Abstract
Retention forces and drop parameters are investigated for drops on the verge of sliding on vertical and inclined surfaces. Using earlier observations of drop geometry, the retentive-force factor relating surface-tension forces to contact-angle hysteresis is reliably determined. The retention force for a drop is found to be insignificantly affected by the aspect ratio of its contour. The maximum size of a drop is predicted with good accuracy, based on the two-circle method for approximating shapes of drops. The Bond number of a critical drop is found to be constant for a given surface and liquid. A general relation is proposed between the characteristic advancing and receding contact angles. The relation is supported by a large set of contact-angle data. In the absence of θR data, the relation allows estimating the receding contact angle and the critical drop size, using only the advancing angle.
Original language | English (US) |
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Pages (from-to) | 841-849 |
Number of pages | 9 |
Journal | Journal of Colloid And Interface Science |
Volume | 299 |
Issue number | 2 |
DOIs | |
State | Published - Jul 15 2006 |
Keywords
- Contact angle hysteresis
- Critical size
- Forces
- Incipient motion
- Liquid drops
- Retention
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Surfaces, Coatings and Films
- Colloid and Surface Chemistry