摘要
为了研究纳米碳纤维掺杂对SiO2气凝胶力学性能和导热性能的影响,以工业水玻璃为前驱体,采用原位法在常压干燥下合成了纳米碳纤维掺杂的SiO2气凝胶材料(CNF-SAs).纳米碳纤维掺入量分别为硅溶胶质量的0%、0.2%、0.5%、0.8%,主要研究了纳米碳纤维掺杂对硅气凝胶力学性能和导热性能的影响.试验结果表明:CNFs的掺入,提高了气凝胶内部SiO2网格的强度,增大了气凝胶的韧性.600℃时,CNFs复合气凝胶的导热系数约为0.04 W/(mK),明显低于纯气凝胶0.09W/(mK),说明CNFs起到了明显的红外遮光作用.制备得到的气凝胶呈海绵状微孔结构,CNFs浓度对复合气凝胶的性能有重要影响,当CNFs掺入量为0.5%时,复合气凝胶的综合物理性能较好,且密度达到最低0.143g/cm3.
Carbon ambient pressure nanofibers doped silica aerogels （CNF-SAs） were synthesized by the in-situ method under the drying, using a waterglass as a precursor. The content of incorporated carbon nanofibers varied from 0%, O. 2%, 0.5%, 0.8%, by mass of silica sol. The CNF-SAs were examined. Experimental results show that CNFs mechanical and infrared optical properties of the can enhance the compression strength and elastic modulus of aerogels, which indicates that the mechanical robustness of aerogels was improved by incorporating CNFs. The CNF-SAs could achieve an ultralow thermal conductivity of 0.04W/（mK） at 600~C, much better than the pristine aerogels （0.09W/ （mK） at 600℃ ）, illustrating that CNFs can act as infrared inhibitor in the aero- gels. The aerogels exhibit sponge morphology and the concentration of CNFs plays a significant role in the properties of aerogels. When incorporated with 0.5% CNFs, the composites achieve the best overall properties with the lowest density of O. 143g/cm3.
出处
《哈尔滨工程大学学报》
EI
CAS
CSCD
北大核心
2013年第5期604-608,共5页
Journal of Harbin Engineering University
基金
中央高校基本科研业务费专项基金资助项目(DUT11NY11)
大连市科技计划基金资助项目(2012A13GX024)
关键词
纳米碳纤维
SIO2气凝胶
力学性能
导热性能
carbon nanofibers
silica aerogels
mechanical property
thermal conductivities
