Generalizable Porous Aromatic Framework-Included Polymer Membranes for Diffusion-Enhanced Gas Separations

Area of Science:

• Materials Science
• Chemical Engineering
• Separation Science

Background:

• Industrial separation processes consume substantial global energy (10-15%).
• Existing membrane technologies require improved performance and stability for broad industrial use.
• Mixed-matrix membranes offer potential for enhanced gas separation but face challenges.

Purpose of the Study:

• To develop a generalizable strategy for creating high-performance mixed-matrix gas separation membranes.
• To enhance gas separation performance and long-term stability beyond current polymer membrane capabilities.
• To address plasticization issues hindering commercialization of gas separation membranes.

Main Methods:

• Incorporating robust porous aromatic framework (PAF) particles into commercial polymer matrices.
• Testing composite membranes for gas separation performance with various industrial gas mixtures (CO2/N2, O2/N2, He/CH4, H2/N2, C2H4/C2H6).
• Evaluating membrane stability under simulated flue gas conditions for 6 years.
• Functionalizing PAFs with polyamines to improve anti-plasticization properties.

Main Results:

• Composite membranes exhibited significantly enhanced gas permeabilities (up to 520%) across diverse gas mixtures.
• Membrane selectivities remained largely unchanged even after 6 years of aging.
• PAF particles' high porosity, chemical compatibility, and unique properties drove performance improvements.
• Polyamines-functionalized PAFs led to membranes with high resistance to plasticization.

Conclusions:

• The developed strategy offers a generalizable approach for high-performance mixed-matrix gas separation membranes.
• PAF-based membranes show promise for energy-efficient industrial gas separations with enhanced stability.
• PAF particles' dispersibility in common solvents suggests broad applicability in membrane design.