Preparation And Property Research Of Modified CNTs And Microwave Absorbing Composite Materials

In this paper, reflection loss (R.L.) was simulated using MATLAB. The affect of different absorbing agent content and different matching thickness towards absorbing property was discussed. The trend that, with the absorbing agent increasing, reflection loss increased, the absorption peak shifted to lower frequency, the effective absorption bandwidth significantly reduced, as well as with the matching thickness increasing, reflecting loss intensity decreased, the effective absorption bandwidth reduced, absorption peaks moved to lower frequency, could be found.Glass fiber reinforced epoxy resin based absorbing composite material plat models with different absorbing agent contents and thickness were made in this paper. 8-absorbing layer plat model with 61ï¼…carbonyl iron powder obtained a maximum reflection loss of - 18dB at 2.5GHz, and a bandwidth of 1.2GHz below-10dB.The R.L.-f curve had a similar trend as the simulated one.8-layer plat model with 80% carbonyl iron powder in single absorbing layer had a maximum reflection loss of-16dB, and a bandwidth of 7GHz below -10dB. The maximum reflection loss of 12-layer plat model with 80ï¼…carbonyl iron powder in single absorbing layer increased to-28dB, while the bandwidth decreased to 5.4GHz below -10dB.Ag-filled and Ni-coated double modified carbon nanotubes (CNTs) were prepared with wet chemical method. TEM and XRD were used to characterise the sample. Electromagnetic parameters testing and reflection loss (R.L.) simulating were also carried out to analyze the microwave-absorbing property of the sample. The result showed that, Ag-filled CNTs had a improved microwave-absorbing property with R.L.-17.5dB at 8.8GHz. The bandwidth below-5dB was about 3GHz while below -10dB 1.2GHz. The electromagnetic loss of double modified CNTs was further improved than simple modified CNTs.