Mechanism of coagulation of disperse elements in media isolated from external actions

A physical model of the experimentally observed coagulation (the mutual approach) of spherical liquid, solid, and gaseous disperse elements (of diameter of up to1 cm) in polar liquid and viscoelastic thixotropic matrices when the system is completely isolated from the external forces and the gradient temperature and concentration fields is proposed. It is shown that a weak stress-field gradient is formed in a polar liquid or viscoelastic matrix in the presence of interphase at the matrix-spherical disperse element interface, i.e., when the capillary pressure is negative at the convex boundary of the matrix. If the second disperse particle enters into this field, the resulting force acts on it in the direction of the first particle, thus ensuring their coagulation over large time lapses. Lavrent’ev Institute of Hydrodynamics, Siberian Division, Russian Academy of Sciences, Novosibirsk 630090. Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 40, No. 4, pp. 156–161, July–August, 1999.