In Situ Synthesis of Imidazolium-Crosslinked Ionogels via Debus–Radziszewski Reaction Based on PAMAM Dendrimers in Imidazolium Ionic liquid

This study reports a remarkably facile method to synthesize novel ionogels with imidazolium cycle crosslinks based on polyamidoamine (PAMAM) dendrimers via one-pot, modified Debus–Radziszewski reaction in ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]). High room temperature ionic conductivity (up to 6.8 mS cm−1) is achieved, and more remarkably, it can still exceed 1 mS cm−1 when the dendrimer content reached 70% because PAMAM dendrimers are completely amorphous with many cavities and the newly formed imidazolium crosslinks contains ions. The elastic modulus of these ionogels can exceed 106 Pa due to the newly-formed rigid imidazolium crosslinks. Crucially, these ionogels are robust gels even at temperatures up to 160 °C. Such novel ionogels with high ionic conductivity, tunable modulus, and flexibility are desirable for use in high-temperature flexible electrochemical devices.