What is the hydrophobic effect?

The hydrophobic effect refers to the tendency of nonpolar molecules to cling together when placed in water. Oil floating on water and water beading on waxy surfaces are examples of the hydrophobic effect.

Water molecules form strong hydrogen bonds with each other. When nonpolar compounds make contact with water, they disrupt the hydrogen bonds of the water molecules. This results in the water molecules reforming around the nonpolar compound, creating a cage-like structure. This is known as the clathrate cage. This promotes clumping of the nonpolar compounds to each other and discourages them from dissolving into the water. Biologically, the hydrophobic effect contributes to the folding of proteins.