Research On Multi-layer Wave-absorbing Composite Based On Electrospun Nanofiber

Wave-absorbing materials are becoming increasingly important, whether in military or civilian. Traditional and single absorbing materials are difficult to meet the requirement of "strong absorption, frequency bandwidth, light weight, thin, etc. ". In addition to the study of new kinds of absorbent, the composition or structure or component is a very efficient way to improve absorbing property. Multi-layer composite based on electrospinning polymer nanofibers according to impedance matching design is able to get a much more good performance.In this thesis, the process control of electrospinning, electrospinning of three absorbing agent particles(nano-iron oxide, nano-silicon carbide, conductive polyaniline) to make nano-fiber membranes, also their microscopic tests, TG analysis, mechanical testing are studied. The nanofiber microstructure, nanoparticle dispersivity, thermal stability and mechanical properties depend on the electrospinning process parameters and the content of the absorbent added.The nanofiber/epoxy composites are prepared and electromagnetic parameters are measured. The influence of each component and its content in the material is analyzed. Matlab simulation program based on impedance matching transmission line theory is made to give a multi-layer design of the absorber.Three-layer(2mm) composite based on electrospun nanofibrous membranes is successfully made. Measurement of its absorbing properties which is compared with simulation, also analysis of the density of the composites and the static tensile and bending properties illustrated that this kind of epoxy composite has good mechanical property and absorbing property. Absorption peak of the composite reaches at-40 d B, the bandwidth of-10 d B is more than 5GHz; Tensile and bending strength is much better than epoxy and the epoxy composites with nanoparticle dispersed directly.