前驱体相对物质的量的变化对氢氧气相爆燃制备纳米SiO_2颗粒的影响

Influences of relative amount of substance of precursor on nano-SiO_2 particles prepared by oxy-hydrogen gaseous deflagration

以SiCl4为前驱体,以H2和O2的混合气体为爆源,通过改变前驱体的相对物质的量,考察前驱体的相对物质的量对产物的影响。并通过XRF、TEM和XRD等测量手段对纳米SiO2粉体进行测试分析:通过XRF对产物进行成分分析,测得所得产物主要由SiO2组成,且纯度达到99.9%以上;由XRD结果得出,生成的SiO2产物属于典型的不定形结构;由TEM图片可以得出,生成的产物粒径大小大部分在50～100nm之间,且呈圆球状。随着前驱体相对物质的量的增加,所得到的产物粒子逐渐出现粘结,分散性下降,前驱体相对物质的量应该控制在1.25以内。

In the experiments,the SiCl4 liquid with the purity of 99 percent was chosen as a precursor and the gas mixtures of H2 and O2 as explosion sources.The relative molar quantity of the precursor was changed and its influences on the products were explored.And the nano-SiO2 powders were characterized with X-ray fluorescence（XRF） spectrometry,X-ray diffraction（XRD） and transmission electron microscopy（TEM）.The XRF measurement shows that the obtained product is mainly SiO2 and its purity is above 99.9 percent.There lie typical halo patterns in the XRD spectra of the products near the diffraction angle of 22 degrees,indicating that the obtained products have amorphous structures.The TEM images display that the obtained main SiO2 powders have particle sizes of 50-100 nm and are spherical.With the increase of the relative molar quantity of the precursor,the products are gradually apt to bonding and their dispersion decreases.So the molar ratio of the precursor should be controlled below 1.25.