Abstract: Disclosed herein is an ion selective separation membrane including: a metal organic framework layer formed on, in, and/or around a substrate, the metal organic framework having a crystal structure that includes a first surface and a second surface and includes ion transport channels formed between respective pore windows in the first surface and the second surface; first and second electrodes to apply a potential difference across the membrane; wherein the respective pore windows have a pore size that is less than the hydrated diameter of the ion for which the ion selective separation membrane is selective.