Facile synthesis and shape control of Fe3O4nanocrystals with good dispersion and stabilization

Abstract

We have reported a facile solution-based strategy for shape-controllable synthesis of Fe₃O₄ nanocrystals (NCs) with high yield, uniform shape and good stability. The low-cost polyisobutene succimide (PIBSI), Fe(oleate)₃ and paraffin oil, are separately used as surfactant, iron precursor and solvent. By controlling the heating rate and growth time, the Fe₃O₄ NCs with cubic, cuboctahedral and octahedral morphology can be successfully prepared with narrow size-distribution and high crystallinity via the thermal decomposition method. The key to realizing shape control of small size (≤15 nm) Fe₃O₄ nanocrystals is choosing PIBSI as the surfactant. It played an important role in tuning the morphology of Fe₃O₄ NCs. Also, its characteristics of a long chain with plentiful non-polar groups can dramatically improve the stability and dispersibility of the Fe₃O₄ NCs in the reaction solvent (paraffin oil). The paraffin oil, in which Fe₃O₄ NCs are dispersed, becomes a magnetic fluid with high stability.