Using Maleimide-Induced Dual Cross-Linking Method to Fabricate High-Performance Mixed Matrix Membrane

Area of Science:

• Materials Science
• Chemical Engineering
• Polymer Science

Background:

• Mixed matrix membranes (MMMs) face challenges in interfacial compatibility and anti-plasticization.
• Zeolitic imidazolate frameworks (ZIFs) are promising fillers, but integration into polymer matrices remains difficult.

Purpose of the Study:

• To develop MMMs with improved interfacial compatibility and anti-plasticization performance.
• To create a dual cross-linking strategy for enhanced gas separation in MMMs.

Main Methods:

• Prepared zeolitic imidazolate framework-8 modified with maleimide (ZIF-8-MI) as filler.
• Blended ZIF-8-MI into a maleimide-functionalized polyimide (PMI) matrix to form MMMs.
• Utilized thermal treatment to induce dual cross-linking via radical cycloaddition between ZIF-8-MI and PMI.

Main Results:

• Achieved excellent interfacial compatibility and in situ cross-linking of the polyimide matrix.
• The optimized MMM (cPI-ZIF-8-SI-20%) exhibited high CO2 permeability (1028 Barrer) and CO2/CH4 selectivity (39.2).
• Demonstrated superior gas separation performance exceeding the Robeson 2008 Upperbound and 2018 upper limit, with a critical plasticization pressure of 44 bar.

Conclusions:

• The dual cross-linking method significantly enhances MMMs' gas separation performance and anti-plasticization ability.
• This approach provides a valuable reference for developing high-performance MMMs.
• The developed MMMs show great potential for industrial gas separation applications.