Development and Characterization of Thermosensitive Polymer- CoatedIron Oxide Nanoparticles as a Novel Ferrofluid

Abstract

In this work, we aim to study the development and characterization of thermosensitive polymer-coated iron oxide nanoparticles as a novel ferroFluid (fF) with thermosensitive properties. For this purpose, polymerization was conducted in the presence of various ratios of N-isopropylacrylamide (NIPAAm), acrylamide (AAm) and N-vinylpyrrolidone (NVP) as monomers, and N,N´-azobisisobutyronitrile (AIBN) as an initiator. Particles having average sizes of 8 nm and 8–10 nm were respectively observed for Fe3O4/fF and Fe3O4/polymers. As visualized by transmission electron microscopy (TEM) images, both the coated and uncoated iron oxide nanoparticles were uniform in shape and seem to have been monodispersed. Vibrating sample magnetometry (VSM) measurements of Fe3O4/VTES-fF and Fe3O4/Poly (NIPAAm- AAm NVP) at room temperature showed that they had a superparamagnetic nature with saturation magnetization values of 23.14 emu/g and 4.33 emu/g, respectively. In the thermosensitivity analysis, the lower critical solution temperature (LCST) was around 36-40°C, as determined by UV-Vis absorption spectroscopy. Furthermore, the polymerization of (NIPAAm-AAm-NVP) with the surface modified magnetic ferroFluid was confirmed by Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). These aqueous, stable, magnetic nanoparticles coated with temperature-sensitive polymers have attracted great attention because of their various applications in the fields of biotechnology and medicine.