超飽和CaCO3溶液における液体-液体分離の顕微鏡の証拠

Adam F Wallace¹, Lester O Hedges, Alejandro Fernandez-Martinez

¹Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. afw@udel.edu

Science (New York, N.Y.)

|August 24, 2013

まとめ

安定したカルシウム炭酸 (CaCO3) クラスターは,液体-液体分離によって密度の高い液体相を形成し,古典的な核化理論と矛盾する. これは,観測されたCaCO3鉱化現象を説明する.

科学分野:

地質化学地質化学
材料科学材料科学とは
化学物理化学物理

背景:

古典的な核化理論は,CaCO3鉱化中に不安定なクラスターを予測しています.
実験的観測は,代わりに安定したCaCO3クラスターが出現することを示唆しています.
不一致は,初期段階の鉱化のための新しいモデルを必要とします.

研究の目的:

水分化されたCaCO3クラスターの構造,動力学,エネルギー学を研究する.
格子ガスのシミュレーションを使用して,核形成前のクラスター集団の行動を調査します.
実験的観測とCaCO3形成の理論的予測を調和させる.

主な方法:

水分化されたCaCO3クラスターの分子動力学シミュレーション.
核形成前のクラスターダイナミクスのための格子ガスシミュレーション.
クラスター構造,動力学,エネルギー学的分析.

主要な成果:

液体-液体分離による密度の高い液体相の形成が予測されています.
特定の濃度範囲内の安定した,水素化されたCaCO3クラスターが観察されました.
ナノスケール滴の凝結と固化により,無形なCaCO3.3が生まれます.
液体-液体バイノダルの識別,相分離メカニズムをサポートする.

結論:

この研究は,CaCO3鉱化のための相分離機構を支持しています.
安定した液体のようなCaCO3クラスターは,無形固体形成に先行する.
発見は,実験データと確立された物理化学の原理を調和させる.

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