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ID 53634
フルテキストURL
著者
望月 建爾 岡山大学大学院自然科学研究科
甲賀 研一郎 岡山大学大学院自然科学研究科
抄録
Nanoconfined liquid water can transform into low-dimensional ices whose crystalline structures are dissimilar to any bulk ices and whose melting point may significantly rise with reducing the pore size, as revealed by computer simulation and confirmed by experiment. One of the intriguing, and as yet unresolved, questions concerns the observation that the liquid water may transform into a low-dimensional ice either via a first-order phase change or without any discontinuity in thermodynamic and dynamic properties, which suggests the existence of solid−liquid critical points in this class of nanoconfined systems. Here we explore the phase behavior of a model of water in carbon nanotubes in the temperature−pressure−diameter space by molecular dynamics simulation and provide unambiguous evidence to support solid−liquid critical phenomena of nanoconfined water. Solid−liquid first-order phase boundaries are determined by tracing spontaneous phase separation at various temperatures. All of the boundaries eventually cease to exist at the critical points and there appear loci of response function maxima, or the Widom lines, extending to the supercritical region. The finite-size scaling analysis of the density distribution supports the presence of both first-order and continuous phase changes between solid and liquid. At around the Widom line, there are microscopic domains of two phases, and continuous solid−liquid phase changes occur in such a way that the domains of one phase grow and those of the other evanesce as the thermodynamic state departs from the Widom line.
キーワード
water
solid−liquid critical point
carbon nanotube
ice
Widom line
備考
The final publication is available at PNAS via http://www.pnas.org/content/112/27/8221
発行日
2015-07-07
出版物タイトル
Proceedings of the National Academy of Sciences of the United States of America
112巻
27号
出版者
National Academy of Sciences.
開始ページ
8221
終了ページ
8226
ISSN
0027-8424
NCID
AA10808769
資料タイプ
学術雑誌論文
オフィシャル URL
http://www.pnas.org/
言語
English
著作権者
Copyright© 2015 Kenji Mochizuki and Kenichiro Koga; licensee National Academy of Sciences.
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