Preparation And Electromagnetic Absorption Properties Of Polyaniline/graphene Composites

In this dissertation,different kinds of electromagnetic wave absorption materials were synthesized based on polyaniline and graphene,in order to achieve the properties of thin thickness,light weight,strong absorption and broad absorption bandwidth.The composites of polyaniline/graphene oxide(PANI/GO),polyaniline/graphene(PANI/RGO),nickel/graphene(Ni/RGO),and polyaniline/nickel/graphene(PANI/Ni/RGO)were prepared and tested to explore their electromagnetic wave absorption properties.Firstly,PANI/GO and PANI/RGO composites were prepared by the approach of in-situ polymerization.A large amount of PANI fibers were loaded on the surface of GO and RGO sheets,and filled between the sheets.By adjusting the amount of aniline,RGO and doping acid,as well as adjusting the the filling amount of the absorber in the paraffin matrix,the morphology and electromagnetic parameters of the composites can be controlled to improve the absorption performance.Add the filling amount of PANI/GO composites to 50%,the absorbing abilities for lower-frequency microwaves of samples are enhanced.PANI/GO and PANI/RGO composites exhibit the excellent absorption performance with lightweight and wide bandwidth.Secondly,Ni/RGO composites were synthesized via a one-step solvothermal in-situ reduction method.Large amounts of Ni microspheres are nearly evenly distributed on the both sides of RGO sheets.The particle sizes of Ni microspheres can be controlled by adjusting the initial concentration of nickel salt.Ni/RGO composites could achieve strong and broad effective absorbing of electromagnetic wave at thin thickness.The reflection loss of NG-1 achieves——31.4 dB and the effective absorption band is from 13.3 to 16.0 GHz with the matching thickness of 1.2 mm.Adjusting the initial concentration of nickel salt could achieve effective absorption for electromagnetic waves of different frequency bands of the materials with different thicknesses.Finally,PANI/Ni/RGO composites were fabricated by in-situ polymerization after preparing Ni/RGO binary composites.The ternary composites with PANI coating on the surface of Ni and RGO exhibit the sandwich structure.Changing the initial concentration of raw materials and filling amount of absorber to the test matrix,could effectively adjust the electromagnetic parameters and improve the absorption performance.When the composite filling amount is 30%,the sample shows strong absorption ability for high-frequency electromagnetic wave.When the absorber loading increases to 50%,the sample exhibits multiple absorption peaks for electromagnetic waves in different frequency regions.The multiple electromagnetic loss mechanisms existed in multi-component composites are conductive to broaden the absorption frequency-band and enhance electromagnetic absorption performance.