日本地球惑星科学連合2015年大会

講演情報

口頭発表

セッション記号 M (領域外・複数領域) » M-IS ジョイント

[M-IS31] 結晶の成長と溶解における界面・ナノ現象

2015年5月27日(水) 11:00 〜 12:45 102A (1F)

コンビーナ:*木村 勇気(北海道大学低温科学研究所)、三浦 均(名古屋市立大学大学院システム自然科学研究科)、塚本 勝男(東北大学大学院理学研究科地学専攻)、佐藤 久夫(三菱マテリアル株式会社エネルギー事業センター那珂エネルギー開発研究所)、座長:木村 勇気(北海道大学低温科学研究所)

12:30 〜 12:33

[MIS31-P01] 天青石の表面自由エネルギー密度

ポスター講演3分口頭発表枠

*中畔 希恵1鈴木 孝臣1 (1.信州大学工学部)

キーワード:天青石, 表面自由エネルギー

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.