弹性气凝胶的制备及其力学、热学性能研究  

Preparation,Mechanical Properties and Thermal Properties of Elastic Aerogels

作　　者：祖国庆[1] 沈军[1] 邹丽萍[1] 王文琴[1] 连娅 张志华[1] 

机构地区：[1]同济大学波耳固体物理研究所,上海市人工微结构材料与技术重点实验室,上海200092

出　　处：《无机材料学报》2014年第4期417-422,共6页Journal of Inorganic Materials

基　　金：国家科技支撑计划(2013BAJ01B01);国家自然科学基金(11074189);国家自然科学联合基金(U1230113);上海市科委纳米专项(11nm0501600;11nm0501300)~~

摘　　要：以甲基三甲氧基硅烷(MTMS)为硅源、水为溶剂、醋酸和氨水作为酸碱催化剂,采用酸碱两步法和酒精超临界干燥制备了透明块体气凝胶。用扫描电镜、比表面积与孔径分析仪、动态力学分析仪和hotdisk热分析仪等表征了气凝胶的微观形貌、孔结构、力学、热学等性能。制备的气凝胶具有很好的弹性性能,压缩60%后可回复到原长的78%,经热处理后反弹到原长的94%。气凝胶同时具有较好的保温隔热性能,常温热导率仅为0.028 W/(m?K)。其接触角达154°,表现出较好的疏水性能。气凝胶的耐热温度为440℃,高于此温度将导致甲基氧化分解。气凝胶优良的保温隔热性能和力学性能使其在保温隔热领域中具有广泛的应用前景。Transparent and monolithic aerogels were prepared via acid-base two step Sol-Gel process with Methyltrimethoxysilane （MTMS）, water, acetic acid and ammonia as precursor, solvent, acid and base accelerators, respectively, followed by drying under a supercritical condition using alcohol as drying medium. Scan electron microscope, N2 adsorption analyzer, dynamic mechanical analyzer, hotdisk thermal analyzer were used to characterize the morphology, pore structure, mechanical properties and thermal properties of the aerogels. The obtained aerogels showed good elastic properties. They could shrink up to 60% in linear scale and rebound to 78% of their original size when unloaded, and finally spring back to 94% of their original size after heat treatment at about 100℃. The aerogels also had good thermal insulation properties. The thermal conductivity was about 0.028 W/（m.K） at room temperature. The contact angle was up to 154°, showing good hydrophobicity. The heat-resistance temperature of the aerogels was about 440℃, above which would result in oxidation of methyl groups in the aerogels. The aerogels have good mechanical and thermal insulation properties, showing prospect in the application of thermal insulation.

关 键 词：气凝胶 甲基三甲氧基硅烷 弹性 低热导率 

分 类 号：O648[理学—物理化学]