15. Surface free energy – the “surface tension” of a solid

What makes a liquid spread more on some surfaces than on others?

In this episode of Season 2 of Science on surfaces we talk to Dr. Susanna Lauren at Biolin Scientific about Surface Free Energy. Susanna did her Ph.D. on microfluidics and superhydrophobic surfaces and is an expert on surface-related phenomena, such as surface tension, wettability, adhesion, and surface free energy.

Susanna describes how the surface free energy of a solid arises and how molecular interactions such as cohesive and adhesive forces are used to determine the value. She then explains how the surface free energy of a solid will determine for example how a liquid will behave when placed on top of it and how much the liquid will spread. We also get to learn more about why the surface free energy is not measured but calculated using Young's equation and how this fairly complicated theory is made simple with existing software. 

Thanks for listening! If you are interested in surface and interface science and related topics, you should check out our blog -  the Surface Science blog