Nakamura Hiroshi, Ishii Masahiko, Tsukigase Azusa, Harada Masashi, Nakano Hideyuki
Toyota Central Research & Development Laboratories, Inc., Aichi, Japan.
Langmuir. 2006 Jan 31;22(3):1268-72. doi: 10.1021/la052034w.
Titania coated monodisperse silica spheres have been synthesized and fabricated as a close-packed colloidal crystalline array. We have demonstrated that the coated colloidal sphere can be used to control the peak position of the optical stop band through variation of the coating thickness. The titania coated silica spheres were prepared by the layer-by-layer assembly coating process, which reciprocally laminates the cationic polyelectrolyte and the anionic titania nanosheets on a monodisperse silica spheres, and were sintered to change the titania nanosheets to anatase. The Bragg diffraction peak of the colloidal crystalline array shifted to the long wavelength region with an increase of thickness of the titania layer. Angle-resolved reflection spectra measurements clarified that the red shift was caused by increasing of the refractive index with increase of the thickness of the layer. The current work suggests new possibilities for the creation of advanced colloidal crystalline arrays with tunable optical properties from tailored colloidal spheres.
已合成并制造出涂有二氧化钛的单分散二氧化硅球体，并将其制成紧密堆积的胶体晶体阵列。我们已经证明，通过改变涂层厚度，涂覆的胶体球体可用于控制光学禁带的峰值位置。涂有二氧化钛的二氧化硅球体是通过逐层组装涂层工艺制备的，该工艺将阳离子聚电解质和阴离子二氧化钛纳米片交替层压在单分散二氧化硅球体上，然后进行烧结，将二氧化钛纳米片转变为锐钛矿型。随着二氧化钛层厚度的增加，胶体晶体阵列的布拉格衍射峰向长波长区域移动。角分辨反射光谱测量表明，红移是由于随着层厚度的增加折射率增大所致。当前的工作为利用定制的胶体球体创建具有可调光学性质的先进胶体晶体阵列提供了新的可能性。
