| 热处理对块状氧化铝气凝胶微观结构的影响 |
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| 引用本文： | 周洁洁,陈晓红,胡子君,孙陈诚,陈海坤,宋怀河.热处理对块状氧化铝气凝胶微观结构的影响[J].宇航材料工艺,2010,40(2). |
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| 作者姓名： | 周洁洁 陈晓红 胡子君 孙陈诚 陈海坤 宋怀河 |
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| 作者单位： | 1. 北京化工大学化工资源有效利用国家重点实验室,北京,100029
2. 航天材料及工艺研究所先进功能复合材料技术国防科技重点实验室,北京,100076 |
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| 基金项目： | 先进功能复合材料技术国防科技重点实验室基金资助 |
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| 摘 要： | 以AlCl_3·6H_2O为前驱体,无水乙醇和去离子水的混合溶液为溶剂,环氧丙烷为凝胶网络诱导荆,通过溶胶-凝胶技术制备得到溶胶,再经超临界干燥制备出块状氧化铝气凝胶.采用SEM、TEM、XRD、BET等手段,对氧化铝气凝胶在不同热处理温度下的微观结构进行了对比和分析.结果表明,氧化铝气凝胶的主要成分为多晶勃姆石相,微观结构由许多叶片状纤维堆积形成,经500和1 000℃热处理后成块性未受到明显的影响,比表面积各为429和174 m~2/g.在20～1000℃内,氧化铝气凝胶发生了由多晶态勃姆石相→γ-Al_2O_3→δ-Al_2O_3的相转变.
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| 关 键 词： | 块状 氧化铝气凝胶 比表面积 热处理 |
EffectofHeatTreatmentonMicrostructureof MonolithicAluminaAerogels |
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| Institution: | StateKeyLaboratoryofChemicalResourceEngineering,BeijingUniversityofChemicalTechnology,Beijing 100029;NationalKeyLaboratoryofAdvancedFunctionalCompositeMaterials,AerospaceResearch InstituteofMaterials& ProcessingTechnology,Beijing 100076 |
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| Abstract: | Alumina aerogels were prepared through addition of propylene oxide to aqueous or ethanolic solutions of hydrated aluminum salts AlCl_3·6H_2O, followed by drying with supercritical ethanol. Microstructure of alumina aerogels were contrasted and analyzed at different temperatur by means of transmission electron microscopy, powder X -ray diffraction and nitrogen adsorption/desorption analysis. The results show that the aerogel microstructures contain highly reticulated networks of boehmite fibers, no significant loss in monolithicity occurred during heat treatment of alumina aerogels at 500℃ and 1 000℃, the surface area is 429 m~2/g and 174 m~2/g. The phase conversion in the range from 20 to 1 000℃ are as follows: boehmite→γ-Al_2O_3→δ-Al_2O_3. |
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| Keywords: | Monolithic Alumina aerogel Surface area Heat treatmen |
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