The New Surface Active Agent Controlled Study Coated Iron Oxide

Since the temporarily water-soluble disperse dyes containing carboxymethylsulfonyl have the characteristics of decarboxylation and long chain fatty acids can be used to prepare the nanomaterial, a temporarily water-soluble and decarboxylatable anion new type surfactant(C₁₆H₃₃SO₂CH₂COOH)containing carboxymethylsulfonyl group was designed and synthesized. Then it was used as surfactant to prepare contoll coated iron oxide nanoparticles by microemulsion process.The synthesis of the anion new type surfactant was carried out in the following process. The anion new type surfactant (C₁₆H₃₃SCH₂COOH) containing carboxymethyl sulfide was synthesized first with thioglycollic acid and 1-chloro-hexadecane as starting materials, and then oxidated with H2O2 using sodium tungstate as catalyzer. Products are characterized by FTIR and ¹HNMR. DSC and TG-DTG are also used to analyze the thermal decarboxylation behavior of the surfactant C₁₆H₃₃SO₂CH₂COOH.The result shows that the decarboxylation temperature is about 150℃.The anion new type surfactant containing carboxymethylsulfonyl group was used to prepare contoll coated iron oxide nanoparticles with toluene and tetralin as solvents, respectively. Thermal decarboxylation behavior of carboxymethylsulfonyl on the surface of the iron oxide nanoparticles was studied using two methods: heating directly and heating in the solvent. All samples were calcined 1h under the protection of N₂, and characterized by FTIR, XRD and TEM. The results show that the obtained iron oxide nanoparticles were Fe3O4. Their transformation temperatures were 250℃and 350℃; the temperatures of the disappearance of the surfactant were 400℃and 200℃, and the sizes of the particles were 11-16 nm and 12-25 nm, respectively.