Preparation And Characterization Of Fe₃O₄ Nanoparticles/Polyurethane Composite Film For Biomedical Applications

Three different processes based on wet chemical routes have been used to prepare magnetite nanaoparticles (Fe₃O₄ NPs), and Fe₃O₄ NPs/Polyurethane composite film has been synthesized by doping Fe₃O₄ NPs directly and mixing Fe₃O₄ NPs which were dispersed in ethanol in PU. The phase composition, size distribution and morphology, magnetic property of the magnetite nanaoparticles have been investigated by X-ray diffraction (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM). The structure, surface morphology, mechanical property, hemocompatibility of Fe₃O₄ NPs/Polyurethane composite film have been studied by Fourier transform infrared (FTIR), atomic force microscopy (AFM), tensile tests and platelet adhesion tests.The experimental results show that phase-pure Fe₃O₄ NPs can be obtained by the co-precipitation process, water bath precipitation process and partial reduction precipitation process. The average diameter of the cubic Fe₃O₄ NPs is below 10nm with good size distribution and dispersibility. The VSM results show that the saturation magnetization of the synthesized nanoparticles was relatively high and the magnetic property of e₃O₄ NPs becomes weak with the size decreasing.FTIR results indicate that there is no chemical bond between Fe₃O₄ NPs and PU in the composite film, which could maintain magnetite particles' magnetic property due to the physical interaction between them.AFM results show that the root-mean-square roughness (RMS) of the composite film increases because of the addition of Fe₃O₄ NPs, and RMS value become larger with the amount of Fe₃O₄ NPs increase. It could meet the requirment as cardiovascular stents' coating when the amount of Fe₃O₄ NPs is 1% and 5%.Tensile tests show that the tensile elasticity of the composite film is still far better than the materials of stents although it decreases with the addition of Fe₃O₄ NPs. For the tensile strength of the composite film, it's better when the amount of Fe₃O₄ NPs in film is 1% and 10% than 5%.