Gyroid-nanostructured all-solid polymer films with exceedingly high proton conductivity and low H2 gas permeability have been created via crosslinking polymerization of mixtures of a zwitterionic amphiphilic monomer and a polymerizable imide-type acid that co-organize into bicontinuous cubic liquid-crystalline phases. The gyroid nanostructures are visualized by reconstructing a 3D electron map from the synchrotron X-ray diffraction patterns. These films exhibit high proton conductivity of the order of 10-1 S cm-1 and extremely low H2 gas permeability of the order of 10-15 mol m m-2 s-1 Pa-1 . These properties can be ascribed to the presence of the ionic liquid-like layer along the gyroid minimal surface. Since these two characteristics are required for improving the performance of proton-exchange membrane fuel cells, the present membrane design represents a promising strategy for the development of advanced devices, pertinent to establishing sustainable energy sources.
Keywords: bicontinuous cubic phases; gyroids; liquid crystals; polymer electrolytes; proton conduction.
© 2021 The Authors. Macromolecular Rapid Communications published by Wiley-VCH GmbH.