Smart Metal‐Organic Frameworks (MOFs): Switching Gas Permeation through MOF Membranes by External Stimuli

Abstract

The switching of gas permeation and adsorption on polymers, zeolites, and metalorganic frameworks (MOFs) by external stimuli like temperature, pressure, light, and electric fields is discussed. Especially MOFs as soft porous crystals are suitable candidates for switching gas transport. If the linker of a MOF contains a cis-trans switchable azo moiety, switching of the trans state into the cis state reduces gas transport through a MOF membrane. On the other hand, MOFs with dipolar or ionic components can be switched upon polarization with an electric field into polymorphs of the starting MOF. A ZIF-8 membrane can be switched into a polymorph with a rather stiff lattice, which sharpens the molecular sieving effect of the membrane, and, as an example, the propene/propane selectivity increases.

Impact of the Preparation Procedure on the Performance of the Microporous HKUST-1 Metal-Organic Framework in the Liquid-Phase Separation of Aromatic Compounds

“…For this purpose, some functional characteristics of the HKUST-1 material were compared with those of the MIL-53(Al) structure previously studied in HPLC [20,21]. The main difference between HKUST-1 and MIL-53(Al) metal-organic frameworks is the presence of the OH vertices in the MIL-53(Al) structure, which results in a highly flexible character of this network and therefore, a pronounced "breathing" effect manifested as a pore diameter change [32][33][34]. As to the pore system, the MIL-53(Al) porous structure is arranged as a fully open system of one-dimensional channels, while the HKUST-1 framework contains a three-dimensional channel system.…”

Metal-Organic Framework-Based Stimuli-Responsive Polymers

“…The last category of MOFs is SRPs capable of altering their properties under multiple stimuli. In addition, there are other comprehensive reviews on the topic of MOFs in a different perspective that the readers can refer to [14][15][16][17][18][19][20][21][22][23][24].…”

Metal Organic Frameworks Modified Proton Exchange Membranes for Fuel Cells

“…As a kind of inorganic-organic hybrid material with a certain crystal structure, MOFs are mainly used in gas storage, gas separation, magnetic materials and reaction catalysis (Makiura et al, 2010 ; Shah et al, 2013 ; Knebel et al, 2018 ; Luo et al, 2018 ; Deng et al, 2019b ; Feng et al, 2019 ). In recent years, modification of PEMs with metal-organic frameworks (MOFs) has been intensively studied (Furukawa et al, 2014 ; Shiqiang et al, 2016 ; Luo et al, 2017 ; Shaari et al, 2018 ; Cai et al, 2019 ; Deng et al, 2019c ; Wang et al, 2019 ).…”