Wetting and Pickering Emulsions: measured receding contact angles on spherical particles as a function of interface shape.

When predicting the effectiveness of particles as droplet stabilizers, one often assumes that the contact angle (advancing or receding) is a property of the materials. We find that, by contrast, the receding angle is sensitive to the interface shape, while the advancing angle remains constant. In particular, we find that the receding angle decreases substantially with increasing anisotropy of the interface shape (parameterized by the deviatoric curvature). Measurements we made with carefully cleaned glass spheres functionalized with PDMS; angles were measured by image analysis and control experiments were done.

在预测颗粒作为液滴稳定剂的效果时，人们通常假设接触角（contact angle）（前进角（advancing）或后退角（receding））是材料的固有属性。相比之下，我们发现后退角（receding angle）对界面形状敏感，而前进角（advancing angle）保持恒定。具体而言，我们发现后退角随界面形状各向异性（由偏曲率（deviatoric curvature）表征）的增加而显著减小。我们使用经PDMS功能化且仔细清洗的玻璃球开展了测量；角度通过图像分析（image analysis）测定，并进行了对照实验。