Synthesis of Temperature-Sensitive Magnetic Microcapsules and Visualization of Cluster Formation

• Published in: IEEE magnetics letters Vol. 10; pp. 1 - 4
• Main Authors: Ishii, Keiko, Aizawa, Ryota, Fumoto, Koji
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Computational fluid dynamics; Electrons; Fluid flow; Fluids; Ion beams; Kerosene; Magnetic fields; magnetic fluid; Magnetic fluids; Magnetic force microscopy; Magnetic Instruments; Magnetic liquids; Magnetic materials; Magnetic particles; Magnetism; microcapsule; Microencapsulation; Scanning electron microscopy; Synthesis; Temperature gradients; temperature-sensitive magnetic fluid; visualization; Working fluids
• ISSN: 1949-307X; 1949-3088
• DOI: 10.1109/LMAG.2019.2945536

Temperature-sensitive magnetic fluids flow spontaneously in a magnetic field when there is a temperature difference and thus may be used in cooling devices operated without external power. However, magnetic fluids are difficult to mass-produce, and the dispersion ability of the working fluid cannot be controlled. We use magnetic material encapsulated in microcapsules of large diameter to function as a new type of refrigerant. By enclosing the magnetic material in capsules, they can be used with any working fluid. We made solid particles containing kerosene-based magnetic fluid in polymer. When a magnetic field was applied, the particles aggregated and formed clusters. A scanning electron microscope and focused ion beam system were used to determine the particle shapes. Particles 5-50 μm in size could be created by varying the rotation speed of the homogenizer during the synthesis.