Evaluation of ion accumulation on particle surface by zeta potential measurement with controlling applied electric field

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05194
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 27010:Transport phenomena and unit operations-related
• Research Institution: Hiroshima University
• Principal Investigator: Fukasawa Tomonori 広島大学, 先進理工系科学研究科(工), 助教 (00589187)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: ゼータ電位 / 電気泳動 / イオン集積 / イオン水和 / 親疎水性 / 降伏応力 / 凝集速度 / ソフト界面

Outline of Final Research Achievements

We measured zeta potential by controlling the applied electric field using model particles focusing on the decrease in zeta potential with decreasing applied electric field, and evaluated the dispersion stability of the particles and rheological properties of the suspension. In addition, based on the obtained results, we evaluated the state of ion accumulation at the particle interface
Polystyrene latex particles and silica particles were used as model particles, and the electrophoretic mobility (zeta potential) was measured for each single particle by optical microscopy. In particular, we focused on the effects of dissolved ion species (hydration ion enthalpy), hydrophilicity/hydrophobicity of the particles, and pH of the dispersing medium on the ion accumulation state.

Free Research Field

コロイド界面化学

Academic Significance and Societal Importance of the Research Achievements

本研究は、今まで実験上の誤差として見落とされてきたゼータ電位に及ぼす印加電場の影響に着目し、粒子界面における溶存イオンの集積状態の評価を試みることに学術的意義がある。
本研究は、広く普及しているゼータ電位測定法の問題点を指摘するものではない。むしろ、得られる知見の活用によって、印加電場を操作因子とした新たな粒子界面の特性評価法の開発が期待される。それによる各種分野への波及効果は極めて大きく、学術上の発展のみならず、産業・社会へも貢献できる。