Thermal Decomposition Synthesis of SPIONs

All the chemicals used were purchased from Sigma Aldrich. SPIONs of average size of 12 nm were synthesized by thermal decomposition method.^{7,26,27 (link)} Briefly, iron(iii) acetylacetonate was added to oleic acid and benzyl ether and heated under nitrogen purging to 110 °C, in order to remove moisture. The temperature was later increased to 160 °C, to initiate nucleation. The reaction was maintained at 280 °C with reflux, to promote growth of the SPIONs. The size of the as-synthesized SPIONs were characterized using transmission electron microscope (TEM, JEOL 100CX). The magnetization properties of the SPIONs were characterized using vibrating sample magnetometer (VSM, Lake Shore Model 7407). The crystal phase and purity of the sample was studied using X-ray diffractometer (XRD, Bruker D8 Advanced Diffractometer System) with Cu Kα (1.5418 Å) source. The as-synthesized hydrophobic SPIONs were stabilized using surfactant cetyltrimethyl ammonium bromide (CTAB) and used in our studies. Dynamic light scattering (DLS) and zeta-potential measurements were performed in a Malvern Zetasizer Nano-ZS device to determine the hydrodynamic size and zeta-potential of CTAB-SPIONs in a colloidal suspension.