School of Chemical Engineering, The University of Queensland, Brisbane QLD 4072, Australia.
Langmuir. 2012 Jan 24;28(3):1924-30. doi: 10.1021/la2036955. Epub 2012 Jan 12.
The evaporation of sessile droplets with a constant base radius (pinning mode) and a constant contact angle (depinning mode) has been experimentally observed. Here we analyzed the effect of substrate hydrophobicity on the lifetimes of evaporating droplets for the two modes. Theoretical predictions were obtained and compared with available experimental results. The theoretical analysis and experimental results show that linear methods of extrapolating limited experimental data for a transient droplet contact angle and base radius overpredict the droplet lifetime. Likewise, the linear extrapolation of limited experimental data for transient droplet volume underpredicts the droplet lifetime. Correct methods of extrapolating limited experimental data for transient droplet parameters are described, discussed, and validated. The new methods removed inconsistencies in the previous theory and experimental analysis. Master equations and master curves for the droplet lifetime for the two evaporation modes are obtained and experimentally confirmed.
我们观察到具有恒定基底半径（钉扎模式）和恒定接触角（去钉扎模式）的固着液滴的蒸发。在这里，我们分析了基底疏水性对两种模式下蒸发液滴寿命的影响。我们得到了理论预测，并将其与现有的实验结果进行了比较。理论分析和实验结果表明，对瞬态液滴接触角和基底半径的有限实验数据进行线性外推的方法过高估计了液滴寿命。同样，对瞬态液滴体积的有限实验数据进行线性外推也过低估计了液滴寿命。描述、讨论并验证了对瞬态液滴参数的有限实验数据进行外推的正确方法。新方法消除了之前理论和实验分析中的不一致性。获得了两种蒸发模式下液滴寿命的主方程和主曲线，并通过实验得到了验证。
