Magnetic Properties and Microstructures of Polyethylene Glycol (PEG)-Coated Cobalt Ferrite (CoFe₂O₄) Nanoparticles Synthesized by Coprecipitation Method

Abstract

Magnetic nanoparticles of cobalt ferrite (CoFe2O4) have been synthesized by co-precipitation method with various synthesis temperatures, concentration of NaOH and stirring duration. The results showed that nanoparticles have well crystallized structure with various grain sizes which depend on synthesis parameters. The grain size increased with increasing synthesis temperature, decreasing concentration of NaOH and decreasing stirring duration. Magnetic characterization of CoFe2O4 nanoparticles measured by Vibrating Sample Magnetometer (VSM) showed that coercive field was decrease with the decreasing of particle size. The saturation and remnant magnetization showed increasing when crystallinity increased. However, it also depends on presence of α-Fe2O3 phases and their grain size. Based on magnetic characterization analysis, sample with parameter of synthesis temperature 80°C, concentration of NaOH 5 M and stirring duration 120 minutes have been selected to be modified using polyethylene glycol (PEG)-4000. XRD and TEM analysis showed that surface modification with PEG-4000 could increase the crystallinity of nanoparticles, decrease agglomeration and control the shape to more spherical. VSM analysis showed that modification PEG-4000 could decrease the saturation magnetization which is due to the existence of α-FeO(OH) and γ-FeO(OH) phases from bonds at interface of CoFe2O4 as confirmed by XRD and Furrier Transform Infra Red (FTIR) analysis. Keywords: magnetic nanoparticles, CoFe2O4, copresipitation, PEG-4000

Advances in Magnetic Nanoparticles for Biomedical Applications

“…Technically, the synthesis procedure is carried out by a stoichiometric mixture of ferric and ferrous salts in aqueous solution, followed by the addition of a base, e.g., NH 4 OH or NaOH to form MNPs, following a chemical reaction: M 2+ + 2Fe 3+ + 8OH − → MFe 2 O 4 + 4H 2 O, where M represents Fe 2+ , Co 2+ , Cu 2+ , Zn 2+ , Mn 2+ , or Ni 2+ . After the pioneering work developed by Massart in 1981, numerous investigations have been performed not just to study and optimize the effects of the synthesis parameters such as the nature and concentration of salts, pH and ionic strength of the medium, reaction temperature, presence of oxygen, injection flux rates, but also adapting the procedure itself in order to control and tailor the size, shape, morphology, magnetic behavior and composition of the MNPs . In addition, surfactants or polymers have been introduced in the reaction in order to control and stabilize the surface of the MNPs to avoid NPs aggregation and to increase biocompatibility .…”

“…After the pioneering work developed by Massart in 1981, numerous investigations have been performed not just to study and optimize the effects of the synthesis parameters such as the nature and concentration of salts, pH and ionic strength of the medium, reaction temperature, presence of oxygen, injection flux rates, but also adapting the procedure itself in order to control and tailor the size, shape, morphology, magnetic behavior and composition of the MNPs . In addition, surfactants or polymers have been introduced in the reaction in order to control and stabilize the surface of the MNPs to avoid NPs aggregation and to increase biocompatibility . Despite the successful production of MNPs at high process yield and high magnetization, MNPs with broad size distributions and irregular morphologies are usually obtained by coprecipitation …”

MICROSTUCTURES AND MAGNETIC PROPERTIES OF BaFe12O19 WITH MgO-Al2O3 ADDITIVES

“…MgO dan Al 2 O 3 pada dasarnya merupakan non-magnetik, sehingga ketika adanya aditif tersebut, maka nilai magnetisasi menjadi turun. Nilai magnetisasi suatu bahan dapat dipengaruhi oleh derajat kristalinitas, ukuran partikel, atau adanya fasa lain (non-magnetik) sebagai pengotor (Suharyadi, et al 2014). Begitupun nilai magnetisasi saturasi dan remanen terhadap suhu sintering, semakin tinggi suhu sintering nilai magnetisasi remanen dan saturasinya semakin besar.…”

Synthesized of PEG-6000 coated MgFe2O4nanoparticles based on natural iron sand by co-precipitation method

“…The material was prepared by coprecipitation method which one method of synthesis of inorganic compounds based on precipitation of more than one substance. Another advantage of co-precipitation method, it can be processed at room temperature easily and control the particle size, so that the required time is relatively short [6,9]. The addition polyethyleneglycol 6000 (PEG-6000) as the coating is used for reducing the effect of nanoparticle agglomeration at the synthesizing process.…”

“…The behavior of this material has a high permeability and resistance, but low coercivity. The spinel ferrite nanoparticles is soft ferrites having a cubic crystal structure [6]. Some methods developed for synthesizing magnetic nanoparticles is such as hydrothermal synthesis, thermal decomposition, microwave plasma synthesis [7], sol gel, sonochemical, co-precipitation and others [6].…”