Contact Angle & Surface Tension
Contact Angle Measurement
Contact angle, θ, is a quantitative measure of the wetting of a solid by a liquid. The instrument of choice to measure contact angles and dynamic contact angles is a optical tensiometer. A force tensiometers can also be used. Both optical and force tensiometers enable static and dynamic contact angle measurements.
Surface tension is a measurement of the cohesive energy present at an interface. The molecules of a liquid attract each other. The interactions of a molecule in the bulk of a liquid are balanced by an equal attractive force in all directions. Whereas molecules on the surface of a liquid experience an imbalance. Sigma force tensiometers as well as Theta and Theta Lite optical tensiometers are well suited to the measurement of equilibrium surface tension.