Construction of Carbon Dots@LiCl‐polyacrylamide with Humidity‐Induced Ultralong Room‐Temperature Phosphorescence to Fluorescence and Rigid‐to‐Flexible Transition Behavior

Abstract

AbstractThe continuous advancement of luminescent materials has placed increasingly stringent requirements on dynamic color‐tunable ultralong room‐temperature phosphorescence (URTP) materials that can respond to external stimuli. Nevertheless, endowing URTP materials with stimuli‐response‐induced dynamic color tuning is a challenging task. This study introduces a carbon dots (CDs)@LiCl‐polyacrylamide (PAM) polymer system that switches from URTP to fluorescence under humidity stimuli, accompanied by a transition from rigidity to flexibility. The obtained rigid CDs@LiCl‐PAM exhibits ultralong green phosphorescence with a lifetime of 560 ms in the initial state. After absorbing moisture, it becomes flexible and its phosphorescence switches off. Moreover, the emission of the CDs@LiCl‐PAM film depends on the excitation wavelength. This property can potentially used in multicolored luminescence applications and displays. Moreover, multicolor luminescent patterns can be constructed in situ using the water‐absorption ability of the obtained thin film and the Förster resonance energy‐transfer strategy. The proposed strategy is expected to promote the interdisciplinary development of intelligent information encryption, anti‐counterfeiting, and smart flexible display materials.