Theory of Surface Phase Transitions and Inhomogeneous Fluids

2014 Fiscal Year Final Research Report

• Project/Area Number: 23340122
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Biophysics/Chemical physics
• Research Institution: Okayama University
• Principal Investigator: KOGA Kenichiro 岡山大学, 自然科学研究科, 教授 (10315020)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: 界面 / 溶液 / 液体 / 不均一流体 / 濡れ転移 / 統計力学 / 分子シミュレーション

Outline of Final Research Achievements

Various kinds of wetting phenomena are commonly observed. The origin of the variety, however, has long been unknown. Here we built an analytically solvable model of wetting transitions, solved it, and found the conditions under which the model gives the first-order, second-order, continuously varying order, and infinite-order wetting transitions. We also studied the effect of thermal fluctuations on wetting transitions.
We proposed the method for calculating the second osmotic virial coefficient B of hydrophobic molecules in water. For an aqueous solution of methane, we found that B is positive at low temperatures, decreases with increasing temperature, and becomes very negative at high temperatures. This indicates that the hydrophobic molecules in water, overall, repel each other at low temperature and they attract each other at high temperature. We also studied how far the hydrophobic effect persists as a hydrophobic solute approaches the liquid-vapor interface of water.

Free Research Field

化学物理