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醇水比对氧化锆气凝胶性能的影响

时间:2019-09-19 20:59来源:毕业论文
由XRD衍射仪、SEM电子显微镜、热重分析对气凝胶进行表征,测试结果表明使用四氯化锆(ZrCl4)无机盐、醇-水体积比3:1、干燥温度控制在60℃等工艺条件下能够实现ZrO2气凝胶常压干燥的

二氧化锆(ZrO2)气凝胶有望兼具ZrO2优异热学稳定性、化学稳定性及催化性能和气凝胶高比表面积、高空隙率特性,拥有诱人的潜在性质和应用前景,可用作催化剂载体、超级隔热材料等。传统制备ZrO2气凝胶方法都是采用超临界干燥,而且大多以锆的金属醇盐为前驱体,成本高,安全性差。发展价格便宜的无机盐前驱体以及常压干燥技术己成为ZrO2气凝胶材料研究及应用的重要方向。本文在综合论述气凝胶及ZrO2气凝胶的基础上,分别以以硝酸氧锆ZrO(NO3)2•3H2O、氧氯化锆(ZrOCl2•8H2O)和四氯化锆(ZrCl4)三种无机锆盐为前驱体进行ZrO2气凝胶的常压干燥制备,其中选择气凝胶特性较好的四氯化锆前驱体,深入研究了四氯化锆前驱体体系中环氧丙烷量、醇-水比、锆盐浓度、干燥温度等各工艺要素对ZrO2气凝胶结构与性能的影响。由XRD衍射仪、SEM电子显微镜、热重分析对气凝胶进行表征,测试结果表明使用四氯化锆(ZrCl4)无机盐、醇-水体积比3:1、干燥温度控制在60℃等工艺条件下能够实现ZrO2气凝胶常压干燥的目的。39294
毕业论文关键词:气凝胶  氧化锆  常压干燥  溶胶-凝胶法 
  Abstract Combining catalytic activity, good thermal and chemical stabilities of zirconia (ZrO2)with high surface area and high porosity of aerogels, zirconia aerogels have various potential applications such as catalyst supporting materials, super heat insulation materials.However, the traditional drying method to prepare ZrO2 aerogels is supercritical drying with zirconium alkoxide as precursor, which is expensive and dangerous.It is necessary to develop ZrO2 aerogels by using inorganic salt as precursor and ambient pressure drying.In this paper, zirconyl nitrate(ZrO(NO3)2•3H2O), zirconyl chloride octahydrate (ZrOCl2•8H2O)and zirconium (Iv) chloride(ZrCl4)were used as inorganic salt precursor to synthesize ZrO2 aerogels through ambient pressure drying.Select airgel characteristics of a good precursor of zirconium tetrachloride, zirconium tetrachloride-depth study of the precursor system in the amount of propylene oxide, alcohol - water ratio of various process elements, zirconium salt concentration, drying temperature on ZrO2 aerogels effect of structure and properties of rubber. By the XRD diffraction, SEM electron microscopy, TGA aerogels were characterized test results show that the use of zirconium tetrachloride (ZrCl4) inorganic salt, alcohol - water volume ratio of 3: 1, and dried at 60 ℃ temperature control and other process ZrO2 airgel can be achieved under the conditions of atmospheric drying purposes. 源¥自%六:维;论-文'网=www.lwfree.cn
Key Words:Aerogel;Zirconia;Ambient pressure drying;Sol-gel
 目  录    4
1 绪论    1
1.1  气凝胶材料    1
1.2  ZrO2材料    2
1.3  ZrO2气凝胶材料    3
1.4  ZrO2气凝胶制备方法简介    3
1.4.1  沉淀法    3
1.4.2  锆醇盐水解法    4
1.4.3  醇-水加热法    4
1.4.4  滴加环氧丙烷法    4
1.5  溶胶-凝胶法    4
1.6  超临界干燥与常压干燥    6
1.6.1  超临界干燥    6
1.6.2  常压干燥    6
1.7  选题的目的和研究内容    7
1.7.1  选题背景    7
1.7.2  研究内容    8
2 实验部分    9
2.1  实验原料及实验仪器和设备    9
2.1.1  实验原料    9
2.1.2  实验仪器及设备    9
2.2  主要仪器设备简介    10
2.2.1  XRD衍射仪    10 醇水比对氧化锆气凝胶性能的影响:http://www.lwfree.cn/cailiao/20190919/39583.html
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