Preparation And Characterization Of PVDF/Fe₃O₄ Composite Nanofibers

The issue is the use of home-made device to prepare the nanofiber from polyvinylidene fluoride (PVDF) and iron oxide Fe₃O₄ (magnetite), and the use of the modern analytical instruments to study the structure and related performance of nanofibers. The issue further promotes the development of magnetite nano-materials and provides a certain basis for their application.In this paper, after preparing the nano iron oxide Fe₃O₄ (magnetite) by chemical precipitation, it prepares the PVDF/Fe₃O₄ nanofibers by the two methods that are direct coating method and sol-gel method. Then, it uses X-ray spectrometer (EDX) and X-ray diffraction (XRD) to verify the existence of iron oxide Fe₃O₄ (magnetite). At the same time, it uses scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscope (AFM) to observe and analyze the micro-structure of the nanofibers and explore the relationship between the experimental parameters and nanofiber's microstructure. The discovery is that the average diameter of nanofibers will increase because of the increasing of consistence; the average diameter of nanofibers by the direct coating method was 150～200nm, but the average diameter of nanofibers by the sol-gel was 30～50nm. In addition, it also analyzed the distinction of appearance and internal structure between nanofibers from the different method and found that sol-gel method can be more effective to improve the phenomenon of magnetite reunion than the direct coating method.Then, the TG experiment analyzed the content of iron oxide Fe₃O₄ (magnetite) in nanofibers. Experiments showed that: the actual content of iron oxide Fe₃O₄ (magnetite) was similar to the theoretic content, which told us iron oxide Fe₃O₄ (magnetite) mostly combining with PVDF. At the same time, the surface roughness of nanofibers was analyzed.Finally, through magnetic experiment, it analyzed the magnetic performance of the nanofibers. It found that nanofibers' saturation magnetization intensity was increasing with the increasing of the consistence, and nanofibers' from the sol-gel saturation magnetization intensity was obviously much higher than that prepared by direct coating; the remanence of the nanofibers from the two kinds of method had the same laws with saturation magnetization intensity; nanofibers coercivity remained unchanged and 38Oe, which showed that nanofibers coercivity had nothing to do with the consistence of iron oxide Fe₃O₄ (magnetite), but was related to the materials.