Critical Surface Tension and Specific Surface Free Energy of Clathrate Hydrate

The specific surface free energy (gamma(sv)) of a solid is the work required to create a unit area of a solid in a vacuum. gamma(sv) is a fundamental physical quantity that plays a central role in cohesion, adhesion, and premelting of a solid and other phenomena like the nucleation work of a solid phase. However, due to experimental difficulties, no specific surface free energy values have been reported for clathrate hydrates. Here we applied the Zisman plot to the determination of the critical surface tension, gamma(c), of ice and tetrahydrofuran (THF) hydrate. The gamma(c) value of ice was found to be very similar to the value reported by Adamson et al. (J. Colloid Interface Sci. 1970, 34, 461-468) for the same homologous series. Then we used the measured gamma(c) value of THF hydrate and the.sv values of ice reported in the literature to deduce the gamma(sv) value of THF hydrate. The deduced gamma(sv) value of THF hydrate was somewhat lower than that of ice and in the range from 60.4 to 124.2 mJ/m(2), with an average of 92.3 mJ/m(2).

Automated summary

The specific surface free energy of a solid is a fundamental physical quantity that affects cohesion, adhesion, and other phenomena. Experimental difficulties have led to a lack of specific surface free energy values for clathrate hydrates, but techniques like the Zisman plot can be used to determine these values for different materials. In this study, the specific surface free energy of THF hydrate was found to be somewhat lower than that of ice.