【作者】 孙吉梅；

【导师】 张宝林； 侯翠红；

【作者基本信息】 郑州大学 ， 化学工程与工艺， 2007， 硕士

【摘要】 超细粉体由于表面自由能大，不易在液相中均匀分散。其在液相中的分散稳定性直接关系到其应用性能和工业前景，因此超细粉体的分散稳定性及其表面改性的研究是目前超细粉体应用研究的一项重要内容。目前，对超细粉体进行表面改性的方法很多。但在实际应用中，由于各种条件的限制，通常采用物理吸附法及酯化法对其进行表面有机修饰。虽然这样做的人很多，但系统地、规律性地研究表面改性的影响因素很少，修饰后的产品的表征也不完善。本文讨论了超细氧化铟锡和氧化锡的性质和用途，根据胶体的分散稳定理论，研究了超细氧化铟锡乙醇分散体系的稳定机理，旨在为实际应用中的超细氧化铟锡在乙醇相的稳定分散提供理论指导和参考的操作条件；采用几种表面改性剂对超细氧化锡粒子进行表面改性，对改性粒子进行表征，并对以超细粉体作为添加材料制得的隔热材料进行研究。本文研究了超细氧化铟锡在乙醇分散体系中的分散性能，以沉降高度、吸光度、透过率为评价指标，考察了pH值、分散剂的种类与用量及分散工艺条件对分散稳定性的影响，对分散稳定性和粒径分布进行了表征；实验结果表明：超细氧化铟锡在乙醇中pH=6时分散性最差，大于或者小于此值分散稳定性均有提高，分散剂KH570分散效果较好，最佳用量为超细粒子质量的1％左右。考察了高速分散和超声分散对分散稳定性的影响，高速剪切用时较长，超声分散可以在短时间内达到较好的分散效果，在上述最佳配比及分散工艺条件下，超细氧化铟锡分散体系的平均粒径从8.17μm降为0.85μm左右，且粒径分布集中。本文分别采用了偶联剂法和酯化反应法对超细氧化锡进行表面改性，通过红外光谱分析和亲油化度值的测定考察了硅烷偶联剂KH570和活化剂硬脂酸对超细氧化锡表面改性的工艺条件，研究了超细氧化锡制备透明隔热涂料的制备工艺及对隔热效果影响。结果表明无论用KH570还是硬脂酸改性，粒子表面均有改性剂包覆，且与粒子表面有效键和，得到表面亲油化粒子，用硬脂酸改性效果要明显好于在用KH570改性效果。KH570优化改性工艺条件为：改性剂用量为粉体质量的2％，反应温度为50℃，反应时间30min，在此条件下得到的改性产品亲油化度值为0.37。硬脂酸优化改性工艺条件为：硬脂酸质量为粉体质量10％；硬脂酸浓度为2.67g／L；反应温度为60℃；反应时间为1h。在此条件下，得到的改性产品亲油化度值为0.56，改性后的超细粉体在有机介质中的分散性得到了提高，表面由亲水性变成了亲油性。通过对透明隔热涂料的隔热效果测试表明，该涂料具有明显的隔热效果，在红外灯照射下透明隔热玻璃和普通玻璃之间的底板温差可以达到10℃左右，通过对比不同粉体添加量和不同喷板厚度对隔热效果的影响，得到优化粉体添加量和喷板厚度，综合其效果和成本，适宜条件为添加粉体量为丙烯酸树脂与粉体的质量比200／3，喷板四遍漆。虽然隔热涂料隔热效果比较明显，但与在线CVD工艺技术、高温热解成膜制作的镀膜玻璃相比尚有一定差距。本研究采用真空喷涂技术不完善，因此有待进一步提高。由于隔热涂料的透明性较好，所以研究该透明隔热涂料有很大的实用价值。更多还原

【Abstract】 The study on the dispersion stability and surface modification is the important part of the application of the ultra-fine powder, which relate directly to the ultra-fine powder performance and prospect in industry. There were many ways to surface modification of Ultra-fine powder up to now. But in application, the surface of ultra-fine powder was usually modified by physical adsorption or esterification for diversified conditions limit. Although many people have done in this subject, few influencing factors which study on surface modification completely and regularly, and the characterization of the surface modified ultra-fine is imperfect.The properties and applications of ultra-fine indium tin oxide and tin oxide have been presented in this thesis. Based on colloidal dispersion stabilization theory, the mechanism of stabilization of ultra-fine indium tin oxide dispersed in a liquid ethanol system is investigated. The purpose of the research is to provide theoretical guide and operation conditions for stabilized ultra-fine indium tin oxide dispersed in a liquid ethanol system in practical applications. The surface of the indium tin oxide powder was modified by several surfactants and the performances of the powder were tested. The preparation of heat insulation material made from the powder was studied.The dispersion behaviors of ultra-fine indium tin oxide in a liquid ethanol system were studied in this paper. The influence of pH value variety and content of dispersants and different dispersing methods on dispersion stability results were discussed, The dispersion stability and diameter of indium tin oxide were tested. The experimental results indicated that the equipotential point determined in liquid ethanol is pH=6. The dispersion stability improves when the pH value are higher or lower than that. The most effective dispersant in the dispersion system is KH570 and its optimum consumption is 1% of the weight of ultra-fine particles. The influences of high-speed dispersing method and ultrasonic dispersing method on the dispersion stability were discussed. High-speed dispersing way needs lots of time and the ultrasonic dispersing way can reach better effect in a short time. The ultra-fine powder whose average diameter is 0.85μm was made under the optimization conditions and its size distributing is narrow.The surface of ultra-fine tin oxide was respectively modified by coupling method with silane coupling agent KH570 and esterification reaction with stearic acid in this thesis. The technologic conditions of surface modification of ultra-fine tin oxide and the preparation of the heat insulation material made from the powder were discussed. The influences factors on heat insulation were studied. The results showed that the surface of the ultra-fine powder modified by KH570 or stearic acid was covered with surfactants and the chemical bond occurred between them. The powder which is lipophilicity was obtained. The effect of the surface modification was better modified by stearic acid than KH570. The hydrophobic value of the ultra-fine powder modified by KH570 was 0.37 under the following conditions: the dosage of modifier reagent is 2%,the modification temperature is 50℃, the time is 30min; The hydrophobic value of the ultra-fine powder modified by stearic acid was 0.56 under the following conditions: the dosage of modifier reagent is 10%, the concentration of the stearic acid is 2.67g/L, the modification temperature is 60℃, the time is one hour. The dispersion of the modified ultra-fine powder in the organic solvent was improved and the surface of the ultra-fine powder was changed from hydrophilicity to lipophilicity. The test results show the production has good obvious performance of heat insulation effect, which has a difference in temperature about 10℃between the heat insulating and ordinary glass under infrared radiation. From the experiment the optimization conditions was discovered: the mass ratio of acrylate resin and the powder is 200/3 and the glasses were sprinkled for four times. Although the production has good obvious performance of heat insulation, there is a bigger difference between the standard and heat insulating glass, So further studies on this should be made. The heat insulating glass has better diaphaneity than the standard glass. The study on the heat insulation production has great significance because of its better transparency.更多还原