Synthesis of α-Fe Nanoparticles by Solventless Thermal Decomposition

Abstract

A new preparation for highly crystalline and monodisperse Fe3O4 nanoparticle is reported. This synthesis requires the use of rather complicated procedures including delicate control of surfactants ratios and inert reaction conditions due to the toxic and unstable nature of the precursors none the less because thermal decomposition methods were tried to synthesize monodispersed inorganic nanocrystallites until very recently. The synthesis of Fe3O4 nanocrystallites by using Fe+2-oleate2 complex was studied. The Fe+2-oleate2 complex was prepared from the reaction of iron chloride and sodium oleate in water. The thermal decomposition of the complex at the reduced pressure (0.3 torr) and about 300° was done without any solvent. We demonstrated that a new solventless synthesis of size- and shape-monodisperse Fe3O4 nanoparticles depends on the amount of Na-oleate. And it is possible to remove the oleate ligand using reduction process. We confirmed that the nanoparticles changed from Fe3O4 to α-Fe phase obtained higher magnetic properties and crystallites by a vibrating sample magnetometer (VSM) and x-ray powder diffraction (XRD). Removal of the organic surfactant and other volatile components surrounding Fe3O4 nanoparticles was detected by fourier transform infrared spectroscopy (FT-IR).

Solventless synthesis of cerium oxide nanoparticles and their application in UV protective clear coatings

“…30 Moreover, in the solventless reaction environment, nanoparticle collisions are limited and particle growth proceeds primarily by monomer addition to the particle surface, leading to monodisperse nanoparticle formation. 28,30,31 The solventless thermal decomposition process typically generates a viscous paste of dispersible nanoparticles that can be readily mixed with low boiling point organic solvents without the need for separation, cleaning or a size-selection process. This is highly desirable for large scale production of solvent dispersible nanoparticles which can be easily re-dispersed in the desired solvent aerwards.…”

“…32 Nanoparticle synthesis by solventless thermolysis of metalorganic complexes has been widely used during the last two decades. Some examples worth mentioning are the monodisperse iron oxide nanoparticles synthesis by thermal decomposition of iron-oleate at low pressure conducted by Cha et al 30,31 and the formation of Cu nanoparticles by thermal decomposition of Cu-oleate powders at low pressure developed by Kim et al 31 34 Therefore, it has been a considerable effort to generate different types of nanoparticles by solventless thermolysis. However, cerium oxide nanoparticles, despite their undeniable relevance, have not been the target of a systematic study yet.…”

Preparation and Characterization of Soft Phase Magnetic α-Fe Nanoparticles by Different Methods

“…A monolayer of α-Fe nanoparticle is observed from the image with almost no any multilayer on it (Figure 2 The superparamagnetic behavior is documented by the hysteresis loop measured at 300 K as shown in Figure 3(a). The magnetic saturation value, M s , id 98 emu/g for α-Fe nanopartiles by using polyol process, which is lower than that of bulk Fe particles [7]. And the magnetic saturation value is 167.2 emu/g for α-Fe nanoparticles by using coprecipitation route.…”

“…Reduction of transition metal salts is the oldest, easiest and still a widely used method for the preparation of metal nanoparticles. As far as magnetic metals are concerned, the most common reducing agents are borohydride derivatives; extensively studied by Klabunde et al This method provides an easy route to nanoparticles of Fe [7], Co and Ni as well as to alloys such as Fe/Pt. The drawback of the method is however the incorporation of boron into the particles which leads to a modification of the magnetic properties of the particles.…”