De Novo Ion-Exchange Membranes Based on Nanofibers

The unique functions of nanofibers (NFs) are based on their nanoscale cross-section, high specific surface area, and high molecular orientation, and/or their confined polymer chains inside the fibers. The introduction of ion-exchange (IEX) groups on the surface and/or inside the NFs provides de novo ion-exchangers. In particular, the combination of large surface areas and ionizable groups in the IEX-NFs improves their performance through indices such as extremely rapid ion-exchange kinetics and high ion-exchange capacities. In reality, the membranes based on ion-exchange NFs exhibit superior properties such as high catalytic efficiency, high ion-exchange and adsorption capacities, and high ionic conductivities. The present review highlights the fundamental aspects of IEX-NFs (i.e., their unique size-dependent properties), scalable production methods, and the recent advancements in their applications in catalysis, separation/adsorption processes, and fuel cells, as well as the future perspectives and endeavors of NF-based IEMs.

Automated summary

Nanofibers exhibit unique functions due to their nanoscale cross-section, high specific surface area, high molecular orientation, and the introduction of ion-exchange groups, leading to de novo ion-exchangers. Ion-exchange nanofibers with large surface areas and ionizable groups demonstrate rapid ion-exchange kinetics and high ion-exchange capacities, providing superior properties in applications such as catalysis and fuel cells. Future advancements in scalable production methods and applications of ion-exchange nanofibers are highlighted in this review.