Lanthanide Polyoxometalate Based Water-Jet Film with Reversible Luminescent Switching for Rewritable Security Printing

Abstract

Luminescent security printing is of particular importance in the information era. However, the use of conventional paper still carries a lot of economic and environmental issues. Therefore, developing new environmentally friendly security printing material with a low cost is imperative. To achieve the aforementioned goals, novel lanthanide polyoxometalate doped gelatin/glycerol films with high transparency, high strength, and good flexibility have been developed via a solution-casting method. The electrostatic interaction between zwitterionic gelatin and polyoxometalate was confirmed by attenuated total reflection Fourier transform infrared spectroscopy. Luminescent spectra and digital images indicated that the films exhibited reversible luminescent switching properties through association and dissociation of hydrogen bonds between glycerol and water molecules, allowing its potential application as water-jet rewritable paper for luminescent security printing. Furthermore, the printed information can be conveniently "erased" by heating, and the film can be reused for printing. The film exhibited excellent ability to be both rewritten and re-erased. A QR code pattern and hybrid printing were employed to improve the security of information. In addition, the rewritable films possessed excellent regeneration ability and low toxicity, as well as good stability against UV irradiation and organic solvents. The water-jet rewritable film based on lanthanide polyoxometalate for luminescent security printing, to the best of our knowledge, has not yet been reported up to date. This work provides an attractive alternative strategy on fabricating rewritable films for luminescent security printing in terms of cutting down the cost, simplifying the preparation process, and protecting the environment.

Lanthanide(III)-Incorporating Polysiloxanes as Materials for Light-Emitting Devices

“…In contrast to publications, , concerning Eu 3+ and Tb 3+ coordination complexes with pyridine-2,6-dicarboxamide- co -polydimethylsiloxanes ( Ln-Py-PDMS ), our approach allows avoiding the preparation of complex mixtures of Eu 3+ and Tb 3+ PDMS with a fixed switch color hue. Simple stacking of Eu 3+ and Tb 3+ Ln-Bipy-PDMS films can be extensively applied for the lighting with the fine color tuning both in LEDs and directly for design , or art (i.e., fluorescent mosaic techniques , ).…”

New alkali lanthanide-free polyoxometalates with remarkable water-responsive turn-off–turn-on luminescence properties

“…They have been undergoing a remarkable development in the last few decades due to their high relevance in many domains connected to materials science including single molecule magnets (SMMs), 3,4 photochromism, 5,6 catalysis, 7 photocatalysis [8][9][10] and photoluminescence (PL) sensing. 11,12 In this very active field, polyoxometalates incorporating visible-emitting lanthanide Ln 3+ ions (Ln-POMs) [13][14][15][16][17] have been intensively investigated to design stimuli-responsive luminescent materials and sensors for luminescence thermometry, 14,18 anticounterfeiting and luminescence security printing, 19 and luminescence bio-sensing. 20,21 In most of the cases, the POM ligands act as sensitizers to enhance the emission of the Ln 3+ ions via the antenna effect, 22,23 in which the photoexcitation of the high energy O -M ligand-to-metal charge transfer (LMCT) bands is followed by intramolecular POM-to-Ln 3+ energy transfers and emission processes due to f-f transitions within the Ln 3+ ions.…”

A series of POM compounds constructed using a flexible ligand containing three coordination groups: electrocatalytic and photocatalytic reduction and amperometric detection of Cr(vi)

“…Polyoxometalates (POMs), as metal-oxo clusters with rich structures and various properties, have been widely used in many fields such as electricity, optics, catalysis, and materials. 1–9 The combination of POMs as inorganic units and transition metal complexes (TMCs) can form a variety of structures. 10 Moreover, the selection of appropriate organic ligands is very important for the construction of POM–TMC structures.…”