Synthesis, characterization and magnetorheological properties of carbonyl iron suspension with superparamagnetic nanoparticles as an additive

• Main Authors: Nikmat Leong, Siti Asma, Mohd. Samin, Pakharuddin, Idris, Ani, Mazlan, Saiful Amri, A. Rahman, Azura Hanis
• Format: Article
• Published: Institute of Physics Publishing 2016
• Subjects: TL Motor vehicles. Aeronautics. Astronautics
• Online Access: http://eprints.utm.my/id/eprint/73955/; https://www.scopus.com/inward/record.uri?eid=2-s2.0-84957044487&doi=10.1088%2f0964-1726%2f25%2f2%2f025025&partnerID=40&md5=e9162d4d9a7b53d2026d17d27bec3bda

Magnetorheological (MR) fluids are suspensions of micron-sized particles dispersed in carrier fluid. Due to high density magnetic particles, MR fluids are facing the problem with the instability of the suspension caused by high settling rate. Recently, researches have been conducted on the advantages of using the mixture of magnetic nanoparticles and microparticles, called bidisperse MR fluids. However, even though the sedimentation stability is improved, there is a reduction in dynamic yield stress when the nanoparticle is introduced. In this work, the investigation of magnetic iron nanoparticles (γ-Fe2O3) as an additive to magnetic carbonyl iron (CI) suspension has been proposed so as to improve the sedimentation stability and redispersibility, but at the same time enhance the MR performance. The results indicated that the addition of nanoparticles reduced the sedimentation rate, improved redispersibility and enhanced the rheological performance of MR fluids as the particle fill the voids between the microparticles and strengthened the interparticle chains contributing to well-arranged particle structures