Frontiers in Chemistry (Jul 2020)

Improving the Selectivity of ZIF-8/Polysulfone-Mixed Matrix Membranes by Polydopamine Modification for H2/CO2 Separation

  • Xueyi Mei,
  • Xueyi Mei,
  • Sheng Yang,
  • Peng Lu,
  • Peng Lu,
  • Yexin Zhang,
  • Yexin Zhang,
  • Jian Zhang,
  • Jian Zhang

DOI
https://doi.org/10.3389/fchem.2020.00528
Journal volume & issue
Vol. 8

Abstract

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Gas separation membranes are essential for the capture, storage, and utilization (CSU) of CO2, especially for H2/CO2separation. However, both glassy and rubbery polymer membranes lead a relatively poor selectivity for H2/CO2 separation because the differences in kinetic diameters of these gases are small. The present study establishing the mixed matrix membranes (MMMs) consist of a nano-sized zeolitic imidazolate frameworks (ZIF-8) blended with the polysulfone (PSf) asymmetric membranes. The gas transport properties (H2, CO2, N2, and CH4) of MMMs with a ZIF-8 loading up to 10 wt% were tested and showing significant improvement on permeance of the light gases (e.g., H2 and CO2). Moreover, the depositional polydopamine (PDA) layer further enhanced the ideal H2/CO2 selectivity, and the PDA-modified MMMs approach the Robeson upper bound of H2/CO2 separation membranes. Hence, the PDA post-modification strategy can effectively repair the defects of MMMs and improved the H2/CO2selectivity.

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