The Adhesion Tool extends the DSA3 shape analysis software with a useful evaluation function

In recent years the measurement of the contact angle has increasingly changed from being an empirical wetting test to becoming a scientific tool. Contact angle measurements can be used to calculate the work of adhesion (WOA) – which can be determined for known systems and even calculated for liquid-solid combinations that have not yet been studied.

The work of adhesion is primarily of interest when one component not only wets the other one, but is also to remain stably bound to it – this is an important quantity for studies into composites, adhesives and coatings. In addition, it is possible to estimate the extent to which the bond is susceptible to phase exchange. This is of primary importance for the estimation of stability to moisture.

The KRÜSS Adhesion Tool provides rapid access to the adhesion work of solid-liquid systems with known surface free energy data. In addition, for a given solid it is possible to determine how the surface energy properties of the wetting liquid must be altered in order to increase the expected work of adhesion.

For example: in an adhesive bond the work of adhesion is required to achieve a standard value of 100mJ/m², while at the same time a contact angle of 30° must not be exceeded during the application process. If the surface free energy of the solid and its polar fraction are known, then the Adhesion Tool can be used to show for which liquid properties the required result (100 mJ/m² at a contact angle of 30°) can be achieved. The values for the required liquid are obtained from the intercept of the wetting envelope for 30° and the WOA curve for 100 mJ/m².