Plasma-treated carbonyl iron particles as a dispersed phase in magnetorheological fluids

Magnetorheology: a review

Magnetic Soft Matter is a rapidly evolving discipline with fundamental and practical interest. This is due to the fact that its physical properties can be easily controlled through external magnetic fields. In this review paper, we revisit the most recent progress in the field (since 2010) emphasizing the rheological properties of these fascinating materials. New formulations and flow kinematics are discussed. Also, new members are integrated into the long-lived magnetorheology family and suggestions are provided for future development.

Two-dimensional Fe3O4/MoS2 nanocomposites for a magnetorheological fluid with enhanced sedimentation stability

Superparamagnetic Fe₃O₄ nanoparticles were successfully deposited on the surface of MoS₂ nanosheets (Fe₃O₄/MoS₂) by a sonochemical method and the obtained Fe₃O₄/MoS₂ nanocomposites were used as a promising candidate for a magnetorheological (MR) fluid. This MR fluid was prepared from the Fe₃O₄/MoS₂ nanocomposites and its corresponding MR performances were examined using a rotational rheometer. The MR fluid based on Fe₃O₄/MoS₂ showed typical MR effects with increasing viscosity, shear stress, yield stress and dynamic shear modulus depending on the applied magnetic fields. Compared with commercial carbonyl iron (CI) particles, the sedimentation stability of the Fe₃O₄/MoS₂-MR fluid was greatly improved because of its unique two-dimensional structure and the reduced fluid-particle density mismatch. Therefore, the prepared Fe₃O₄/MoS₂-based MR fluid with typical MR effects and good sedimentation stability would have great potential in practical applications.

The chemical stability and cytotoxicity of carbonyl iron particles grafted with poly(glycidyl methacrylate) and the magnetorheological activity of their suspensions

Carbonyl iron (CI) particles were grafted with poly(glycidyl methacrylate) (PGMA) using atom transfer radical polymerization with suitable cytotoxicity and improved anticorrosion stability.

The enhanced magnetorheological performance of carbonyl iron suspensions using magnetic Fe3O4/ZHS hybrid composite sheets

The facile two-step microwave-assisted synthesis of Fe₃O₄/ZHS hybrid composite sheets with 2D morphology considerably improves the MR performance and suspension redispersibility.

To the theory of rheological properties of magnetopolymer suspensions

This paper deals with the theoretical study of the magnetorhelogical properties of dilute suspensions of polymer coils with ferromagnetic nanoparticles adsorbed on the macromolecules. The analysis shows that, under an applied magnetic field, these coils elongate in the field direction and swell. Both these factors lead to a significant increase in the effective viscosity of the system. Estimates show that in the magnetopolymer compositions, strong magnetoviscous effects are expected even though in standard ferrofluids these effects are negligible.