Strong Hints of Antiplasticization by Multivariate ZIF-8-67 in PIM-EA(Me2)-TB-Based Mixed-Matrix Membranes for...

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Separating olefins and paraffins is energy-intensive due to similar physical properties.
• Membrane technology offers a sustainable alternative to traditional separation methods like cryogenic distillation.
• Zeolitic imidazolate frameworks (ZIFs) show promise for gas separation applications.

Purpose of the Study:

• To investigate the use of mixed matrix membranes (MMMs) for efficient C3H6/C3H8 separation.
• To explore the performance of ZIF-8, ZIF-67, and ZIF-8-67 incorporated into a Tröger's base polymer of intrinsic microporosity (PIM-EA(Me2)-TB).
• To evaluate the impact of ZIF loading on membrane selectivity and permeability.

Main Methods:

• Synthesis of ZIF-8, ZIF-67, and ZIF-8-67 via aqueous-media methods.
• Fabrication of MMMs by dispersing ZIFs into PIM-EA(Me2)-TB.
• Gas permeation testing of MMMs for C3H6/C3H8 separation.
• Analysis of permeation data using the modified Maxwell model.

Main Results:

• MMMs with 20 wt % ZIF loading showed enhanced performance compared to neat membranes.
• ZIF-67 based MMMs achieved the highest ideal selectivity for propene/propane (17).
• ZIF-8-67 MMMs offered comparable selectivity with reduced propene permeability loss.
• Selected MMMs surpassed the 2020 upper bound for C3H6/C3H8 separation.

Conclusions:

• ZIF/PIM-EA(Me2)-TB MMMs are effective for challenging gas separations like propene/propane.
• The incorporation of ZIFs, particularly bimetallic ZIF-8-67, enhances membrane performance.
• These MMMs present a promising solution for industrial gas purification and separation processes.