초록 |
We report ionic liquid containing block copolymer electrolyte membranes, which can be used at high temperature above 100 oC without humidification. The matrix block copolymer investigated is partially sulfonated poly(styrenesulfonate-b-methylbuthylene) (SnMBm) with different molecular weight and ion contents. Imidazolium based ionic liquids with different anions are selectively incorporated into hydrophilic domains of SnMBm copolymers. Various morphologies such as lamellae, perforated lamellae, hexagonal cylinder, and spherical domains have been observed upon increasing the amount of the ionic liquids. In particular, it has been found that the morphologies of resulting composite membranes are crucially depending on kinds of ionic liquids due to the different compatibility between hydrophilic domains of SnMBm copolymers and anions of ionic liquids. The quantitative relationship between morphology and conductivity has been investigated by combining SAXS, TEM, and impedance spectroscopy. |