On the Theory of Phase Transitions in Magnetorheological Suspensions

The “condensation” of the particles of magnetorheological suspensions (MRSs) under the action of an external magnetic field is theoretically studied. The analysis demonstrated that the formation of rather long linear chain aggregates preceded the condensation of particles into the dense phase. The phase transition of the “gas-liquid” type proceeded in a particle ensemble via the “condensation” of such chains caused by their magnetic interaction. In thin MRS layers oriented perpendicular to the external magnetic field, the scenario of phase transition differs from that observed in systems with infinite volume. After the completion of the phase transition, the ensemble of dense domains discretely distributed in dilute dispersion is formed in thin layers rather than two simple connected phases with different particle concentrations, as it takes place in infinite media. Under fairly strong external magnetic fields, the transition of the “gas-solid” type occurs in a system of particles.