Multicolored Electrochromic Dichroic Dye PDLC With Scattering‐Enhanced Absorption for Single‐Layer Full‐Color Reflective Dynamic Displays and Multi‐Dimensional Anti‐Counterfeiting

ABSTRACT

Currently, the application of polymer‐dispersed liquid crystals (PDLCs) in the display field is constrained by the inability to achieve color display. The incorporation of dichroic dyes enables PDLCs to exhibit chromatic properties, providing a feasible method to overcome the limitations of monochrome display in PDLC systems. However, the dichroic dye absorbs the ultraviolet (UV) light required for polymerization, thereby slowing down the polymerization rate, increasing the liquid crystal (LC) droplet size, and reducing the contrast (CR). Herein, the study enhances CR of dichroic dye doped PDLCs (DPDLCs) by adding thiol‐functionalized silica microspheres (SiO ₂ –SH), which acts as nucleation site to accelerate polymerization and physical barrier to suppress the coarsening of LC droplets. The synergistic effect of PDLCs’ light scattering and dichroic dyes’ light absorption effectively improves their apparent dichroism ratio. Furthermore, dynamic displays, single‐layer reflective full‐color display verification models, and complex color pattern displays of DPDLCs are successfully realized by combining laser etching and screen‐printing techniques. A series of security and anti‐counterfeiting strategies with multi‐dimensional information encryption are developed using the dual characteristics of visible light and fluorescence of dichroic dyes. Accordingly, our developed DPDLCs exhibit substantial application potential in the fields of advanced anti‐counterfeiting and display devices.