Processable microporous membranes: emerging platforms for separation technologies.

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Microporous materials are crucial for membrane technologies, but fabricating them into large-area, defect-free membranes remains a significant challenge.
• Processability is a critical bottleneck hindering the translation of promising porous frameworks into scalable membrane applications.

Purpose of the Study:

• To review recent advances in purely organic microporous membranes and metal-organic framework (MOF)-based membranes from a processability-centered perspective.
• To highlight how molecular design, interfacial engineering, and processing methods impact membrane fabrication, porosity, and mechanical properties.

Main Methods:

• Examined literature on microporous organic polymers, crystalline microporous organic frameworks, polycrystalline MOFs, MOF-polymer composites, and MOF-derived glasses.
• Analyzed how different fabrication strategies, including melt- and solution-processing, influence film-forming capabilities and structural stability.
• Investigated emerging strategies like in situ crystallization and polymer-MOF hybridization.

Main Results:

• Molecular design and processing techniques enable tunable porosity, enhanced mechanical robustness, and scalable fabrication of microporous membranes.
• Different material types (amorphous polymers, crystalline frameworks, composites, glasses) exhibit distinct film-forming abilities and manufacturing feasibility.
• Emerging strategies address challenges in defect control, mechanical integrity, and scalability.

Conclusions:

• Advances in processability offer pathways to overcome limitations in defect control, mechanical robustness, and scalability for next-generation microporous membranes.
• Established design principles and processing routes facilitate industrial implementation in gas separation, water purification, and energy processes.