Keywords: superparamagnetic nanoparticles, Fe3O4, iron oxide, ferric oxide, iron(II,III) oxide, biocompatible SiO2, silicon dioxide, silica, GPTMS, glycidoxypropyltrime thoxysilane, chitsan, dispersion, nanotechnology, sol gel
Synthesis and characterisation of superparamagnetic Fe3O4–SiO2 nanoparticles and mod
The superparamagnetic nanoparticles (Fe3O4) were prepared by co–precipitation method, then the biocompatible silicon dioxide (SiO2) was coated on the surface of these Fe3O4 nanoparticles (designated as Fe3O4–SiO2) by using the sol–gel method. In order to graft chitosan on the surface of Fe3O4–SiO2 particles, the surface modifier γ–glycidoxypropyl–trimethoxysilane (GPTMS) was first grafted on the surface of Fe3O4–SiO2 through the sol–gel reaction with SiO2 layer. Then the epoxide groups of GPTMS can react with the amino groups of chitosan to form chemical linkages between GPTMS and chitosans. In summary, by changing core–shell structure and pH value of reaction solution, we could obtain various particles with diameters in the range of 3-143 nm. Morphology, particles size, dispersion, physical and chemical structure of the particles were analysed by using scanning electron microscopy, transmission electron microscopy, dynamic scattering analyser, Superconducting Quantum Interference Device, energy dispersive analyser, X–ray diffraction and Fourier transform infrared spectroscopy.