Abstract
The strength of CO_2 hydrate membrane which forms at the interface between liquid CO_2 and CO_2 rich water at about 45MPa was measured by Du-Nouy type surface tension meter. As the result, the strength at the saturated condition shows about 10 times stronger than the case of fresh water. In addition, the membrane shows abnormal strength and stiffness compared with the un-saturated condition. The abnormality just below the dissociation temperatures, which had been found in fresh water, also appeared in this experiment. However, its peak decreases with CO_2 concentration rise. In this paper, the abnormality just below the dissociation temperatures was quantitatively estimated with the idea that the diffusion of H_2O molecules is derived by analogy with Gibbs-Free-Energy. In addition, the stiffness was qualitatively explained by taking into consideration the diffusion and the arrangement of CO_2 molecules in the membrane.
