A Highly Selective Supramolecule Array Membrane Made of Zero‐Dimensional Molecules for Gas Separation

Abstract

We orderly assembled zero‐dimensional 2‐methylimidazole (mim) molecules into unprecedented supramolecule array membranes (SAMs) through solvent‐free vapor processing, realizing the intermolecular spacing of mim at ca. 0.30 nm available as size‐sieving channels for distinguishing the tiny difference between H2 (kinetic diameter: 0.289 nm) and CO2 (kinetic diameter: 0.33 nm). The highly oriented and dense membranes yield a separation factor above 3600 for equimolar H2/CO2 mixtures, which is one order of magnitude higher than those of the state‐of‐the‐art membranes defining 2017’s upper bound for H2/CO2 separation. These SAMs define a new benchmark for molecular sieve membranes and are of paramount importance to precombustion carbon capture. Given the range of supramolecules, we anticipate SAMs with variable intermolecular channels could be applied in diversified separations that are prevalent in chemical processes.

Tailoring Lewis Acid Properties of Metal–Organic Framework Nodes via Anion Post-Replacement for Gas Adsorption and Separation

“…As shown in Figure 4b, the Cr 2p peaks of MIL-101-X series material decreased in the following order: MIL-101-NO 3 (587.05 eV) < MIL-101-COOH (587.15 eV) < MIL-101-F (587.25 eV) < MIL-101-Cl (587.30 eV), demonstrating a lower electron density of Cr(III) in the modified material. 42,43 This result was further confirmed by UV−vis absorption spectra analysis. As seen from Figure 4c, broad optical absorption was observed for the MIL-101-X series material covering the UV−visible region, which can be attributed to the presence of μ-O-Cr clusters.…”

Multidimensional Building Blocks for Molecular Sieve Membranes

“…We proposed supramolecular array membranes (SAMs) as a representative of 0D MSMs. 3 SAMs epitomize fundamental design criteria, such as simple molecules as primary building blocks and ordered alignment of molecules to make intermolecular spacings fully opened. A vapor−sublimation− crystallization (VSC) process triggered by temperature was employed in our study to facilitate Mim assembly, considering the ease of sublimation of Mim at high temperature.…”

“…We proposed supramolecular array membranes (SAMs) as a representative of 0D MSMs . SAMs epitomize fundamental design criteria, such as simple molecules as primary building blocks and ordered alignment of molecules to make intermolecular spacings fully opened.…”

Gradient monolayered porous membrane for liquid manipulation: from fabrication to application

“…A monolayered porous membrane is an efficient, stable and durable membrane material because of its good durability and difficult stratication, which plays an important role in selective liquid separation, water collection, unidirectional penetration and intelligent controllable wettability. 31,59,[78][79][80][81][82][83][84][85][86][87][88][89][90][91] 4.1 Unidirectional penetration Articial three-dimensional porous membranes with special wettability show directional transport behavior; that is, liquid can be transported from one surface of the membrane to the other, but the reverse transport is blocked. 18,85,92,93 Typically, unidirectional penetration membranes are composed of porous structures with an anisotropic surface structure and opposite wettability owing to the Laplace pressure of the bent liquid itself, which could drive the directional transport of the liquid through the porous structure.…”

“…A monolayered porous membrane is an efficient, stable and durable membrane material because of its good durability and difficult stratication, which plays an important role in selective liquid separation, water collection, unidirectional penetration and intelligent controllable wettability. 31,59,[78][79][80][81][82][83][84][85][86][87][88][89][90][91]…”