无添加剂条件下文石型碳酸钙晶须制备及影响因素研究

在不加任何结晶控制剂或模板条件下,以CaCl2和Na2CO3为原料,利用复分解反应法制备了具有较好形貌和高长径比,且分布均一的文石型碳酸钙晶须,并利用扫描电镜(SEM)、X-射线粉末衍射(PXRD)和傅里叶转换红外光谱图(FT-IR)等手段对其进行了表征。研究了浓度、滴加速度、反应温度、搅拌速度以及滴加方式等因素对碳酸钙晶须的影响。结果表明最佳制备工艺为:CaC12溶液与Na2CO3溶液的浓度为0.05 mol.L-1,溶液滴加速度为1 mL.min-1,反应体系温度为80℃,搅拌速度为250 r.min-1。

Preparation of aragonite calcium carbonate whiskers without the additive and the study of influencing factors

Without adding any crystalline controller or templates,uniform aragonite calcium carbonate(CaCO3)crystals with smooth surface and high aspect ratios were prepared by double decomposition reaction of calcium chloride(CaCl2)and sodium carbonate(Na2CO3).CaCO3 crystals were characterized by scanning electron microscopy(SEM),powder X-ray diffraction(PXRD)and Fourier transform infrared spectroscopy(FT-IR).The effects of reactants concentration,dropping speed of Na2CO3 solution,reaction temperature,stirring speed,and dropping way on polymorphs of CaCO3 were investigated.The results indicate that the optimum reaction conditions are as follows:concentration of CaC12 and Na2CO3 are both 0.05 mol·L-1,dropping speed of Na2CO3 solution is 1 mL·min-1,reaction temperature is 80 ℃,stirring speed is 250 r·min-1.