ABSTRACT
PEDRO GEA-JODAR, 1 MIGUEL ANGEL RODRIGUEZ-VAL VERDE2 and MIGUEL ANGEL CABRERIZO-VILCHEZ'·* 1Biocolloid and Fluid Physics Group, Department of Applied Physics, Faculty of Sciences, University of Granada, E-18071 Granada, Spain 2Polymers and Composites Laboratory, Department of Materials Engineering and Industrial Technologies, University ofTrento, I-38050 Trento, Italy
Abstract-In this work, wetting on rigid, flat and chemically heterogeneous solid surfaces is studied theoretically. For this purpose two different methods have been employed: (i) computer calculations performed with the public-domain software Surface Evolver and (ii) an approximation to describe the sessile drops on non-ideal solid surfaces, called pseudo-spherical caps in this study. The use of these two methods was complementary and allowed us to interpret the behavior of a drop on a heterogeneously patterned surface, besides predicting the values of contact parameters, such as contact angle, contact area, etc. Two different chemical heterogeneity patterns have been analyzed: a striped pattern and a chessboard pattern. The results are also compared with the values expected from the Cassie equation. The good agreement obtained using these two methods allows us to extend the pseudo-spherical approximation to more complex surfaces.
