ABSTRACT
In contrast to the sessile droplet method, Wilhelmy balance force measurements are obtained while the three-phase contact line is moving with respect to the polymer surface. This dynamic method requires the immersion and withdrawal of a sample of specific geometry through liquid water. Both advancing and receding contact angles are calculated from the force balance data; therefore, values of contact angle hysteresis can be obtained even for very fast changes in surface configuration. The Wilhelmy balance method is a more versatile and sensitive tool for monitoring the surface dynamics of polymeric surfaces than the sessile droplet method. By the same token, it should be recognized that contact angle is not a simple parameter to describe the surface property of a sample.
