Nano-scale changes in structure can help optimize ion exchange membranes for use in devices such as redox flow batteries

 https://www.imperial.ac.uk/news/258053/finetuning-exchange-membranes-better-energy-storage/

"longer lasting, lower cost, more energy-efficient... sustainable ,synthetic, conductive, selective polymer membranes, based on polymers of intrinsic microporosity with rigid, twisted backbones shot through with hour-glass shaped micropores... membrane swelling control opening pores/ reduce selectivity... adding hydrophobic pendant oxadiazole/ benzene rings to PIM polymer backbone tunes local hydrophobicity/ pore size/ ion transport... membrane swells a little, but pores still below 1 nm diameter... 2 months stable"