Carbon nanotube-coated silicated soft magnetic carbonyl iron microspheres and their magnetorheology

Core-shell structured magnetic microspheres were fabricated by coating the surface of silicated soft magnetic carbonyl iron particles with multi-walled carbon nanotubes using a facile layer-by-layer method involving an alternative sequential adsorption of positive and negative polyelectrolytes. The morphology of the fabricated particles was observed by scanning electron microscopy. The magnetorheological (MR) behavior affected by the non-magnetic coatings was examined using a rotational rheometer under a controlled magnetic field. The flow curves of typical MR characteristics with improved shear stresses were observed under a range of magnetic field strengths. (C) 2012 American Institute of Physics. [doi: 10.1063/1.3670603]