Cover Image, Volume 51, Issue 24



The image shows an ion-conducting membrane sample being immersed into a dish of water. In this special issue on anion exchange membranes some of the leaders in ion-conducting polymer membrane research report a number of cutting-edge papers that detail advances in cationic polymers for anion conduction, as also presented in the review by Michael A. Hickner, Andrew M. Herring, and E. Bryan Coughlin on page 1727. The polymer backbone composition, cation type, and modes of ion conductivity are probed. In all current reports, reaching high anion conductivity requires water. Water also stabilizes the cations against degradation by strong hydroxide nucleophiles at high pH. Thus, water is an integral component of these types of membranes. Photo credit: Mike Fleck, Department of Materials Science and Engineering, Penn State.