Reflective Band Memory Effect of Cholesteric Polymer Networks Based on Washout/Refilling Method

• Published in: Macromolecular chemistry and physics Vol. 221; no. 22
• Main Authors: Zhang, Dongdong, Shi, Weiting, Cao, Hui, Chen, Yinjie, Zhao, Limin, Gan, Ping, Yang, Zhou, Wang, Dong, He, Wanli
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.11.2020
• Subjects: Cholesteric liquid crystals; Gratings (spectra); memory effects; Networks; polymer networks; Polymers; Refilling; selective reflection; Shielding; washout/refilling methods
• ISSN: 1022-1352; 1521-3935
• DOI: 10.1002/macp.201900572

The method of washout/refilling is applied to a polymer stabilized cholesteric liquid crystal. Polymer networks are prepared with different concentrations of monomers under different polymerization conditions. By refilling different solvents or liquid crystals into the polymer network, reflective bands with different central wavelength and bandwidth are observed. It is confirmed that the polymer network can reproduce the initial reflection band of cholesteric phase, and corresponding explanations are given. When polymers have denser networks and smaller micropores, it shows better memory effects on the reflective band. These results can be potentially used in reflective displays, optical shielding films, diffraction gratings, sensors, and so on. Cholesteric liquid crystals have many potential applications as the results of their special optical properties. Cholesteric liquid crystals can selectively reflect incident light in a certain wavelength range. The achiral polymer networks prepared can reproduce the reflection properties of the cholesteric liquid crystals when refilled with liquid crystals.