A multifluorescent supramolecular hydrogel system to fabricate 3D/4D codes was introduced as an applicable approach to encrypt information, as well demonstrated by Sessler and Tang et al. By taking advantage of these features, Zhao and coworkers recently developed a light-controlled information encryption material by using a photoresponsive supramolecular coordination polyelectrolyte as a fluorescence ink 34. In addition, the fluorescence (either intensity or wavelength) can be controlled by an external stimulus 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, providing an accessible approach to control information display. Developing dynamic molecular systems is therefore important for fabricating advanced data encryption materials.Ī smart fluorescence system is indeed a potential candidate for fabricating information encryption materials due to its security in natural light 34, i.e., information can be recognized only under UV light. Usually, the fabrication of such materials involves embedding a smart molecular system in a polymeric or gel matrix or functional modification of the side chain of the polymers 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, thus endowing the materials with stimuli-responsive and dynamic properties 31, 32, 33. This work provides an inspiring point for the design of information encryption materials with higher security requirements.Ĭurrently, storing and delivering information in a secure manner is an essential issue, and many efforts have been devoted to exploring an accessible approach to achieve information encryption 1, 2, 3, 4, 5, such as fluorescent ink 6, 7, 8, 9, holographic anticounterfeiting 10, and 3D codes 11, 12, 13, 14, 15, 16, 17, 18, 19, where encoded information can be recognized only under specific conditions. Moreover, time-dependent information encryption materials, such as temporal multi-information displays and 4D codes, are also developed by enabling the fluorescence-controllable supramolecular system in the solid phase, showing multiple pieces of information on a time scale, and the correct information can be identified only at a specified time. By taking advantage of the tuneable fluorescence, dynamically controlled information encryption materials with orthogonal encryption functions, e.g., 3D codes, are successfully developed.
Multicolour fluorescence, including blue, orange and even white light emissions, is achieved by controlling the supramolecular assembly of pyrene derivatives by tailoring the solvent composition. Herein, smart materials with orthogonal and temporal encryption properties are successfully developed based on a dynamic assembly-induced multicolour supramolecular system. The development of advanced materials for information encryption with time-dependent features is essential to meet the increasing demand on encryption security.