Volume 137, Issue 8 e202420290
Forschungsartikel

Excitation-Dependent Circularly Polarized Luminescence Inversion Driven by Dichroic Competition of Achiral Dyes in Cholesteric Liquid Crystals

Dr. Kun Yao

Dr. Kun Yao

School of Chemical and Printing-Dyeing Engineering, Henan University of Engineering, Zhengzhou, 450007 Henan Province, China

School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023 Jiangsu Province, China

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Zhentan Wang

Zhentan Wang

School of Energy, Materials and Chemical Engineering, Hefei University, Hefei, 230601 Anhui Province, China

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Dr. Peng Wang

Dr. Peng Wang

School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023 Jiangsu Province, China

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Dr. Yang Li

Dr. Yang Li

School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023 Jiangsu Province, China

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Dr. Liangyu Hu

Corresponding Author

Dr. Liangyu Hu

School of Energy, Materials and Chemical Engineering, Hefei University, Hefei, 230601 Anhui Province, China

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Prof. Yixiang Cheng

Corresponding Author

Prof. Yixiang Cheng

School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023 Jiangsu Province, China

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Dr. Zhongxing Geng

Corresponding Author

Dr. Zhongxing Geng

School of Energy, Materials and Chemical Engineering, Hefei University, Hefei, 230601 Anhui Province, China

School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023 Jiangsu Province, China

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First published: 29 November 2024

Abstract

The development of stimuli-responsive chiral cholesteric liquid crystals (CLCs) materials holds significant potential for achieving three-dimensional (3D) anti-counterfeiting and multi-level information encryption. However, constructing phototunable CLCs systems with easy fabrication and fast response remains a great challenge. Herein, we exploit an excitation-dependent CLCs (ExD-CLCs) material by establishing dynamically photoresponsive dichroic competition between two achiral dyes: a negative dichroic dye (SP-COOH) and a positive dichroic dye (Nile Red, NR) within a CLCs medium. The ExD-CLCs exhibits a negative circularly polarized luminescence (CPL) signal (glum=−0.16) at 625 nm when excited at 365 nm. Remarkably, under excitation at 430 nm, the CPL signal is inverted, and the glum value increases to +0.26. Notably, the helical superstructure and handedness of the ExD-CLCs remain unchanged during this reversal process. The CPL signal reversal is driven by the dichroic competition between the SP-COOH dimer, which displays strong negative dichroism in its open-ring isomer form and silent negative dichroism in its closed-ring isomer form, and the NR dye, which exhibits static positive dichroism. Leveraging these excitation-dependent CPL properties, the quadruplex numerical anti-counterfeiting using ExD-CLCs is achieved.

Conflict of Interests

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

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