Control of Magnetic Particle Size in Ferrofluid and Its Effect on Rheological Properties  

作　　者：Siyu Chen Decai Li 

机构地区：[1]State Key Laboratory of Tribology,Tsinghua University,Beijing 100084,China

出　　处：《Chinese Journal of Mechanical Engineering》2022年第3期227-235,共9页中国机械工程学报（英文版）

基　　金：National Natural Science Foundation of China(Grant Nos.51927810,51735006,U1837206);Beijing Municipal Natural Science Foundation of China(Grant No.3182013).

摘　　要：Rheological properties are the theoretical basis and the key to common problems in ferrofluid applications,therefore they are expected to be adjustable to satisfy different technical requirements through altering the microstructure of ferrofluid during the process of preparation.In this paper,Four ferrofluid samples with different magnetic particle size were prepared by controlling the concentration of precursor solution during co-precipitation process and the rheological properties of these samples were investigated.These samples exhibited field-controlled rheological properties.Eternal magnetic field would enhance the formation of microstructures,resulting in an increase of viscosity.While with the increase of shear rate,microstructures tended to be destroyed,causing viscosity to decrease.There were two opposing mechanisms of the influence of precursor solution concentration.On one hand,the reduction of the precursor solution concentration would produce primary magnetic particles of smaller size.But on the other hand,the surfactant became insufficient to completely coat the magnetic particles because of an increased specific surface area,causing the magnetic particles to aggregate and form secondary clustering structures which strongly enhanced the magnetoviscous effect and weakened the viscoelastic effect.

关 键 词：FERROFLUID RHEOLOGY Magnetoviscous effect Viscoelastic effect 

分 类 号：TB381[一般工业技术—材料科学与工程]