| Nowadays, accompany with the rapid development of economy and society, the crisis caused by the imbalances between resources reserve and social consumption speed exposures continuously in the public view. Therefore, the scientific research activities of world at present were guided by environmental friendly and resource intensive principles, to the whole human society, exploring both fully functional and practical to sustainable development trend of the materials produced by the meaning will be far greater than its own economic value. Carbon fiber as a very important strategic resource, its production and scientific research activities had gained the world wide attention. Within few decades, it developed from high modulus and strength, lightweight structure materialsto the high surface area activated rich pore structure carbon fiber, the application range of the carbon fiber materials continuously expanded, as well as more far-reaching strategic significance. However, relatively limited carbon source material blocks the capacity and controll ability of carbon fiber structure, the limitations of fabricate technology also obstacle fiber diameter cannot reach a more ideal standard. Espically need to breakthrough the bottleneck in some areas of application and so on. With the rise of nano-science and technology, the carbon fiber materialsare obtained a very rare opportunity for diversified developing, so the research of carbon nanotubes fiber gradually become the new hot point.In our research, hierarchical porous, magnetic Fe3O4@carbon nanofibers (Fe3O4@CNFs) comprising of graphitic nanofibers and embedded Fe3O4nanocrystals were prepared by using electrospun polyvinylbutyral/polybenzoxazine(PBZ) and polyacrylonitrile/polybenzoxazine nanofibers as composite carbon precursor. By the combination of precursor design and activation process, a series of Fe3O4@CNFs with tunable porous structure including the surface area, pore volume and micro/mesopore ratio were obtained, and could achieve the extremely high surface area of1885m2g-1and pore volume of2.325cm g-1. Quantitative pore size distribution and fractal analysis were employed to investigate the hierarchical porous structure using Na adsorption methods and synchrotron radiation small-angle X-ray scattering measurements. The role of precursor structure and activation treatment for the tuning of the porous structure and surface fractal dimension is discussed, and the relative fraction of closed and open pores in CNFs is confirmed. Furthermore, the as-prepared Fe3O4@CNFs exhibit efficient adsorption for organic dyes in water and excellent magnetic separation performance, which suggesting a promising adsorbent for water treatment, and also provided a new insight into the design and development of functional carbon nanomaterials based on PBZ precursorThe conclusions we achieved are as follows1. Choose benzoxazine type phenolic resin as the main source of carbon fiber materials and successfullysynthesised of carbon nanotubes fiber. Carbon nanotubes fiber preparation process in each stage fiber morphological structure and chemical properties of the change rule of this new type of carbon nano fiber material formed a preliminary understanding.2. Combined with electrospinning technology in carrier nanofibrous membrane surface achieved benzoxazine molecular in situ polymerization was successfully achieved good magnetic benzoxazine carbon nano fiber materials, and the organic pollutants in water adsorption performance and magnetic separation ability were investigated.3. With the assistance of Shanghai synchrotron radiation light source technical, the carbon nanofibrous material preparation process of each phase of the microscopic structure of the synchrotron radiation small angle scattering characterization, and combining the results of laboratory routine testing means, the characteristics of carbon nanofiber microscopic pore structure were thoroughly discussion, innovate investigated the open/closed hole structure. |
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