A computational study of the stability ratios of spherical coloidal particles

We have examined numerically and analytically the validity of the usual assumptions implicit in the calculation of stability ratios of colloidal particles within the scope of DLVO theory for the description of aggregation phenomena. We found that the usual criterion, that requires the distance between the surfaces of the particles to be much smaller than the particle size is not sufficient to guarantee the appropriate behaviour of the integral that defines the stability ratio. The importance of additional constraints is of particular importance in the slow aggregation regime. We present a detailed study of the set of parameters that must be used in the DLVO potential such that the approximate expression for the stability ratio can be determined with an error smaller than 5% compared to the exact solution.