Investigation about suitability of hard core attractive Yukawa potential as a model potential for short-range attractive interactions in colloidal dispersions

An investigation is carried out about the suitability of mapping attractive short-range potential of colloidal systems onto both hard core attractive Yukawa (HCAY) potential and adhesive hard sphere (AH) potential for prediction of the solid-liquid (S-L) transition. Asakura and Oosawa's depletion potential of asymmetrical binary hard sphere mixture is taken as example of the attractive short-range potential. The S-L transition of the AH potential is based on a modified weighted density approximation, and that of the HCAY potential is based on first order thermodynamic perturbation theory for solid phase and a recently proposed analytical expression for the free energy of fluid phase. It is found that the second virial coefficient can be served as a tool for mapping between similar but different potentials for the case of S-L transition as well as for the case of fluid structure properties, and the HCAY potential is more suitable as a mapping potential than the AH potential.