小角X線散乱による超臨界流体のゆらぎ構造の研究

抄録

The present authors have investigated the density fluctuation for supercritical fluids by means of small-angle X-ray scattering, interested in the inhomogeneity of the distribution of molecules. For supercritical CO₂ and supercritical CF₃H, similar curves of density fluctuations were obtained independent of the substances, which shows that these variables may be universal ones to describe the state of supercritical region. To study whether or not the similarities hold true for other substances with different intermolecular interactions, experiments for supercritical water have been also tried. Supercritical water is in hard condition in regard to its porosity, in addition to the high temperature and high pressure. The design of the sample holder for supercritical water and the results of small-angle X-ray scattering measurements are presented in the present paper.