Highly Thermal Stable Polymer Stabilized Cholesteric Liquid Crystals Smart Window

In this paper, we reported a highly thermal stable YP-11 polymer stabilized cholesteric liquid crystal (YP-11 PSCT) for smart windows that can be electrically switched from transparent to opaque. The polymerization between photo-sensitive monomers (RM 257) has been characterized using a polarized optical microscope (POM), which has been found to become much firmer and denser by raising the doping concentration. The 3D polymer matrices remarkably affect the electro-optical performances of YP-11 PSCT, and the cholesteric liquid crystals (Ch LCs) within polymer matrices were found merely able to be reversibly switched until the doping concentration of RM 257 was raised up to 3%. Specifically, the threshold voltage, raising time and decaying time of a 3% YP-11 PSCT cell were determined as 22.908 V, 85.442 ms and 18.617 ms, respectively. The critical thermal-stable temperature of the 3% YP-11 PSCT was further evaluated using a hot stage and was confirmed as high as up to 100 °C. These findings in this paper will significantly contribute to the development of smart windows.