Water-Soluble and Low-Toxic Ionic Polymer Dots as Invisible Security Ink for MultiStage Information Encryption

Abstract

Nanodots are attractive stimuli-responsive luminescence materials for anti-counterfeiting and information encryption. However, their applications are limited by low water solubility and single-mode information identification by naked eyes under UV light illumination. Herein, we report one type of new nanodots, main-chain imidazoliumbased ionic polymer dots (IPDs). There is no edge effect in IPDs, and the ionic groups are homogenously distributed in the entire dot. IPDs exhibit high water solubility, good stability, narrow size distribution, low toxicity, and exceptional optical performance without additional modification. Written information using aqueous IPD solution is invisible in natural light, but can be recognized by a portable UV lamp. Moreover, they can be further encrypted and decrypted using easily available and nontoxic sodium carbonate and acetic acid, respectively. The encrypted information is invisible in natural light and/or UV light. This study provides a new prospect for high-level data recording and security protection by using water-soluble IPDs as invisible security ink.

Recent Advances in the Design of Ionenes: Toward Convergence with High‐Performance Polymers

“…Miller and co‐workers have demonstrated that cross‐linked imidazolium networks with a combination of ionene and polyelectrolyte character can be formed from divinyl‐functionalized ILs and thiols through thiol–ene chemistry . Hypercrosslinked imidazolium ionenes have been synthesized from species such as 1,1′,1″‐(1,3,5‐benzenetriyl) trisimidazole and 2,4,6‐tris[4‐(bromomethyl) phenyl]‐1,3,5‐triazine …”

Ionic Liquid-Modified Porous Organometallic Polymers as Efficient and Selective Photocatalysts for Visible-Light-Driven CO 2 Reduction

“…The optical absorption and band gaps of Re-POMP and Re-POMP-IL1.0 were studied by UV/Vis diffuse reflectance spectra as illustrated in Figure 4(a) , in which the good visible-light absorption of polymers was observed. Compared with Re-POMP, Re-POMPIL1.0 shows about 50 nm blue shift in absorption onset, probably being ascribed to the existence of IL reduce the conjugated structures [ 41 ]. According to their absorption edges, the optical band gaps of Re-POMP and Re-POMP-IL1.0 were obtained from the Tauc plots, in which the band gap is broadened as the presence of IL unit (Figure S7 , see Supplementary Materials).…”

Preparation of 1, 3, 6, 8-Pyrenesulfonic Acid Tetrasodium Salt Dye-Doped Silica Nanoparticles and Their Application in Water-Based Anti-Counterfeit Ink

“…In the system of water-based ink, the stability of pigments represents an important variable, crucial for their application potential [ 13 ]. Therefore, the as-prepared PTSA-SiNP material was applied to the water-based fluorescent anti-counterfeiting ink, and the fluorescence stability in the application process was tested.…”

“…In the past several years, various fluorescent materials have been explored in the preparation of water-based anti-counterfeit ink, such as organic fluorescent dyes [ 4 , 5 ], rare-earth luminescent materials [ 6 , 7 , 8 ], carbon dots [ 9 , 10 , 11 , 12 ], organic polymers [ 13 , 14 ] etc. Compared with other fluorescent materials, organic fluorescent dyes have the advantages of easy access to raw materials, more variety, bright colors and a low cost.…”