Photoinitiated Copper(I)-Catalyzed Azide-Alkyne Cycloaddition Reaction for Ion Conductive Networks

The photoinitiated copper(I)-catalyzed azide alkyne cycloaddition (photo-CuAAC) is a "click" reaction that enables spatially and temporally controlled polymerizations. The solventless photopolymerization of multifunctional azide and cationic alkyne monomers results in the rapid formation of a charged polymer network. Full conversion of these monomers is achieved within 30 min under mild, blue-light irradiation conditions (470 nm light at 30 mW/cm2). The modulus of the material is readily tuned by controlling the ratio of di- and trifunctional alkyne monomers. Facile exchange of the hydrophobic bistriflimide counterion for a hydroxide anion yields an ion conductive polymer network with photopatternable charged regions. The spatiotemporal nature of the ionic photo-CuAAC reaction coupled with the chemical stability and mechanical flexibility suggests this chemistry as a facile and novel approach for ion-containing material synthesis (e.g., alkaline fuel cell components).