Affiliation: | a Research and Engineering Company “Phores”, Kiev, Ukraine b Institute of Physical Chemistry, Leninsky Prospect 31, Moscow 117915, Russian Federation c Institute of Theoretical Physics, Kiev, Ukraine |
Abstract: | The spontaneous time evolution of systems containing N colloidal particles (N = 12, 24, 100) in a spherical cell of volume V at a constant volume fraction φ=0.1 was studied by a molecular dynamics method in the NVT ensemble. The starting velocities of the particles are allocated according to the Maxwell distribution at T=273 K. Pairwise interaction of the particles was specified by molecular, electrostatic and elastic forces. The changes in the potential energy of the systems were calculated during the establishment of dynamic equilibrium. Coagulation takes place at sufficiently high values of the Hamaker constant. The value of the coefficient of Brownian diffusion, which is calculated from the half-time of coagulation, is found to be close to the known value for aqueous dispersions. The inclusion of electrostatic forces prevents coagulation. The results obtained are in agreement with those obtained using theories of aggregate formation. Some structural characteristics of aggregates and stable systems are discussed. |