Defect-Engineered Metal-Organic Framework/Polyimide Mixed Matrix Membrane for CO₂ Separation.

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Metal-organic frameworks (MOFs) offer tunable properties for separation applications.
• Defect engineering in MOFs is an emerging strategy to enhance functionality.
• MOF-based mixed matrix membranes (MMMs) are promising for gas separation but require further development.

Purpose of the Study:

• To synthesize a novel defect-engineered MOF (Q-ZrFum) using controlled thermal deligandation.
• To incorporate Q-ZrFum into a CO2-philic polyimide (PI) matrix to create MMMs.
• To evaluate the characteristic properties and gas separation performance of the fabricated MMMs.

Main Methods:

• Controlled thermal deligandation to create defect-engineered MOFs (Q-ZrFum).
• Fabrication of Q-ZrFum loaded MMMs using a CO2-philic PI matrix.
• Characterization of MOF and MMM properties, including gas separation performance testing.

Main Results:

• Defect engineering in MOFs increased pore size and unsaturated metal sites, enhancing CO2 transport.
• Improved interfacial compatibility between Q-ZrFum and PI matrix led to enhanced mechanical strength.
• MMM with 5 wt.% Q-ZrFum showed a 99% increase in CO2 permeability (1308 Barrer) and significant CO2/CH4 and CO2/N2 selectivity improvements.

Conclusions:

• Defect-engineered MOFs are effective fillers for enhancing MMM performance.
• The developed MMMs demonstrate superior CO2 separation capabilities.
• This strategy holds promise for advancing membrane-based gas separation technologies.