Triluminescent Functional Composite Pigment for Non‐Replicable Security Codes to Combat Counterfeiting

Abstract

Herein, a novel strategy to design of unclonable triluminescent pigment derived security ink is formulated to protect valuable merchandise, bank notes, pharmaceuticals, confidential documents etc. against counterfeiting, by embedding luminescent security codes/images. This triluminescent security ink is designed with combinatory chemistry that involves the strategically admixing of the triluminescent functional composite pigments in commercially available polyvinyl chloride gold medium. The triluminescent functional composite pigment is composed of NaYF4: Yb3+, Er3+(Sodium Yttrium Fluoride doped with Ytterbium and Erbium ions), NaYF4: Eu3+ (Sodium Yttrium Fluoride doped with Europium ion) and ZnO (Zinc Oxide) materials which have multifunctional features as it looks white in ambient light and shows strong green (NaYF4: Yb3+, Er3+), red (NaYF4: Eu3+) and green (ZnO) colors at three different excitations of 980 nm, 254 nm and 379 nm wavelengths, respectively. The structural/microstructural and photoluminescence properties of triluminescent functional composite are confirmed by XRD (X‐ray diffraction), SEM (Scanning electron microscope), TEM (Transmission electron microscope) and photoluminescence spectroscopic techniques, respectively. The quality and spatially distributed PL intensity of printed images/code from triluminescent ink was investigated by photoluminescence confocal mapping microscopy technique. Hence, the obtained results suggest that the security code/images printed by using ink formulated from triluminescent functional composite pigment provides one step ahead novel security features which could be easy to detect but extremely difficult to replicate.

Rare-earth coordination polymers with multimodal luminescence on the nano-, micro-, and milli-second time scales

“…This unique triluminescent compound exhibits three luminescent decay mechanisms with lifetimes on the nano-, micro-, and milli-second timescale, respectively. We note that recently also a triluminescent material was demonstrated by Gangwar et al by admixing an upconverting Yb 3+ , Er 3+ -based phosphor (green emission), a down-converting Eu 3+ -based phosphor (red emission), as well as a downshifting zinc oxide phosphor (green emission) (Gangwar et al 2018). However, due to the spectrally separated absorption bands of the three mixed emitters, this material requires a distinct excitation wavelength for each emission spectrum, and also, no time-resolved photoluminescence (TRPL) measurements were presented (Gangwar et al 2018), which clearly delimits it from the triluminescent material presented here.…”

“…We note that recently also a triluminescent material was demonstrated by Gangwar et al. by admixing an upconverting Yb 3+ , Er 3+ -based phosphor (green emission), a down-converting Eu 3+ -based phosphor (red emission), as well as a downshifting zinc oxide phosphor (green emission) ( Gangwar et al. 2018 ).…”

“…2018 ). However, due to the spectrally separated absorption bands of the three mixed emitters, this material requires a distinct excitation wavelength for each emission spectrum, and also, no time-resolved photoluminescence (TRPL) measurements were presented ( Gangwar et al. 2018 ), which clearly delimits it from the triluminescent material presented here.…”

Poly Vinyl Chloride Additives and Applications-A Review

“…Pigments for PVC must be thermally and light stable, have good dispersibility, and be compatible within the formulation. Table 4 shows the different types of pigment [33,39].…”

Super modules-based active QR codes for smart trackability and IoT: a responsive-banknotes case study

“…The well-known advantages of QR codes such as fast and easy readability independent from the orientation, the ability to endure physical damages recurring to error correction codes, place them as good candidates to be part of the next evaluative step of tag elements. Moreover, compared to electronic labels, QR codes optical elements provide extra advantages such as easy manufacturing (materials based ink printing) [15][16][17][18][19][20] and reading (smartphones) with lower production and operation costs (CAPEX and OPEX), strictly visual and tactile (appealing for societal applications), environmentally sustainable (easy recycling), among others.…”