Evolution of surface structure of bilayer oleic acid-coated Fe_3O_4 nanoparticles during ethanol washing

摘要

The excess amount of oleic acid must be added to synthesize the bilayer oleic acid-coated Fe_3O_4 nanoparticles by one-step method. To know the evolution of surface structure during removing the residual oleic acid by ethanol washing, the surface structure of bilayer oleic acid-coated Fe_3O_4 nanoparticles synthesized by one-step method was studied using TEM, FTIR and TGA with washing times. The results showed that after five times washing, the bilayer oleic acid-coated structure still remained; after twenty times washing, the bilayer oleic acid-coated structure evolved into the single layer one.