期刊
JOURNAL OF POROUS MATERIALS
卷 15, 期 6, 页码 705-713出版社
SPRINGER
DOI: 10.1007/s10934-007-9156-9
关键词
Silica aerogels; Supercritical drying; Porous texture; Shrinkage; Plackett-Burman
资金
- Ministerio de Ciencia y Tecnologia [BQU2002-04090-CO2-02, CTQ2005-08099-CO3-02-BQU]
- Universidad Publica de Navarra
Research on the preparation and characterization of silica aerogels has focused mainly on transparency and monolithicity. In this paper, we address the effect of supercritical drying conditions in ethanol on the shrinkage and porous texture of aerogels. The variables studied included the initial amount of ethanol added to the reactor, initial pressure of N(2), heating rate and stabilization time above supercritical conditions. The starting material was an alcogel obtained by the sol-gel process in acidic media. All aerogels were amorphous. In general, skeletal density increased when the initial amount of ethanol added into the body of the autoclave was decreased and the volume fraction of porosity was above 91%. According to infrared spectra, skeletal SiO(2) network was independent of supercritical drying conditions. N(2) adsorption isotherms identify the macroporous character of aerogels, which was confirmed by SEM and TEM. Specific surface area significantly increased when the initial volume of ethanol added to the reactor was increased and the stabilization time above supercritical conditions decreased, whereas surface area decreased when autoclave pre-pressurization was increased.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据