Adsorption of polymer coated magnetite composite particles onto carbon nanotubes and their magnetorheology

Polymer coated nano-sized magnetite (Fe3O4) Particles with multiwalled carbon nanotube (MWNT) nanohybrid were prepared by four step procedures in this Study. Initially, magnetic particles were synthesized by a co-precipitation method with ammonium hydroxide and oleic acid, and then the produced particles were coated with polyacrylamide (PAAm). Finally PAAm coated magnetite particles (Mag-PAAm) were physically adsorbed onto multiwalled carbon nanotubes (MWNT) under ultrasonication. Transmission electron microscopy (TEM) was used to investigate the formation of Mag-PAAm-MW nanohybrids nanostructure, confirming that prepared Mag-PAAM particles were well adsorbed onto the surfaces of MWNT. In addition, MR characteristics of PAAm coated magnetite particles with MWNT (Mag-PAAm-MW) nanohybrids were investigated under six different external magnetic field strengths via a rotational rheometer, exhibiting typical MR behavior of yield stress and shear stress. (C) 2009 Elsevier B.V. All rights reserved.