Monte Carlo simulation of interactions between nano-particles

The effective potential of interaction between two particles in a colloidal dispersion involves the interactions between the two particles as well as their interactions with all other particles of the system. The above potential has been calculated via Monte Carlo simulations, for volume fractions of solid particles varied between 0.005 and 0.24, for van der Waals and electrostatic pair interactions, or only van der Waals pair interactions. The results show that in the first case the effective potential is affected by van der Waals interactions only for short distances between the two particles. When the pair potential involves only van der Waals interactions, in addition to the attractive potential between the two particles a repulsive potential caused by the attraction between the two particles and all the other particles of the system can occur. When the pair potential involves only a repulsive electrostatic component, an attractive potential can be generated by the repulsion between the two particles and all the other particles of the system.