Experimental search for liquid-liquid critical point in hydrogen-bonding liquids

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K05475
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Mathematical physics/Fundamental condensed matter physics
• Research Institution: Hiroshima University
• Principal Investigator: KAJIHARA Yukio 広島大学, 総合科学研究科, 助教 (20402654)
• Research Collaborator: INUI Masanori ; Baron Alfred Q. R. ; YAMAGUCHI Toshio ; YOSHIDA Koji ; NISHIGORI Shijo
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 液体－液体相転移 / ゆらぎ / 非弾性X線散乱 / ガラス転移

Outline of Final Research Achievements

We have studied to aim at the search for liquid-liquid phase transition critical point (LLCP) for liquid methanol which is a same hydrogen-bonding liquid as water. We have developed a liquid container capable of x-ray measurement under low temperature down to 170K and high pressure up to 500 MPa and succeeded in inelastic x-ray scattering experiment with using synchroton radiation facilicy SPring-8. We will analyze the data and discuss the existence of LLCP in liquid methanol.
On the other hand, we have discussed the relationship between liquid-liquid phase transition and glass transition phenomena. As a result, it was possible to construct the framework that glass transition can be interpreted as a part of liquid-liquid phase transition phenomena. We made presentations of this framework at several conferences, and we are planning to publish papers near future.

Free Research Field

不規則系物理学

Academic Significance and Societal Importance of the Research Achievements

水の熱力学異常を包括的に説明するとされる液体－液体相転移臨界点（LLCP）仮説。1990年代に説が提唱されたものの、これまで水のLLCPは実験的には検証されておらず、仮説の域を出ていない。もし検証に成功すれば、仮説が大きく進展することになり、学術的意義は大きい。
一方でLLCP仮説は単に水の異常を説明するだけではなく、その他一般の液体の熱力学を解釈する基礎理論となり得るのではないかと我々は睨んでいる。今回実際にガラス転移現象への適用を試みた。現時点では推論にすぎないものの、これまでのガラス転移研究にはない新たな視点を与えることができたと考えている。