The Design Of Composite Materials Based On Tubular Nano-materials And Their Microwave Absorbing Properties

With the progress of society in recent years,electronic technology innovation has brought a lot of convenience to people's lives.But the use of electronic products and electronic equipment has brought electromagnetic pollution and other issues to the environment.Electromagnetic pollution not only affects people's health,but also affect the normal work of other electronic equipment.Electromagnetic wave absorption materials can reduce the harm caused by electromagnetic pollution,and the same in military field,electromagnetic wave absorption material can effectively reduce the radar on the detection of military facilities.Polypyrrole aerogels have attracted much attention because of their light weight and good microwave absorbing properties.However,their use as absorbers alone cannot meet the requirements in all environments.In this paper,the carbonyl carbon nanotubes(MCNT-COOH)and silicon carbide nanotubes(SiCNT)were used to modulate the polypyrrole(PPy)aerogels to form hybrid composites,and then their electromagnetic wave absorption properties were analyzed.The main work has shown in following aspects.(1)MCNT-COOH and SiCNT were used to control the preparation of PPy aerogels.Firstly,carboxyl MCNT(MCNT-COOH)was prepared via a similar process according to the literature then different ratios of MCNT-COOH were mixed with pyrrole monomer and the oxidizing agent has been used to oxidizing pyrrole monomers to form carboxyl carbon nanotubes and polypyrrole composites(MCNT-COOH @ PPy).SiCNT@PPy were prepared by the above-mentioned methods,the aerogels of MCNT-COOH @ PPy and SiCNT@PPy with different microstructural morphology were obtained finally.(2)In order to further invastigate the morphologies of MCNT-COOH@PPy and SiCNT@PPy aerogels,scanning electron microscopy,transmission electron microscopy,infrared spectroscopy,Raman spectroscopy,X-ray diffraction,X-Ray photoelectron spectroscopy were used to characterize the products.Using the above analytical method,we can found that the pyrrole monomer preferentially polymerized on the surface of MCNT-COOH and SiCNT to form a thin film,and then the excess of pyrrole monomer continue polymerized on the surface of the thin film through self-assembled to form an aerogels which containing the above two substances.(3)Different proportions of MCNT-COOH@PPy and SiCNT@PPy aerogels were mixed with paraffin respectively.Using vector etwork analyzer to test products/wax composites and obtain the electromagnetic parameters of the mixture.Through the analysis of their dielectric properties and electromagnetic wave absorption properties we can see that MCNT-COOH@PPy and SiCN@PPy exhibit excellent electromagnetic wave absorption properties.The maximum effective absorption widths are 6.12GHz and 6.52GHz,respectively,which are much wider than those of pure polypyrrole,and the thickness is thin and light.Therefore,the above-mentioned two products can be prepared as electromagnetic wave absorbing materials.