Manor Ofer
Wolfson Department of Chemical Engineering, Technion-Israel Institute of Technology , Haifa, Israel.
Langmuir. 2014 Jun 17;30(23):6841-5. doi: 10.1021/la5006924. Epub 2014 Jun 5.
We suggest a simple quantitative model for the diminution of contact angle hysteresis under the influence of an oscillatory force invoked by thermal fluctuations, substrate vibrations, acoustic waves, or oscillating electric fields. Employing force balance rather than the usual description of contact angle hysteresis in terms of Gibbs energy, we highlight that a wetting system, such as a sessile drop or a bubble adhered to a solid substrate, appears at long times to be partially or fully independent of contact angle hysteresis and thus independent of static friction forces, as a result of contact line pinning. We verify this theory by studying several well-known experimental observations such as the approach of an arbitrary contact angle toward the Young contact angle and the apparent decrease (or increase) in an advancing (or a receding) contact angle under the influence of an external oscillating force.
我们提出了一个简单的定量模型，用于描述在热涨落、基底振动、声波或振荡电场引起的振荡力影响下接触角滞后的减小。我们采用力平衡而非通常基于吉布斯能量对接触角滞后的描述，强调了诸如附着在固体基底上的静态液滴或气泡等润湿系统，由于接触线钉扎作用，在长时间尺度上似乎部分或完全独立于接触角滞后，进而独立于静摩擦力。我们通过研究几个著名的实验观测结果来验证这一理论，比如任意接触角趋近于杨氏接触角，以及在外部振荡力影响下前进（或后退）接触角的明显减小（或增大）。
