Synthesis of magnetic nanoparticles of Fe3O4 and CoFe2O4 and their surface modification by surfactant adsorption

Abstract

Fe3O4 and CoFe2O4 magnetic nanoparticles have been synthesized successfully in aqueous solution and coated with oleic acid. The solid and organic solution of the synthesized nanoparticles was obtained. Self-assembled monolayer films were formed using organic solution of these nanoparticles. The crystal sizes determined by Debye-Scherre equation with XRD data were found close to the particle sizes calculated from TEM images, and this indicates that the synthesized particles are nanocrystalline. Especially, EDS, ED, FT-IR, TGA/DTA and DSC were used to characterize the nanoparticles and the oleic acid adsorption, and it was found that oleic acid molecule on the Fe3O4 nanoparticle is a bilayer adsorption, while that on CoFe2O4 nanoparticle is single layer adsorption. The superparamagnetic behavior of the nanoparticles was documented by the hysteresis loop measured at 300 K.