Effect of Synthesis Conditions on Physiochemical Properties of Lauric Acid Coated Superparamagnetic Iron Oxide Nanoparticles

Abstract

Lauric acid coated iron oxide nanoparticles (LAIONPs) is very promising in biomedical applications. Understanding the influences from synthesis processes on physiochemical properties of LAIONPs is very important for their implementations in in vivo and in vitro studies. Here, the superparamagnetic spherical-shaped LAIONPs samples have been prepared based on coprecipitation method (CP-LAIONPs) and through thermal decomposition using FeO(OH) as iron precursor (TD-LAIONPs), respectively. The effects of different stirring speeds in coprecipitation reaction and different heating profiles in thermal decomposition route on the products properties (including size, mass ratio of surfactants, and saturation magnetization) were revealed. For nanoparticles with similar cores sizes ( $\sim 11$ nm) obtained from two different synthesis methods, the TD-LAIONPs showed more spherical morphologies, narrower size distributions in both core sizes and hydrodynamic sizes, and stronger magnetic properties than the CP-LAIONPs. In addition, ferromagnetic cubic-shaped LAIONPs with sizes larger than 50 nm could be obtained using another iron precursor in thermal decomposition route. Thus, the synthesis methods and fabrication conditions should be appropriately chosen to obtain LAIONPs with desirable properties for specific purposes.