defects in MMMs greatly hindered gas separation performance improvement. Therefore, designing an MMM with high loading and good interfacial compatibility remains a critical issue in promoting the application of MMMs. Herein, during in - situ heating process, the melting of liquid ZIF-62 in PBI polymer can largely fill the interfacial defects in MMMs. The microporous transport channels of ZIF-62 glass in MMMs promoted the H 2 diffusion and inhibited the CO 2 and CH 4 diffusion, thus enhancing the H 2 /CO 2 and H 2 /CH 4 separation of MMMs. For mixed gas testing, the 45 wt% ZIF-62 glass/PBI membrane had the maximum H 2 permeability of 459 barrer, and its H 2 /CO 2 and H 2 /CH 4 selectivities were 23 and 57, higher than the gas separation upper bonds. In addition, ZIF-62 glass/PBI membrane exhibited stable separation performance under 1–5 bar pressure. Therefore, the rational combination of MOF glass and polymer matrix could provide promising potential for reducing the interfacial defects of high-loading MMMs, thus enhancing the gas separation performance.
Dudu Li,Zibo Yang,Lixia Yang,Chao Ma,Mao Ye,Yuxiu Sun,Zhihua Qiao,Aibing Chen
Metal-organic framework (MOF) glass is a promising candidate material for gas separation. However, MOF glasses have low porosity, which is not conducive to prepare high permeance membranes. Herein, we incorporated porous ZIF-7 into ZIF-62 glass membrane to prepare self-supported flux melted glass membranes for gas separation. The introduction of ZIF-7 not only improved pore continuity but also enhanced the porosity of the resulting glass membranes. In addition, the melting nature of ZIF-62 promotes the co-melting of ZIF-7 and thus effectively improves the interfacial compatibility. In such cases, the typical a g [(ZIF-62) 0.7 (ZIF-7) 0.3 ] membrane exhibits the ideal selectivity of 98.6 for H 2 /CH 4 and 35.3 for CO 2 /CH 4 , with H 2 permeance and CO 2 permeance of 120.3 and 43.1 GPU, respectively, exceeding the corresponding Robenson upper bounds. Besides, the a g [(ZIF-62) 0.7 (ZIF-7) 0.3 ] membrane displays good long-term test stability for 48 h under variable pressure conditions. This work may provide a new design concept and experimental support for the construction of new MOF membranes for gas separation.
危险品化学品经营许可证（带存储）