Amination surface-modification of ferriferous oxide magnetic nanoparticles

3-Aminopropyl triethoxysilane(APTES) was used as the amination agent and coated onto the surface of ferriferous oxide(Fe3O4) magnetite nanoparticles via silanization reaction.The chemical bonding feature of as-synthesized APTES-coated Fe3O4 nanoparticles was analyzed by Fourier transform infrared spectrometry,and its surface-NH2 content was determined by potentiometric titration technology.Furthermore,the influences of activation method,solvent,feeding ratio,reaction temperature,and reaction time on the modification effect of Fe3O4 nanoparticles by-NH2 group were investigated.Results show that Fe3O4 nanoparticles have been successfully coated by APTES.The best surface-modification effect is reached after Fe3O4 nanoparticles are coated with APTES at a feeding ratio of 3∶8 and a temperature of 60 ℃ for 12 h in the presence of ethanol/water as the solvent.Resultant surface-modified Fe3O4 nanoparticles have a surface-NH2 content of about 1400 ± 50 μmol·g-1.