Mechanical Stretch -Cyclodextrin Pseudopolyrotaxane Elastomer with Reversible Phosphorescence Behavior

Polyethylene glycol chains in two terminals of the naphthalene functional group are threaded into alpha-cyclodextrin cavities to form the pseudopolyrotaxane (NPR), which not only effectively induces the phosphorescence of the naphthalene functional group by the cyclodextrin macrocycle confinement, but also provides interfacial hydrogen bonding assembly function between polyhydroxy groups of cyclodextrin and waterborne polyurethane (WPU) chains to construct elastomers. The introduction of NPR endows the elastomer with enhanced mechanical properties and excellent room temperature phosphorescent (RTP) emission (phosphorescence remains in water, acid, alkali, and organic solvents, even at 160 degrees C high temperatures). Especially, the reversible mechanically responsive room temperature phosphorescence behavior (phosphorescence intensity increased three times under 200% strain) can be observed in the mechanical stretch and recover process, owing to strain-induced microstructural changes further inhibiting the non-radiative transition and the vibration of NPR. Therefore, changing the phosphorescence behavior of supramolecular elastomers through mechanical stretching provides a new approach for supramolecular luminescent materials. A reversible mechanically stretch enhanced organic room temperature phosphorescent elastomer with excellent mechanical properties and ultrastable afterglow emission is constructed by pseudopolyrotaxane (NPR) and waterborne polyurethane matrix, in which NPR is composed of alpha-cyclodextrin and naphthalene modified polyethylene glycol. This strain-induced microstructural changes driven tunable phosphorescence performance of elastomer provides a new approach for the development of luminescent materials. image