Nano Absorbign Materials Prepared Via Electrospinning

Absorbing materials are one of functional materials, and they have been widely used in civilian and military. Previous studies on microwave absorption materials have aimed to synthesize light-weight, wide-absorption-band, and high-absorption-rate materials. The electrospinning technology has the apparent advantage of simple, high spinning material variety, low cost, process control. It has become one of the main ways of preparing nanofibers. In this work, electrospinning is the main method with the advantage of wide choice and high efficiency to prepare SrFe12O19 nanofibers. What's more, hollow SrFe12O19 nanofibers and SrFe12O19/BaTiO3 composite nanofibers have been prepared via coaxial electrospinning with low density and high microwave-absorption performance. The main contents are summarized as follows:1. Preparation, characterization and analysis magnetic and absorption performance of SrFe12O19 and SrFe12O19 nanotubes.We discuss the influence of the spinning system, distance, voltage and inorganic salt on electrospinning. Both inside and outside layer of solvent, heating rate, calcination temperature also were discussed on the preparation of hollow SrFe12O19 via coaxial electrospinning. Slow heating rate as conducive to the formation of hollow structure. High calcination temperature makes the nanotube structure decreases, the crystallinity increases, and the magnetic enhances. The characterization methods such as X-Ray diffraction, TG-DTA technology, scanning electron microscope, transmission electron microscopy have been used to illustrate the formation of hollow struction and SrFe12O19. In order to studying the effect of structure on absorbing properties, we set the controlled trials. The results show that compared with the solid nanofibers, the denisity reduced by 48.5%, the wave absorption performance developed 14.5%, the effective bandwidth increased loss of 0.48 GHz and the thickness declined 0.2 mm.2. Preparation, characterization and analysis magnetic and absorption performance of shell-core SrFe12O19/BaTiO3 composite nanofibers. Based on the the principle of ideal absorbing material, SrFe12O19 absorbing materials and BaTiO3 absorbing materials have been combined through coaxial electrospinng to make the composite relative permeability and dielectric are nearly constant. The characterization methods such as XRD, TEM have been used. Composite nanobers can obviously observe its outer-inner structure. The advantage of this method is material uniform stability and high process controllability. Compared with the ordinary nanofibers, the absorption proformance of the shell-core SrFe12O19/BaTiO3 composite nanofibers has developed nearly 348.6%, the effective bandwidth increased loss of 1.60 GHz and the thickness declined 1.4 mm.