Exploring the nature and origin of long-range attractive force between hydrophobic surfaces(Fostering Joint International Research)

2018 Fiscal Year Final Research Report

• Project/Area Number: 15KK0238
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research)
• Allocation Type: Multi-year Fund
• Research Field: Properties in chemical engineering process/Transfer operation/Unit operation
• Research Institution: Okayama University
• Principal Investigator: Ishida Naoyuki 岡山大学, 自然科学研究科, 准教授 (80344133)
• Project Period (FY): 2016 – 2018
• Keywords: hydrophobnic attraction / solvophobic force / origin of force / atomic force microscopy

Outline of Final Research Achievements

In this project, the specific long-range forces acting between solvent-repelling surfaces, namely hydrophobic attraction in aqueous solution and solvophobic force in non-aqueous solution, were investigated using atomic force microscopy to explore the origin of the forces. The hydrophobic attraction between asymmetric hydrophobic surfaces were measured, and dependency of the hydrophobic and solvophobic forces on the radius of curvature of the surfaces were investigated. From the characteristics of the forces analyzed with the molecular order, the possible origins of the forces that are caused by the surface solvophobicity itself have been successfully suggested.

Free Research Field

コロイド・界面化学

Academic Significance and Societal Importance of the Research Achievements

疎水（液）性引力は、溶媒をはじく性質を持つ表面間に長距離から強い引力が働く現象であり、工業的に重要な液中の微粒子の分散挙動だけでなく、液中の気泡や油滴の合一、ひいては生体分子の挙動などにも大きな影響を及ぼす。本研究でこの疎水（液）性引力の発生起源が推定されたことは、これら広範囲の現象の起こるメカニズムに一定の解釈を与え、その効率的な制御方法に対する指針を確立するための重要な手がかりをもたらすものと期待できる。