Cholesteric Liquid Crystal Network Composite Film with Structure, Dual-Band Responsive Luminescent Color for Multiple Anti-Counterfeiting and Information Encryption.

Anti-counterfeiting technology plays an indispensable role in the high-tech field and various critical application areas. However, traditional anti-counterfeiting approaches currently in widespread use are too simplistic and easily replicated or forged, while advanced technologies with multiple anti-counterfeiting functions remain in the developmental stage. This study presents a novel multiple anti-counterfeiting technique. By employing a patterned cholesteric liquid crystal polymer network (CLCN) film as a template, a composite film endowed with multiple anti-counterfeiting capabilities was successfully fabricated by filling the hollow patterned areas with a light-cured acrylate monomer mixed with commercial infrared and ultraviolet phosphors. The prepared composite film exhibits high transmittance and excellent flexibility, enabling its application across various applications. By utilizing the thermochromic and angular chromic properties of the CLCN film, along with ultraviolet-excited colorful fluorescent materials and infrared-excited upconversion luminescent materials incorporated within the acrylate film in the CLCN patterned area, a film featuring multiple anti-counterfeiting attributes is achieved. Furthermore, by modifying the mask, adjusting the content of the chiral dopant, and selecting the type of phosphors, a multiple anti-counterfeiting color image can be produced, which has significant implications for enhanced anti-counterfeiting measures and information encryption storage.