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8624871 
Journal Article 
Evaluation of the surface tension measurement of axisymmetric drop shape analysis (ADSA) using a shape parameter 
Hoorfar, M; Kurz, MA; Neumann, AW 
2005 
Yes 
Colloids and Surfaces A: Physicochemical and Engineering Aspects
ISSN: 0927-7757 
Elsevier 
AMSTERDAM 
260 
1-3 
277-285 
English 
WOS:000230714500033 
A quantitative criterion called "shape parameter" to evaluate the quality of surface tension measurement of Axisymmetric Drop Shape Analysis (ADSA) is presented. ADSA is a powerful technique for the measurement of interfacial tensions and contact angles of pendant drops, sessile drops, and bubbles. Despite the general success of ADSA, deficient results may be obtained for drops close to spherical shape. Therefore, the "shape parameter" was used to determine the range of drop shapes in which ADSA succeeds or fails. The "shape parameter" is a dimensionless parameter that expresses quantitatively the difference in shape between a given experimental profile and an inscribed circle. The surface tension measurements of ADSA were evaluated for both pendant drop and constrained sessile drop configurations using the shape parameter. Different shapes of the pendant drop were studied using different sizes and materials of holders. For each drop configuration, a "critical shape parameter" was defined based on the minimum value of the shape parameter that guarantees an error of less than ±0.1 mJ/m2. Furthermore, the effects of the type of liquid and constellation on the "critical shape parameter" were studied. © 2005 Elsevier B.V. All rights reserved. 
Axisymmetric Drop Shape Analysis (ADSA); Constrained sessile drop; Critical shape parameter; Pendant drop; Shape parameter