Tan Beng Hau, An Hongjie, Ohl Claus-Dieter
Cavitation Lab, Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
Phys Rev Lett. 2017 Feb 3;118(5):054501. doi: 10.1103/PhysRevLett.118.054501. Epub 2017 Jan 31.
Many of the remarkable properties of surface nanobubbles, such as unusually small contact angles and long lifetimes, are related to the force that pins them onto their substrates. This pinning force is yet to be quantified experimentally. Here, surface-attached nanobubbles are pulled with an atomic force microscope tip while their mechanical responses are observed with total internal reflection fluorescence microscopy. We estimate that a pinning force on the order of 0.1μN is required to unpin a nanobubble from its substrate. The maximum force that the tip can exert on the nanobubble is limited by the stability of the neck pulled from the bubble and is enhanced by the hydrophobicity of the tip.
表面纳米气泡的许多显著特性，如异常小的接触角和较长的寿命，都与将它们固定在基底上的力有关。这种固定力尚未通过实验进行量化。在这里，用原子力显微镜探针拉动附着在表面的纳米气泡，同时用全内反射荧光显微镜观察它们的力学响应。我们估计，要使纳米气泡从其基底上脱离，需要约0.1μN的固定力。探针能够施加在纳米气泡上的最大力受到从气泡拉出的颈部稳定性的限制，并因探针的疏水性而增强。
