2023 Fiscal Year Final Research Report

Development of an evaluation system for the stability of particle dispersions in non-aqueous liquids based on a new perspective

Research Project

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Project/Area Number	21H01639
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Review Section	Basic Section 26030:Composite materials and interfaces-related
Research Institution	Doshisha University (2023) Okayama University (2021-2022)
Principal Investigator	Naoyuki Ishida 同志社大学, 理工学部, 教授 (80344133)
Co-Investigator(Kenkyū-buntansha)	森隆昌法政大学, 生命科学部, 教授 (20345929) 今村維克岡山大学, 環境生命自然科学学域, 教授 (70294436)
Project Period (FY)	2021-04-01 – 2024-03-31
Keywords	分散評価体系 / 非水系 / 微粒子 / 相互作用力
Outline of Final Research Achievements	The interaction forces between solid surfaces in organic solvents were measured using atomic force microscopy (AFM). The correlation between the affinity of solvent molecules to surfaces was evaluated using pulsed nuclear magnetic resonance (NMR) to investigate their influence on particle dispersion stability. It was confirmed that a high affinity between the surface and solvent molecules leads to repulsion between the surfaces due to the formation of a solvation layer. Conversely, low affinity to the solvent molecules results in attraction between the surfaces due to the absence of a solvation layer. Additionally, it was found that the formation of this solvation layer on surfaces coated with linear hydrocarbons is significantly influenced by factors such as chain length and molecular shape, in addition to the affinity between the surface and solvent molecules.
Free Research Field	コロイド・界面工学
Academic Significance and Societal Importance of the Research Achievements	工業プロセスや製品において、化粧品、塗料から電子デバイスや電池材料に至るまで非水系液体にコロイド粒子を分散させた分散系が数多く使われている。この分散系の分散・凝集の挙動評価はこれら分散系を扱う上で最も重要であるが、分散・凝集を司る非水系で微粒子の表面間力への理解がこれまでは決定的に不足しており、プロセスの最適化は、勘や経験に依存せざるをえなかった。今回の結果は、表面と溶媒分子の相互作用の視点から、非水系での表面間力を解釈・予測できることを示したものであり、今後の科学的根拠に基づいた分散プロセスの合理的な設計や高度な制御・最適化に大いに貢献するものと考えられる。