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题名	SiO2气凝胶隔热复合材料的制备与表征
作者	姜小青
学位类别	硕士
答辩日期	2009-05-10
授予单位	中国科学院过程工程研究所
授予地点	过程工程研究所
导师	王丹
关键词	SiO2气凝胶 芳纶增强 PMMA交联 隔热
其他题名	Preparation and Characterization of SiO2 Aerogels
学位专业	化学工程
中文摘要	SiO2气凝胶具有热导率低、比表面积大、孔隙率高、密度小等特点，在热学、光学、电学、力学、声学等方面都表现出独特的性质。尤其作为一种轻质高效的隔热材料，与其它传统隔热材料相比具有显著的优越性，是目前密度最小、隔热性能最好的固态材料（室温下热导率为0.013 W/m•K）。在航空航天、化工、冶金及节能建筑等领域具有广泛的应用前景。 本文采用酸/碱两步法催化下的溶胶凝胶工艺及常压分级干燥工艺制备了纳米多孔SiO2气凝胶、芳纶纤维增强SiO2气凝胶复合材料及PMMA交联SiO2气凝胶复合材料。 探索了对凝胶时间有重要影响的因素：溶剂EtOH含量、酸-碱催化剂的含量和水的含量。溶剂EtOH用量越多，加入酸-碱催化剂越少，酸催化时水含量越少，凝胶时间越长。所得纳米多孔氧化硅气凝胶密度可低至0.09g/cm3，孔隙率为96%，热导率为0.020 W/m·K。 以芳纶纤维作为增强相，制备了密度在0.151-0.377 g/cm3 ，孔隙率在93.1-85％之间，热导率可低至0.021W/m·K，抗压强度可达1.1MPa的芳纶纤维增强SiO2气凝胶隔热复合材料。纤维的掺杂可有效地克服SiO2气凝胶的脆性，增强其韧性。研究了芳纶纤维掺入量与材料的各项性能之间的关系：随纤维掺入量的增加，复合材料的密度逐渐增大，比表面和孔隙率逐渐减小。而热导率由于受多因素共同影响，随纤维掺杂量的增加呈先增大后减小的趋势。 以PMMA作为增强相，制备了力学强度好、光学透明度高、具有良好的成型及可加工性能的PMMA交联SiO2气凝胶复合材料，其硬度及断裂韧性分别可达894MPa和1.25 MPa• m1/2。研究了PMMA含量对复合材料性能的影响：随PMMA含量的增加，复合材料的热导率、硬度及断裂韧性均随之增大。
英文摘要	Silica aerogel has many unique properties in thermotics, optics, electrics and acoustics fileds for its low heat conductivity, large specific surface area, high porosity and low density. Especially as a light heat insulation material, silica aerogel possesses absolute advantage comparing with other traditional heat insulations, because of its best properties in thermal insulation and the lowest density in all solid materials (the heat conductivity is 0.013 W/m•K at room tempreture). It could be applied in aerospace, chemical industry and energy saving buildings areas extensively. The nano porous silica aerogel, aramid fiber reinforced and PMMA bonded silica aerogel composites were prepared by acid/base two step sol-gel process, followed by ambient drying method. The influences of solvent content, acid-base content and H2O content were researched. The more solvent, less acid and base, less H2O content at the first step, gel time would be longer. The density of aerogel is low to 0.09g/cm3, the porosity is 96%, and thermal conductivity is 0.020 W/m·K. The high malleable silica aerogel composites were prepared, reinforced by aramid fiber. The density is 0.151-0.377 g/cm3, porosity is between 93.1-85％, the heat conductivity is low to 0.021W/m·K, and the compressive strength can reach 1.1MPa. The fiber can conquer or decrease the brittleness of silica aerogel, increase its toughness. The relationship between fiber contents and the properties of composite was studied. The results indicated that the density increased, whereas the special surface aera and porosity decresed as the fiber content increasing. Influenced by several aspects, the heat conductivity increased at first and then decreased. The PMMA bonded silica aerogel composites were prepared, which had good mechanical properties, high optical transparency, favorabel moldability and processability. The hardness and fracture toughness can reach 894Mpa and 1.25 Mpa• m1/2. The influences of PMMA contents on properties of composites were studied. The results showed that the heat conductivity, hardness and fracture toughness all increased as PMMA contents increasing.
语种	中文
公开日期	2013-09-16
页码	69
内容类型	学位论文
源URL	[http://ir.ipe.ac.cn/handle/122111/1273]
专题	过程工程研究所_研究所（批量导入）
推荐引用方式 GB/T 7714	姜小青. SiO2气凝胶隔热复合材料的制备与表征[D]. 过程工程研究所. 中国科学院过程工程研究所. 2009.

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