Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
ACS Nano. 2012 Oct 23;6(10):9326-34. doi: 10.1021/nn304250e. Epub 2012 Oct 3.
Surfaces with special wetting properties not only can efficiently repel or attract liquids such as water and oils but also can prevent formation of biofilms, ice, and clathrate hydrates. Predicting the wetting properties of these special surfaces requires detailed knowledge of the composition and geometry of the interfacial region between the droplet and the underlying substrate. In this work we introduce a 3D quantitative method for direct nanoscale visualization of such interfaces. Specifically, we demonstrate direct nano- to microscale imaging of complex fluidic interfaces using cryostabilization in combination with cryogenic focused ion beam milling and SEM imaging. We show that application of this method yields quantitative information about the interfacial geometry of water condensate on superhydrophilic, superhydrophobic, and lubricant-impregnated surfaces with previously unattainable nanoscale resolution. This type of information is crucial to a fundamental understanding as well as the design of surfaces with special wetting properties.
具有特殊润湿性的表面不仅可以有效地排斥或吸引水和油等液体，还可以防止生物膜、冰和笼形水合物的形成。预测这些特殊表面的润湿性需要详细了解液滴和基底之间界面区域的组成和几何形状。在这项工作中，我们引入了一种用于直接纳米尺度可视化这种界面的 3D 定量方法。具体来说，我们展示了使用冷冻稳定化结合低温聚焦离子束铣削和 SEM 成像对复杂流态界面进行直接纳米到微尺度成像。我们表明，该方法的应用可提供关于超亲水、超疏水和涂有润滑剂表面上水冷凝的界面几何形状的定量信息，其纳米级分辨率是以前无法达到的。这种类型的信息对于理解以及设计具有特殊润湿性的表面至关重要。
