(Invited) The Latest Developments in Radiation-Grafted Anion-Exchange Membranes

This invited lecture will discuss the latest developments in radiation-grafted anion-exchange membranes (RG-AEM) that are being developed for a wide range of electrochemical technologies including fuel cells, electrolysers, and reverse electrodialysis. This presentation will discuss the following key points: RG-AEMs can have very high conductivities and water diffusivities, however they generally have excessive water uptakes and degrees of swelling in water, as well as poor permselectivities when in contact with aqueous salt solutions. Crosslinking can reduce swelling and improve permselectivities, but this is at the expense of conductivity. The cationic headgroup chemistries can alter the water uptakes of the RG-AEMs, which can impact properties such as their alkali stability and permselectivity. Subtle changes in amination can lead to RG-AEMs with very different water contents and diffusivities. When fully hydrated, RG-AEMs in the alkali forms can have usefully high stabilities at temperatures above 60 o C. RG-AEMs can be made with multiple chemical functionalities either via the co-grafting of more than one monomer or via amination using more than one amine reagent (see scheme below). Finally, the presentation will present some recent undergraduate project results that probe the homogeneity of grafting using a new titration technique.