A real-time temperature responsive material based on partial inverse opal photonic crystals and cholesteric liquid crystals

In this paper, we fabricated a temperature-sensitive material with a partial inverse opal structure, which can reversibly and quickly identify small temperature changes at room temperature and show significant color differences. First, we synthesized silica microsphere and prepared silica photonic crystals (PCs), then we composited PCs with polymer. After covering the mask, we prepared partial inverse opal silica PCs template by using selective etching. The temperature-sensitive liquid crystals (LCs) composed of cholesterol oleyl carbonate (COC), cholesterol nonanoate (CPE) and cholesterol benzoate (CBZ) were filled in partial inverse opal silica PCs template. In the end, we sealed the film by methyl methacrylate (MMA) and polyethylene glycol diacrylate (PEGDA). In this way, we prepared the fast temperature-sensitive dual-opal PCs/LCs composite film, and studied the mechanism of temperature regulation on material display mode. As the temperature gone from 26 °C to 30 °C, the material changed colors rapidly from red to blue. The result showed that this PCs/LCs composite film had well temperature response performance, which can monitor slight environmental temperature change. By selective etching the material, we designed PCs film patterns. The different patterning states displayed and changed fast at different temperatures, showing that the material had a good application prospect in the fields of temperature sensor, anti-counterfeiting, and display device.