Yuan Guimei

Fabrication of Colloidal Photonic Crystals with Heterostructure by Spin-Coating Method

Colloidal photonic crystal heterostructures, composed of two opaline photonic crystal films of silica spheres with different diameters, are fabricated by a two-step spin-coating method. Scanning electron microscopy (SEM) and UV-vis spectrophotometer are used to characterize the heterostructures. The SEM images show good ordering of the two-layer colloidal crystals constituting the heterostructures. The transmission spectra measured from the (111) plane in the heterostructure show that the composite colloidal photonic crystals have double photonic stop bands. Furthermore, when the sizes of the silica spheres used for fabricating the composite photonic crystal are slightly different, the transmission spectrum shows that the composite photonic crystals have more extended bandgap than that of the individual photonic crystals due to partial overlapping of its two photonic stop bands.

Self-Assembling of Colloidal Particles Dispersed in Mixture of Ethanol and Water at the Air-Liquid Interface of Colloidal Suspension at Room Temperature

Self-assembling of colloidal particles dispersed in a mixture of ethanol and water at the air-liquid interface of the colloidal suspension at room temperature is investigated, and a method of rapidly assembling colloidal particles is proposed. By this method, a uniform colloidal crystal thin film over ten square centimeters in area can be fabricated in 10 min without special facilities and heating the suspension. SEM images and a normal incidence transmission spectrum of the sample show that the colloidal crystal film fabricated by this method is of high quality. In addition, this method is very suitable for fabricating colloidal crystal heterostructures.

TiO 2 反蛋白石结构膜材料改性及其光催化活性研究

利用液相沉积技术对TiO 2 反蛋白石结构材料进行表面处理, 通过在反Opal孔内表面生成一层TiO 2 颗粒, 增加其有效比表面积。以降解罗丹明B为探针反应, 研究了经LPD表面处理之后的TiO 2 反Opal材料的光催化活性, 考察了硼酸用量对TiO 2 反Opal材料表面形貌和光催化活性的影响。结果表明LPD处理之后的TiO 2 反Opal膜比未处理的膜具有更高的光催化活性, 硼酸用量在0.0183 g/mL时处理的TiO 2 反Opal膜具有最高的光催化活性, 相比未处理的膜催化剂活性提高了6倍。利用液相沉积技术对TiO 2 反蛋白石结构材料进行表面处理, 通过在反Opal孔内表面生成一层TiO 2 颗粒, 增加其有效比表面积。以降解罗丹明B为探针反应, 研究了经LPD表面处理之后的TiO 2 反Opal材料的光催化活性, 考察了硼酸用量对TiO 2 反Opal材料表面形貌和光催化活性的影响。结果表明LPD处理之后的TiO 2 反Opal膜比未处理的膜具有更高的光催化活性, 硼酸用量在0.0183 g/mL时处理的TiO 2 反Opal膜具有最高的光催化活性, 相比未处理的膜催化剂活性提高了6倍。