Covalent organic framework membranes for ion separation and ion-driven energy conversion

separation, COF selective layers and COF-enabled polyamide architectures illustrate how charge density, pore uniformity, and interfacial control can raise monovalent to divalent anion selectivity while maintaining practical flux. We further connect these transport principles to salinity-gradient energy conversion and coupled thermal or photo fields, where permselectivity and internal resistance jointly set power output under polarization and stability constraints. Looking forward, translation will depend on scalable fabrication with reproducible defect control and orientation, mechanistic validation in complex electrolytes under operando conditions, and process-relevant benchmarking that links membrane descriptors to module-level performance and durability.