Liquid/solid contact angle measurement

Do you want to measure the contact angle between your liquid and solid samples? The Calnesis Laboratory performs these measurements with precision tools in a wide temperature range.

A contact angle corresponds to the angle formed between a liquid product and a solid surface on which it has been deposited.

Diagram of the contact angle formed between a solid surface and a liquid

This angle, which is all the lower as the liquid product spreads over the solid surface, is dependent on the interactions between:

  • the solid surface and the liquid product
  • liquid product and air
  • solid surface and air

This angle is therefore linked to the different interfacial tensions involved and its determination makes it possible to evaluate the wettability of the surface studied by the liquid product tested. The wettability being correlated with the surface energy of the support, the measurement of the contact angle therefore makes it possible to characterize the adhesion between the liquid product and the solid surface.

How to measure a contact angle?

The determination of the contact angle generally consists of analyzing a drop of liquid deposited on a solid surface (sessile drop method). This analysis can be carried out statically (no change in the shape and volume of the drop) or dynamically (change in the shape and volume of the drop).

Profile photograph of a drop of water on a flat surface obtained with an optical bench

In both cases, the measurement is carried out using a contact angle goniometer equipped with an optical subsystem allowing the capture of high resolution images of the drop formed in the liquid-solid system analyzed. Software processing of the images obtained then makes it possible to calculate the contact angle with precision.

Measurements can be made as a function of temperature or time. Indeed, the composition of the drop of liquid may possibly evolve over time (presence of solvent for example), implying a continuous evolution of the contact angle. It must then be established whether the measurement should be made immediately after depositing the drop, after a certain delay, or after the possible disappearance of the volatile species (equilibrium).

Other measurements
Measurement of the specific surface of Samples: Powders, Granules, Solids, etc.
Measurement of the porosity of samples carried out for all types of solids (powder, etc.)
Liquid sample refractive index measurement carried out at controlled temperature.