(538f) Magnetorheological Emulsions: Synthesis and Properties

Magnetorheological fluids (MRFs) are a type of smart fluid that can change their rheological properties in response to an external magnetic field. They are composed of magnetic particles dispersed in a carrier fluid, and their rheological behavior can be precisely controlled by adjusting the magnetic field strength.

Magnetorheological emulsions (MREms) are a type of MRF that has an increased shear strength, without additional increase to field strength, due to the presence of emulsions. MREms are composed of two immiscible liquids, such as oil and water, that are stabilized by a surfactant, and magnetic particles that are dispersed within the continuous phase. When a magnetic field is applied to the MREm, the magnetic particles align themselves along the field lines, leading to a change in the viscosity and rheological properties of the emulsion. Of critical importance are the MREm properties that most impact their behavior.

First, we will discuss the emulsification process, including the use of emulsifying agents and the optimization of the emulsification conditions. We will also describe the method that has been developed for the preparation of MREms, including continuous phase and magnetic particle selections.

We will then discuss the factors that influence the rheological behavior of MREms, including the volume fraction and size distribution of emulsions, the strength of the magnetic field, and the viscosity and density of the base liquids. We also describe the magnetization behavior of MREms and how it affects their response to an external magnetic field. Finally, we discuss the stability of MREms, including the factors that can lead to aggregation or creaming.

The ability of MREms to change their rheological properties in response to an external magnetic field makes them attractive for a wide range of applications in various fields. Further research is needed to explore the full potential of MREms and to develop new and innovative applications for these smart fluids.