Study On Synthesis Of Silicon Dioxide By Gaseous Deflagration

Due to its special performance, Silicon Dioxide nanoparticles have a very good prospect in many fields, so the study of a good preparation methods are particularly important. Gaseous deflagration methods of synthesizing nanoparticles is a new synthesis method which can prepares nanoparticles by detonated combustible gas which contain precursor. The main research contents of nano SiO2 synthesis with gaseous deflagration are as follows:1. Through the theory of gas explosion,we calculated explosion parameters after mixing in SiCl4 with hydrogen and oxygen, hydrogen and air respectively. Taking SiCl4 as the precursor, by means of pressure test and high-speed photography for gaseous deflagration of mixtures which composed of hydrogen and oxygen, hydrogen and air respectively, we also got detonation velocity and detonation pressure of deflagration precess.2. By changing the temperature of mixture of hydrogen and air before initiation, changing the injection quantity of precursor, we prepared amorphous nano SiO2 by a series of experiments and characterized particle morphology, dispersion and particle size of product through testing means, such as XRF, XRD, TEM etc. It was found that the particle size of prepared nano-SiO2 were more uniform and smaller, about 10nm or so.The product was spherical shape and its purity was more than 99%. With the temperature of the tube rising before detonating, the dispersion of SiO2 products was improved and particle distribution was more uniform. Excessive precursor injection will make the bond between the particles, the relative amounts of precursors should be controlled within the molar ratio of 1.5.3. As a comparison, we also conducted the gas mixture of hydrogen and oxygen with SiCl4 as the precursor. The products were characterized. The nano particles SiO2 were spherical most, well dispersed, but the size became larger.4. Synthesizing nano SiO2 particles through gaseous deflagration is a very promising preparation methods. Its operation is simple, cost is low and purity is high. If its reaction conditions and equipment could be perfected, we can hope to achieve industrial production.