The Study Of Functional Coatings Based On Magneto-orientation

With the development of nano-measurement and characterization technology, the application of the magnetic nanomaterial was attracted increasing attention in different fields such as magnetism, machinery, optics, chemistry and biology. A great number of reports focus on the magnetic coating, but general magnetic coating has single function, without further study on the magnetic Orientation methods and multifunctional magnetic coating. To broader the fields of magnetic coating application, the research of the magnetic Orientation methods and multifunctional magnetic coating is an important issue. In this paper, we chose epoxy resin which has high mechanical strength, good stability and low curing conditions as matrix resin of coating, and chose Fe₃O₄ nanoparticles and Ag-Fe₃O₄ particles as filler of coating. Then the effects of curing conditions with different applied magnetic field on coating were researched.1. Fe₃O₄ nanoparticles, which have excellent magnetic response performance and stability, was synthesized with the method of water phase co-precipitation. The properties of the Fe₃O₄ nanoparticles were investigated by XRD, SEM, TEM and VSM, respectively, the grain size of the Fe₃O₄ nanoparticles is about 10 nm, particle diameter is about 50 nm, morphology is a more homogeneous spherical, saturation magnetization Ms = 73.3 emu/g, coercivity Hc = 43.9 G and remanence Mr=4.7 emu/g. Magnetic coating was prepared with the different content of Fe₃O₄ magnetic nanoparticles（1 g, 2 g and 5 g）, cured under different applied magnetic field, then the impact on the distribution of magnetic filler and property of coating was studied. The results showed that, magnetic filler was in an orderly arrangement along the direction of the applied magnetic field magnetic induction line in the coating, orderly distribution of filler has little or no effect on the basic properties of the coating, but could reduce the coating corrosion resistance.2. Ag which has chemical stability and high conductivity, is deposited to the Fe₃O₄ particles surface by chemical plating method, Ag-Fe₃O₄ particles have excellent coated effect, magnetic responsiveness and conductive performance. Magnetic coating was prepared with the different content of Ag-Fe₃O₄ magnetic nanoparticles, cured under different applied magnetic field. We studied the influence of magnetic field on the conductive coating performance, the basic performance and the anti-corrosion performance. It was suggested that, curing in magnetic field 1, Ag-Fe₃O₄ nanoparticles was in an orderly arrangement and formed chain-bundle structure along the direction of the magnetic field magnetic induction line in the coating, this would reduce the corrosion resistance of coating, however that could increase the electrical conductivity by two orders of magnitude, so that the coating becomes antistatic coating. The chain-bundle structure also has little effect on the basic properties of the coating. Besides, the acid resistance of composite particles and coating increase because of the Ag coating.