Japan Geoscience Union Meeting 2015

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Poster

Symbol M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS31] Interface- and nano-phenomena on crystal growth and dissolution

Wed. May 27, 2015 6:15 PM - 7:30 PM Convention Hall (2F)

Convener:*Yuki Kimura(Institute of Low Temperature Science, Hokkaido University), Hitoshi Miura(Graduate School of Natural Sciences, Department of Information and Biological Sciences, Nagoya City University), Katsuo Tsukamoto(Graduate School of Science, Tohoku University), Hisao Satoh(Naka Energy Research Laboratory, Mitsubishi Materials Corporation)

6:15 PM - 7:30 PM

[MIS31-P01] Specific Surface Free Energy of Celestine

*Kie NAKAGURO1, Takaomi SUZUKI1 (1.Facluty of engineering, Shinshu University)

Keywords:celestine, surface free energy

The morphology of crystal is determined by the stability of each crystal face. Especially, Wulffs relationship is well known: growth length of the crystal face is proportional to the specific surface free energy (SSFE) of the crystal face. Though SSFE is theoretically discussed, experimental determination of SSFE is very few. We calculated the SSFE of some single crystals using contact angle of liquid droplets. We observed some sulfates such as, gypsum, anhydrite, and barite. This time we observed celestine (SrSO4), and determined the SSFE of natural and polished face in order to discuss stability of each face. Though natural celestine crystal do not have (001) face, the natural celestine crystal was cut and polished in order to produce (001) face. SSFE of (210) and (001) faces were 25.3 and 51.2 mN/m. SSFE of (210) face was much smaller than that of (001) face, indicating that (210) face is more stable than (001) face. Dispersion component which causes van der Waals force and polar component which causes permanent dipole moment interaction of SSFE were obtained separately. Dispersion and poplar component for SSFE of (001) face was 47.9 and 3.3 mN/m, respectively. On the other hand, they were 13.0 and 12.3 mN/m for the SSFE of (210) face. (001) face of celestine is considered to be neutral face and the dispersion component for the interaction between liquid and solid is dominant. Though contact angle of liquid is macroscopic value, we can discuss microscopic, as atomic scale structure of crystal face.