DESIGNED STRUCTURE AND MAGNETIC CHARACTERISTIC STUDIES OF MAGNETIC IRON OXIDE (Fe3O4) NANOPARTICLES COATED BY POLYVINYL ALCOHOL AND POLYVINYL ALCOHOL-LINKED WITH GLUTARALDEHYDE

In this work, polyvinyl alcohol (PVA)–coated Fe3O4 (PVA–Fe3O4) and PVA–grafted Fe3O4 using glutaraldehyde (GA) as a crosslinker (PVA–GA–Fe3O4) were prepared. These two materials were prepared by in-situ coprecipitation method due to the simplicity synthesis procedures which accompanied with mild and clean conditions to produce excellent materials. The effects of preparation and synthesis conditions toward the characteristics of PVA–Fe3O4, and PVA–GA–Fe3O4 nanoparticles were investigated in detail. Then, the resulted nanoparticles of PVA–Fe3O4 and PVA–GA–Fe3O4 were characterized by Fourier transform infrared spectroscopy (FTIR), electron spin resonance (ESR) spectroscopy, and X-ray diffraction (XRD). The result showed that PVA with and without crosslinker was successfully coated onto the surface of Fe3O4 nanoparticles. Increasing PVA concentration triggered a decline in the abundance of Fe3O4 phase, its lattice parameter and magnetism. However, once GA as crosslinker was added to the system, the amount of Fe3O4 phase, its lattice parameter and magnetism raised whereas its crystallite size decreased. The influence of each crystallographic parameter on their magnetism was discussed systematically in detail.