Wettability is typically studied by a contact angle measurement that can be defined with the well-known Young equation on ideal surfaces. Surface free energy theories are also based on assumptions that Young contact angles are used for calculations. Thus, the surface is assumed to be chemically homogenous and topographically smooth. This is, however, not true in the case of real surfaces. It is well established that surface roughness enhances the existing wetting behavior and influence on adhesion.
Theta Topography makes it possible to define Young contact angle and surface free energy measurements as well as measurements for rough surfaces according to the Wenzel theory. The roughness corrected contact angles make it possible to understand the influence of roughness and chemistry on the wettability of your surface, separately. By using the highly accurate motorized XYZ sample stage, you can perform both measurements from the exact same location and map the complete surface to check homogeneity and cleanliness.
Images show a paper sample measured with Theta Topography. Optical image to the left, 2D representation in the middle and 3D to the right.
