High Temperature-Responsive Autonomous Reswelling Polymer Based on Dynamic Host-Guest (De)complexation of Cyclodextrin

Autonomous recovery for original states is a distinctivepropertyin living organisms that stimulates the development of artificialmaterials with unprecedented responsiveness and autonomy because suchbioinspired functions can be potentially applied to biomedical materialsand devices. Therefore, excellent responsivity to external subtlestimuli is highly desirable. We designed a poly(NIPAM-co-CD-co-DBD) bearing a & beta;-cyclodextrin (CD)host and dimethylaminosulfonyl-2,1,3-benzoxadiazole (DBD) guest torealize highly responsive temperature-induced autonomous reswellingdue to interchain cross-linking of the polymer chains via CD-DBDcomplexation, though a previous poly(NIPAM-co-CD)needs stronger temperature stimuli for its autonomous reswelling.Density functional theory calculations indicate a promising stericconformation of the CD-DBD complex for the autonomous reswelling.Thus, a small temperature change, heating with 0.5 & DEG;C steps,can lead to repeated autonomous reswelling. Furthermore, the autonomousreswelling was successfully detected based on the fluorescent characterof DBD, which proved the capability for visual detection of the autonomousreswelling.