双乳液的冷诱导的拓过渡
Jochem G Meijer1, Pallav Kant2, Detlef Lohse1,3
1Physics of Fluids group, Max Planck Center Twente for Complex Fluid Dynamics, Department of Science and Technology, Mesa+ Institute and J. M. Burgers Center for Fluid Dynamics, University of Twente, P.O. Box 217, Enschede 7500 AE, The Netherlands. j.g.meijer@utwente.nl.
Soft matter
|February 22, 2024
概括
水-在-油-在-水乳液的结可以导致拓过渡,驱逐内部水滴. 当内滴小于临界尺寸时,可以避免这种过渡.
科学领域:
- 体和接口科学科学
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
背景情况:
- 复杂的液体如乳液在自然界和工业中至关重要.
- 了解它们的相变,如固化,至关重要.
- 层次化乳液,如水中的油中的水 (W/O/W),具有独特的固化行为.
研究的目的:
- 为了研究W/O/W双乳液的固化过程.
- 在结过程中识别和描述任何拓过渡.
- 阐明观察到的转变背后的机制,并确定关键参数.
主要方法:
- 制备和处理 W/O/W 双重乳液.
- 有控制的冷实验.
- 高速成像以捕捉动态过程.
- 显微镜分析滴滴形态和大小.
主要成果:
- W/O/W 乳液的固化可以诱导拓过渡.
- 观察到从W/O/W过渡到O/W (水中的油) 单重乳液配置.
- 在这个过渡过程中,内部水滴从油滴中排出.
- 确定了一个关键的内滴大小 (R_in,crit ≈ 19 μm),在此以下的过渡被抑制.
结论:
- 外部油层从外面结到内面会产生紧张,破坏 W/O/W 结构的稳定.
- 拓过渡是这种诱导的紧张和随后的内部水核心的驱逐的结果.
- 在临界内滴大小以下的W/O/W乳液的稳定性归因于结过程中减少的界面应力.
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