Iron oxide nanoparticles fabricated by electric explosion of wire: focus on magnetic nanofluids

Abstract

Nanoparticles of iron oxides (MNPs) were prepared using the electric explosion of wire technique (EEW). The main focus was on the fabrication of de-aggregated spherical nanoparticles with a narrow size distribution. According to XRD the major crystalline phase was magnetite with an average diameter of MNPs, depending on the fraction. Further separation of air-dry EEW nanoparticles was performed in aqueous suspensions. In order to provide the stability of magnetite suspension in water, we found the optimum concentration of the electrostatic stabilizer (sodium citrate and optimum pH level) based on zeta-potential measurements. The stable suspensions still contained a substantial fraction of aggregates which were disintegrated by the excessive ultrasound treatment. The separation of the large particles out of the suspension was performed by centrifuging. The structural features, magnetic properties and microwave absorption of MNPs and their aqueous solutions confirm that we were able to obtain an ensemble in which the magnetic contributions come from the spherical MNPs. The particle size distribution in fractionated samples was narrow and they showed a similar behaviour to that expected of the superparamagnetic ensemble. Maximum obtained concentration was as high as 5 % of magnetic material (by weight). Designed assembly of de-aggregated nanoparticles is an example of on-purpose developed magnetic nanofluid

Magnetite nanoparticles prepared by co-precipitation method in different conditions

“…A fixed divergence and anti-scattering slit giving a constant volume of sample illumination were used. XRD diffraction data were fitted using the FULLPROF program included in WinPLOTR [18]. The profile refinement calculated the unit cell parameters a, peak shape (pseudoVoigt), background, systematic 2q shift, overall isotropic, displacement, U, V, W, half-width parameters for the profile function and asymmetry parameters.…”

“…Ferrite MNPs with controlled sizes and morphology can be prepared by electric explosion of wire, laser target evaporation, biomineralization [10e13], but wet chemical methods like solegel and co-precipitation are still the most used techniques [14e16]. Other applications of the ferrite MNPs are magnetic biosensing, hyperthermia and thermal ablation e promising forms of cancer therapy, toxic metals adsorption, microwave absorption and electromagnetic interference (EMI) [1,3,6,17,18]. These different applications have their specific requests such as narrow size distribution for biomedical applications and particular shapes and anisotropy features for controlled microwave absorption and EMI.…”

Thermal-Chemical Characteristics of Al–Cu Alloy Nanoparticles

“…In this work, alloy nanoparticles were fabricated by the electrical explosion of wires (EEW) method, which is a process of explosive destruction of a metal wire under the action of high density current. It has been successfully used to produce various pure metal and metal oxide particles such as Al, Fe, Ni, Si and Fe2O3 [20][21][22][23][24], as well as a few alloy nanoparticles (i.e., Al-Cu, Al-Ni) [25]. For alloy particles, coated metal wires were generally used where one metal component was electrodeposited onto the surface of another metal wire and EEW was subsequently applied [25].…”

Encapsulation of metallic iron magnetic nanoparticles by polyacrylamide in water suspensions

“…The detailed description of EEW equipment designed at the Institute of Electrophysics of RAS (Ekaterinburg, Russia) is given elsewhere [6][7][8]. The method is based on the evaporation of a portion of metal wire by the electric high power pulse in the explosion chamber filled with the inert atmosphere.…”