Glassy Cholesteric Liquid Crystals Containing Menthyl Groups Demonstrating Tunable Visible Reflection with Temperature and Reflection Angle Dual‐Mode

Responsive dual‐modal cholesteric liquid crystal (CLC) optical materials demonstrating tunable optical behaviors possess significant application in optical devices. Introducing chiral groups into liquid crystal structures is a common strategy. The design of CLC optical structure by two identical menthyl elements is seldom reported. Herein, novel CLC oligomers (Gn) combining 4‐(4‐(4‐menthyloxy‐4‐oxobutanoyloxy)benzoyloxy)phenyl 4‐allyloxybenzoate (M1) and 4′‐(4‐menthyloxy‐4‐oxobutanoyloxy)biphenyl‐4‐yl 4‐allyloxybenzoate (M2) on organosilicon oligomers by molecular grafting are proposed. The as‐prepared oligomers Gn display brilliant visible light reflection in the chiral nematic (N*) phase. And when the oligomers Gn are rapidly cooled from the N* temperature to below 0 °C, the reflection color on the glassy CLC oligomers can be preserved at room temperature over 1 year. Furthermore, the glassy Gn present dual‐mode thermochromic performances, the blue (or red)‐shift reflection with the increase of temperature, and the blue‐shift reflection with the increase of reflection angle.