Tunability of ion gel properties via copolymer blending that forms the gel networks

초록

The tunability of ion gel properties is demonstrated by blending random copolymers of different compositions that form the ion gel scaffolds. Ionic liquids have the advantage of having low vapor pressure at room temperature and excellent thermal, chemical, and electrochemical stability. Ion gels are made of polymer networks and ionic liquids. The network structure in ion gels minimizes the risk of ionic liquid leakage while ion gels retain the excellent properties of neat ionic liquids mentioned above. In addition, ion gels are characterized by facile processability and enhanced mechanical properties due to the polymer scaffold. Based on the characteristic ionic conductivity and capacitance, ion gels have been implemented in various applications, including transistors, batteries, and biosensors. In the past, various investigations implemented ion gel networks consisting of more than one polymer species, and the blending was shown to be effective in the modulation of the network interactions and the notable improvement in mechanical properties. We recently investigated ion gel fabrication using crystallizable random copolymers of controlled compositions. In this study, ion gels were prepared by blending the previously synthesized copolymers of various compositions, and we tried to examine resulting ion gel properties compared to the existing precursors. Two copolymers of different compositions and an ionic liquid were mixed in various ratios to prepare gels, and the phase separation behavior of the ternary system was monitored. The thermal stability, crystallinity, and mechanical properties of the gels were characterized as a function of the ratio.