Liquid crystal-assisted manufacturing of flexible holographic polymer nanocomposites for high-security level anticounterfeiting

Abstract

Holographic polymer nanocomposites show considerable value for advanced anticounterfeiting due to their unique capabilities of reconstructing three-dimensional (3D) images to the naked-eye. However, their flexible manufacturing without using common volatile...

Computational Insight into Phase Separation of a Thiol-Ene Photopolymer with Liquid Crystals for Holography by Dissipative Particle Dynamics Simulation

“…To start, we attempted to follow the phase separation process of the POSS-8SH/TATATO/5CB system with 30 wt % of 5CB, as this system was similar to the experimentally studied POSS-8SH/TATATO/P0616A system . The LC P0616A is a cyanobiphenyl mixture comprising 5CB but has a much higher refractive index.…”

“…As illustrated in Figure 2a, remarkable phase separation can be achieved in the DPD simulated system, which is consistent with the experimental trends. 21 However, it is difficult to quantify the phase separation degree only based on the visual observation of phase separation snapshots from the simulations. To evaluate the degree of phase separation of different systems, a suitable parameter to quantify the phase separation is required.…”

Orthogonal integration of holographic and fluorescent dual images based on energy transfer from liquid crystals to a photocleavable AIEgen

“…1–5 To this end, plenty of optical methods have been extensively exploited based on photoswitches, 6–8 fluorescence, 7,9–12 phosphorescence, 13–17 upconversion, 3,18,19 phase change, 20 structural colors 5,21 and holography. 22–28 Particularly, orthogonal integration of dual-mode optical patterns in the same region has drawn considerable attention since 2020 for significantly increasing the information density, capacity and security of optical labels. 7,12,20,29–32…”

“…[1][2][3][4][5] To this end, plenty of optical methods have been extensively exploited based on photoswitches, [6][7][8] fluorescence, 7,[9][10][11][12] phosphorescence, [13][14][15][16][17] upconversion, 3,18,19 phase change, 20 structural colors 5,21 and holography. [22][23][24][25][26][27][28] Particularly, orthogonal integration of dual-mode optical patterns in the same region has drawn considerable attention since 2020 for significantly increasing the information density, capacity and security of optical labels. 7,12,20,[29][30][31][32] Among all optical methods for advanced security, optical labels created by holography are continuously gaining scientific and practical significance, 24,32,33 and have become indispensable for authentication of plastic banknotes, ID cards and passports.…”

“…This is not only because structural colors generated by the diffraction of holographic patterns can be utilized as a security feature, 23,24,34 but also because the added optical information can be encrypted by holography using other degrees of freedom of light apart from the wavelength, including but not limited to the amplitude, phase, polarization and orbital angular momentum. 22,26,35,36 Furthermore, electro-optic or thermo-optic responsibilities can be enabled in the holographic labels by incorporating liquid crystals (LCs), 26,31,32,[37][38][39] providing more powerful tools to combat illegal forgery. More excitingly, by deliberately designing upconversion nanoparticles 3,40 or AIE (aggregation induced emission) 41,42 -active fluorescent dyes and carefully tuning their spatial distribution in holographic polymer nanocomposites, the orthogonal integration of holographic function with upconversion [43][44][45] or fluorescence functions 31,32 has been successfully achieved, opening up a new door for designing higher security-level optical labels.…”