(398aa) A Highly Permeable Microporous Polyamide Membrane for Molecularsieving of Nitrogen from Volatile Organic Compounds

Microporous polymer membranes continue to receive tremendous attention for their energy-efficient gas separation owing to their high separation performance^{[1, 2]}. However, it remains challenging to simultaneously achieve the solution processability of polymers along with the molecular-sieving ability of membranes for the separation of mixtures containing condensable gases, such as N₂/volatile organic compound (VOC) mixtures. Here, we report a new network microporous polyamide membrane with good molecular-sieving performance for the separation of N₂ from VOC mixture. Triple-substituted triptycene was used as the main monomer to form a fisherman’s net-shaped polymer, which readily form a composite membrane by solution casting. This membrane exhibited outstanding separation performance and good stability for the molecular-sieving separation of N₂ over VOCs, such as cyclohexane. Its rejection rate reached 99.2 % with 1104 GPU N₂ permeance at 24 ^oC under 4 kPa. This approach opens the door for the development of microporous membranes to separate condensable gases.

[1] Jimenez-Solomon, M. F., et al. . Nature Mater. 2016 15 760

[2] Du, N., et al. Nature Mater. 2011 10  372