一种非球形纳米二氧化硅颗粒制备新方法

An Innovative Preparation Methodology of Non-spherical Nanosize Silica Particle

以低成本工业级硅酸钠为原料,采用离子交换法制备了非球形纳米二氧化硅颗粒。在制备过程中,采用控制无机碱催化剂1%(质量分数)氢氧化钠水溶液滴加到活性硅酸速度的方法来控制二氧化硅晶核成核的形貌,进而控制二氧化硅颗粒的形貌,避免了传统方法(通过引入有机碱或者引入二价或三价阳离子)制备非球形二氧化硅颗粒的不足。扫描电镜显示所制备的二氧化硅颗粒为非球形(呈花生、哑铃或枣状),轴向粒径为10~20nm,径向粒径为45~80nm。激光粒度分析仪测试表明非球形颗粒高斯分布平均粒径为39.0nm,多分散指数高达0.261。该方法制备非球形二氧化硅颗粒步骤简单、环境友好,非常有利于工业化生产与应用。

Non-spherical nanosize silica particles were prepared by ion exchange method using low cost industrial sodium silicate as raw material.In the preparation process,the morphology of the silica particle was controlled by the shape of the silica nuclei,which was dominated by the feeding rate of inorganic alkali catalyst 1%（mass fraction）NaOH solution to the fresh active silicic acid during nuclei formation process.This method avoided the deficiency of conventional methods（by introducing organic bases or by introducing double or triple valence cations）for synthesizing non-spherical silica particles.Scanning electron microscopy（SEM）demonstrated that the morphology of the prepared silica particles were not spherical（like peanut,dumbbell or jujube）,the axial size was about 10—20 nm,the range of the radial size was about 45—80 nm.Dynamic light scattering（DLS）test revealed that the average size of Gaussian distribution of non-spherical particle was 39 nm,and the polydispersity index was as high as 0.261.This method of preparing non-spherical silica particles is simple and environment-friendly,and is very beneficial to industrial production and application.