Title :
Octahedral shaped magnetite nanoparticle added carbonyl iron suspension and its magnetorheology
Author :
Kwon, S. ; Jung, H. ; Choi, H.
Author_Institution :
Dept. of Polymer Sci. & Eng., Inha Univ., Incheon, South Korea
Abstract :
Magnetorheological (MR) fluids, magnetic particles such as carbonyl iron (CI) and magnetite dispersed in a nonmagnetic liquid, change tunably and reversibly from a liquid-like to a solid-like state under applied magnetic field strengths, thus possessing huge engineering applications. Among the many magnetic particles available, CI microspheres have been widely used as magnetizable particles for MR fluids due to their high magnetic permeability, soft magnetic property and common availability. However, their high density causes serious sedimentation drawback and abrasion within equipment of application . A range of strategies including the introduction of additives or coating technologies to the particles have been reported to prevent the CI particles from caking or decreasing the particle density, thereby reducing the sedimentation rate . Three major methods have been applied to improve the sedimentation stability of MR fluids . These include adding surfactants, adding nanoparticles or using nanomagnetizable particles or coating magnetizable particles with polymer. In this study, we used octahedral shaped Fe3O4 nanoparticles as an additive for the CI based MR fluids to solve the sedimentation problem . MR properties of two MR fluid systems with and without the octahedral shaped Fe3O4 nanoparticles were examined using a rotational rheometer with magnetic field supply device .
Keywords :
additives; coatings; iron; iron compounds; magnetic particles; magnetic permeability; magnetorheology; nanoparticles; sedimentation; soft magnetic materials; surfactants; suspensions; CI based MR fluids; Fe3O4-Fe; abrasion; additive; applied magnetic field strengths; carbonyl iron; carbonyl iron suspension; coating technology; liquid-like state; magnetic field supply device; magnetic particles; magnetic permeability; magnetizable particles; magnetorheological fluids; microspheres; nonmagnetic liquid; octahedral shaped magnetite nanoparticle; particle density; rotational rheometer; soft magnetic property; solid-like state; surfactants; Fluids; Iron; Magnetic fields; Magnetic liquids; Magnetic resonance imaging; Magnetomechanical effects; Soft magnetic materials;
Conference_Titel :
Magnetics Conference (INTERMAG), 2015 IEEE
Conference_Location :
Beijing
Print_ISBN :
978-1-4799-7321-7
DOI :
10.1109/INTMAG.2015.7157581