-
摘要：由于Si02气凝胶是一种具有低的密度、高的比表面和高的孔隙率品质的纳米多孔材料，使它在保温隔热领域等方面有着广阔的应用前景。
- 上一篇：绞股蓝总皂苷的提取制备+文献综述
- 下一篇：Au/C催化剂的制备表征及其性能研究
本文通过对Si02气凝胶的制备工艺研究现状与发展进行详细综述，考虑到通过传统制备Si02气凝胶的超临界干燥工艺方法存在着工艺较复杂、设备比较昂贵、产率低、存在安全隐患而且难以实现产业化生产等得缺点，所以，本文以正硅酸乙酯(TEOS)为前驱体，并通过溶胶-凝胶过程、老化处理、表面改性及溶剂置换等工艺的优化，采用常压干燥法制备出了成块性比较好的Si02气凝胶。同时，也探讨了硅相对含量对气凝胶成块性和物理性能方面的影响，并运用了X射线衍射(XRD)、扫描电镜(SEM)、傅里叶红外光谱(FT-IR)、热重（TG）等多种测试手段，对实验所得的Si02气凝胶进行物相分析、微观形貌、表面化学基团等方面的表征。24355
实验结果表明：2号所得的气凝胶性能最佳，所对应原料的质量比TEOS／无水乙醇/去离子水=11:34:3。
此外,还备了掺杂玻璃纤文的二氧化硅气凝胶,并对它的结构和耐热性也进行了研究。结果表明,添加一定量的玻璃纤文后产品的耐热性会提高，性能也更加优异。
毕业论文关键词： SiO2气凝胶；溶胶-凝胶；保温隔热
Preparation and the performance study of SiO₂
aerogels
Abstract:Silica aerogel has a widely application prospects in thermology carriers,owning to its advantages of the low density，high surface area and high porosity．
The research smms and developments of silica aerogels prepared by ambient pressure drying were summarized in detail in this thesis.Considering the disadvantages of supercritical drying method such as complex technology,expensive equipments，low yield，high safety risks and difficult to achieve the industrial production in traditional preparation of silica aerogels hydrophobic silica aerogels with large block size were prepared using TEOS as silicon source by the optimization of preparation technologies of sol-gel method，ageing process，surface modification and solvent exchange with ambient pressure drying in this thesis．The influences of block size and physical properties of silica aerogels with the content of Si were discussed mainly.The silica aerogels were characterized by X.raydiffraction (XRD)，scanning electron microscopy(SEM)，fourier infrared spectroscopy(FT-IR)and Thermogravimetric Analysis (TG) to study the phase analysis，microstructure，surface chemical groups and so on.
The results indicate that the optimum molar ratio is determined by analysis that TEOS：C2H5OH：H20=11:34:3.
Moreover，silica aerogels doped with glass fiber were also prepared，and the effects of doping amount on structure and heat-proof quality of product were also investigated．Results showed that the heat-proof quality of products increasing with the addition of a certain amount of glass fiber.And the quality of product is more excellent.
Keywords: SiO2 aerogel；sol-gel；thermology
目录
1 引言 1
1.1 课题背景 1
1.2 课题研究目的与意义 1
2 文献综述 3
2.1 气凝胶的诞生和发展历史 3
2.2 纤文增强二氧化硅复合气凝胶和SiO2 气凝胶概述 4
2.2.1 纤文增强二氧化硅复合气凝胶 4
2.2.2 SiO2气凝胶概述 5
2.2.3 SiO2气凝胶的热学性质及其在隔热领域中的应用 7
2.3 气凝胶的制备 8
2.4 气凝胶的表征手段 12
2.5 SiO2气凝胶的研究动向和存在问题 13
2.6 研究内容 13
3 二氧化硅气凝胶的原料及制备工艺选择 14