抄録
Supercritical fluids have attracted much interest as promising solvent of a new type. The characteristic properties of supercritical fluids as solvents are said to be mainly due to the ability of clustering. Several studies on clustering of supercritical fluids by neutron and X-ray diffraction methods are presented. The paging of molecules in the clusters are determined by wide-angle diffraction experiments. The studies on water and carbon dioxide are presented. The infonnation on the cluster size and inhomogeneity are obtained by small-angle diffraction experiments. The density fluctuation and the correlation length are the measures of inhomogeneity of the systems and cluster size, respectively. The temperature and pressure dependence of these parameters is shown for supercritical carbon dioxide.
