Dynamic anti-counterfeiting security features using multicolor dianthryl sulfoxides

Abstract

A new concept for difficult-to-replicate security inks for use in advanced anti-counterfeiting applications is presented.

Multi-Angular Colorimetric Responses of Uni- and Omni-Directional Femtosecond Laser-Induced Periodic Surface Structures on Metals

“…Figure 4 shows the dependence of structural colors from the three samples on the rotation and detection angles. The CIELAB color space is employed because it is deviceindependent [25] and the color and its difference can be easily quantified by three coordinates, L*, a*, and b* [26,27]. L* stands for the lightness value, brightness in the color space, and a* and b* represent colors changing from green to red and blue to yellow, respectively, as their values increase from negative to positive.…”

“…The neutral gray color appears when a* and b* equal zero. The difference in color between two points, and in the CIELAB color space, , is defined as the Euclidian distance between these points, [ 26 , 27 ], and is perceptible when [ 25 ]. By considering the structural symmetry of UD- and OD-LSFLs in terms of their orientations, L* , a* , and b* values are measured in the rotation angle ( φ ) range of 180° at all detection angles ( θ ), and each data point is described by a small dot with actual true color, as shown in Figure 4 .…”

Multidimensional Information Encryption and Storage: When the Input Is Light

“…After extruding the SO bridge between anthracene units under UV irradiation, the luminescent molecules with blue light, 9,9′-bianthryl, was yielded quantitatively ( Figure 3(a) ). On the basis of AnSO structure, red and green fluorescence molecules could also be achieved by modifying triarylamine and phenothiazine at 10,10′-positions of the original dianthracene hosts, respectively [ 75 ]. To illustrate the three-color photoresponsive materials applied in the multidimensional information encryption and storage, a controlled experiment between products with the correct RGB ratio (1 : 1 : 1) and with the incorrect one (2 : 1 : 3) was carried out.…”

Organic photoresponsive materials for information storage: a review

“…S1 in the Supplemental Materials) that can produce red, green, and blue (RGB) fluorescence for advanced anticounterfeiting. 85 Corresponding bianthracene photoproducts with RGB emission were produced by eliminating the SO bridge of compounds 29 to 31 upon light irradiation. The chromaticity coordinates of PMMA thin film containing three photochromes changed with the irradiation time and the irradiation wavelength.…”