PDLC flexible films with multiple fluorescence and voltage modulated modes and intelligent coding for applications in anti-counterfeiting and transparent displays

Abstract

Currently, polymer-dispersed liquid crystal (PDLC) exhibits great potential in anti-counterfeiting and display device applications, but they still have serious disadvantages of poor stability, small voltage-variable color range, low recognition rate, long response time and single-color variation. In this work, the developed novel multiple modulated anti-counterfeiting modes that combined red, yellow and green fluorescent colors and voltages by using the modification strategy of PDLC. A series of anti-counterfeiting PDLC films with multicolor-modulated decoding modes were prepared by introducing fluorescent materials with different emission wavelengths into PDLC. In order to further enhance anti-counterfeiting ability, the model of the dynamic change of micrometer-sized pixel points under different voltages was developed, which greatly increased the difficulty for PDLC being counterfeited. For display application, our developed PDLC-based flexible electronic papers with single- and multi-pattern displays exhibited dynamic change of patterns that could be intelligently adjusted. Noteworthily, the electronic paper had a fast response time (11.6 ms) and high contrast ratio (234.06). Furthermore, the prepared flexible electronic paper served as a billboard for supermarkets that could dynamically regulate real-time prices. In short, the developed PDLC flexible films with multiple anti-counterfeiting and coding modes will have great promising in anti-counterfeiting and display device applications in real life.