Colloquium January 23

Date: Friday, January 23

Time: 16:00 to 17:00

Place: 455 McBryde (Commons Room)

Speaker: Philip Yecko of Montclair State Univ

Title: Looking into Magnetic Liquids

Abstract: Magnetic liquids, or Ferrofluids, are dilute colloidal suspensions of magnetic nanoparticles in a carrier liquid. Because they are easily manipulated with modest magnetic fields, ferrofluids are in use in a wide range of applications. Continuum descriptions of their behavior are complicated by the presence of asymmetric and magnetic field dependent stresses and by the need for phenomenological models of the magnetization. In this talk I will describe recent work at Montclair State University and the Advanced Photon Source at Argonne National Laboratory in which direct numerical simulations and high resolution, high energy X-ray imaging are used to examine complex multiphase flows of ferrofluids. Flows involving single and multiple bubbles and droplets reveal that chaining of bubbles is common, as is the chaining of magnetic nanoparticles. The first case leads to significant changes in the bulk flow characteristics while the second case leads to changes in the basic material properties, such as the viscosity. In these ways, ferrofluids can be controlled both macroscopically and microscopically; potential future applications of these unique liquids are discussed.


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