Guo Fei, Xiao Wu, Ma Canghai, Ruan Xuehua, He Gaohong, Wang Hanli, Yang Zhendong, Jiang Xiaobin
State Key Laboratory of Fine Chemicals, Department of Chemical Engineering, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China.
Shandong Huaxia Shenzhou New Material Co., Ltd., Zibo 256401, China.
Membranes (Basel). 2023 Apr 19;13(4):444. doi: 10.3390/membranes13040444.
Two-dimensional (2D) nanomaterials, due to their high aspect ratio and high specific surface area, which provide a more tortuous pathway for larger gas molecules, are frequently used in membrane separation. However, in mixed-matrix membranes (MMMs), the high aspect ratio and high specific surface area of 2D fillers can increase transport resistance, thereby reducing the permeability of gas molecules. In this work, we combine boron nitride nanosheets (BNNS) with ZIF-8 nanoparticles to develop a novel material, ZIF-8@BNNS, to improve both CO permeability and CO/N selectivity. Growth of ZIF-8 nanoparticles on the BNNS surface is achieved using an in-situ growth method where the amino groups of BNNS are complexed with Zn, creating gas transmission pathways that accelerate CO transmission. The 2D-BNNS material acts as a barrier in MMMs to improve CO/N selectivity. The MMMs with a 20 wt.% ZIF-8@BNNS loading achieved a CO permeability of 106.5 Barrer and CO/N selectivity of 83.2, surpassing the Robeson upper bound (2008) and demonstrating that MOF layers can efficiently reduce mass transfer resistance and enhance gas separation performance.
二维（2D）纳米材料因其高纵横比和高比表面积，能为较大气体分子提供更曲折的传输路径，故而常用于膜分离。然而，在混合基质膜（MMMs）中，二维填料的高纵横比和高比表面积会增加传输阻力，从而降低气体分子的渗透率。在本研究中，我们将氮化硼纳米片（BNNS）与ZIF-8纳米颗粒相结合，开发出一种新型材料ZIF-8@BNNS，以提高CO渗透率和CO/ N选择性。通过原位生长法，使BNNS表面的氨基与Zn络合，从而在BNNS表面生长ZIF-8纳米颗粒，形成加速CO传输的气体传输通道。二维BNNS材料在MMMs中起到阻挡作用，以提高CO/ N选择性。负载量为20 wt.%的ZIF-8@BNNS的MMMs实现了106.5 Barrer的CO渗透率和83.2的CO/ N选择性，超过了Robeson上限（2008年），表明MOF层可有效降低传质阻力并提高气体分离性能。
