softmatter:Van der Waals interaction
From NSDL Materials Digital Library Soft Matter Wiki
Van der Waals interactions are a type of intermolecular interactions arising from dipoles. There are three types of van der Waals interactions:
- Keesom interactions, which are a result of permanent dipoles
- Debye interactions, which are a result of induced dipoles
- Dispersion (London) interactions, which are a result of fluctuating dipoles.
The total van der Waals interaction is of the form:
where,
![C = \frac{1}{(4\pi\epsilon_{0})^2} \left[(u_{1}^2\alpha_{02}+u_{2}^2\alpha_{01})+\frac{u_{1}^{2}u_{2}^{2}}{3K_{B}T}+\frac{3\alpha_{01}\alpha_{02}h\nu_{1}\nu_{2}}{2(\nu_{1}+\nu_{2})}\right]](/matdlwiki/images/math/3/d/d/3dd64347818c66b71e86df194beed5a7.png)
.
- u1 and u2 are the permanent dipole moments of atom/molecules 1 and 2.
- α0's are the polarizibilities
- ν's are the ionization frequencies
- h is Planks constant (6.625 x 10 -34 J
s )
- ε0 is the permittivity of free space (8.8 x 10 -12 C2J-1m-1)
The last term term in C represents dispersion (London) interactions.
Additional Sources
- van der Waals interactions are addressed in depth in chapter 2.3 of the first edition of The Structure and Rheology of Complex Fluids starting on page 78.
