Unprecedented gas separation performance of a difluoro-functionalized triptycene-based ladder PIM membrane at low temperature

Advanced membrane materials are playing increasingly important roles in solving global energy intensive separation problems. Herein, we introduce a high-performance intrinsically microporous Troger's base-derived ladder polymer (DFTTB) as an advanced membrane material for low-temperature gas separation applications. DFTTB was obtained by design of a 2,3-difluoro-functionaLized triptycene (DFTrip) budding block. The resulting ladder poLymer exhibited high microporosity (S-BET = 918 m(2) g(-1)) , good thermal and mechanical properties, and excellent gas separation performance at or above the Latest 2015 permeability/selectivity trade-off curves for H-2/N-2, H-2/CH4 and O-2/N-2 with H-2 and O-2 permeabilities of 5468 and 650 barrer coupled with H-2/N-2, H-2/CH4 and O-2/N-2 selectivities of 50, 38 and 6.0, respectively. Furthermore, DFTTB displayed unprecedented performance at sub-ambient temperatures with an O-2/N-2 selectivity of 10.1 and O-2 permeability of 137 barrer at similar to 30 degrees C. This high selectivity coupled with up to similar to 100-fold higher O-2 and H-2 permeability than commercial glassy polymer membrane materials, provides new opportunities for Low temperature air separation and hydrogen recovery from petrochemical process streams.

Automated summary

Advanced ladder polymer membrane material DFTTB exhibits high microporosity, good thermal and mechanical properties, and excellent gas separation performance, surpassing the 2015 permeability/selectivity trade-off curves for H-2/N-2, H-2/CH4 and O-2/N-2. With unprecedented performance at sub-ambient temperatures, DFTTB provides new opportunities for low temperature air separation and hydrogen recovery from petrochemical process streams.