DEFORMATION OF AEROGELS DURING CHARACTERIZATION

被引：133

作者：

SCHERER, GW ^{[1
]}

SMITH, DM ^{[1
]}

STEIN, D ^{[1
]}

机构：

[1] UNIV NEW MEXICO,CTR MICROENGINEERED CERAM,ALBUQUERQUE,NM 87131

来源：

JOURNAL OF NON-CRYSTALLINE SOLIDS | 1995年 / 186卷

关键词：

D O I：

10.1016/0022-3093(95)00058-5

中图分类号：

TQ174 [陶瓷工业]; TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

Aerogels have such low moduli that they can exhibit large strains under very small loads, and this leads to errors in measurements of porosity and pore size. The use of porosimetry, thermoporometry and nitrogen sorption on aerogels is examined and it is shown that all of these techniques underestimate the pore volume and pore size of typical aerogels. Even at the highest pressures there may be no intrusion of mercury at all, so porosimetry serves only to measure the bulk modulus of the aerogel network, not its pore size distribution; an analysis of the conditions for intrusion as a function of modulus and pore size of the gel is presented. Direct experimental observation of a silica aerogel indicates that its volume shrinks by similar or equal to 50% as liquid nitrogen condenses in its pores. Consequently, it is likely that the quantity of macropores in aerogels has been seriously overestimated in the past.

引用

页码：309 / 315

页数：7

共 18 条

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