Preparation And Microwave Absorbing Properties Of Polyaniline-ZnO Composites

In this paper,Zinc Oxide(ZnO)was prepared by solvothermal and sol-gel method,respectively.The Polyaniline(PANI)/ZnO composite was synthesized using in-situ polymerization method.The X-ray Diffraction(XRD),Scanning Electron Microscope(SEM)and Fourier Transform Infrared Spectrometer(FT-IR)were used to characterize the structure and morphology of the all samples,and the Vector Network Analyzer was used to measure microwave absorbing property of the ZnO and Pani/ZnO composites.The results are as follow:(1)The XRD results show the ZnO nanopowders,which was prepared by the solvothermal method,is the pure phase and hexagonal wurtzite structure.When the reaction temperature is 120?,140?,150?,160? and 180?,respectively,the average diameter of the ZnO nanoparticles is about 18.67 nm,18.68 nm,19.52 nm,22.74 nm and 27.29 nm,respectively,which is calculated through the Debye-Scherrer Formula.As it is seen in the SEM images,the morphology of the ZnO nanoparticles is sphere,rod-shape and petal-shape,respectively.When measuring frequency is 18.4 GHz,the dielectric constant(?'),the dielectric loss(?'')and the reflection loss(R)of the ZnO nanopowders is 3.65,0.1 and 0.53 dB,respectively.(2)The XRD results show the ZnO nanopowders,which was prepared by the sol-gel method,is also the pure phase and hexagonal wurtzite structure.When the calcining temperature is 400?,500?,600?,700? and 750?,respectively,the average diameter of the ZnO nanoparticles is about 16.43 nm,20.54 nm,29.35 nm,37.45 nm and 37.44 nm,respectively,which is calculated through the Debye-Scherrer Formula.As it is seen in the SEM images,the morphology of the ZnO nanoparticles is flakiness and rod-shape,respectively.When measuring frequency is 15.7 GHz,the ?',?''and R of the ZnO nanopowders is 6.45,2.7 and-3.42 dB,respectively.(3)The PANI/ZnO(solvothermal method)composite was prepared by the in-situ polymerization method.The doping content of the ZnO nanopowders is 5%,10% and 15%,respectively.As we can see in the SEM images,the morphology of the PANI/ZnO composite is like sphere.When the doping content of ZnO is 10% and the measuring frequency of the samples is 18 GHz,the ?',?'' and R of the PANI/ZnO composite is 7.05,0.1 and-4.8dB,respectively.(4)The PANI/ZnO(sol-gel method)composite was prepared by the in-situ polymerization method.The doping content of the ZnO nanopowders is 5%,10% and 15%,respectively.As we can see in the SEM images,the morphology of the PANI/ZnO composite is like sphere.When the doping content of ZnO is 15% and the measuring frequency of the samples is 18 GHz,the ?',?'' and R of the PANI/ZnO composite is 6.8,3.8 and-4.8dB,respectively.