PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION
·
2019
·Vol. 36
·期 3
·1800412
·
IF 4.194
Lin Gan,Na Feng,Siyuan Liu,Shuyu Zheng,Zhen Li,Jin Huang
Fluorescent-labeled cellulose nanocrystal (CNC) films have been used to record and protect information in paper materials, whereas the fluorescent materials usually suffer photobleaching. Herein, a strategy of solid-state emission induced by the vertical assembly of CNCs was established. The assembly-induced emission starts from the structural diffraction of CNC, whose wavelength is adjusted into the ultraviolet (UV) region for hiding information under natural light. The small diameter (≈10 nm) of CNCs then promotes the resonance between the vertically assembled CNCs and the UV light, leading to a strong blue emission with an emitting quantum efficiency as high as 13.90%. By introducing the vertical-assembly film with a specific pattern into paper materials, an anti-counterfeiting image is obtained under a UV radiation. Since CNCs are a kind of cellulose with high crystallinity, this material can be a wear-resistant anti-counterfeiting material for banknotes or other paper applications.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 32
·11264-11271
·
IF 4.099
Mengxiao Li,Yu Feng,Qingyong Tian,Weijing Yao,Li Liu,Xuan Li,Huanjun Wang,Wei Wu
Advanced fluorescent materials have demonstrated great value in the anti-counterfeiting field for information storage and hiding. In this work, a novel strategy for producing UV light-switchable fluorescent patterns to hide and store information is proposed based on carbon dots (CDs) and Y2O3:Eu composites with exceptional optical properties. CDs can present blue emission under both 254 nm and 365 nm UV light excitation, but Y2O3:Eu can only arouse a red color under 254 nm light excitation. Under conventional 365 nm excitation, a single blue color and partial information are shown, however, the whole information in patterns can be displayed under specific 254 nm excitation. The functional anti-counterfeiting patterns are made by screen printing using as-prepared polyvinyl alcohol (PVA)-medium fluorescent inks. Moreover, the hidden information retained its integrity after printed patterns were exposed to an ambient environment for 90 days. Such invisible, tunable and ultra-stable fluorescent patterns utilizing 254 nm UV light well achieve information hiding and storage and increase information security for anti-counterfeiting applications.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2025
·
IF 3.6
Yanni Jie,Zengbo Fan,Jiang Yan,Fuchun Li,Ting Meng,Zhenli Guo,Penggao Dai
Carbon dots (CDs) with room-temperature phosphorescence (RTP) characteristics have drawn considerable attention because of their broad applications in various area. However, achieving water-soluble RTP CDs remains highly challenging owing to the severe phosphorescence quenching effect caused by dissolved oxygen in aqueous solutions. Herein, a realizable strategy of attaining long-lifetime and high stability RTP CDs-based composites in aqueous solutions is proposed via constructing a rigid hydrogen-bonded network. The synthesized composites display an ultra-long phosphorescence lifetime of 1.38 s in solid state and 316 ms in aqueous phase. Moreover, the RTP emission remains visible to naked eye for up to 10 s even under strongly acidic or alkaline conditions. TEM, XRD, FT-IR, and XPS analyses confirmed the successful conjugation of cyanuric acid (CA) with carbon dots (CDs) which the rigid CA framework effectively restricted the chromophore vibrations and rotations, minimizing non-radiative recombination of triplet excitons. Finally, applications of CDs in screen printing, anti-counterfeiting and information protection were explored.
研究领域:
材料科学
·
纳米技术
·
光学材料
·
生物医学工程
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Soft Matter
·
2022
·Vol. 18
·期 11
·2149-2156
·
IF 4.046
Li Xin Hou,Hongyao Ding,Xing Peng Hao,Chao Nan Zhu,Miao Du,Zi Liang Wu,Qiang Zheng
Fluorescent hydrogels have attracted tremendous attention recently in the field of information security due to the booming development of information technology. Along this line, it is highly desired to improve the security level of concealed information by the advancements of materials and encryption technologies. Here we report multi-level encryption of information in a bilayer hydrogel with shape-morphing ability and patterned fluorescence. This hydrogel is composed of a fluorescence layer containing chromophore units in the poly(acrylic acid) network and an active layer with UV-absorption agents in the poly(N-isopropylacrylamide-co-acrylic acid) network. The former layer exhibits tunable fluorescence tailored by UV light irradiation to induce unimer-to-dimer transformation of the chromophores, facilitating the write-in of information through photolithography. The latter layer is responsive to temperature, enabling morphing of the bilayer hydrogel. Therefore, the bilayer hydrogel encoded with patterned fluorescent patterns can deform into three-dimensional configurations at room temperature to conceal the information, which is readable only after successive procedures of shape recovery at an appropriate temperature and under UV light irradiation from the right direction. The combination of morphing materials and patterned fluorescence as a new avenue to improve the encryption level of information should merit the design of other smart materials with integrated functions for specific applications.
研究领域:
材料科学
·
信息安全
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2021
·Vol. 9
·期 6
·2002038
·
IF 9.926
Yuqing Gu,Chang He,Fugang Liu,Jian Ye
Steganography, also known as “invisible” communication, refers to the technique of hiding information into another medium such as video, audio, image, and text. Surface-enhanced Raman scattering (SERS) nanotags are well suited to information encoding owing to their nanoscale dimensions, fingerprint optical spectral features, and remarkable multiplexing capability. Herein, Raman ink, fabricated by doping a new type of SERS nanotags (gap-enhanced Raman tags, GERTs) into commercial ink, is demonstrated as security ink for multiplexing steganography. A stego-text is written using two types of Raman ink containing different GERTs with diverse Raman signals, imaged via a confocal Raman system, and processed by the classical least squares method to extract the hidden message. The Raman ink generates distinct spectral profiles with low background from pure ink upon near-infrared laser irradiation. A multiplexing combination of seven kinds of messages extracted from the written stego-text is demonstrated, which adds enhanced safety and flexibility to information encoding. In addition, Raman ink exhibits good photostability and long-term stability. Therefore, GERTs-based Raman ink is promising for steganographic use in information security.
研究领域:
材料科学
·
光学
·
信息安全
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Lingqi Wu,Huajing Fang,Kai Jing,Liyan Zhang,Haolin Yu,Yang Chai
Global data traffic growth poses unprecedented challenges to information security. This necessitates robust next-generation solutions, particularly multidimensional protection frameworks that integrate spatial, temporal, and multispectral modulation capabilities. To address this, inspired by structure-function coupling mechanisms in biological neurons and synapses, this study develops a novel biomimetic artificial synaptic device based on electrochromic materials. The device integrates PEDOT:PSS (enabling millisecond-level response) and WO 3 ·H 2 O (providing stable memory) with an optimized Mg 2+ gel electrolyte. Key performance metrics include 82.9% optical modulation at 700 nm, precisely controlled multi-state transitions, and real-time synaptic visualization. It mimics biological learning/forgetting via paired-pulse facilitation (PPF: 152–168%) and physiological timescale dynamics (τ 1 = 2.91 s, τ 2 = 6.97 s). Notably, these neuromorphic properties are translated into an innovative spatiotemporal dual-encryption logic: spatially, pixelated color-depth modulation generates geometric Morse code patterns (dot/dash = light blue/deep blue pixels); temporally, programmable optical attenuation below the 5% visual perception threshold produces time-locked, self-erasing encryption keys. This approach constructs a synergistic space/time/pulse-field encryption system, fundamentally breakthrough traditional encryption frameworks. It provides an innovative physical-layer information protection solution and expands electrochromic materials’ technological boundaries in dynamic information concealment and visual security.
研究领域:
神经形态工程
·
光电子器件
·
信息安全
·
智能材料
·
电致变色
·
信息物理系统
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）