微米级球形二氧化硅粉体的控制制备研究

【作者】 吴家胜；

【导师】 李凤生； 顾志明；

【作者基本信息】 南京理工大学 ， 材料学， 2009， 硕士

【摘要】 球形硅微粉是航空、航天、电子信息等高端产业的重要材料,同时也在新型涂料、特种陶瓷,高档化妆品等领域有着广泛的应用,具有很高的实用价值。本文旨在通过乳液法制备粒径可控球形二氧化硅并对其性能进行研究,主要内容如下:(1)研究水相、乳化剂用量、油相、转速、温度等因素对乳状液稳定性的影响。在固定水相和乳化剂用量的条件下,乳化剂用量在1%～4%(质量分数)之间、转速高于500r/min时能够形成稳定的柴油乳状液。(2)考察了乳化剂用量、转速、酸量和反应温度等因素对乳液法样品粒径的影响。乳化剂用量、转速对产品的粒径影响最为显著,酸量和反应温度对粒径几乎没有影响。乳液法产品的粒径随着乳化剂用量的增加、转速的增大而减小,通过调整乳化剂用量、转速可以制备出平均粒径在5μm～40μm之间的乳液法球形二氧化硅产品。(3)研究了原料水玻璃加入量、乳化剂用量、转速、酸量和反应温度等因素对得率的影响。原料水玻璃加入量、酸加入量对得率的影响最为显著,乳化剂用量、转速对得率有一定程度的影响,反应温度对得率几乎没有影响。乳液法产品密度的研究结果表明随着煅烧温度的升高产品的密度增大。(4)在前期实验室研究的基础上经过几何相似放大设计了反应釜放大实验,放大反应釜的反应过程与实验室烧杯的反应过程存在着质的区别,放大实验得率下降了30%左右,样品球形度变差,粒度分布变宽。更多还原

【Abstract】 Spherical silica which has great applied value is not only an important supporting material of some high-end industries such as electronic information, aviation, but also was widely used in new paint, special type ceramics and slap-up cosmetics industries. The aim of this paper was to synthesize the spherical shape SiO₂ powder through the emulsion method presented in this article. The details are described as below.The factors that impact the stability of emulsion were researched and the results indicated that the emulsion could maintain stability when the dosage of emulsifying agent reached from 1%to 4%（by quantity） and the rotate speed reached 300r/min.The factors which impact the diameter of sample which was synthesized through the emulsion method were researched. The quantity of emulsifying agent and rotate speed were the most important factors that influence the diameter of sample after analyzing all the factors which may influence the reaction. The experimental results indicated that the diameter of samples will change when the quantity of emulsifying agent and rotate speed change. Samples which diameter change from 5μm to 40μm could be synthesized by adjust the quantity of emulsifying agent and rotate speed.The factors which impact the yield were researched. The amount of water glass and 5% sulfuric acid were the most important factors which influence the yield and the quantity of emulsifying agent and rotate speed influence the yield by somewhat means. The reaction temperature can hardly influence the yield. The density experiments indicated that the sample density would increase when the temperature increase.Lastly, the magnified experiment was designed and its results indicated that the reaction process was extreme different from the laboratory reaction process and the quality was not as good as the laboratory’s samples: the yield decreased about 30%, the sphericity got bad and the distributing of sample became wider.更多还原