Chemically stable fluorescent anti-counterfeiting labels achieved by UV-induced photolysis of nanocellulose

Abstract

The cellulose-based fluorescent patterning strategy is developed by UV exposure to achieve covert, chemically stable and solvent tolerant security labels.

Erasable invisible ink based on a TPE-based AIE pigment

“…Preparation of (2-(4-bromophenyl)ethene-1,1,2-triyl)tribenzene (1). Under a nitrogen environment, diphenylmethane (6.76 g, 40.20 mmol) was added to a round-bottom flask containing anhydrous THF (60 mL).…”

“…Information and data security is a global challenge, while invisible ink is one of the safeguards for achieving information security. [1][2][3][4][5] In recent years, invisible ink has witnessed a greater prominence in terms of fluorescent anti-counterfeiting, [6][7][8] information encryption and decryption, [9,10] fingerprint visualization, [11,12] to name just a few. Organic fluorescent dyes are currently regarded as ideal candidates for making invisible ink owing to their rich colors, tunable emission outputs in response to light and a high degree of structural designability.…”

“…1 H NMR (600 MHz, CDCl 3 , δ, FigureS3): 7.79-7.77 (d , 2H, Ar-H), 7.76-7.74 (t , 1H, Ar-H), 7.64-7.62 (d , 1H, Ar-H), 7.33-7.32 (d , 1H, Ar-H), 7.15-7.13 (d , 2H, Ar-H), 7.12-7.03 (m , 15H, Ar-H), 3.98 (s , 2H, -CH 2 -). SI HRMS (FigureS4): Calcd: 448.57(TPE-PA).…”

Smart Anti‐Counterfeiting Inks: Controlled Luminescence Polarization and Its Fixation by Photoisomerization and Subsequent Photopolymerization of Cyanostilbene‐Based Liquid Crystal Monomers

“…In various anti-counterfeiting DOI: 10.1002/adom.202300844 strategies, photoluminescence is one of the important and intuitive elements, with the result that a diverse array of luminescent materials has been already developed, including inorganic and organic materials, organic-inorganic complexes, quantum dots (QDs), and perovskite materials. [3][4][5][6][7] However, their simple emission property is easy-to-follow and not a strong enough deterrent to current counterfeiting. To satisfy the demand for high level anti-counterfeiting, a new generation of luminescent anti-counterfeiting materials have been created.…”

Triple optically modulated and enzymatically responsive organic afterglow materials for dynamic anti-counterfeiting

“…For example, as claimed by the Global Brand Counterfeiting Report 2018, the total global economic losses from counterfeiting reached $1.2 trillion in 2017 and rocketed to $1.82 trillion in 2020. 1 In response to the severe situation, many security labels, such as topographical markers, 6 luminescent labels, [7][8][9][10] luminescent magnetic labels, [11][12][13] and plasmonic security taggants, 4,14,15 have been developed to protect valuable documents and brands. Among these, luminescence anti-counterfeiting is one of the commercialized techniques with benefits of relatively high photostability, multicolor, facile design, and easy to visualize by eye or read using an authentication tool such as a digital camera or a spectrometer.…”