Surface Tension Measurement (Ring Method) and Characterization of Coating Materials

Abstract

A detail discussion of the theoretical aspects of surface tension measurements by ring method is provided with special emphasis on the sources of error. The accuracy of the measured data is mainly limited by the correction factor “f”, which compensates for the non-symmetrical shape of the surface. Based on the experimental findings, it is suggested to include the correction factor during the evaluation of the surface tension, especially if an accuracy of less than 0.1mN/m is required. The effect of meniscus shape and size on the surface tension is discussed. In addition to the surface tension measurements, several other physical properties of the coating systems such as settling behavior and hardness of the settlement can be measured by using the dynometer from BYK-Gardner as a measuring device. The results on different coating systems are presented to study the settling and hardness of the settled material.