Dynamic contact angle measurements can give more information about the liquid to surface interaction. The advancing contact angle is measurement of how a liquid wets a surface at it advances across the surface. Receding contact angles give information about how well a liquid dewets from the surface and is typically smaller than the advancing angle. The difference between the two angles or contact angle hysteresis can give an indication of the roughness of the surface being tested.
LPD can measure advancing and receding contact angles of a sessile drop using a Dataphysics Optical Contact Angle (OCA35). Optical contact angle measurements allow the volume of a drop to be increased and decreased repeatedly in small targeted areas of a surface. This allows the differences between the first wetting and rewetting to be studied.
Alternatively, depending on the sample, the Wilhemy plate method can be used in conjunction with a Dataphysics Dynamic Contact Angle Tensiometer (DCAT21). This method can also be used to assess fibre wetting characteristics.