Prof. Tao Chen’s Smart Polymer Materials Group at the Chinese Academy of Sciences’ Ningbo Institute of Materials Technology and Engineering (NIMTE) has developed a new fluorescent organohydrogel with shape-memory, allowing for photo-writing/photo-erasing and dual encryption of fluorescent information.
The research was published in the journal Advanced Optical Materials.
Counterfeiting data has unavoidably become a pressing global problem, posing possible hazards to human health, social economy, and even national security, as a result of the fast growth of information technology, which provides considerable ease to people’s everyday lives.
Fluorescent hydrogels are regarded as one of the best candidates for anticounterfeiting due to their responsiveness to ultraviolet (UV) light, diversity of vivid colors, and exceptional modifiability, though information security needs to be improved further to cope with sophisticated hacking techniques.
The researchers created a high-performance luminous organohydrogel for information encryption by interpenetrating hydrogel and organogel polymer networks.
The hydrophilic Poly (N, N-dimethylacrylamide) hydrogel network was used to introduce the green-yellow-emitting fluorescent unit, whereas the hydrophobic Polystearate Methacrylate Organogel Polymer Network was used to copolymerize the blue-emitting anthracene unit (blue emission).
UV light at 365 nm caused the unimer–dimer transition, resulting in the dynamic fluorescence change of organohydrogel from blue to pale yellow, thanks to the photoswitching characteristics of the anthracene moieties.
Furthermore, when exposed to UV radiation of 254 nm, the organohydrogel returns to a blue luminous hue. Photomasks can be used to perform cyclic light-writing/light-erasing of information in this scenario.
Furthermore, the fluorescent organohydrogel’s crystallization feature confers shape-memory capability, allowing for dual encryption of data.
The research on the synthesized fluorescent organohydrogel could lead to a new notion for the design and manufacture of smart anti-counterfeiting materials, allowing for high-level information encryption and decryption.
The National Natural Science Foundation of China, National Key Research and Development Program of China, and Zhejiang Provincial Natural Science Foundation of China, among several others, supported this work.
Shang, H., et al. (2022) Integrating Photorewritable Fluorescent Information in Shape-Memory Organohydrogel Toward Dual Encryption. Advanced Optical Materials. doi:10.1002/adom.202200608.