A Frequently Asked Question BTG Labs Decided to Answer
When measuring and quantifying surface energy, a common question arises: "Does roughness impact contact angle measurements obtained by the Surface Analyst?" While there exists some studies and speculations, this was still a grey area. So, BTG Labs decided to take matters into their own hands. The Materials & Process Specialists at BTG Labs constructed a research project to study the effect--or lack thereof--of roughness on contact angle measurements.
BTG Lab's Scientists used a Surface Finish Comparator. This nickel plate containing 21 panels of varying roughness and texture is representative of surfaces typically encountered in manufacturing processes. The Surface Analyst showed no correlation of contact angle with roughness.
The figure below shows a graph from the experiment results. A benchtop goniometer also took measurements on the Surface Finish Comparator. The results show that the Surface Analyst had a very low standard deviation of 1.8°. On the other hand, the benchtop goniometer showed a higher standard deviation of 3.6°.
Read the full paper to learn how the Surface Analyst overcomes roughness.
Visit the technical resource section to read the full paper, "Effect of Surface Roughness on Contact Angle Measurements Obtained with the Surface Analyst."