A dissipative particle dynamics method for modeling the geometrical packing of filler particles in polymer composites

A method is presented for modeling the geometrical packing of polydisperse mixtures of both spherical and nonspherical particles, which are models for filler particles used in the manufacture of polymer composites. The techni que is based on the calculation of the dissipative dynamics of an ensemble of fused soft spheres at constant temperature and pressure. After validatio n of the method at low pressures by comparison with analytical equations of state for monodisperse and binary mixtures of hard spheres, the random pac king of fused soft sphere cubes was studied. The effect of packing cubes to gether with spheres of varying size was then examined, with the aim of deve loping an understanding of how to minimize the amount of void space in comp osites containing angular particles. In one case, entropically driven demix ing was observed in a cube-sphere mixture. (C) 2000 American Institute of P hysics. [S0021- 9606(00)50846-0].