Microwave-assisted synthesis of iron oxide nanoparticles in biocompatible organic environment

Abstract

The development of magnetite and maghemite particles in uniform nanometer size has triggered the interest of the research community due to their many interesting properties leading to a wide range of applications, such as catalysis, nanomedicine-nanobiology and other engineering applications. In this study, a simple, time-saving and low energy-consuming, microwave-assisted synthesis of iron oxide nanoparticles, is presented. The nanoparticles were prepared by microwave-assisted synthesis using polyethylene glycol (PEG) or PEG and β-cyclodextrin (β-CD)/water solutions of chloride salts of iron in the presence of ammonia solution. The prepared nano-powders were characterized using X-Ray Diffraction (XRD), Transition Electron Microscopy (TEM), Fourier-transform Infrared Spectroscopy (FTIR), Raman Spectroscopy, Vibrating Sample Magnetometer (VSM), X-Ray Photoelectron Spectroscopy (XPS) and Thermal analysis (TG/DSC). The produced nanoparticles are crystallized mostly in the magnetite and maghemite lattice exhibiting very similar shape and size, with indications of partial PEG coating. Heating time, microwave power and presence of PEG, are the key factors shaping the size properties of nanoparticles. The average size of particles ranges from 10.3 to 19.2 nm. The nanoparticles exhibit a faceted morphology, with zero contamination levels. The magnetic measurements indicate that the powders are soft magnetic materials with negligible coercivity and remanence, illustrating super-paramagnetic behavior.

Raman spectroscopy to unravel the magnetic properties of iron oxide nanocrystals for bio-related applications

“…Whereas most metal-oxygen lattice vibrations occur below 750 cm À1 , the main vibrations of organic molecules take place above 1000 cm À1 , and therefore, do not interfere with each other. [43][44][45] This implies an arrangement of magnetic phases that will delineate the magnetic behavior. For instance, the presence of magnetic materials with different magnetic orders can establish exchange coupling between two phases, contributing to the effective magnetic anisotropy.…”

Synthesis and characterization of nontoxic silver nano-particles with preferential bactericidal activity

“…Recently, microwave-assisted synthesis is widely applied to produce several nanoparticles [27]. In comparison to convenient hydrothermal methods, the microwave has the advantages of being quick, simple and short time reaction resulting in the controllable morphology of the developed nano-particles.…”

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

“…There are several routes for the synthesis of magnetic nanoparticles of different sizes, such as water-oil microemulsion [25], microwave processing [26], mechanical grinding [27], reverse micelle [28], combustion [29], co-precipitation [30], pyrolysis [31] and among others. The magnetic core of the magnetic nanoparticles can be coated with a polymeric layer of not active sites or anchoring organic molecules to a metal surface [32].…”