Coalescence of dispersed micrometer-scale droplets is an essential step toward separation of emulsions. The thin film between droplets must form, drain, and rupture for coalescence to occur. In surfactant-stabilized emulsions, the film drainage and droplet coalescence processes are known to be hindered due to reduced interfacial mobility. However, a clear correlation between this mobility and the underlying surfactant transport and interfacial response to shear and dilatational deformations is under-characterized. For microscale droplets, the effect of surfactant transport to the interface and along the interface is often difficult to isolate from other bulk effects on emulsion stability. In this work, we review surfactant-mitigated coalescence in both macroscale and microscale experiments, highlighting the importance of interfacial curvature and length scales when establishing a correlation between coalescence theory and film mobility.

分散的微米级液滴的聚结是乳液分离的重要步骤。液滴之间的薄膜必须形成，排干和破裂，才能发生聚结。在表面活性剂稳定的乳液中，由于界面迁移率降低，已知阻碍了膜的排水和液滴的聚结过程。但是，这种迁移率与潜在的表面活性剂传输以及对剪切和膨胀变形的界面响应之间的明显关联性不足。对于微滴，表面活性剂向界面和沿界面传输的影响通常很难与乳液稳定性的其他整体影响区分开。在这项工作中，我们将在宏观和微观实验中回顾表面活性剂减轻的聚结，