摘要
气凝胶是一种新型的纳米多孔材料 ,其独特的性质与微观结构密切相关 ,本文结合气凝胶的制备过程阐述了气凝胶结构控制原理和方法。溶胶 -凝胶过程是气凝胶结构形成的过程 ,催化剂浓度是主要的影响因素 ,对于硅气凝胶而言 ,催化剂浓度通过影响水解和缩聚的相对速率而影响凝胶结构 ,而对于酚醛气凝胶而言 ,催化剂浓度的影响体现在由交联诱发并控制的微相分离上。在凝胶干燥过程中 ,由于干燥应力的产生常使凝胶织构遭到破坏 ,本文对凝胶干燥过程中的应力进行了分析 ,并比较了几种维持凝胶织构的干燥方法。
Aerogels are nanoporous materials whose properties are closely associated with the micro-structure.The principles and methods to tailor the structure of aerogels have been reviewed combined with the preparation proccess of aerogels.The micro-structure of aerogels primarily origins from the sol-gel proccess which is strongly effected by the catalyst concentration.These effects have been discussed according to kinetics and thermaldynamics.The textural structure of aerogels is apt to be damaged by the drying stress.In this paper,the stress has been analysed.The safe drying methods to preserving the textural structure of aergels have been discussed.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2000年第1期26-28,共3页
Journal of Functional Materials
基金
国家自然科学基金资助项目! (59672 0 2 6)
关键词
气凝胶
结构控制
溶胶-凝胶
超临界干燥
aerogels
control of structure
sol-gel process
supercritical drying
