Preparation and Characterization of Amino-coated Maghemite Nanoparticles

The ferrous salt and ferric salt were used as raw materials to prepare magnetite (Fe3O4) nanoparticles as precursors, and then maghemite (gamma-Fe2O3) nanoparticles were obtained from the precursors via high temperature pyrolysis for further oxidation, and corresponding amino-coated maghemite nanoparticles are also obtained via surface modification of 3aminopropyltriethyloxy silane (APTES). The properties and structure of nanoparticles are characterized by transmission electron microscopy(TEM), energy dispersive spectroscopy (EDS), X-Ray photoelectron spectroscopy (XPS), ultraviolet visible spectra (UV-vis), fourier transform infrared (FT-IR) spectrometer and magnetic property measurement system (MPMS) with superconducting quantum interference device (SQUID) magnetometry. The result reveals that the amino-coated maghemite particles have a slight dimensional increase in average diameter, and maintain almost original saturation magnetization that decreases from 109.2 emu center dot g(-1) to 102.3 emu center dot g(-1) after APTES coating. The finding is instructive for surface functionalization of MNPs related to sensing application.