新型球形纳米空心SiO_2的模板合成方法研究

Study on a Novel Template Synthesis Method for Hollow Silica Nanospheres

以纳米碳酸钙颗粒为新颖的无机模板剂,硅酸钠为无机硅源,通过溶胶-凝胶法形成CaCO3/SiO2的核壳结构;随后通过高温煅烧、酸溶和干燥处理,合成出了具有高比表面积的球形纳米空心二氧化硅粒子.然后,分别采用TEM,SEM,EDS,XRD,FTIR和TG等测试手段对样品进行了分析和表征,并考察了不同合成条件,如反应温度、反应pH值、煅烧温度和包覆反应时SiO2/CaCO3的配比对纳米空心二氧化硅粒子的比表面积变化.实验结果表明:较高的反应温度如60～80℃,pH值9左右、SiO2包覆量为碳酸钙质量的10%,以及煅烧温度为700℃,有利于形成空心形貌较好、比表面较大的球形纳米空心二氧化硅.

Hollow silica nanospheres with high specific surface area were prepared by a sol-gel route using CaCO3 nanoparticles as novel templates and sodium silicate as the silica source, followed by calcination, washing in acidic solution and a drying treatment. The samples were characterized by TEM, SEM, BET, EDS, XRD, FTIR and TG The morphology and the BET of the prepared hollow silica were influenced by the synthesis conditions such as reaction temperature, pH, calcination temperature and SiO2/CaCO3 ratio, and the results indicated that hollow silica nanospheres with good morphology and large BET could be obtained under the conditions of SiO2/CaCO3= 10%, a reactive temperature of 60-80 degrees C, pH approximate to 9 and a calcination temperature of 700 degrees C.