ULTRASTRUCTURAL ASPECTS OF SONOGELS

被引:10
作者
BARRERASOLANO, MC
DELAROSAFOX, N
ESQUIVIAS, L
机构
[1] Department of Structure and Properties of Materials, University of Cádiz, Puerto Real, 11510 Cádiz
关键词
D O I
10.1016/S0022-3093(05)80617-9
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
The ultrastructure of silica sonogel is discussed from data obtained by wide angle X-ray scattering (WAXS) and magic angle spinning nuclear magnetic resonance (MAS-NMR). WAXS data are very useful for measuring the skeletal density at the scale of angstroms since the Fourier transform of the interference function of the scattered radiation implicitly involves this parameter. This is evaluated maximizing the entropy of the system to obtain an atomic radial distribution function compatible with the experimental data and, in particular, with the solid backbone density which, in the case of silica, is 2.09 g/cm3. The results indicate that aerogels from sonogels are formed by very uniform aggregates exhibiting two levels in a hierarchical structure of near spherical-shaped particles.
引用
收藏
页码:194 / 200
页数:7
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