Fluid of hard spheres with dipolar-like patch interaction and effect of adding an isotropic adhesion

Abstract

Abstract\n We compare two fluid models of spherical molecules with anisotropic, \npurely surface interactions. Both models admit an analytical solution of the \nmolecular Ornstein-Zernike integral equation, within the Percus-Yevick \napproximation plus orientational linearization. In the first model, the \nmolecular surface corresponds to a unique nonuniform patch, with a potential \nobtained by truncating a long-ranged dipolar interaction exactly at the \ncontact distance between two hard sphere particles. In the second model, a \nfurther isotropic adhesion is added to the intermolecular potential. The \nstudy is focused on the local orientational ordering. Differences and \nsimilarities with respect to hard spheres with full long-ranged dipolar \nforces are analysed in detail. The effect of the competition between \nanisotropic patch interaction and isotropic adhesion is investigated through the \npair correlation function as well as via two novel anisotropic order \nparameters.