Recently, the Graduate School of Engineering at Nagoya University achieved new research results by synthesizing monodisperse FCLC particles with circularly polarized luminescence (CPL) using the CF756 (also known as LC756, CAS: 223572-88-1) liquid crystal material provided by CHEMFISH and the RM257 (CAS: 174063-87-7) liquid crystal monomer.

 https://nagoya.repo.nii.ac.jp/records/2007902

https://nagoya.repo.nii.ac.jp/record/2010131/files/k14902_thesis.pdf

In this study, First, a cholesteric phase liquid crystal layer with structural color was prepared by mixing liquid crystal monomer (RM257) with 6 wt% chiral agent (LC756) and coating this mixture onto a substrate using spray coating, followed by polymerization under UV light. Subsequently, the desired pattern is printed onto a transparent PVC film using a thermal printer. This PVC film is covered over the formed structural color coating. After this step is completed, FCLC particles are uniformly coated onto the surface of the PVC film by spraying using a mask. In the final step, to increase durability and provide protection, a PDMS coating is applied to the surface of the label and allowed to cure. In this way, the PDMS layer not only provides protection, but also enhances the overall stability and durability of the label.

The research team synthesized monodisperse FCLC particles with CPL using a dispersion polymerization method. A cyano-substituted fluorescent molecule-FD was introduced to enhance solubility in the liquid crystal monomer RM23, enabling the modulation of FCLC particles' CPL characteristics by varying the FD concentration, affecting color and fluorescence intensity. The team produced FCLC particles of different sizes by adjusting the solvent proportion, noting an increase in CPL intensity and glum with particle size. Changing the content of chiral dopant- iCD led to a decrease in intermolecular forces within the particles, inducing a transition from disordered structure to bipolar structure and finally radial structures. The transition from a bipolar structure to a radial arrangement resulted in a highly ordered arrangement of liquid crystals, maximizing CPL intensity. The transition of the liquid crystal phase from cybotactic to cholesteric, and finally to TGB phase, was key for CPL chirality inversion, controlled by the concentration of iCD. Additionally, the study explored the potential of FCLC particles in dual optical anti-counterfeiting applications, developing a novel system that hides information under natural light and reveals encrypted messages under left circularly polarized light and ultraviolet light. This dual anti-counterfeiting system shows promise for protecting high-value goods and sensitive documents.

Overall, the CF756 (CAS:223572-88-1) supplied by our company in this study advances the research team's understanding of the optical properties of liquid crystal materials and contributes to the development of innovative optoelectronic devices and anti-counterfeiting technologies.