On the viscosity of magnetic fluid with low and moderate solid fraction--颗粒学报PARTICUOLOGY

Ren, Z., Han, Y., Hong, R., Ding, J., & Li, H. (2008). On the viscosity of magnetic fluid with low and moderate solid fraction. Particuology, 6(3), 191–198. https://doi.org/10.1016/j.partic.2008.01.004

On the viscosity of magnetic fluid with low and moderate solid fraction

Zhiqiang Ren ^a, Yanping Han ^a, Ruoyu Hong ^a^b *, Jianmin Ding ^c, Hongzhong Li ^b

a Department of Chemical Engineering and Key Laboratory of Organic Synthesis of Jiangsu Province, Soochow University, SIP, Suzhou 215123, China
b State Key Laboratory of Multiphase Reaction, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080, China
c IBM, HYDA/050-3 C202, 3605 Highway 52 North, Rochester, MN 55901, USA

10.1016/j.partic.2008.01.004

Volume 6, Issue 3, June 2008, Pages 191-198

Received 10 April 2007, Accepted 26 January 2008, Available online 14 May 2008.

E-mail: rhong@suda.edu.cn

Highlights

Abstract

The design of a pressurized capillary rheometer operating at prescribed temperature is described to measure the viscosity of magnetic fluids (MFs) containing Fe₃O₄ magnetic nanoparticles (MNPs). The equipment constant of the rheometer was obtained using liquids with predetermined viscosities. Experimentally measured viscosities were used to evaluate different equations for suspension viscosities. Deviation of measured suspension viscosities from the Einstein equation was found to be basically due to the influence of spatial distribution and aggregation of Fe₃O₄ MNPs. By taking account of the coating layer on MNPs and the aggregation of MNPs in MFs, a modified Einstein equation was proposed to fit the experimental data. Moreover, the influence of external magnetic field on viscosity was also taken into account. Viscosities thus predicted are in good agreement with experimental data. Temperature effect on suspension viscosity was shown experimentally to be due to the shear-thinning behavior of the MFs.

Graphical abstract

Keywords

Rheology; Capillary rheometer; Magnetic fluid; Viscosity; Peclet number

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