 Derjaguin approximation

The Derjaguin approximation is a concept in colloid and surface science that helps to estimate the interaction forces between spherical particles or between a spherical particle and a flat surface. It is particularly useful in the context of colloidal suspensions and thin films, where understanding the forces acting between particles is essential for predicting their behavior. The Derjaguin approximation states that the interaction force between two spheres can be approximated by considering the force between a flat surface and a sphere.