Heterogeneous Fluorescent Organohydrogel Enables Dynamic Anti‐Counterfeiting

Abstract

Fluorescent patterns showing the unique color change in response to external stimuli are of considerable interest for their applications in anti-counterfeiting. However, there is still a lack of intelligent fluorescent patterns with high-security levels, presenting a dynamic display of encrypted information. In this study, a fluorescent organohydrogel is fabricated through a two-step interpenetrating technique, leading to the co-existence of naphthalimide moieties (DEAN, green-yellow fluorescent monomer) contained Poly(N,N-dimethylacrylamide) (PDMA) hydrogel network and Polyoctadecyl methacrylate (PSMA) organogel network bearing spiropyran moieties (SPMA, photochromic monomer). Due to the unique heterogeneous networks, the fluorescence color goes through a continuous change from green to yellow to red via the fluorescence resonance energy transfer (FRET) process with the extension of irradiation time. In addition, when H + is introduced into the system, SP units exhibit transformation into the protonated merocyanine (MCH + ) rather than merocyanine (MC) under UV light, which inhibits the FRET process. By selectively being treated with H + , the fluorescent organohydrogel can act as an effective platform for encrypting secret information, making them more difficult to forge.

Information Storage Based on Stimuli‐Responsive Fluorescent 3D Code Materials

“…Information code materials, defined as a kind of novel information storage carriers that utilize specific patterns to encode information, have permeated all aspects of human life. [ 28–48 ] According to the pattern classes, information codes can be classified into 1D barcodes, 2D codes, and 3D colored codes, composed of parallel lines, black and white patterns, and colored patterns, respectively. [ 28,29 ] 1D barcodes and 2D codes are the two kinds of most prevalent information codes, having been widely applied in the fields of commodity identification, package tracking, mobile payment, etc.…”

“…[28,29] 1D barcodes and 2D codes are the two kinds of most prevalent information codes, having been widely applied in the fields of commodity identification, package tracking, mobile payment, etc. [30][31][32][33][34][35][36][37][38][39][40][41][42][43] However, with the increase in the demand for information storage carriers, there is an urgent need for an information code with a larger information storage capacity to store more complex information. In this context, colored 3D codes attract widespread attention due to their excellent information storage capacity.…”

Highly Plasticized Lanthanide Luminescence for Information Storage and Encryption Applications

“…[31] In addition to the need for luminescent materials with good mechanical properties, [32] the developments of encoding and decoding systems are also important for information storage, especially for information encryption. [33,34] Previous information storage systems prepared using functional materials are generally limited to simple patterns, making it hard to design information encryption and thus greatly limiting their widespread applications. [21,35,36] The advancements of image processing techniques will enable the design of complex patterns for information encoding and decoding, which could greatly broaden the designs of information storage styles.…”

Unraveling Molecular Assembly and Tracking Lipid Droplets Dynamics using Fluorescent Phenanthroimidazole Derivatives

“…25,[32][33][34] Such morphology-dependent emissive organic aggregates receive a vital consideration owing to their applications in optoelectronic devices, sensors, and switches. [34][35][36][37][38][39][40][41][42][43] However, small strategic perturbations in the molecular structures for multifaceted function are intriguing. In this context, the integration of long alkyl chains into the rigid and π-conjugated molecular backbone prevents the π-π stacking in the aggregated state, resulting in enhanced fluorescence.…”