閉じ込められた水における高密度の液体と低密度の無形相の間の第一級の移行

K Koga¹, H Tanaka, X C Zeng

¹Department of Chemistry, Fukuoka University of Education, Japan. kenkoga@fukuoka-edu.ac.jp

Nature

|December 16, 2000

まとめ

水嫌の毛穴に閉じ込められた水は,冷却時に二重層の無形段階に移行する. この新しい液体からビライアールへの無形な移行は,大量の水の凍結温度を超えて発生します.

科学分野:

物理化学物理化学について
マテリアルサイエンス材料科学
計算物理学の物理

背景:

超冷凍水と無形氷は,複雑なメタステーブル相行動を示す.
以前の研究で,高/低密度の無形固体と液体の間の移行と,閉じ込められた水における脆弱から強い液体への移行が特定されました.

研究の目的:

水性割れ孔に閉じ込められた水における新しい相変遷を調査する.
大量の水の凍結点より上の液体からバイレアへの無形な移行を特定し,特徴づけること.

主な方法:

水の振る舞いを研究するために,分子動力学シミュレーションが採用されました.
焦点は,ナノメートル未満の幅の水嫌性割れ孔に閉じ込められた水に焦点を当てました.

主要な成果:

閉じ込められた水の中で,第1次流体からバイレアへの無形な移行が観察されました.
この移行は,大量水の凍結温度を超えて,特に広さ1nm未満の水害性スリットの毛穴で起こります.
冷却により,閉じ込められた水は,不完全な水素結合ネットワークから,完全な多角形の水素結合ネットワークを持つ二重層の無形相へと変化しますが,長距離の秩序はありません.

結論:

閉じ込められた水には,新しいタイプの相変化,液体からバイレアアモルフォスが存在します.
この移行は,毛孔の水性および閉じ込め幅に依存しています.
観測された移行は,シリコン,炭素,リンなどの他の四面体協調物質の相移行と類似点を共有しています.

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