Van der Waals force is the attraction of one molecule to another as a result of the molecules being slightly polar in charge. Van der Waals forces are responsible for many properties of water.
Molecules that are neutral may be slightly more positive at one pole. When these molecules interact with other molecules that have the same dipolar property, the positive end of one molecule attracts the negative end of the other molecule, creating a very weak bond.
Water is one example of the effect of van der Waals forces. The attraction of the positive end of a water molecule to the negative end of another makes water adhere to itself. This property of water is known as cohesion. Cohesion is responsible for the ability of water to move upward against gravity in small spaces, such as the fiber of a plant. Water also exhibits a tendency to adhere to other surfaces as a result of van der Waals forces. Cooling water breaks the attraction created by van der Waals forces, causing the molecules to expand.
Van der Waals force is named after Johannes Diderik van der Waals. He is credited with discovering this phenomenon while experimenting with critical temperatures in gases.