Synthesis and characterization of magnetic nanoparticles of cobalt ferrite coated with silica

Abstract

There are several methods available for magnetic nanoparticles (MNP) synthesis, and in this study the coprecipitation method is employed. The cobalt ferrites (CF) were prepared using aqueous solutions of Co2+ and Fe3+ chloride with a stoichiometry proportion of Co:Fe = 1:2. Thus, the aging temperatures were 27, 27/98, 60, 80 and 98 ºC, during which the precipitation occurred at 27 °C and the aging one at 98 °C for the FC27/98 sample. As a result, the study showed that a single crystal phase material was obtained at the aging temperature of 98 °C during 1 h and with a mean particle size of 42 nm ± 7.4 nm and degree of polydispersity of 18%. The FC98/SiOH coated nanoparticle had a surface area of 11 m2 g-1, saturation magnetization of 10.05 emu g-1 a mean particle size of 773.4 nm ± 131.1 nm and a degree of polydispersity of 17 %. It was possible to confirm that it had a silica coating of cobalt ferrite nanoparticles by DRIFT and EDX indicated the presence of silica.

Tailoring Interfacial Exchange Anisotropy in Hard–Soft Core-Shell Ferrite Nanoparticles for Magnetic Hyperthermia Applications

“…Recent reports suggested that bi-magnetic core-shell nanocrystals can improve the energy production of the magnetic nanoparticles beyond the superparamagnetic limit for applications, particularly in magnetic storage [11]. The magnetic properties of core-shell structures are usually determined by several parameters such as the size, order (soft-hard or hard-soft), and geometric shape of the core and shell [12][13][14]. Furthermore, the magnetic properties are affected by differences in magnetic parameters between the core and shell materials, as well as the presence of dipolar and exchange-coupled interactions that affect spin reversal processes [15].…”

Nanocomposites of Ferrites with TiO2, SiO2 and Carbon Quantum Dots as Photocatalysts for Degradation of Organic Pollutants and Microbes

“…Figure 5 The influence of aging temperature on the synthesis of nanocomposites of ferrit with silica by the Stöber method was studied. Queiroz et al [104] investigated vario aging temperatures-98, 80, 60, 27/98, and 27 °C-for the synthesis of silica-coated cob ferrite. Aging temperatures of 98 and 27/98 °C give the best suited conditions for prepa ing the single phase of cobalt ferrite.…”

Anti-Biofilm Coatings Based on Chitosan and Lysozyme Functionalized Magnetite Nanoparticles

“…Nevertheless, the properties of Fe 3 O 4 nanoparticles depend on their preparation method, and many synthesis techniques have been employed to obtain optimal characteristics for different end purposes. Methods, such as co-precipitation, thermal decomposition, sol-gel, microemulsion, hydrothermal, sonochemical, electrochemical, and biological synthesis have been shown to successfully produce Fe 3 O 4 nanostructures [24,28,[32][33][34]. One of the simplest and most widely used chemical methods for obtaining nanosized Fe 3 O 4 is co-precipitation [35][36][37], particularly due to its simplicity, high yields, and potential for reduced time-consuming, making it easily scalable in industrial applications [37].…”