Synthesis of α–Fe₂O₃ particle/oligomer hybrid material

A nanocrystalline α–Fe₂O₃ particle/oligomer hybrid can be synthesized by polymerization of iron (III) 3-allylacetylacetonate (IAA) followed by in situ hydrolysis. The polymerization of IAA was dependent upon the polymerization temperature and solvent. GPC measurement showed that the polymerization degree of the IAA oligomer ranged from ∼3 to ∼6. The magnetic particle/oligomer hybrid was synthesized by hydrolysis of the IAA oligomer under a neutral or alkaline condition. Crystalline particles from 10 to 40 nm were finely dispersed in the oligomeric matrix, depending upon the hydrolysis conditions. The nanocrystalline particles below 10 nm in diameter were identified to be α−Fe₂O₃ by electron diffraction. The nanosized α−Fe₂O₃/oligomer hybrid was found to show superparamagnetic behavior.