Light-responsive multimode luminescence in photochromism transparent wood for anti-counterfeiting application

Abstract

With the rapid development of information technology, people’s security awareness of information protection is enhanced, and the requirements for anti-counterfeiting technology have become higher and higher on different occasions. Smart materials with light stimulus response have attracted extensive attention in the development of anti-counterfeiting materials, especially next-generation intelligent transparent wood. Inspired by the color-changing behavior of plants and animals in nature, a photochromic transparent wood (PTW) composite with light-stimulated response was prepared by compounding rare earth luminescent complexes with transparent wood (TW). PTW exhibits high transmittance (85.5 %). Moreover, PTW exhibits different optical states under different light conditions, namely, colorless under sunlight and bright red fluorescence under 365-nm UV light, and the process is reversible. Additionally, PTW patterned by laser etching offered greater flexibility and personalization in terms of stimulus-response, and its information security under different light stimuli is demonstrated. Meanwhile, the PTW prepared can be applied to different products and their packaging as an invisible anti-counterfeiting label, and the storage and protection of information is realized under visible light, and the decoding of information is implemented in UV light, so as to achieve the invisible anti-counterfeiting of information. More importantly, invisible information can be clearly identified even in black packaging. The design concepts and techniques of this study provide an inspiration to combine smart responsive materials with wood-based materials to develop intelligent responsive materials, and also provides support for the subsequent design and preparation of invisible anti-counterfeiting materials.