Characterization of Products Consisting of Synthetic, Amorphous Silica and Water with Different Moistures by Means of NMR

摘要

Mixtures of liquid and powder have usually totally different structures dependent on the moisture content. They vary from dry powders with small amounts of liquid to suspensions with a low solid concentration. For all moisture contents the binding mechanisms between the solid particles and the molecules of the liquid play an important role. In order to study these interactions, various products composed of synthetic, amorphous precipitated silica and water were produced using a special spraying technology with supercritical carbon dioxide. Thus, it is possible to produce disperse solid/fluid systems wiht high homogeneity. All samples were studied by means of nuclear magnetic resonance (NMR) which allows to distinguish between different types of water with regard to their mobility. The aim of this study is to develop a method for the characterization of solid/liquid systems in terms of their loading of the liquid.