The microscopic structure of supercritical water-CO2 mixture is investigated by neutron diffraction experiments exploiting the isotopic H/D substitution. The investigated water reach mixtures are in the liquidlike region of the phase diagram, according to the behavior of the radial distribution functions, yet a reduction of the average number of hydrogen bonds, compared to equivalent states of pure water, is found. As a consequence, the average dimension of water clusters is reduced and the system stays below the percolation threshold. These results, along with the shift of the main peaks of the site-site radial distribution functions, suggest that the excess volume in these supercritical mixtures is likely associated with the CO2 solvation shell.
A., B., Bruni, F., R., M., Ricci, M.A., F., L.C., R., T., et al. (2008). Study of percolation and clustering in supercritical water-CO2 mixtures. THE JOURNAL OF CHEMICAL PHYSICS, 128, 164504 [10.1063/1.2898538].
Study of percolation and clustering in supercritical water-CO2 mixtures
BRUNI, Fabio;RICCI, Maria Antonietta;
2008-01-01
Abstract
The microscopic structure of supercritical water-CO2 mixture is investigated by neutron diffraction experiments exploiting the isotopic H/D substitution. The investigated water reach mixtures are in the liquidlike region of the phase diagram, according to the behavior of the radial distribution functions, yet a reduction of the average number of hydrogen bonds, compared to equivalent states of pure water, is found. As a consequence, the average dimension of water clusters is reduced and the system stays below the percolation threshold. These results, along with the shift of the main peaks of the site-site radial distribution functions, suggest that the excess volume in these supercritical mixtures is likely associated with the CO2 solvation shell.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.