Experimental study of fundamental mechanisms in inductive heating of ferromagnetic nanoparticles suspension (Fe3O4 Iron Oxide Ferrofluid)

Abstract

An experimental investigation of the initial heating rate of 50 nm ferromagnetic nanoparticles (Fe3O4) suspended in water and incorporated in an agar gel was conducted to study the thermal heating effects resulting from Brownian motion and hysteresis losses. Particles were placed in an alternating current magnetic field with intensities of 28.6, 35.8, 38.9, and 43.0 kA m−1, at frequencies ranging from 161 to 284 kHz. The specific absorption rate based on the heating rate was calculated and the contributions from the Brownian motion and hysteresis losses are compared and analyzed.

Magnetization and Specific Absorption Rate Studies of Ball-Milled Iron Oxide Nanoparticles for Biomedicine

“…Specific absorption rate measurements were taken by placing a sample of 0.5 mL ferrofluid solution (20% of ferrofluid in hexane by weight) in an alternating magnetic field created inside a water-cooled solenoid, as previously described [8]. An alternating current (AC) of 191.2 A amplitude and 282 kHz frequency was used to generate an alternating magnetic field strong enough to cause combined Néel and Brownian relaxation [8] in the nanoparticle solution.…”

“…An alternating current (AC) of 191.2 A amplitude and 282 kHz frequency was used to generate an alternating magnetic field strong enough to cause combined Néel and Brownian relaxation [8] in the nanoparticle solution. An optical temperature sensor (Neoptix Nomad portable fiber optic thermometer) was placed inside the sample to record the temperature of the solution as a function of exposed time to the AC magnetic field.…”

“…With the means of achieving subsingle-magnetic domain particle sizes through various physical and chemical methods [9][10][11][12][13][14], superparamagnetic particles in the form of ferrofluids can be attained. When subjected to a magnetic field whose direction alternates rapidly, ferrofluids can absorb electromagnetic energy, which is readily dissipated to their environment by Brownian (particle rotation) and Néel (moment reorientation) relaxation mechanisms [8]. In vitro studies indicate that these processes result in heat dissipation and an increase in local temperature.…”

“…Research in nonsurgical means for cancer treatment is vigorously being pursued, in an effort to efficiently eradicate cancerous cells via chemical or physical processes without collateral damage to neighboring healthy tissue, most notably through the use of magnetic nanoparticles for targeted drug delivery and for localized heating by absorption of electromagnetic radiation [1][2][3][4][5][6][7][8]. Hyperthermia cancer treatment is possible due to the capabilities of manufactured nanoparticles.…”

Aminooxy reagents in nanomedicine and bioanalysis.

“…This can take place through a few different mechanisms depending upon the size of the particles as illustrated in Figure 1.7. 49 In the case of small superparamagnetic NPs (<20 nm diameter),…”