Rapid Millifluidic Synthesis of Stable High Magnetic Moment FexCy Nanoparticles for Hyperthermia.

Katerina Loizou,Orestis Kalogirou,Stefanos Mourdikoudis,Maximilian Otto Besenhard,Nguyen Thi Kim Thanh,Charalampos Sarafidis,Asterios Gavriilidis,Shinya Maenosono,Andreas Sergides,Koichi Higashimine

doi:10.1021/acsami.0c06192

Abstract

A millifluidic reactor with a 0.76 mm internal diameter was utilized for the synthesis of monodisperse, high magnetic moment, iron carbide (FexCy) nanoparticles by thermal decomposition of iron pentacarbonyl (Fe(CO)5) in 1-octadecene in the presence of oleylamine at 22 min nominal residence time. The effect of reaction conditions (temperature and pressure) on the size, morphology, crystal structure, and magnetic properties of the nanoparticles was investigated. The system developed facilitated the thermal decomposition of precursor at reaction conditions (up to 265 °C and 4 bar) that cannot be easily achieved in conventional batch reactors. The degree of carbidization was enhanced by operating at elevated temperature and pressure. The nanoparticles synthesized in the flow reactor had size 9–18 nm and demonstrated high saturation magnetization (up to 164 emu/gFe). They further showed good stability against oxidation after 2 months of exposure in air, retaining good saturation magnetization values with a change of no more than 10% of the initial value. The heating ability of the nanoparticles in an alternating magnetic field was comparable with other ferrites reported in the literature, having intrinsic loss power values up to 1.52 nHm2 kg–1.

Highlights

The synthesis of well-controlled magnetic nanomaterials has been of great interest during the past couple of decades as these materials have a plethora of applications in the field of high-density magnetic recording media and biomedical nanotechnology.[1−4] In particular, magnetic nanoparticles have been receiving increased attention due to their suitability as therapeutic and diagnostic agents in magnetic resonance imaging (MRI) and magnetic particle imaging (MPI)[5] as well as thanks to their potential for cancer treatment via magnetically induced hyperthermia.[1]
The method of hot injection is employed, where Fe(CO)[5] is injected in a preheated solvent/ ligand mixture typically at 180 °C under an inert atmosphere. This system was translated to flow with some modification: all the reactants were premixed under an inert atmosphere and introduced to the capillary reactor that was heated to the required temperature
We have investigated the synthesis of FexCy nanoparticles in a continuous millifluidic system

Summary

Introduction

The synthesis of well-controlled magnetic nanomaterials has been of great interest during the past couple of decades as these materials have a plethora of applications in the field of high-density magnetic recording media and biomedical nanotechnology.[1−4] In particular, magnetic nanoparticles have been receiving increased attention due to their suitability as therapeutic and diagnostic agents in magnetic resonance imaging (MRI) and magnetic particle imaging (MPI)[5] as well as thanks to their potential for cancer treatment via magnetically induced hyperthermia.[1] Magnetic fluid hyperthermia causes the increase of temperature locally upon application of an alternating magnetic field that can destroy mostly the tumor tissue, without harming surrounding healthy cells.[1,6] The most common magnetic nanoparticles studied for hyperthermia cancer treatment are iron oxide nanoparticles (IONPs). They are reported to offer a trade-off between the stability against oxidation in solution, which is comparable to iron oxide nanoparticles, while offering superior heating abilities.[8]

Methods

Results

Conclusion