Surface Energy

Surface Energy is the energy excess the surface of a material has compared to the bulk, it is measured in J/m². It is caused by the disruption of chemical bonds within the material boundary. In liquids, surface energy becomes surface tension, measured in N/m which, in SI units, is identical to J/m².

Surface energy differences between two phases are crucial for their wetting behavior. A liquid will maximize the liquid-solid-interface by spreading into every microscopic dent and hollow of the solid surface only if its surface tension is smaller than the surface energy of the solid. On the other hand, if the surface energy of the solid is lower than the surface tension of the liquid, the liquid will minimize the liquid-solid-interface, forming beads instead of spreading out.

Plasma Activation greatly enhances the surface energy of many materials and therefore improves their wettability.

Return to Plasma Knowledge Base