(693h) Poly(N-isopropylacrylamide-co-benzo-12-crown-4-acrylamide) Hydrogels with Dual Molecular-/Ion-Recognition Responsive Properties

Wei, Y. Y., Sichuan University
Liu, Z., Sichuan University
Zhu, L., Sichuan University
Xie, R., Sichuan University
Ju, X. J., Sichuan University
Wang, W., Sichuan University
Chu, L., Sichuan University

A novel poly(N-isopropylacrylamide-co-benzo-12-crown-4-acrylamide) (poly(NIPAM-co-B12C4Am)) hydrogel with dual molecular-/ion-recognition responsive properties is prepared by using 12-crown-4 as both guest unit for molecular-recognition and host unit for ion-recognition.  This smart hydrogel exhibits high responsivity toward γ-cyclodextrin (γ-CD) and Na+.  Due to the stable formation of 1:1 γ-CD/B12C4 host-guest complexes, the volume phase transition temperature (VPTT) of poly(NIPAM-co-B12C4Am) hydrogel shifts to a higher value at the presence of γ-CD; while, the VPTT shifts to a lower value when crown ethers capture Na2+ and form 2:1 “sandwich” complexes of B12C4/Na+. The results provide valuable guidance for designing and applying poly(NIPAM-co-B12C4Am) smart hydrogels in various applications such as chemical valves, sensors and actuators.