Inkless Rewritable Photonic Crystals Paper Enabled by a Light-Driven Azobenzene Mesogen Switch

Abstract

Rewritable paper, as an environment-friendly approach of information transmission, has potential possibility to conserve energy and promote a sustainable development of our society. Recently, photonic crystals (PCs) have become a research hotspot in the development of rewritable paper. However, there are still many shortcomings that limit the further application of PC paper, such as slow response sensitivity, short-cycle lifetime, poor storage stability, and so on. Herein, we constructed an optically rewritable azobenzene inverse opals (AZOIOs) with a thin film (ca. 1 μm) plated on an inverse opal structure based on the UV/vis switchable structure color of the sample. The top thin film acts as a protective layer to avoid the large deformation of the pore structure and the bottom inverse opal structure with refractive index/pore structure change that provides reversible structure color. Large, reversible, and rapid bandgap shift (ca. 60 nm, 2 s) of AZOIOs can be repeated more than 100 times under alternating UV/vis irradiation based on isomerization of high content of the azobenzene group. On-demand long-time preservation pattern can be obtained by the appearance of azobenzene’s intrinsic color. The proof of concept for rewritable PC paper is demonstrated herein. Such inkless rewritable colorful paper paves a way for developing novel display technology.

A hybrid hydrogel system composed of CdTe quantum dots and photonic crystals for optical anti-counterfeiting and information encoding–decoding

“…The overfilling of the contact part between the SiO 2 nanospheres and glass substrate led to the formation of this unique morphology. 49…”

Electrostatic Assembly of Photochromic TiO2/Phosphomolybdic Acid Composite Nanoparticles for Light-Responsive Rewritable Papers

“…18,19 Tremendous efforts have recently been devoted to develop several photochromic materials/systems, which are the core to fabricate LRP. For example, a wide range of photochromic molecules, such as azobenzenes, 20 spiropyran, 21 diarylethene, 6 and their derivatives, 22 have been explored for fabricating LRP.…”

UV-Responsive, wide color gamut, inkless dynamic photonic paper enabled by disulfide-containing polyurethane based Fabry-Perot resonant cavity

“…[7][8][9][10][11][12] Furthermore, by introducing an active substance into or as the building blocks of the microstructure, dynamic photonic paper with tunable color and patterns can be achieved based on the responsive feature of the building blocks under external stimuli. [13][14][15][16][17] As one of the most commonly reported dynamic photonic paper, responsive photonic crystals generate dynamic color patterns by combining with a responsive polymer and changing the effective refractive index or lattice constant in the specific area under the stimuli, [18][19][20][21][22] which are widely used in information security materials and anti-counterfeiting materials. 23,24 However, in order to obtain color patterns with high quality, specific fabrication processes, which are complicated and time-consuming, are needed to prepare photonic crystals with a strictly ordered periodic structure, greatly hindering the practical applications of dynamic photonic paper.…”