Preparation of Fe3O4 magnetic fluid by one-step method with a microemulsion reactor

Abstract

A W/O microemulsion was prepared with Span80-PS (petroleum sulfonate) as complex emulsifier, isopropanol as cosurfactant and kerosene as oil phase. The optimal constituents of microemulsion were found from pseudoternary phase diagrams: the mass ratio of Span80 to PS was 4:1 and complex surfactant to cosurfactant was 1:1. The Fe3O4 magnetic fluid was obtained by one-step method with the W/O microemulsion as microreactor to synthesize magnetic nanoparticles (reaction temperature was 30 °C and reaction time was 5 h) and kerosene as carrier liquid. The magnetic fluid was investigated by TEM, XRD and fluorescence microscope. The magnetism was determined by Gouy magnetic balance. The average particle size of Fe3O4 was 7.4 nm, and magnetic particles were well-dispersed. The stable Fe3O4 magnetic fluid with good magnetism may be produced by one-step method in the W/O microemulsion. Accordingly, the traditional preparation method of magnetic fluid can be simplified greatly.