Laboratory for Biointerfaces, Department Materials Meet Life, Empa, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014 St. Gallen, Switzerland.
Phys Chem Chem Phys. 2018 Aug 29;20(34):21903-21909. doi: 10.1039/c8cp03205j.
Functional coatings based on self-assembled lyotropic liquid crystals have the potential for applications such as biosensing, drug delivery and nanotemplating. Here we demonstrate the design and in-depth characterization of glycerol monooleate based liquid crystalline coatings on silicon wafers using drop casting and spin coating techniques. In situ time-resolved grazing incidence small angle X-ray scattering (GISAXS) measurements were used to monitor the coating formation and its response to increasing relative humidity conditions between 5 and 100%. Additional atomic force microscopy (AFM) measurements were applied to visualize the coating nanostructure. Structural transformations through ordered intermediate phases to the sponge- and lamellar phase were observed during ethanol evaporation. Relative humidity dependent GISAXS results revealed gradual phase transitions from the lamellar via the gyroid type cubic phase to the diamond type bicontinuous cubic structure between 5 and 100% relative humidity. The detailed insights into the formation and transformation of the coating nanostructures in this system may provide essential knowledge for the comprehensive design of functional nanostructured surfaces in biomedical applications.
基于自组装溶致液晶的功能性涂层在生物传感、药物输送和纳米模板等方面具有应用潜力。在这里，我们使用滴铸和旋涂技术展示了基于甘油单油酸酯的液晶涂层在硅片上的设计和深入表征。原位时间分辨掠入射小角 X 射线散射（GISAXS）测量用于监测涂层的形成及其对相对湿度在 5%至 100%之间增加的响应。还应用了原子力显微镜（AFM）测量来可视化涂层的纳米结构。在乙醇蒸发过程中观察到通过有序中间相到海绵相和层状相的结构转变。相对湿度依赖的 GISAXS 结果表明，在 5%至 100%相对湿度之间，从层状相通过向列型立方相到钻石型双连续立方结构的相逐渐转变。该系统中涂层纳米结构形成和转变的详细信息可能为生物医学应用中功能性纳米结构表面的综合设计提供必要的知识。
