Synthesis Of Magnetic Fe₃O₄ Nanoparticles And Its Application Research

With the development of modern society and the enhancement of people's material life level,the application of anti-counterfeiting technology is increasing,people also pay more attention to research and development of anti-counterfeiting materials.In numerous anti-counterfeiting materials,magnetic anti-counterfeiting printing ink aroused great concern,through dark-color appearance,simple testing equipment,remarkable anti-counterfeiting,have huge exploration and application potential in the field of anti-counterfeiting materials.Magnetic Fe₃O₄ nanomaterials is the most common magnetic pigment,preparation of high performance Fe₃O₄ nanoparticles is the key to obtain high quality magnetic anti-counterfeiting printing ink.This article aims to synthesis Fe₃O₄ nanoparticles by hydrothermal method,and surface-modified with oleic acid to improve dispersion stability of nanoparticles,finally high performance magnetic security ink was prepared with homemade Fe₃O₄ nanoparticles as magnetic pigment.The main contents include the following:(1)Used citric acid as electrostatic protective agent,adopt hydrothermal method to synthesis of Fe₃O₄ nanoparticles.By adjusted the reaction conditions to synthesis magnetic Fe₃O₄ nanoparticles with different particle size and morphology,characterized by X-ray diffraction,scanning electron microscope,vibrating sample magnetometer.(2)Used surface modification to modified magnetic Fe₃O₄ nanoparticles by oleic acid,aimed to improve the solvent dispersing stability,made it can be used in the preparation of magnetic anti-counterfeiting printing ink and other fields.Composition and magnetic of nanoparticles were characterized by IR spectra and vibrating sample magnetometer,magnetic stability and magnetic targeting property were characterized by sedimentation distance and targeted time.The experimental results showed that the dispersion stability of magnetic Fe₃O₄ nanoparticles modified by oleic acid was improved significantly.(3)With homemade modified magnetic Fe₃O₄ nanoparticles as pigments,manufactured magnetic anti-counterfeiting printing ink.Through a large number of experiments and performance tests,to study the effect of the content of magnetic pigment,links and carbon black to ink viscosity,dry,fineness,friction resistance and liquidity,optimized basic formula,got the formula of magnetic anti-counterfeit printing ink,the magnetic response of ink is strong,ink anti-counterfeit effect is good and relatively environmental friendly.