高压碳化法可控制备微纳米分级结构中空棒状碳酸钙及其表征

以氢氧化钙为钙源，D-葡萄糖酸钠为添加剂，在高压碳化釜中采用二氧化碳鼓泡碳化法制备出分散均匀，由立方状纳米粒子组装而成具有微纳米分级结构的中空棒状碳酸钙聚集体。探究了各因素对高压碳化法制备碳酸钙的影响，通过改变反应温度、D-葡萄糖酸钠的添加量、氢氧化钙的浓度等考察制备的最佳条件。采用SEM、TEM、XRD、FTIR和BET等测试手段对产品的结构和性能进行了表征。实验结果表明，所制备的微纳米分级结构中空棒状碳酸钙的平均直径约300nm，长度为1~2μm，壳壁由粒径为50~100nm的纳米立方状粒子聚集而成，壳层厚度约100nm。同时，在反应温度为120℃、氢氧化钙质量分数为2%、D-葡萄糖酸钠添加量为氢氧化钙质量的2%、反应时间为4h的条件下，所制备的中空棒状碳酸钙的分散性和均匀性最好。

Preparation and characterization of micro-nano hierarchical hollow rod-like calcium carbonate by high pressure carbonization

With calcium hydroxide as the calcium source, D-sodium gluconate as the additives, micro-nano hierarchical hollow rod-like calcium carbonate aggregates assembled with nano cubic grains were prepared by bubbling CO₂ in high-pressure reactor. The influences of various factors on the preparation of calcium carbonate were studied, and the optimum conditions are investigated by changing the reaction temperature, the amount of D-sodium gluconate, and the concentration of calcium hydroxide. The products were characterized by SEM, TEM, XRD, FTIR, and BET. The result shows that the hollow rod-like calcium carbonate aggregates with micro-nano hierarchical structure have an average diameter of about 300nm and a length of 1—2μm, and the thickness of the wall of the aggregate is about 100nm, composed with 50—100nm cubic shape nanoparticles. Moreover, high uniform and disperse hollow rod-like calcium carbonate aggregates can be obtained with a calcium hydroxide concentration of 2%, D-glucose acid sodium content of 2% (total weight of calcium hydroxide added), the reaction temperature of 120℃, and the reaction time of 4h.