Small particle at a fluid interface: Effect of contact angle hysteresis on force and work of detachment
Small particle at a fluid interface: Effect of contact angle hysteresis on force and work of detachment
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DOI：
10.1021/la020300p
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发表时间：
2002-12-10
期刊：
影响因子：
3.9
通讯作者：
Chateau, X
中科院分区：
文献类型：
--
作者：
Pitois, O;Chateau, X
本文讨论了初始附着在液体界面上的小球的去除问题。球体足够小（0.3-1 mm），以使毛细管力主导相互作用，并且足够大以使线张力效应可以忽略。我们已经同时测量的力和系统的几何参数作为一个函数的相对（球/界面）分离距离在分离过程中，具有高精度。该程序使我们能够量化在分离过程中接触角滞后相对于力路径曲线的影响。结果表明，以前的工作，假设一个恒定的后退接触角，不描述我们的实验数据时，滞后效应占主导地位。通过对球体在脱附过程中所受毛细力的解析积分，首次得到了脱附功的解析表达式。与我们的实验数据和现有的数值计算的比较表明，良好的协议。接触角滞后对分离工作的影响也被量化。
This paper deals with the removal of a small sphere initially attached to a liquid interface. The sphere is small enough (0.3-1 mm) for the capillary force to dominate the interaction and large enough for the line tension effect to be negligible. We have measured simultaneously the force and the geometric parameters of the system as a function of the relative (sphere/interface) separation distance during the detachment process, with a high precision. This procedure allows us to quantify the effect of the contact angle hysteresis during the detachment process with respect to the force-path curve. It is shown that the previous work, which assumes a constant receding contact angle, does not describe our experimental data when the hysteresis effect dominates. By analytical integration of the capillary force experienced by the sphere during the detachment process, the first closed-form analytical expression for the detachment work was obtained. Comparison with our experimental data and with the existing numerical calculations showed good,agreement. The effect of contact angle hysteresis on the detachment work is also quantified.