On the theory of viscoelastic properties of magneto- and electrorheological suspensions

Viscoelastic properties of magneto- and electrorheological suspensions cont aining chain linear aggregates are theoretically analyzed. The model develo ped makes it possible to predict that small amount of short chains is forme d in a suspension placed in a weak magnetic field. If the field strength ex ceeds some critical value depending on the concentration and substance comp rising particles, a peculiar phase transition presenting the formation of a large number of very long chains occurs in this system. Long chain aggrega tes essentially (by several decimal orders of magnitudes) change the macros copic physical properties of a suspension. Steady-state susceptibility, eff ective viscosity, parameters of viscoelasticity, and normal stresses of sus pensions with chain linear aggregates are estimated. The dependence of thes e parameters on an external field is studied.