Advances in organic microporous membranes for CO₂ separation

Abstract

This Perspective focuses on innovation and advanced design of membranes for carbon dioxide separation, triggered by new organic microporous materials.

Engineering HOF-Based Mixed-Matrix Membranes for Efficient CO2 Separation

“…Mixed-matrix membrane (MMM) has deemed as an advanced membrane platform, with the merit of deploying distinct separation properties of fillers into processable matrix [ 6 – 10 ]. Along with the emergence of reticular chemistry, porous framework materials have been widely developed into advanced fillers to achieve membrane structure optimization and performance enhancement [ 11 – 13 ].…”

“…Hydrogen-bonded organic frameworks (HOFs) have emerged as a new class of organic framework materials with high crystallinity and designable structure [ 13 – 15 ]. Due to the reversible nature of hydrogen bond, the HOF materials could be assembled under mild condition and maintained stable after solvent removal, showing excellent potential for gas separation [ 16 – 22 ].…”

Two-step fabrication of COF membranes for efficient carbon capture

“…S8, ESI †). Within 500 ps, compared with COF-316-CN, fewer CO 2 molecules passed 29,30 The data were obtained from the previous literature listed in Table S1 (ESI †).…”

“…(d) Comparison of the CO 2 /N 2 separation performances of the membranes and representative membranes in the literature. The light-yellow region is the target area for post-combustion capture of CO 2 29,30. The data were obtained from the previous literature listed in TableS1(ESI †).…”

(3,3)-Connected Triazine-Based Covalent Organic Frameworks for Efficient CO2 Separation over N2 and Dye Adsorption

“…Excessive carbon dioxide emissions from the uncontrolled burning of fossil fuels have led to serious environmental problems such as global warming, rising sea levels, and increasing ocean acidity. − Organic dyes in wastewater, which are structurally stable and difficult to degrade, will cause serious pollution of scarce freshwater resources if discharged directly. − To solve these difficult issues and meet the needs of sustainable development, researchers have been committed to developing novel porous materials, such as porous carbons, zeolites, metal–organic frameworks (MOFs), and covalent organic frameworks (COFs), which have high chemical and thermal stability, Brunauer–Emmett–Teller (BET) specific surface area, permanent porosity, and regenerability, etc., to efficiently capture carbon dioxide and organic dyes. − Among them, COFs are a class of crystalline porous networks made up of covalent bonds between organic small-molecule linkers with light elements such as C, H, N, O, and B. , COFs are usually constructed through thermodynamically controlled reversible reactions guided by the theory of dynamic covalent chemistry, − which allows precise skeleton construction and enhanced crystallinity while reducing structural defects. − Compared to other porous materials such as natural zeolites, artificial molecular sieves, and MOFs, COFs have several advantages. First, the variety of organic small-molecule linkers and their functional groups makes the structure and function of COFs highly predesignable. , Second, the covalent bonds form a stable network structure that gives COFs good thermal and chemical stability .…”