Preparation Of The Magnetic Composite Chitosan Nano-Materials Belectrospinning And Study On Their Properties

Magnetic materials is found a very wide range of applications in the information materials, chemical industry and the biomedical sciences. While the nanometer magnetic materials have been received more and more attention because of their special magnetism which is different from the conventional magnetic materials. Especially in the new century, with the development of nanometer materials science and technology, the applications of nanometer magnetic materials has been extended to a lot of fields. Therefore, research on the magnetic composite nano-materials will be important and realistic significances.In this paper, the thick acetic acid was used as solvent and preparation process of chitosan nanofibers by electrospinning were studied. Different adding PVA proportions, the mass fraction and the spinning parameters such as spinning voltage, receiving distance and spray flow were analyzed. The composite chitosan/PVA nanofiber membranes were prepared and their mechanical and hydrophobic properties were studied. By controlling the substance ratio of Fe2+ to Fe3+,pH of precipitation, temperature of reaction and time of reaction we successed in preparing Fe3O4 nanoparticles by the chemical co-precipitation method. Then, they were scattered into the organic solvent containing some surfactants, the stable magnetic liquid was also prepared. The composite nanofiber membranes were immersed in that liquid, the great surface energy of the nanofibres could be used to adsorb Fe3O4 nanoparticle so that the nanometer magnetic composite materials were prepared. The chitosan nanometer magnetic materialswere investigated by scanning electron microscope (SEM), Fourier transformed infrared spectroscopy (FT-IR),X-ray diffraction (XRD) and magnetic testing, we could draw the following conclusions:1.If the thick acetic acid was used as solvent, the electrospun chitosan were particles and not nanofibers although the change of the viscosity, surface tension and conductivity of pure chitosan solution along with the alteration of the molecular weight and concentration of chitosan. But when PVA was added into the spinning solution the composite formability was effectively improved. If the concentration of PVA was 40%,the mass fraction wased 4% and the spinning voltage was 25kV, the receiving distance was 120mm,the rate of flow was 0.2 ml/h, the morphology of the chitosan/PVA composite nanofiber membranes were good and had some mechanical and hydrophobic propertises.2.When the substance ratio of Fe2+ to Fe3+ was 1:1.75, pH of precipitation was 11, the reaction temperature was 80℃, the reaction time of was 1 hour and thestirring rate of was 1000r permin, Fe3O4 nanoparticles could be prepared by the chemical co-precipitation method. SEM showed the diameter size of Fe3O4 nanoparticle was 10nm.If the Fe3O4 nanoparticles are scattered into the styrene liquor with sodium acetate as surfactant, we could obtain the stable magnetic liquid.3.In the surface of the chitosan nanometer magnetic materials most of Fe3O4 nanoparticles existed in the aggregation state, only a small proportion of Fe3O4 nanoparticles were well dispersed in the nanofibers. The FT-IR spectrum showed both of them had not the chemical bond. The magnetic testing showed the nanometer magnetic composite materials preserved propertises of the chitosan composite nanofiber membranes and had the surplus paramagnetic characteristics, their saturation magnetization could be 15.4 emu/g.