Synthesis and Characterizations of Surface-Coated Superparamagentic Magnetite Nanoparticles

The uncoated magnetite and the 2, 3-meso-dimercaptosuccinic acid (DMSA)-coated Fe₃O₄ nanoparticles were synthesized by a coprecipitation method, respectively. The DMSA surface modification on magnetite nanoparticles was observed by FT-IR. The average particle sizes of the uncoated magnetite and the DMSA coated magnetite were exhibited approximately 10.4 and 12.3 nm by TEM results. DMSA surface-coated Fe₃O₄ can introduce a dense and thin outer hydroxyl group (-OH) shell. In order to characterize the magnetic behaviors, the magnetization processes of the magnetic nanoparticles were measured with the temperature range of 5 K to 300 K. The mean blocking temperatures of the uncoated Fe₃O₄ and the DMSA surface-coated Fe₃O₄ exhibited about 172 ±28 K and 215 ±30 K, respectively. The value of magnetization of the DMSA-coated Fe₃O₄ nanoparticles was not so different with that of the uncoated Fe₃O₄.