(519f) Thermal Cross-Linking of Ultra-Robust Membranes for Plasticization Resistance and Enhanced Permeability

Polymers are the most widely used membrane materials for gas separations due to high processability and relatively low material cost. Most polymeric membranes, however, are susceptible to a significant selectivity loss upon exposure to condensable gases at high pressure due to undesirable plasticization. In this talk, I will present a novel method for enhancing both the permeability and plasticization tolerance of polymeric membranes via a combination of amidation and decarboxylation between a carboxylated polyimide (PI) and an amine-containing ladder-structured polysilsesquioxane (LAPSQ) [1]. Gas transport properties of a series of BTDA-Durene:DABA PI/LAPSQ membranes with different Durene:DABA molar ratios (3:2, 2:1, and 4:1) were examined with mechanical properties before and after thermal cross-linking. Also, molecular dynamics simulations were conducted to rationalize the enhanced CO₂ permeability as well as high plasticization resistance in the thermally cross-linked PI/LAPSQ (80/20) membranes. With that, a new approach of manufacturing hollow fiber membranes will be demonstrated for the scale-up of our highly plasticization-resistive membranes.

[1] H. J. Yu, C-H Chan, S. Y. Nam, S-J Kim, J. S. Yoo, J. S. Lee, Thermally cross-linked ultra-robust membranes for plasticization resistance and permeation enhancement – A combined theoretical and experimental study, J. Membr. Sci. 646 (2022), 120250.