Van Der Waals forces are weak intermolecular attractive forces that hold closely various atoms and molecules without any physical linkage or bond.
The atoms or molecules participating in van Der Waals interactions are neutral, polar, or /and non-polar ones. Ion interactions are stronger and are classified separately from the weaker van Der Waal interactions.
The weaker van der Waal force works only within a short range. If the distance between the atoms or molecules increases, their attractive Vander Waal interactions weaken.
Few examples below illustrate van Der Waal forces-
1) The structure of protein molecules is quite complex. Van der walls forces are responsible for maintaining the structural integrity of proteins. Different structural forms are closely associated with using van Der Waal forces to obtain the functional form of protein, its quaternary structure.
2) The graphite consists of a honeycomb lattice of carbon atoms that are stacked on each other. These layers are held using van Der Waals forces that allow the layers to glide past each other and easily separate.
3) A polymer chain is long and is formed of several monomer units. Therefore, the monomer is a basic building block of a polymer chain. For example, polyethylene is a polymer that consists of repeated units of monomer ethylene. The polymer chains are held together with the help of van der Waals forces to give the final plastic material.
Vander Wall Forces are of three types depending on the nature of interacting atoms and molecules.
The above excerpt supports the chapter Intermolecular Forces part of CurlyArrows' Introductory Organic Chemistry Course. Preview the Book.
Related Reading: Introduction to the van Der Waal force with examples