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

The 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". The excited-state multi-channel radiative relaxation photophysical processes of excitation-dependent organic chromophores for dynamically regulating polychromic luminescence on a time scale are systematically investigated, and an intelligent rewritable anti-counterfeiting system is established by adopting the cascading processes of "spatial protection- optical trigger- fluorescent multi-level output-time rewriting", which enables 4D spatiotemporal dynamic regulation multi-level, multi-mode, on-demand encryption/ instantaneous decryption.image