基于染料掺杂型液晶微胶囊的电刺激响应智能纺织品的制备及其性能

针对电致变色液晶易流动,难以塑形而不易与纺织品结合应用的问题,在向列相液晶中掺杂二色性染料形成宾主材料,采用乳液聚合方法将其作为芯材封装在以聚甲基丙烯酸甲酯为壁材的微胶囊内,得到染料掺杂型液晶微胶囊。通过偏光显微镜分析液晶在限域条件下的独特光学性质,借助扫描电子显微镜、透射电子显微镜、热重分析仪等表征微胶囊的形貌结构及热学性能,并探讨微胶囊包覆对染料掺杂型液晶的驱动电压与使用寿命的影响。结果表明:制备的染料掺杂型液晶微胶囊具有明显的核壳结构,粒径为3 μm,芯材载量约为70%,驱动电压为3.6 V,远低于人体安全电压;以微胶囊为原料涂敷在导电织物上,其光学外观可在直流电源刺激下于无色态和有色态之间发生可逆转变,从而为优化电致变色液晶微胶囊器件制备工艺和提高纺织品柔性显示性能奠定基础。

Preparation and property of dye-doped liquid crystal microcapsules for electro-stimulated responsive smart textiles

Aiming at the problems that the electrochromic liquid crystal is easy to flow, difficult to shape and difficult to apply to textiles, the dichroic dyes were doped in nematic liquid crystal to form a guest-host material, which was further encapsulated in a microcapsule with polymethyl methacrylate as the shell material by emulsion polymerization. In addition, the unique optical properties of liquid crystals confinement effect were analyzed by polarizing microscope. The morphology and structure of microcapsules were characterized by scanning electron microscope, transmission electron microscope and thermal gravimetric analyzer. The influence of microcapsule coating on the driving voltage and service life of dye-doped liquid crystal were also investigated. The results show that dye-doped liquid crystal microcapsule have obvious core-shell structure, with particle size of 3 μm, core material loading of 70%, and driving voltage of 3.6 V, which is far lower than the human safety voltage. The optical appearance of the microcapsule coated on the conductive fabric can be reversibly changed from colorless state to colored state under the stimulation of direct-current power supply, which lays the foundation for optimizing the preparation process of electrochromic liquid crystal microcapsule devices and improving the flexible display performance of textiles.