In our line of work, the measure of surface tension and understanding of surface energies are very important. We measure surface tension with the hanging drop technique or using deNouy or Wilhelmy plate methods. Surface tension is commonly used to study surfactants and for example assess the critical micellar concentration (cmc). Studying the surface tension of surfactants in the presence of a polymer could also be done, providing information on the interactions between these ingredients and if there is for example a critical association concentration (cac) to take into account.

Contact angle measurements and the effect on capillary forces are also visual and very informative ways of understanding the effect of surface energies and how they are modified. We choose method based on the system, the quantities available and the reason why we need the information.

For tensiometry and contact angle, talk to Mimmi, Jonas and Frida!