Polymeric molecular sieve membranes via in situ cross-linking of non-porous polymer membrane templates

Abstract

High-performance polymeric membranes for gas separation are attractive for molecular-level separations in industrial-scale chemical, energyand environmental processes. Molecular sieving materials are widely regarded as the next-generation membranes to simultaneously achieve high permeability and selectivity. However, most polymeric molecular sieve membranes are based on a few solution-processable polymers such as polymers of intrinsic microporosity. Here we report an in situ cross-linking strategy for the preparation of polymeric molecular sieve membranes with hierarchical and tailorable porosity. These membranes demonstrate exceptional performance as molecular sieves with high gas permeabilities and selectivities for smaller gas molecules, such as carbon dioxide and oxygen, over larger molecules such as nitrogen. Hence, these membranes have potential for large-scale gas separations of commercial and environmental relevance. Moreover, this strategy could provide a possible alternative to 'classical' methods for the preparation of porous membranes and, in some cases, the only viable synthetic route towards certain membranes.

Layered microporous polymers by solvent knitting method

“…To the best of our knowledge, the Friedel-Crafts alkylation reaction used to produce HCPs with layered structure using dichloroalkane as an economical solvent has not been previously reported ( 34 – 36 ). The HCPs show excellent thermal stability, high surface area, and gas uptake and could be used as layered bulk materials to produce 2D SHCP nanosheets by the ultrasonic-assisted solvent exfoliation method.…”

Plasticization and Swelling in Polymeric Membranes in CO2 Removal from Natural Gas

“…The potential methods of polymer modification by cross-linking include chemical cross-linking, thermal treatment, cross-linking by ultraviolet irradiations, and ion beam cross-linking [2,3,[142][143][144]. Cross-linking can control the swelling behavior of membranes and increases the chemical and thermal stability of membranes [145,146]. It reduces chain mobility and leads to a consequent increase of glass transition temperature.…”

Knitting hypercrosslinked conjugated microporous polymers with external crosslinker

“…Indeed, the monomer can be as simple and inexpensive as benzene, and the mild synthesis conditions as well as the cheap solvent should allow economical and larger-scale production of such materials. This strategy is versatile and flexible and a wide range of possible structural building block can be employed in the synthesis of functional materials with diverse pore structures and unique properties for tremendous applications in CO 2 capture, [19,20] separation, [21,22] heterogeneous catalysis, [23,24] drug release [25] and so on.…”