光に反応するナノエムルションから証明されたナノスケールの電荷調節
Dana Glikman1,2, Leonard Wyszynski1, Valentin Lindfeld3,4
1Institute of Physical Chemistry, University of Münster, Corrensstraße 28/30, 48149 Münster, Germany.
Journal of the American Chemical Society
|March 14, 2024
まとめ
研究者は光に反応する表面活性物質を使って 油と水のインターフェースを調整しました ナノ粒子の安定化と持続的な表面活性剤の使用に関する洞察を提供した.
科学分野:
- コロイドと表面科学
- 材料科学
- 物理化学
背景:
- エムルションは日常生活において不可欠であり,その性質を制御することが必要である.
- 分子レベルで 油と水の相互作用を理解することは 極めて重要ですが 実験的に難しいことです
- 現在の方法は,エミュルションのインターフェイスを現地で探査するのに苦労しています.
研究 の 目的:
- 光に反応する表面活性物質を用いてエムルションのインターフェイスを調節する.
- マクロエムルションとナノエムルションの特性に対する表面活性物質の光同化の影響を探求する.
- マクロエムルションとナノエムルションの間のインターフェイスの基本的違いを理解する.
主な方法:
- 光に反応する表面活性物質 (ブチル-AAP) が使用され,可視光および紫外線照射でE/Z光異性化が行われます.
- インターフェースの張力測定,臨界ミセル濃度測定,二次ハーモニー散乱,パルスフィールドグラデント核磁気共鳴 (NMR) などの技術が採用されている.
- マクロエムルションとナノエムルションの両方のドロップレットサイズ, ζ-ポテンシャル,表面過剰,および界面特性の変化を調査した.
主要な成果:
- ブチル-AAP表面活性剤の光異性化により,マクロエムルションの界面張力と臨界ミセル濃度が大幅に変化し,安定性と相分離を制御することが可能になった.
- ナノエムルション (R_H ~90 nm) は,光異性化によるドロップレットサイズまたは ζ-ポテンシャルに有意な変化を示さなかった.
- ナノエムルションでは,マクロエムルションの振る舞いとは異なる,表面活性剤の表面余剰の可逆的な変化が観察されました.
- 確固たる電荷対粒子の比率とカウンターイオン凝縮がナノエムルションの安定化に不可欠であるという証拠がある.
結論:
- 光に反応する表面活性剤は,乳液の性質を制御するための新しい方法を提供します.
- ナノエムルションは,サイズに依存する静電安定化により,マクロエムルションと比較してユニークなインターフェイス行動を示す.
- 発見は,より低い濃度の要求により,ナノ粒子安定化におけるより持続可能な表面活性剤の使用を支持する.
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