Carbon Quantum Dots doped Cholesteric Liquid Crystal Films and Microdroplets for Anti-Counterfeiting

Developing superior and adaptable structural colors for anticounterfeiting technologies remains a challenge, despite the widespread usage of structurally colored materials in anticounterfeit-ing applications. We present a anticounterfeiting material, structural colored cholesteric liquid crystals (CLCs), in conjunction with synthesized fluorescent carbon quantum dots (CQDs). CQDs doped with a CLC mixture display a green reflection in daylight owing to the structural chiral arrangement of CLCs and a cyan color when exposed to UV light (365 nm) due to the fluorescence emission of CQDs. A glass capillary microfluidic approach was also used to create CLC microdroplets doped with fluorescent CQDs. In daylight, the fluorescent CLC microdroplets showed center spot reflection with a green hue and photonic cross communication and fluorescent cyan emission color when exposed to UV light. CLC microdroplets with fluorescent CQDs have potential applications in smart dual-mode displays, anticounterfeit labeling, and smart decoratives.

Automated summary

Developing superior and adaptable structural colors for anticounterfeiting technologies is still a challenge. In this study, a materials called structural colored cholesteric liquid crystals (CLCs) is presented, along with synthesized fluorescent carbon quantum dots (CQDs), for anticounterfeit applications. The CLCs doped with CQDs exhibit green reflection in daylight and cyan fluorescence emission under UV light. Glass capillary microfluidic method is also used to create CLC microdroplets doped with fluorescent CQDs.