Preparation And Research On The Surface Properties Of Stable Single-Component Fe₃O₄ Ferrofluid

Magnetic fluid As a kind of special functional material both have the magnetism of the magnetic solid materials and the fluidity of the liquid materials, Magnetic fluid is widely noted. Water-based single-component Fe₃O₄ magnetic fluids have a good prospect because it has the advantages of biocompatibility, nontoxic and pollution-free which is widely applied in the fields of medical service, biology and so on. Therefore, the research and development of single-component Fe₃O₄ magnetic fluids is of great significance to the immobilization of biological molecules, the enzymatic immobilization, the reducing of environmental pollution, and so on. In this paper, the stable single-component Fe₃O₄ magnetic fluids were developed successfully at low temperatures in our laboratory. We also evaluated its surface properties, and activated the condition of surface hydroxyl of Fe₃O₄@SiO₂ by means of orthogonal experiment design. The main contents are as follows:(1)Prepared stably single-component Fe₃O₄ magnetic fluids at low temperatures.without stabilizer and surfactant. This kind of magnetic fluids take much less energy, and that the preparative method is simple and low cost.(2)Analyzed the crystal structure of the Fe₃O₄ nanoparticles were prepared in different temperature by X-ray diffraction, characterized the surface properties of Fe₃O₄ nanoparticles in the magnetic fluid by XPS and FTIR, and tested the similar H₂O₂ enzyme activity of Fe₃O₄ magnetic fluids.(3)Reflowed and activated the experimental condition of Fe₃O₄@SiO₂ by means of orthogonal experiment design, X-ray photoelectron spectroscopy (XPS) as the test method, surface Si-OH groups of Fe₃O₄@SiO₂as the testing indicator. Analyzed various of factors on the experimental results,appropriate conditions to abtain surface Si-OH content are obtained.