The characteristics of magnetic inductive heating and their impacts by the particle anisotropy and ferrofluid viscosity

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In recent decades, nanotechnology and nanoscience have been of great interest so they are
considered as a revolution in the 21st century. Nanotechnology encompasses design, analysis, fabrication
and application of structures, devices or systems by controlling the shape, size on a nanometer scale. The
subject of these technologies is nanomaterialsNanomaterials with very small sizes (about 1-100 nm) exhibit
exciting properties that are different from those of the bulk materials. Based on their size effects,
nanomaterials have open new applications in electronics, mechanics, environmental remediation, especially in biomedicine.
For dielectric and magnetic materials, inductive heating is the physical phenomenon by which the
materials become thermo-seeds when they are irradiated by proper alternating electromagnetic field. In the case of bulk magnetic materials, the Magnetic Inductive Heating (MIH) using alternative magnetic field
(AMF) relies on two mechanisms of energy dissipation, which are energy losses due to Joule heating and
energy losses associated with magnetic hysteresis. In nano scale, it is generally known that the energy losses associated with magnetic properties such as hysteresis loss and relaxation loss mainly contribute to the heating.
For biomedical applications, magnetic nanoparticles (MNPs) have to be dispersed in a solvable
solvent to create nano ferrofluids. MNPs are coated by a surfactant for preventing the nanoparticles from
aggregation and keeping them well dispersed for many years. So, the nano ferrofluids in fact consist of core, shell and solvent. Various magnetic nanoparticles such as magnetic metal nanoparticles, magnetic alloy nanoparticles or magnetic metal oxide nanoparticles have been used as the core of nanofluids. The shell materials can be polymer, copolymer or an oxide material. The fabrication of a magnetic nanofluids may be realized using water or other solvents such as benzyl ether, phenyl ether. It is generally known that there are many methods such as co-precipitation, sol – gel, solvo-thermal, hydrothermal, thermal decomposition or reverse micelle, normally used in synthesing MNPs . The size and size distribution or magnetic properties of nanoparticles depend on the synthesis method. Therefore, it is difficult to experimentally study the effect of one or more parameters of a nano ferrofluid on the physical phenomenon.