摘要
以仲丁醇铝为前驱体,盐酸为催化剂,采用溶胶-凝胶法再经过超临界修饰和干燥,制备出块体Al_2O_3气凝胶。将莫来石纤维跟Al_2O_3溶胶混合,用同样的方法制备出纤维复合Al_2O_3气凝胶。用场发射扫描电子显微镜(FESEM)、热分析仪、孔径分布仪和X线衍射仪(XRD)表征Al_2O_3气凝胶及复合样品的结构和热学性能。结果表明:经过超临界修饰的Al_2O_3气凝胶具有更高的结晶度和耐温性能,并通过与莫来石纤维复合,其力学强度得到了有效的提高。
monolithic alumina aerogels were prepared by a sol-gel method combined with the ethanol supercritical drying and modification technique using alumina tri-sec butoxide and hydrochloric acid as the precursor and the catalyst respectively. Fiber composite alumina aerogels were prepared with the same method. The micro-structure and thermal properties of the alumina-based aerogels were characterized by field emission scanning electron microscope（ FESEM）,thermal analyzer,pore size distribution analyzer,and X-ray diffraction（ XRD）. Results showed that the alumina aerogels prepared by the supercritical modification had higher crystallinity and thermal stability,thus their mechanical strength was effectively improved by compositing with fiber.
出处
《南京工业大学学报（自然科学版）》
CAS
北大核心
2016年第2期15-19,共5页
Journal of Nanjing Tech University(Natural Science Edition)
基金
国家科技支撑计划(2013BAJ01B01)
国家自然科学基金(51172163)
关键词
超临界修饰
Al2O3气凝胶
耐高温
纤维复合
supercritical modification
alumina aerogels
thermal stability
fiber composition
