Theoretical studies on controlling the crystallization of clathrate materials and on designing the novel crystal/quasicrystal structures

2014 Fiscal Year Final Research Report

• Project/Area Number: 24550025
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Physical chemistry
• Research Institution: Okayama University
• Principal Investigator: MATSUMOTO Masakazu 岡山大学, 自然科学研究科, 准教授 (10283459)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 理論化学 / 物理化学 / 分子動力学シミュレーション / 統計力学理論 / クラスレート化合物 / 相転移と臨界現象 / 核生成・結晶成長 / 準安定相

Outline of Final Research Achievements

We investigated the intermediate stages toward the phase transition between liquid and solid phases of water. It is found that the melting and crystallization is not that simple, but many intermediate states and structures intervene the initial and final states. For example, in the process that ice melts when it is heated homogeneously, separation of pair defects play the crucial role. Methane bubbles in the dissociation process of methane hydrate, unknown metastable ice phase in the freezing process of ice VII, plastic ice and tricritical phenomena in the melting process of ice VII, are other examples of the newly discovered events in the phase transition processes. We also expand the theory of evaluating the stability of clathrate hydrates more precisely, and also propose a concept of generalized phase diagram to understand the polymorphism of clathrate hydrates.

Free Research Field

理論化学