A Spatiotemporal Cascade Platform for Multidimensional Information Encryption and Anti‐Counterfeiting Mechanisms

Abstract

AbstractThe efficient collaboration of light tunability and intelligent deformation of fluorescent materials can create an advanced spatiotemporal cascade platform that enables multi‐level and multidimensional information storage and encryption. Here, cellulose‐based dynamic double‐network hydrogels with excitation‐dependent (Ex‐De) behavior are proposed. The mechanism of multi‐channel radiative relaxation and multiple excited state transition of the photoactive component 4′‐([2,2′:6′,2″‐terpyridin]−4′‐yl)‐[1,1′‐biphenyl]−4‐carbaldehyde (TPy‐CHO) has been established, and a desirable regulation of excitation energy (wavelength, intensity) on the time scale for multi‐level encryption has been achieved. Notably, the dense hydrogen bonds and non‐covalent interactions in polymer networks not only enhance the Ex‐De behavior, but also provide excellent optical resolution and richer polychromic fluorescence. Even ideal cold white fluorescence is obtained through energy transfer between organic (TPy‐CHO) and inorganic (lanthanide ion) hybrid materials. Simultaneously, this unique network structure endows the hydrogel with temperature‐mediated self‐healing, controllable shape programming behavior and anti‐swelling ability, allowing to achieve dynamic multidimensional information encryption capability. The encoded information can reversibly emerge and disappear, allowing for instantaneous on‐demand decryption and intelligent re‐writability. As a result, a promising multi‐level and multidimensional synergistic anti‐counterfeiting mechanism is established through the cascade process of “spatial security‐ light trigger‐ fluorescence multilevel output‐temporal rewriting”.