Due to their strong shape anisotropy, one-dimensional (1D) nanomaterials, including nanotubes, nanowires and nanofibers exhibit specific properties that are not observed in the case of their bulk or particle counterparts.1 Moreover, when such nanomaterials display a superparamagnetic behavior; they are of interest for a broad range of applications in drug delivery, for clinical diagnostic and therapeutic applications2. For example, the tubular structure of magnetic nanotubes presents an important advantage as its distinctive inner and outer surfaces can be differently functionalized3. Up to nowadays, various methods have been used for the synthesis of 1D iron based nanomaterials such as hydrogen reduction in nanochannels4, template directed growth5, Hydrothermal/solvothermal processes6. In those methods, the aspect ratio is sometimes limited, and the amount of materials that can be produced is often restricted. As a consequence, we have chosen the promising alternative of the electrospinning process that is an effective way to produce macroscopic amounts of nanofibers with tunable properties7. Iron based 1D nanostructures have been successfully prepared by electrospinning technique, varying the pyrolysis atmosphere. Hematite nanotubes and polycrystalline Fe3C nanofibers are obtained by simple air or mixed gases (H2, Ar) annealing treatments. Using air annealing treatment, great control on the tubular morphology as well as wall thickness variation is demonstrated with a direct influence of the starting polymer concentration. When mixed gases (H2 and Ar) have been used for the annealing treatments, for the first time polycrystalline Fe3C nanofibers composed of carbon graphitic planes were obtained, ensuring Fe3C nanoparticles stability and nanofibers cohesion. Morphology and structural properties of all these iron based 1D nanostructures are fully characterized by SEM, TEM, XRD and Raman spectroscopy.
Journal: TechConnect Briefs
Volume: 2, Nanotechnology 2010: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational
Published: June 21, 2010
Pages: 95 - 98
Industry sector: Advanced Materials & Manufacturing
Topics: Advanced Materials for Engineering Applications