The nature of van der waals forces

Abstract The last few years have seen tremendous advances in our understanding of van der Waals forces. In this article we shall first survey the common types of forces that exist between atoms and molecules, and then concentrate on van der Wads forces. These forces are always present, so that they play a role in a host of different phenomena (for example, surface tension, adhesion, the strength of solids, the stability of membranes and colloidal suspensions). But van der Waals forces have also remarkably varied properties: they may be attractive or repulsive; they may align molecules relative to each other; they may deform the shapes of large bodies, and they may promote the migration of molecules across interfaces. In the first part of this article the different aspects of these forces are discussed with illustrations of how they determine or are otherwise involved in a wide range of important phenomena in physics, chemistry and biology. The second part will be devoted to a description of recent experim...