Fabrication of magnetite-coated attapulgite magnetic composite nanoparticles and their magnetorheology

We synthesized magnetite (Fe3O4) -coated attapulgite clay magnetic composite particles via a co precipitation method and investigated their magneto-responsive characteristics. Along with examination of their physical characteristics using transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and vibrating sample magnetometer patterns, the magneto-responsive properties of the fabricated magnetic composite particles when dispersed in non-magnetic carrier fluid were examined using a rotational rheometer under various external magnetic field strengths. The flow curves revealed a typical Bingham fluid behavior under applied magnetic field, and the slope of the dynamic yield stress as a function of magnetic field strength was 1.5. (C) 2016 Elsevier B.V. All rights reserved.