Combined investigation of experimental characterization and theoretic calculation on the structure of dextran-Fe3O4 clusters

Dextran-Fe3O4 hybrid clusters were fabricated by coprecipitating ferric and ferrous ions in the presence of dextran, and after characterization of these clusters combined with calculation based on classical nucleation theory, a structure model of these hybrid clusters was proposed. The hybrid cluster was believed including small Fe3O4 nanoparticles and dextran which acted as both nucleating agent and stabilizer, so that exist in both the inside of magnetite nanoparticles and the periphery of the hybrid clusters. Besides, the effects of WCD (weightiron cation:weightdextran) and molecular weight of dextran on the size, morphology and magnetic property of clusters were also investigated in this paper. It was found that the variation of WCD and molecular weight of dextran have great effect on the size of the hybrid clusters, but have almost no effect on the size of the Fe3O4 nanoparticles. The characterization of magnetic property demonstrated that the Fe3O4 nanoparticles are of a single domain and the saturation magnetization was affected by the size of dextran-Fe3O4 hybrid clusters.