SiO2胶体晶体垂直沉积自组装方法的改进

采用垂直沉积技术及相应的改进方法,使用化学合成的400 nm单分散二氧化硅微球自组装制备了胶体晶体薄膜。通过扫描电镜与分光光度计对样品的微观结构与透过光谱进行了表征,并对比研究了不同的垂直沉积方法对胶体晶体的影响。结果表明,通过温度与流量控制两种改进手段,均能制备具有六方密堆结构周期排列的胶体晶体薄膜。在垂直沉积过程中适当的升高温度有利于降低胶体粒子的用量,而通过流量控制的垂直沉积技术则可以有效缩短自组装时间。通过调节蠕动泵改变液面与基板的相对运动速度,或者调控温度改变胶体溶液的蒸发速率,可在材料表面形成单层或多层的胶体晶体薄膜。改进的垂直沉积技术将有望应用于快速沉积大面积、高质量的胶体晶体材料。

Self-assembly of Silica Colloidal Crystals by Improved Vertical Deposition Methods

The fabrication and characterization of silica colloidal crystal films self-assembled from suspension of monodisperse silica spheres are reported through different improvement on vertical deposition. Three vertical deposition methods on the crystal formation were compared in terms of microstructure and optical transmission measurements. The results show that both the temperature-controlled vertical deposition and the flow-controlled vertical deposition could gain closely packed structures as traditional method but with lower colloid consumption and shorter time of self-assembly. By adjusting the rate of solvent evaporation or the relative movement between the liquid-surface and substrate, it is possible to transfer monolayer or multilayer of silica colloidal crystals onto the substrates. The improved methods can be used for rapid deposition of high-quality colloidal crystal films over large surface area without any special equipment.