Related Experiment Video
Updated: Jan 22, 2026

Inkjet-printed Polyvinyl Alcohol Multilayers
Published on: May 11, 2017
On-Off switching of the phosphorescence signal in a carbon dot/polyvinyl alcohol composite for multiple data
Xin Bao1, Elena V Ushakova, Enshan Liu
1State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, PR China.
Abstract:
Phosphorescence processes in composite systems based on luminescent carbon dots (CDs) are of great fundamental and practical interest. Herein, the control of the phosphorescent signal in a CD/polyvinyl alcohol (PVA) composite is realized. Enhanced green phosphorescence is obtained via thermal annealing of the composite under 200 °C, which can be quenched via water treatment, and then recovered again, via either repeated annealing or near-infrared laser irradiation. Water molecules infiltrating the CD/PVA composite lead to considerable vibrational motions of the CD surface groups through destruction of the rigid composite structure together with an increase in the possibility of the penetration of the phosphorescence quenchers, and thus a decrease in the phosphorescence intensity. After repeated annealing, the nonradiative transitions are restricted, and the phosphorescence signal is recovered again. Based on such on-off switching of the phosphorescence signal, a concept of multiple data encryption is realized by using the CD@PVA composite.
Related Concept Videos
Photoluminescence: Fluorescence and Phosphorescence
A pair of electrons in a...
¹H NMR Signal Multiplicity: Splitting Patterns
Variables Affecting Phosphorescence and Fluorescence
Fluorescence and Phosphorescence: Instrumentation
Switching of BJT
Cut-off Mode ("Off" State): In this state, both the emitter-base and collector-base junctions are...
Classifying Matter by Composition
According to its composition, the matter can be classified into two broad categories — pure substances and mixtures.
A pure substance is a form of matter that has a constant composition throughout with uniform properties. For example, any sample of sucrose has the same composition and same physical properties, such as melting point, color, and sweetness, regardless of the source from which it is isolated.
A mixture is composed of two or...

