硅溶胶的制备及其在硅酸盐长余辉材料中的应用研究

发布时间：2017-12-30 19:37

  本文关键词：硅溶胶的制备及其在硅酸盐长余辉材料中的应用研究　出处：《上海应用技术学院》2016年硕士论文　论文类型：学位论文

  更多相关文章： 单质硅溶解法 离子交换法 硅溶胶 长余辉材料 硅酸盐

【摘要】：硅溶胶作为一种重要的无机高分子材料,因其具有良好的分散性、较好的耐磨性、较大的比表面积、亲水性和憎水性等性能,被广泛应用在精密铸造、涂料、蓄电池、粘结剂和催化剂等工业,而且国内外对其产品种类的要求越来越高。另外,硅酸盐体系长余辉发光材料,有极强的耐水性,发光颜色与铝酸盐体系形成互补,越来越受到人们的重视。本文的研究内容主要分为两部分：实验前一部分结合单质硅溶解法和离子交换法制备酸性硅溶胶,并对制备过程中影响产品性能的各种工艺参数进行分析和探讨；另一部分利用前一部分制备的酸性硅溶胶作为硅的来源,采用燃烧合成法制备了离子掺杂硅酸盐长余辉材料,通过X射线粉末衍射(XRD)和荧光分光光度计以及扫描电镜等对其进行物相结构和发光性能进行了分析。主要得到以下结论：(1)在制取酸性硅溶胶的过程中,母液浓度、硅粉量、催化剂、反应温度、反应时间等都会对最终产品的粒径以及稳定性有一定的影响。当母液浓度小于2.5wt%时,平均粒径和SiO2含量随着母液浓度的增加而变大；当母液浓度大于2.5wt%时,平均粒径随着母液浓度的增加而变小。每200m1水溶液中硅粉加入量在26g之前,硅溶胶的平均粒径随着硅粉的加入量的增加而增加,且在20g以前增加迅速,在20g-26g之间增加缓慢。当硅粉加入量超过26g之后,硅溶胶的平均粒径随着硅粉的加入量增加反而缓慢减小,最终趋于稳定。用不同种类的催化剂时,最终硅溶胶产品的平均粒径也会不同,用氨水和九水硅酸钠溶液作为复合催化剂时,硅溶胶的平均粒径会比单独使用一种催化剂或者不使用催化剂时的硅溶胶的平均粒径大。反应温度由75℃升至95℃时,硅溶胶平均粒径呈现逐渐增大的趋势。硅溶胶平均粒径随着反应时间的延长先增加后减小。(2)制备酸性硅溶胶的最佳工艺条件：活性硅酸母液为2.5wt%,用量为200ml,硅粉用量为26g,采用氨水和九水硅酸钠作为复合催化剂,反应温度为90℃,反应时间为8h。在此基础上进行实验,制得的酸性硅溶胶产品粒径可达30nm以上,常温下稳定时间可达200天左右。(3)以自制酸性硅溶胶为硅源合成的Sr2MgSi2O7:Eu2+,Eu3+,Dy3+材料发射光谱为一半宽带,主发射峰位于568nm处,为Eu3+的5D→7F特征峰值,次发射峰位于475 nm处,为Eu2+的4f5d→4f跃迁引起的发光,该材料主要为黄光发射。(4)本实验合成硅酸镁锶粉体的最佳工艺参数为：n(硝酸锶)/n(硅溶胶)=1：1.1,n(尿素)/n(硝酸盐)=3：1,燃烧温度为850℃。用自制的酸性硅溶胶作为原料采用燃烧合成法制备的Sr2MgSi2O7:Eu2+,,Eu3+,Dy3+,产物颗粒均匀细小,易粉碎,生产周期短,可成为合成硅酸锶镁的一种新型技术路线。
[Abstract]:As an important inorganic polymer material, silica sol has been widely used in precision casting and coating because of its good dispersion, good wear resistance, large specific surface area, hydrophilicity and hydrophobicity. Batteries, binders, catalysts and other industries, but also at home and abroad to its product types of higher and higher requirements. In addition, silicate system long afterglow materials, has a strong water resistance. Luminescent colors complement each other with aluminate system, and people pay more and more attention to it. The research contents in this paper are divided into two parts: one is the synthesis of acidic silica sol by the combination of simple silicon dissolution method and ion exchange method before the experiment. The process parameters that affect the properties of the product during the preparation process are analyzed and discussed. In the other part, the ion-doped silicate long afterglow material was prepared by combustion synthesis using the acidic silica sol prepared in the former part as the source of silicon. The phase structure and luminescence properties of the samples were analyzed by X-ray powder diffraction (XRD), fluorescence spectrophotometer and scanning electron microscope. The main conclusions are as follows: 1). In the process of preparing acidic silica sol. The concentration of mother liquor, amount of silica fume, catalyst, reaction temperature and reaction time all have some effects on the particle size and stability of the final product, when the concentration of mother liquor is less than 2.5 wt%. The average particle size and SiO2 content increased with the increase of mother liquor concentration. When the concentration of the mother liquor is more than 2.5 wt%, the average particle size decreases with the increase of the concentration of the mother liquor. The amount of silicon powder added into the water solution of 200m1 is before 26g. The average particle size of silica sol increases with the addition of silica fume, and increases rapidly before 20g, and slowly between 20g and 26g, when the addition of silica fume exceeds 26g. The average particle size of silica sol decreases slowly with the increase of silica fume content and eventually tends to be stable. The average particle size of the final silica sol product will be different with different kinds of catalysts. Ammonia and sodium silicate solution were used as composite catalysts. The average particle size of silica sol is larger than that of silica sol using one catalyst alone or without catalyst. The reaction temperature increases from 75 鈩，

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