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C. W. Extrand, and Y. Kumagai
[Adhesion, Vol.30, No.5, pp.23-27, 1994]
Retention of elongated liquid drops by solid surface has been studied. A tiltable plane was used to dislodge water drops from silicon wafers and three polymer surfaces. Due to contact angle hysteresis, drops remained stationary until a critical force F (Fig.1) was exceeded, than began to slide down the plane. Although, drops elongated before moving, their width did not contract much. Critical values of F were higher than predicted for drops with circular contact lines. F was calculated numerically for elongated drops by integrating the surface forces around an elliptical contact line. The calculation showed F increases with elongation, in fair agreement with experimental data (Fig.2).
