二氧化钛粒子的合成及光子晶体的制备
发布时间：2018-10-22 08:15
【摘要】：二氧化钛粒子,是一种非常重要的功能材料。因其具有较高的折射率和优异的光学特性,有望以二氧化钛胶体微球为组装原料,制备近红外和可见光波段的高质量光子晶体。单分散二氧化钛微球的合成是制备胶体光子晶体的基础。本论文在溶胶-凝胶法的基础上,以钛酸四丁酯为原料,合成了单分散亚微米和窄分散纳米二氧化钛粒子,并通过离心自组装法制备了高质量的光子晶体,具体内容如下:在乙醇体系中加入KCl水溶液,其中KCl作为稳定剂,成功合成出粒径范围为100~465nm的单分散亚微米二氧化钛微球,并制备了多分散指数在0.05~0.25之间的窄分散纳米级二氧化钛粒子,研究了不同反应时间(0~8h)、KCl浓度(4.06×10~(-4)~1.74×10~(-3)mol/L)、水钛摩尔比(4.05~9.45)、反应温度(15~40℃)等因素对二氧化钛微球的粒径尺寸及粒径分布的影响规律。结果表明:KCl的加入能够有效抑制粒子聚沉现象的发生;采用适当的反应条件可以得到不同粒径的二氧化钛粒子。以丙酮-乙醇或二甲基亚砜(DMSO)-乙醇混合溶剂为反应介质,KCl作为稳定剂,合成了粒径范围为100~480nm的单分散二氧化钛规则微球。实验发现:随着KCl浓度(4.06×10~(-4)~1.45×10~(-3)mol/L)的增大,微球的粒径依次减小,单分散性保持良好;丙酮或DMSO的含量增加,导致微球的粒径变大,单分散性变差,DMSO的影响程度尤为明显。混合溶剂法为单分散亚微米二氧化钛规则微球的制备提供了一种思路。采用两步法,先在常温下生成沉淀,然后80℃回流胶溶,通过调控钛酸四丁酯的用量和回流体系中pH值的大小,成功实现水溶性良好的纳米二氧化钛粒子的合成,确定了最小尺寸纳米粒子的合成条件:回流体系中pH值为1.5,钛酸四丁酯浓度为0.5mol/L。分别以预先合成的145nm,179nm,200nm和230nm单分散二氧化钛微球为自组装原料,利用离心法在2500rpm,3500rpm和4500rpm转速下制备出大面积的三维胶体光子晶体,使用扫描电子显微镜和紫外-可见分光光度计表征,结果表明:离心法工艺操作简单,制备周期短;制备的胶体光子晶体具有明显的光子带隙,随着颗粒增大,禁带位置红移;离心转速会影响胶体光子晶体的质量,根据微球的大小选择合适的转速至关重要。这为光子晶体在光学器件中的应用提供了实验依据和有效指导。
[Abstract]:Titanium dioxide particles are very important functional materials. Due to its high refractive index and excellent optical properties, it is expected to prepare high quality photonic crystals with near infrared and visible light bands using titanium dioxide colloidal microspheres as the assembly material. The synthesis of monodisperse titanium dioxide microspheres is the basis for the preparation of colloidal photonic crystals. Based on the sol-gel method, monodisperse submicron and narrow dispersed nano-TiO _ 2 particles were synthesized from tetrabutyl titanate, and high quality photonic crystals were prepared by centrifugal self-assembly method. The main contents are as follows: the monodisperse submicron TIO _ 2 microspheres with the particle size range of 100~465nm were successfully synthesized by adding KCl aqueous solution and KCl as stabilizer in ethanol system. Narrow dispersed nanometer TIO _ 2 particles with polydispersity index of 0.05 ~ 0.25 were prepared. The effects of different reaction time (0 ~ 8 h), KCl concentration (4.06 脳 10 ~ (-4) ~ 1.74 脳 10 ~ (-3) mol/L), molar ratio of water to titanium (4.05 ~ 9.45) and reaction temperature (1540 鈩，
本文编号：2286617
[Abstract]:Titanium dioxide particles are very important functional materials. Due to its high refractive index and excellent optical properties, it is expected to prepare high quality photonic crystals with near infrared and visible light bands using titanium dioxide colloidal microspheres as the assembly material. The synthesis of monodisperse titanium dioxide microspheres is the basis for the preparation of colloidal photonic crystals. Based on the sol-gel method, monodisperse submicron and narrow dispersed nano-TiO _ 2 particles were synthesized from tetrabutyl titanate, and high quality photonic crystals were prepared by centrifugal self-assembly method. The main contents are as follows: the monodisperse submicron TIO _ 2 microspheres with the particle size range of 100~465nm were successfully synthesized by adding KCl aqueous solution and KCl as stabilizer in ethanol system. Narrow dispersed nanometer TIO _ 2 particles with polydispersity index of 0.05 ~ 0.25 were prepared. The effects of different reaction time (0 ~ 8 h), KCl concentration (4.06 脳 10 ~ (-4) ~ 1.74 脳 10 ~ (-3) mol/L), molar ratio of water to titanium (4.05 ~ 9.45) and reaction temperature (1540 鈩，
本文编号：2286617
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