表面活性剂对超细BaTiO_3纳米颗粒制备的影响

Effect of Surface Active Agent in Synthesis of Ultrafine BaTiO_3 Nano-particle

以钛酸四丁酯为钛源,醋酸钡为钡源,采用改进的水热法（即溶剂热法）在低温条件下合成钙钛矿结构的超细钛酸钡纳米颗粒,重点研究表面活性剂对产物的影响,探讨了不同表面活性剂影响产物形貌和种类的作用机理.通过扫描电子显微镜（SEM）、X射线衍射（XRD）及能谱（EDS）对产物进行表征,结果表明加入不同的表面活性剂时,制备的产物不同,其产物的形貌分别为超细纳米线、纳米棒（直径约几十纳米）和纳米颗粒（尺寸约50～100nm）.通过调节反应过程中的表面活性剂,可以实现从线状钡的硫酸盐到纯相的超细钛酸钡纳米颗粒的转变.此方法为尺寸小于20nm的钛酸钡颗粒的制备及铁电材料尺寸限制效应的研究提供了重要参考.

Ultrafine barium titanate （BaTiO3） nanoparticles with perovskite structure was successfully synthe- sized under low temperature through a modified hydrothermal method （i. e. sol-thermal synthesis）, using tetrabutyl titanate and barium acetate as titanium source and barium source, respectively. The surfactants were introduced to in- vestigate their influence on final product of BaTiO3. Additionally, the effects on the morphology and crystal structure of the BaTiO3 were discussed for the mechanisms behind. Scanning electron microscope （SEM）, X-ray diffraction （XRD）, and energy dispersive spectrometer （EDS） were used to characterize and analyze the synthesized nanomate- rials. The results indicate that the structure and chemical phase of the final nanomaterial were highly dependent on the choice of the surfactant in the preparation process. Furthermore, the morphologies of the materials, including ultra- fine nanowires, nanorods （about dozens of nanometers）, and nanoparticles （50--100 nm）, were obtained by changing the surfactant types. It turns out that the pure barium sulfate fibers can be transformed into the ultrafine nanoparticle of BaTiO3. This method could suggest the clue to prepare BaTiO3 nanoparticles with the scale down to 20 nm, and provide good candidate for the understanding of the size effect of its ferroelectric properties.