High‐Resolution Erasable “Live” Patterns Based on Controllable Ink Diffusion on the 3D Blue‐Phase Liquid Crystal Networks

Abstract

Colorful blue phase liquid crystal (BPLC) patterns have attracted wide research attention owing to their intriguing and advantageous properties and promising applications. However, it remains a challenge to develop novel and highresolution patterns from BPLC owing to the complicated synthetic procedure for the functional molecules. This study reports a high-resolution "live" pattern by well-designed diffusion of 5CB ink on the wettability-modified BPLC networks. Interestingly, the shape and color of the as-prepared pattern change with time, which results in unique spectra change of the printed pattern, "first red-shift and subsequent blue-shift of the stopband position" and "continuous growth in reflectivity intensity" with time. The hydrophobic substrate greatly suppresses the random spreading and diffusion of ink, contributing to highresolution patterns. The promising applications of live patterns for program display and active labels are demonstrated. Various high-resolution erasable colorful patterns are obtained. The structure reconfiguration of the writing and erasing processes is proved by transmitted electronic microscope images and Kossel diffraction diagrams, which ensures the reversible writing/erasing of the pattern on the membrane. This work is of significance for the development of novel rewritable paper and high-quality optic devices based on BPLC materials.

Over 200 °C Broad‐Temperature Lasers Reconstructed from a Blue‐Phase Polymer Scaffold

“…Then the central circle and four ellipses of BPI (110) crystal plane began to shrink as the temperature increased over 70 °C but the result was toward the reverse direction, and four arcs of ellipses gradually withdrew from the field of view (at around 150 °C), while the shrinking (110) central circle returned to view (at around 150–230 °C, Figure 6A,B). The above phenomenon indicated that the BPI lattice parameters decreased, [ 74,75 ] as the phase transition occurred during the heating process from 70 to 230 °C (Figure 6A; Figure S28, Supporting Information). Figure 6B schemes the change trend of the BPI lattice size/Kossel diagrams with temperature, which could illustrate the blueshift of the stopband (excitation peak) of DD‐PSBPLCs during the heating process.…”

“…Kossel diffraction is known as a simple approach to characterize the crystal structures of BPLCs and the typical Kossel diffraction of BPI (110) plane features as one central circle and four ellipses [66,67,72,73] (Figure 6B The above phenomenon indicated that the BPI lattice parameters decreased, [74,75] as the phase transition occurred during the heating process from 70 to 230 °C (Figure 6A; Figure S28, Supporting Information). Figure 6B schemes the change trend of the BPI lattice size/Kossel diagrams with temperature, which could illustrate the blueshift of the stopband (excitation peak) of DD-PSBPLCs during the heating process.…”

Scalable Photonic Liquid Crystal Nanoscale-Thick Films for Deformation and Discoloration

“…Though substantial efforts have been made to harness these properties for multi-functional intelligent applications in soft actuators, − displays, lasers, , shape-memory materials, − sensors, , and anti-counterfeiting, the fabrication of three-dimensional (3D) LC elastomers has rarely been investigated yet. Blue phase LCs (BPLCs) are self-assembled 3D photonic crystal materials with nanoperiodic structures and complete photonic band gaps, − corresponding to the structural color in the visible region. In addition, when the periodicity of the crystal lattice is changed by an external field, including the electric field, − temperature, organic gas, , humidity, and other external fields, the reflection color can be changed accordingly.…”

Spatial Patterning of Fluorescent Liquid Crystal Ink Based on Inkjet Printing

“…Some work on processing liquid crystal materials using inkjet printing technology has been reported. Jiang et al and Stephen M’s group used inkjet printing technology to achieve precision processing of blue-phase liquid crystals (BPLCs) and polymer dispersed liquid crystals (PDLCs), respectively [ 28 , 29 ]. Such methods show a high degree of accuracy at the micro-scale, although these techniques often require multiple additional processing steps, and it is not possible to prepare samples of several different compositions simultaneously.…”