摘要
用TiCl4水解法,以Na2CO3溶液为中和剂,通过相转移反应制备出纳米TiO2颗粒,此制备方法未见报道。制备产物经透射电子显微镜(TEM)和X-射线衍射仪(XRD)表征分析。实验证明,在Na2CO3溶液55℃条件下,将TiCl4从正辛醇溶液相中转移到水相,与水发生反应制得了纳米TiO2的前驱体Ti(OH)4。经过70℃真空干燥6h,在400℃下煅烧3h后,得到了分布均匀,少团聚的纳米TiO2颗粒。结合实验现象讨论了TiO2制备机理,包括TiCl4水解法反应机理、相转移反应机理和液相中生成固相微粒机理,说明了升高体系温度、以Na2CO3水溶液中和H+,使得反应液pH值在碱性条件下,有利于水解反应向正向移动。采用相转移反应方法和在液相中生成固相微粒过程中通过产物控制浓度,可以获得分布均匀,少团聚的纳米TiO2颗粒。
Nano titanium dioxide particles were synthesized by drolysis of TiCl4, and the system is neutralized by Na2CO3 through the phase thransfer. At the same time, the particles were characterized by means of Transmission Electronic Microscope （TEM） and X -Ray Diffraction（XRD）. The results showed that when the temperature is 55℃, the TiCI4 solution was thransformed from n- octyl alcohol to deionized water phase and reacted with the deionized water, the precursors of nano -TiO2 -Ti （ OH）4 was dried for 6 hours in vacuum at 70℃, then calcined 3 hours in muffle furnace at 400℃. At lssi, the nano - TiO2 which is uniform distribution, weak agglomeration was synthesized. The mechanism of both TiCl4 hydrolysis reaction and phase - transfer reaction showed that temperature increase and pH of reaction system is in alkaline conditions by Na2CO3 solution neutralized H^＋ conducive to hydrolysis reaction to the positive movement.
出处
《材料开发与应用》
CAS
2009年第6期33-37,共5页
Development and Application of Materials
基金
国家自然科学基金项目(50873081)
陕西省教委专项基金(08JK292)
西安工程大学基础研究基金(XGJ07005)资助
关键词
纳米二氧化钛
水解法
相转移
表征
Nano titanium dioxide
Hydrolysis
Phaseransfer
Characterization
