Excellent optical, flexible, and mechanical properties of cellulose liquid crystal films induced by carbon quantum dots

Abstract

Recently, cellulose liquid crystals (LCs) have received attention due to their unique photophysical properties. However, their fragility and single structural color mode (birefringence) restricts their further development. Herein, a flexible optoelectronic LC film was reported composed of carbon quantum dots (CQDs) and cellulose nanocrystals (CNCs) produced by evaporation-induced self-assembly (EISA). Due to weak interactions between CQDs and CNCs, the optimal tensile strength and curvature reached 65.5 MPa and 2×102, respectively, thereby solving the fragility of LC films. In addition, these products retained not only the structural color of cellulose LC in the birefringent mode, but also introduced fluorescence in the CQD ultraviolet excitation mode. This was conducive for improving anticounterfeiting performance. Related work also addressed the issue of cellulosic LC fragility and provided a new method.