Porous Structure Design of Polymeric Membranes for Gas Separation

Abstract

High‐performance polymeric membranes for gas separation are of interest for molecular‐level separation in industrial‐scale chemical, energy, and environmental processes. To overcome the inherent trade‐off relationship between permeability and selectivity, the creation of permanent microporosity in polymeric matrices is highly desirable because the porous structures can provide a high fractional free volume to facilitate gas transport through the dense layer. Here, recent developments regarding the formation of porous polymeric membranes and potential strategies for pore structure design are reviewed.

Synthesis of Polymeric Carbon Nitride Films with Adhesive Interfaces for Solar Water Splitting Devices

“…Film is fundamental to devices, ranging from electronics, optoelectronics, and electrochemical cell to photocatalytic devices. − As an example, a solar water splitting device or photoelectrochemical (PEC) cell is capable of storing solar energy by photocatalysis. − The structure of the device generally consists of two functional layers, namely, the charge collector films and photocatalytic films. , Specifically, the films of charge collector are normally transparent conductor oxides (TCOs). − The photoactive films are semiconductors to serve multiple tasks, − including harvest of solar energy, generation of charge carriers, and proceeding of surface redox reactions. , Beyond the layers themselves, the interfaces between them are also significant to influence the performance, because the photoinduced free carriers must be transferred across the interfaces to the electrode on the other side. The defects along the interfaces are very likely to affect the migration of charge and thus promote recombination.…”

Membranes with Intrinsic Micro-Porosity: Structure, Solubility, and Applications

“…The microporous polymer membranes (including PIMs) have exhibited extremely high separation performance in gas separation, and have been leveraged in polymer membranes to surpass the Robeson upper bounds, which open an entirely new methodology for gas separation [21,26]. Many reviews on gas separation using microporous polymer membranes have, thus, been published [4,5,16,21,91,92,93]. Besides excellent separation performance in gas separation, microporous polymer membranes can also exhibit good separation performance in other separations such as nanofiltration, pervaporation, and gas/vapor separation.…”

Recent Advances of Gas Transport Channels Constructed with Different Dimensional Nanomaterials in Mixed‐Matrix Membranes for CO2 Separation

“…The gas transport channels constructed with different dimensional nanomaterials can be classified into 1D nanomaterials such as carbon nanotube as the representative, 2D nanomaterials such as graphene oxide (GO), metal organic framework (MOF)‐derived nanosheets, covalent organic frameworks (COFs), layered double hydroxides (LDHs), and molybdenum disulfide (MoS 2 ) as the representative, 3D nanomaterials like MOFs including zeolitic imidazolate frameworks (ZIF‐8), zirconium terephthalate‐based frameworks (like UiO‐66), copper benzene tricarboxylate‐based frameworks (like CuBTC), chromium terephthalate‐based frameworks (like MIL‐101(Cr)) as the representative and microporous polymers including polymers of intrinsic microporosity (PIMs), conjugated microporous polymers (CMPs), covalent triazine‐based frameworks (CTFs), hyper‐crosslinked polymers (HCPs), and porous aromatic frameworks (PAFs) …”