Surface-modified quantity of Fe3O4 particles by thermogravimetric analysis

Different Fe 3 O 4 particles are synthesised with silane and carboxylic acid, surface modified by co-precipitation, and subsequently are characterised by Fourier transform infrared spectroscopy, wide-angle X-ray diffraction, laser particle size analyser (LPSA) and thermogravimetric analyser (TG). Based on the LPSA results, Fe 3 O 4 particles are micrometre size due to the experimental condition and modifiers. It is therefore suggested that the vacuum freeze-drying and the long-chain modifiers tend to obtain small size particles. The modifiers density on the surface of Fe 3 O 4 particles is obtained by TG and formula calculation. It is shown that the silane coupling agent is more effective modifier for Fe 3 O 4 particles compared with carboxylic acid. In accordance with the molecular structure and functional group number of carboxylic acids, different carboxylic acids have different modifiers density.