When two particles approach each other, interparticle attraction can result due to the van der Waals potential between the molecules of the two bodies. As a result, particles can adhere to each other, especially for fine particles, i.e., less than 100
μm. As discussed in detail in
Seville et al. (1997), the van der Waals attractive potential for two molecules in vacuum can be given as
Using pair-wise addition,
Hamaker (1937) analyzed the adhesive force between two rigid spherical particles at a separation distance
s, for which ...