Fluid Deposition Style of Contact Angle Measurements
Measuring the contact angle of a fluid on a surface provides an accurate reading of surface energy. However, methods of depositing the droplet and measuring the contact angle vary. With this sensitive process, every detail and particularity effects the measurement.
Common surface measurement instruments, such as goniometers, use an automated syringe needle to deposit a single drop of fluid. However, the manner in which the drop of fluid is deposited greatly impacts the contact angle and entails precise control. Furthermore, the composition of fluid used effects the measurement and potentially the surface.
Alternative fluids can be dangerous to the user and contamination to the material. This often requires the use of a coupon, or sample rather than a measurement on the actual surface of the material in question. Furthermore, a single drop does not have the ability to measure on diverse surfaces.
Advantages of Ballistic Deposition
BTG Labs’ Surface Analyst™ uses patented Ballistic Deposition™ to deposit a stream of micro drops that coalesce into a single drop on the surface. By constructing a drop of highly purified water out of these micro droplets, the Surface Analyst is able to take measurements on various surfaces—non-planar, textured, non-horizontal—without threat to the user or damage to the material.
The article delves deeper into this topic and discusses a comparison between the Surface Analyst and a goniometer.