Microporous Organic Materials for Membrane‐Based Gas Separation

Abstract

Membrane materials with excellent selectivity and high permeability are crucial to efficient membrane gas separation. Microporous organic materials have evolved as an alternative candidate for fabricating membranes due to their inherent attributes, such as permanent porosity, high surface area, and good processability. Herein, a unique pore-chemistry concept for the designed synthesis of microporous organic membranes, with an emphasis on the relationship between pore structures and membrane performances, is introduced. The latest advances in microporous organic materials for potential membrane application in gas separation of H , CO , O , and other industrially relevant gases are summarized. Representative examples of the recent progress in highly selective and permeable membranes are highlighted with some fundamental analyses from pore characteristics, followed by a brief perspective on future research directions.

Progress Report on Phase Separation in Polymer Solutions

“…In academia, another method is proposed based on the pore formation through templating. [1] For instance, PPM shows its extraordinary efficiency in various membrane separation processes [7] where a transmembrane gradient forces a fluid to pass the porous membrane through the pores and particles are filtered by the physical principle of size exclusion. As a result, the intrinsic properties of the template are inherited to the PPM.…”

HiGee Strategy toward Rapid Mass Production of Porous Covalent Organic Polymers with Superior Methane Deliverable Capacity

“…High porosity with well‐defined molecular reticulation is desired for gas adsorption, separation, catalysis, etc. Porous organic materials are extended porous structures entirely composed of light elements and connected by strong covalent bonds .…”

Ionic Liquids‐Based Membranes for Carbon Dioxide Separation

“…A gas mixture at higher pressure will move across the membrane that is selectively permeable to a certain component of the gas mixture in the gas separation process and the membrane permeate is enriched in this species. However, the performance still suffers from the limitation of the trade‐off relationship between membrane permeability and selectivity . That is, the increase of permeability (Gas permeability was expressed in term of barrer, 1 barrer=1×10 −10 cm 3 (STP) cm cm −2 s −1 cm Hg −1 ) comes from the sacrifice of selectivity, and vice versa.…”

“…However, the performance still suffers from the limitation of the trade-off relationship between membrane permeability and selectivity. [12] That is, the increase of permeability (Gas permeability was expressed in term of barrer, 1 barrer = 1 × 10 À 10 cm 3 (STP) cm cm À 2 s À 1 cm Hg À 1 ) comes from the sacrifice of selectivity, and vice versa. Robeson [13] summarized and plotted the relationship between gas permeability and selectivity of membranes, coming up with the so-called Robeson upper bounds that are valid for numerous gas pairs including CO 2 / CH 4 , CO 2 /N 2 , H 2 /CO 2 , H 2 /CO 2 and etc ( Figure 1).…”