Alkaline fuel cell membranes have the potential to reduce the cost and weight of current fuel cell technology, but they still have not been broadly commercialized due to poor hydroxide conductivities and mechanical properties, in addition to low chemical stability. One approach to address these mechanical and transport shortcomings is forming a morphologically bicontinuous network of an ion transporting phase and a hydrophobic phase to provide mechanical strength. In this report, membranes having bicontinuous morphologies are fabricated by cross-linking cation-containing block copolymers with hydrophobic constituents. This is accomplished in a single step and does not require postpolymerization modification. The resulting materials conduct hydroxide ions very rapidly, as high as 120 mS cm-1 in liquid water at 60 C. The methodological changes required to obtain a bicontinuous morphology from such strongly self-segregating block copolymers, relevant to other applications in which bicontinuous structures are desired, are also described. 2013 American Chemical Society.
