“…Recently, a series of ion-recognition responsive smart materials, such as linear polymers, [ 6,7,15,16 ] linear-grafted membranes, [ 8,9,17 ] hydrogels, [ 10,11,18,19 ] microcapsules [ 12,20 ] and microspheres [ 13,14 ] have been developed with 18C6 or 15C5 as the ion-recognition receptor and thermo-responsive poly( N -isopropylacrylamide) (PNIPAM) as the actuator. However, these smart materials only exhibit single ion-responsive characteristics based on crown ether as the host molecule, while their molecular-responsive properties based on crown ether as a guest molecule have not yet been reported.…”