A simple straightforward thermal decomposition synthesis of PEG-covered Gd2O3 (Gd2O3@PEG) nanoparticles

Abstract

Paramagnetic polyethylene glycol (PEG) functionalized gadolinium oxide (Gd2O3@PEG) nanoparticles were synthesized by a facile thermal decomposition of gadolinium acetate hydrate (Gd(CH3CO2)3·XH2O) precursors in PEG-1000. PEG-1000 was used as a solvent, and as a size reducing and functionalizing agent. The advantages of the present method are that it is simple and relatively fast, and it only needs a small amount of reagents. The resulting nanoparticles were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectroscopy (EDX). From the XRD data, the average crystallite size, t, of the Gd2O3@PEG nanoparticles was calculated to be about 5.4, 3.8, and 3.1nm at decomposition temperatures of 260°C, 280°C and 300°C respectively. The SEM images revealed that the synthesized nanoparticles had a homogenous spherical shape while the coated nanoparticle diameters were about 178nm at 260°C. Synthesis at higher temperatures tended to cause agglomeration. FTIR analysis showed that the oxidation of PEG is linked to the Gd2O3 surface. Magnetization was investigated using a Vibrating Sample Magnetometer (VSM). The magnetization vs. magnetic field (M–H) curve, measured at 300K, showed that the Gd2O3@PEG nanoparticles exhibit characteristic paramagnetic behavior. We confirmed that the dispersibility and functionalization behavior of the PEG was successfully transferred to the Gd2O3 nanoparticles.