Capillary Forces between Submillimeter Spheres and Flat Surfaces at Constant Liquid Volumes

• Published in: Chinese physics letters Vol. 26; no. 12; pp. 198 - 201
• Main Author: 王乐锋 荣伟彬 孙立宁 陈立国 邵兵
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.12.2009
• Subjects: Capillarity; Contact; Contact angle; Flat surfaces; Hysteresis; Liquid bridges; Liquids; Separation; 亚毫米波; 接触角; 毛管力; 毛细管力; 液体表面; 液体量; 边界条件; 间隔距离
• ISSN: 0256-307X; 1741-3540
• DOI: 10.1088/0256-307X/26/12/126801

We investigate the capillary forces between submillimeter spheres and flat surfaces at constant liquid volumes theoretically and experimentally. An iterative method is used to estimate the capillary force with contact angles as the boundary conditions and the constant volume as a constraint. The theoretical analysis shows that the maximum capillary force between them decreases with the increase of the liquid bridge volume at small contact angles. The experimental results show that the force is smaller than the theoretical values at the initial separation distances. It is also observed that the force first increases and then decreases with an increasing separation distance in some cases. These phenomena of capillary forces hysteresis are explained according to the wetting hysteresis.