Advertisement

Young's Equation

What Does Young's Equation Mean?

Young’s equation is a formula developed by the English physicist Thomas Young, which is used to define the relationship between the contact angle, the surface tension, the interfacial tension between a liquid and a solid surface, and the surface free energy of the solid. In simpler terms, the equation helps describe the shape and behavior of a liquid where the liquid-vapor interface meets a solid surface.

Young’s equation is also known as the Young–Dupré equation.

Advertisement

Corrosionpedia Explains Young's Equation

Young’s equation is defined as:

σsg = σsl + σlg ⋅ cosθ

Where:

σsg = the surface free energy of the solid

σsl = the interfacial tension between the liquid and the solid

σlg = the surface tension of the liquid

cosθ = the contact angle between the liquid-vapor interface and the solid surface

Young’s equation takes into consideration the thermodynamic equilibrium between the three phases of matter: solid, liquid and gas. As the three elements come into contact with each other, such as when a droplet of water lands on a solid surface, the water droplet assumes a shape where all three phases are balanced.

This equation, therefore, plays a crucial role in describing the wettability of a surface. If variables, such as σsg = σsl + σlg are known, then the contact angle can be calculated. The higher the contact angle formed between the liquid and the surface, the lower the surface’s wettability.

Advertisement

Synonyms

Young–Dupré Equation

Share this Term

  • Facebook
  • LinkedIn
  • Twitter

Related Reading

Tags

Preventative CoatingsScientific PropertiesSubstancesPaints and Plastics CoatingsPhysical Property MeasurementWater and WastewaterCoatingsEngineering and Spec Writing

Trending Articles

Go back to top