Preparation and characterization of carbonyl iron/strontium hexaferrite magnetorheological fluids--颗粒学报PARTICUOLOGY

Liu, J., Wang, X., Tang, X., Hong, R., Wang, Y., & Feng, W. (2015). Preparation and characterization of carbonyl iron/strontium hexaferrite magnetorheological fluids. Particuology, 22, 134-144. https://doi.org/10.1016/j.partic.2014.04.021

Preparation and characterization of carbonyl iron/strontium hexaferrite magnetorheological fluids

Jianrong Liu ^{a b}, Xianjun Wang ^b, Xia Tang ^a, Ruoyu Hong ^{a b c *}, Yaqiong Wang ^c, Wenguo Feng ^d

a College of Chemistry, Chemical Engineering and Materials Science & Jiangsu Provincial Key Laboratory of Organic Synthesis, Soochow University, Suzhou 215123, China
b School of Chemical Engineering, Fuzhou University, Fuzhou 350108, China
c Jiangsu Provincial Key Laboratory of Environmental Materials and Engineering, Yangzhou University, Yangzhou 225002, China
d Suzhou Nanocomp Inc., Suzhou New District, Suzhou 215011, China

10.1016/j.partic.2014.04.021

Volume 22, October 2015, Pages 134-144

Received 17 December 2013, Revised 3 April 2014, Accepted 13 April 2014, Available online 15 November 2014, Version of Record 4 August 2015.

E-mail: rhong@suda.edu.cn

Highlights

• Carbonyl iron/strontium hexaferrite (SrFe₁₂O₁₉) magnetorheological fluids (MRFs) were prepared.

• Stability of carbonyl iron-based MRFs was improved remarkably by adding SrFe₁₂O₁₉ nanoparticles.

• MRF's shear stress could be predicted using improved Herschel–Bulkley model.

• A theoretical model was proposed to predict MRF's yield stress under an applied magnetic field.

Abstract

The heat transfer oil-based magnetorheological fluid (MRF) was prepared using oleic acid-modified micron carbonyl iron powder as a magnetic dispersed phase and strontium hexaferrite (SrFe₁₂O₁₉) nanoparticles as an additive. The sedimentation stability of MRFs was studied. The results indicated that the stability of MRFs was improved remarkably by adding SrFe₁₂O₁₉ nanoparticles and the sedimentation ratio was only 0.88 in 20 days when the content of nanoparticles reached 10 wt%. The rheological properties were characterized by a HAAKE rheometer without a magnetic field and a capillary rheometer with and without a magnetic field. The effects of SrFe₁₂O₁₉ nanoparticles, the temperature, and magnetic field strength were investigated. In addition, the rheological properties could be predicted well using the improved Herschel–Bulkley model, even under a magnetic field. A theoretical model was also proposed to predict the yield stress based on the microstructure of the MRF under an applied magnetic field.

Graphical abstract

Keywords

Strontium hexaferrite; Magnetorheological fluid; Stability; Rheological property

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