Light-responsive metal–organic framework sheets constructed smart membranes with tunable transport channels for efficient gas separation

Abstract

New light-responsive MOF sheets were synthesized to fabricate a smart membrane, which displays switchable gas separation performance stimulated with UV-Vis light.

Switching gas permeation through smart membranes by external stimuli: a review

“…stimuli can switch. Polymers can change their physicochemical properties upon external stimuli like electrical, [22][23][24]30,31,33 light, 25,26,32,[34][35][36][37][38][39][40][41] pressure, [44][45][46] thermal, 27,42,43 magnetic eld, 28 and humidity. 29 As in Fig.…”

“…Several attempts exist to develop smart interactive organic polymer membranes that external stimuli can switch. Polymers can change their physicochemical properties upon external stimuli like electrical, 22–24,30,31,33 light, 25,26,32,34–41 pressure, 44–46 thermal, 27,42,43 magnetic field, 28 and humidity. 29 As in Fig.…”

“…39) to increase CO 2 permeance or Azo@NH 2 -MIL-53 (ref. 40) and [Co(azpy)] 37 for SO 2 separation. The schematic illustration of tunable, remote-controllable molecular selectivity by a photo switchable MOF membrane is shown in Fig.…”

“…Inspired by cell membranes with a stimuli-responsive channel for self-regulating permeability and selectivity in response to environmental signals, [57][58][59] switching the selectivity of gas transport through a membrane by external stimuli is highly desired in chemical engineering. There are rst attempts to develop smart interactive membrane that can be switched by external stimuli like electrical voltage, [22][23][24]30,31,33 photo, 25,26,32,[34][35][36][37][38][39][40][41] temperature, 27,42,43 pressure effect, [44][45][46] magnetic eld, 28 and humidity. 29 Their functional gates provide a conformational switch for adjusting the pore sizes and the surface properties of the membranes and thus manipulating the permeability and selectivity.…”

“…1 shows a variety of different materials and technical approaches required for each method, such as absorption, adsorption, 20 membrane separation, 21 and smart gating membranes. 22–46 Nowadays, gas capture by membrane technology is commercially available because it is relatively simple, environment-friendly, cost-effective, not energy-intensive, and it's an easily-scalable technique extensively studied for gas removal. 22–29,47–55 Thus, membrane-based gas separation to reduce pollutants such as CO 2 , H 2 , O 2 , N 2 , and SO 2 gas molecules is essential to attain sustainable global development.…”