The viscosity of a moderately dense suspension of particles with piece-wise constant potentials of interaction

A recently developed formalism is used to construct an expression for the viscosity second virial coefficient (proportional to the Huggins coefficient) of a monodisperse suspension of spherical colloid particles with piece-wise constant potentials of interaction. Numerical values are generated for the two special cases of square-well and square-step potentials, both with stick boundary conditions at the solute–solvent interface. Also, presented is a demonstration that the so-called “sticky-sphere” model is incapable of representing a suspension of particles interacting with a square-well potential.