Chain Dynamics in Magnetorheological Suspensions
نویسنده
چکیده
Magnetorheo]ogical (MR) fluids are colloidal suspensions of pammagnetic particles in a non-magnetic fluid. These fluids, along with their electrical analogues, electrorheologica] (ER) fluids, have been proposed as controllable fluids, for use in electromechanical devices such as dampers, clutches and brakes. [1] When exposed to an external magnetic field, the particles acquire dipole moments aggregate to form chains in the field direction. The fluid structure depends on the volume fraction; dilute suspensions form weakly-interacting singleparticle chains, while when more concentrated, the particle chains cross-link laterally into a dense network. The latter structure is responsible for the unique rheo/ogical properties of MR fluids: the quick formation of a network in response to an external field creates a rapid liquid-to-solid transition. Aside from their practical applications, MR fluids are of fundamental interest because they allow us to probe the structure and dynamics of a suspension of particles interacting via a "tunable" anisotropic interaction.
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