Network completeness enables angstrom-scale transport pathways in polymer membranes.

Area of Science:

• Materials Science
• Chemical Engineering
• Polymer Chemistry

Background:

• Achieving high molecular selectivity and mechanical robustness simultaneously is a major challenge in separation science.
• Existing polymer materials often struggle to balance these two critical properties for advanced applications.

Purpose of the Study:

• To design and synthesize novel polymer networks with integrated diffusion channels for enhanced molecular separation.
• To establish a quantitative design descriptor linking network structure to separation performance.
• To demonstrate superior performance in hydrogen-selective separations.

Main Methods:

• Systematic tuning of crosslinking motifs to control network completeness.
• Utilizing a density-probe approach to experimentally verify sub-3 Å pores.
• Fabricating and testing hydrogen-selective membranes (ms-oDMB-DB50).

Main Results:

• Experimental evidence of sub-3 Å diffusion channels within the polymer matrix.
• The ms-oDMB-DB50 membrane achieved record-breaking performance for polymer-based separations.
• Demonstrated stable operation and mechanical robustness over extended periods.

Conclusions:

• Introduced 'network completeness' as a key design descriptor for polymer networks.
• Established a framework for reticular-style design in polymers for dual-domain functionality.
• The developed membranes offer a promising solution for advanced molecular separations requiring high selectivity and durability.