Synthesis of finest superparamagnetic carbon-encapsulated magnetic nanoparticles by a plasma expansion method for biomedical applications

Abstract

This paper demonstrates fine size-controlled synthesis of superparamagnetic carbonencapsulated iron nanoparticles, by a supersonic plasma jet assisted rapid, bulk-production process, by manipulation of the pressure in the sample collection chamber. Transmission electron microscopy and small angle x-ray scattering measurements confirmed the formation of single-crystals with a narrow size distribution, having core average size of 5.0 nanometer and encapsulated by an ultrathin carbon coating, for sub-mbar pressure. VSM and Mossbauer characterization established the nanocrystallites to be superparamagnetic in nature, with saturation magnetization 67 emu/g and coercive field 7.4 Oe. Controlled plasma heating during synthesis led to the burning down of extra carbon that resulted in further enhancement of the magnetization of the product. Graphitization of the encapsulating layers also enhanced, which could successfully protect the metallic core from oxidation, as well as improved its cyto-compatibility. This purified sample could be ideal for targeted drugs delivery and water treatment applications. Another sample was processed through controlled reaction with oxygen, the as-synthesized sample having magnetic properties approaching that of the first sample, which may be more attractive especially for water treatment processes because of the simpler single-step processing of the material.

Air‐Stable Fe3O4@SiO2‐EDTA‐Ni(0) as an Efficient Recyclable Magnetic Nanocatalyst for Effective Suzuki‐Miyaura and Heck Cross‐Coupling via Aryl Sulfamates and Carbamates

“…Although all bases were effective to produce the desired product, the best result was obtained in the presence of KOH (2.0 mmol) ( Table 1, entry 4). Subsequently, the model reaction was carried out with different amounts of the catalyst (Table 1, entries [24][25][26][27]. In the absence of the catalyst, no product formation was observed even after 48 hr (Table 1, entry 24).…”

“…Magnetic Fe 3 O 4 nanoparticles (MNPs) are non‐toxic, biodegradable, and biocompatible particles that have been attracted much attention giving to surface functionalization ability makes them an exciting option for the separation point of view. [ 22 ] They are interesting candidates for ongoing researches owing to their unique physiochemical properties and outstanding usages including medical diagnostics and therapeutics, [ 23 ] hyperthermia, [ 24 ] data storage, [ 25 ] magnetic resonance imaging (MRI), [ 26 ] biomedical protection, [ 27 ] sensor applications, [ 28 ] magnetic inks for jet printing, [ 29 ] and catalysis. [ 30 ]…”

Influence of He and N2 plasma on in situ surface passivated Fe nanopowders by plasma arc discharge

“…Core-shell iron nanoparticles have application in a wide range of different fields, including magn etic recording media, magnetic resonance imaging contrast enhancement, hyperthermia cancer treatment, ground water remediation, removal of heavy metal ion contamination and dye degradation [5][6][7][8][9]. Different methods were used to synthesize these magnetic nanoparticles viz, chemical vapour deposition [10], biosynthesis [11], magnetron sputtering [12], laser irradiation [13], spray pyrolysis [14], pulsed plasma [15,16], non-thermal plasma synthesis [17], ICP-RF plasma technique [18] and thermal plasma assisted techniques [19][20][21][22]. Transferred arc thermal plasma technique can be used to synthesize and process wide range of materials.…”

Single-step, DC thermal plasma-assisted synthesis of Ag-C nanocomposites with less than 10 nm sizes for antibacterial applications

“…Elimination of the bigger particles may lead to even better antibacterial efficiency at a relatively lower amount of the nanocomposite material. The performance of the material may be enhanced further by a single-step oxygen functionalization during the same plasma synthesis process for better dispersion in water [37], or through further optimization of the ratio between carbon and silver in the product, which we propose to undertake in the future.…”