Hierarchical Fibrous Metal-Organic Framework/Ionic Liquid Membranes for Efficient CO₂/N₂ Separation

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Metal-organic frameworks (MOFs) offer tunable structures for CO2 adsorption but suffer from fragility and poor processability.
• Developing robust and efficient membranes is crucial for industrial CO2 separation applications.

Purpose of the Study:

• To design and fabricate a hierarchical fibrous MOF/ionic liquid (IL) membrane for enhanced CO2/N2 separation.
• To improve the processability and mechanical stability of MOF-based materials for gas separation.

Main Methods:

• Fabrication of a composite membrane by integrating ZIF-8 MOF nanounits and an ionic liquid (IL) onto polyimide (PI) fibers.
• Characterization of the membrane's structural properties, including surface area, porosity, and mechanical stability.
• Evaluation of the membrane's performance in CO2 adsorption capacity, CO2/N2 selectivity, and recyclability.

Main Results:

• The hierarchical fibrous PI/ZIF-8/IL membranes exhibited a high specific surface area (79.89 m2/g) and porosity (93.28%).
• The membranes demonstrated enhanced CO2 adsorption capacity (3.32 mmol/g at 298 K and 1 bar) and high CO2/N2 selectivity (28).
• The developed membranes showed excellent mechanical stability and recyclable regeneration capability.

Conclusions:

• The integrated hierarchical pore structure of MOF/IL membranes enhances gas transfer and CO2 affinity.
• This approach provides a viable strategy for creating robust and high-performance membranes for CO2 separation.
• The study offers a practical direction for designing advanced MOF-based materials for targeted gas separation applications.