Zisman plot

A Zisman plot is a graph used in surface science to understand how different liquids interact with a solid surface, especially regarding wetting behavior. It plots the cosine of the contact angle (a measure of how well a liquid spreads on a surface) against the liquid’s surface tension. This helps identify a specific surface tension value—called the critical surface tension—below which the liquid won’t spread and will form droplets. Essentially, the Zisman plot helps scientists predict how well a liquid will wet a surface, informing material design and surface treatments.