在疏水表面上普遍形成的凝聚气体分子层的三维表征
1Department of Physics and the Russell Berrie Nanotechnology Institute , Technion - Israel Institute of Technology , Haifa 3200003 , Israel.
Journal of the American Chemical Society
|July 25, 2018
概括
当水中的疏水表面接触到空气或时,会形成凝结气层,而不是水化层. 这种通用层影响了表面相互作用,并揭示了纳米泡结构.
科学领域:
- 表面科学
- 物理化学
- 纳米技术
背景情况:
- 了解疏水表面的溶解层对于水溶液中的相互作用至关重要.
- 现有的实验方法缺乏侧面分辨率或探针稳定性进行详细研究.
研究的目的:
- 在疏水表面上绘制溶解/水化层的3D结构.
- 研究溶解气体对这些层的影响.
- 在疏水表面描述纳米泡.
主要方法:
- 高分辨率的频率调制原子力显微镜 (FM-AFM) 具有刚性悬臂和水友性尖端.
- 用于克服探测器的不稳定性并实现详细的表面测绘.
- 在脱气和非脱气水溶液中进行测量.
主要成果:
- 在脱气溶液中,观察到不同的相互作用:范德瓦尔斯吸引力与石墨 (HOPG) 和静电排斥与-单层 (FDTS).
- 在非脱气溶液中,两面都形成2-5纳米厚的凝聚气层,导致类似的尖端表面相互作用.
- 凝结的气体层表现出具有0.5-0.8纳米组成距离的内部结构,并确定了不同的纳米泡结构.
结论:
- 与空气或平衡水接触的疏水表面具有通用冷凝气层,而不是简单的水化层.
- 与脱气条件相比,这种凝结的气体层显著改变了表面相互作用.
- 这项研究为这些层和相关的纳米泡的结构和行为提供了前所未有的3D洞察力.
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