A hypernetted chain structure factor for charged colloidal dispersions

Abstract

The structure factor for charged colloidal dispersions is obtained by solving the multicomponent hypernetted chain (HNC) equation in the framework of the primitive model. To remove the instability of an ordinary iterative method, the iteration process is separated into two parts, and the Newton–Raphson method is applied in one of these cases. By using this method, we can obtain the solution for states close to the spinodal line. The height of the first peak of the structure factor S(k_max ) is plotted as a function of colloidal charge, and is found to have a maximum near this spinodal line. The maximum of S(k_max ) is larger than the result of the jellium approximation and agrees well with experimental results of small angle neutron scattering at moderate colloidal concentration.