Hydrophilic Microporous Polymer Membranes: Synthesis and Applications

Abstract

Ion and water transfer in subnanometer‐sized confined channels of hydrophilic microporous polymer membranes show enormous potential in tackling the ubiquitous trade‐off between permeability and selectivity for energy and environment‐related membrane technologies. To this end, a variety of hydrophilic polymers of intrinsic microporosity (HPIMs) have been developed. Herein, the synthetic strategies toward HPIMs are summarized, including post‐synthetic modification of polymers to introduce polar groups (e. g., amines, hydroxy groups, carboxylic acids, tetrazoles) or charged moieties (e. g., quaternary ammonium salts, sulfonic acids), and the polymerization of hydrophilic monomers. The advantages of HPIM membranes over others when employed in energy conversion and storage, acid gas capture and separation, ionic diodes, and ultrafiltration, are highlighted.

Advances in Polymers of Intrinsic Microporosity (PIMs)-Based Materials for Membrane, Environmental, Catalysis, Sensing and Energy Applications

“…Additionally, some of these reviews focused on the chemistry part of PIMs covering monomer and polymer synthesis, with an attention to the structure-property relationship of PIMs, and their performance in different applications. 1,25,35,80 Nevertheless, to the best of our knowledge, no report shows all applications of PIMs and highlights the importance of these materials in modern applications. This review has summarized the advances in PIM-based materials for various applications using PIMs literature up to the end of 2022.…”

Current Challenges and Perspectives of Polymer Electrolyte Membranes

“…The quaternary bicyclic ammonium groups can undergo ring-opening side reactions under alkaline conditions, resulting in poor stability. Under this reaction, quaternized TB units are converted to diazacyclooctane units, causing the loss of charged functional groups and the decrease in chain rigidity . In addition, the number of cationic groups that are obtained through postmodification of Troger’s base polymers is limited, so that the conductivity improvement encounters a bottleneck.…”

“…Under this reaction, quaternized TB units are converted to diazacyclooctane units, causing the loss of charged functional groups and the decrease in chain rigidity. 48 In addition, the number of cationic groups that are obtained through postmodification of Troger's base polymers is limited, so that the conductivity improvement encounters a bottleneck. Furthermore, Troger's base polymers are generally rigid because the repeating units are connected by more than two bonds.…”

“…The power density of PEMFCs assembled with SPX-BP-0.95 (PIM-based membrane) provides a higher power output than that with Nafion 117 under the same test conditions, further demonstrating the promise of PIM-based membranes for fuel cells. 48 This concept of designing cation exchange membranes and the synthetic approach may be broadly applicable and can be extended to develop a variety of synthetic membranes for electrochemical devices.…”

Advances in Functional Separation Membranes

“…For example, depending on the pore size, membrane classifications are reverse/forward osmosis (RO/FO), electrodialysis/ion exchange (ED), nanofiltration (NF), ultrafiltration (UF), and microfiltration (MF) (see Figure 1.1b). [3][4][5] As one of the most energy-efficient separation technologies, membrane technology can play a significant role in sustainable development. 6,7 Although many traditional separation technologies, including evaporation, precipitation, crystallization, salting out, solvent extraction, and ion exchange have been used in industry, their accompanying high costs and energy use, and low separation efficiency limit their sustainability.…”