纳米碳酸钙的制备及表征

研究了以氧化钙和二氧化碳为原料,化学法制备纳米碳酸钙的工艺条件、添加剂的影响及形态。结果表明:中间体氢氧化钙的初始浓度、二氧化碳的流量、反应温度、搅拌速度及添加剂等在控制制备纳米碳酸钙颗粒的形状和尺寸中均十分重要。透射电镜观察结果表明:通过控制反应及添加剂,可以得到尺寸规整的链锁形、纺锤形和球形纳米碳酸钙。表面能谱证实产品为高纯的碳酸钙。X射线衍射和电子衍射的结果进一步表明:所制纳米碳酸钙均属方解石型六方晶系,a0=0.498 9 nm,c0=1.706 2 nm;为多晶结构。

PREPARATION AND CHARACTERIZATION OF NANOMETER CALCIUM CARBONATE

The preparing conditions and morphology of nanometer calcium carbonate prepared by chemical method with calcium oxide and carbon dioxide as the reagents was studied. The influence of different additives on shapes of crystals was also introduced. Results show that initial concentration of calcium hydroxide, the flow of carbon dioxide, reaction temperature, stirring speed, and the additives play an important role in controlling the morphology and size of nanometer calcium carbonate in the preparation. TEM observation results show that the regular nanometer calcium carbonate with chain-like shape, spindle shape and sphere shape were obtained by controlling the reaction conditions and additives. The product is pure calcium carbonate verified by EDS. Further research of XRD and ED patterns shows that the nanometer calcium carbonate prepared are identified as polycrystalline with hexagonal structure, a0=0. 498 9 nm, c0 = l. 706 2 nm.