Abstract:

PAn-co-PPy/Fe3O4 network nanofiber composites have been synthesized in Fe3O4 magnetic fluid by in situ chemical oxidative polymerization of aniline (An) and pyrrole (Py) monomers in the presence of cationic surfactant cetyltrimethylammoniun bromide (CTAB). Experimental results show that nanocomposites with controllable morphology and electromagnetic properties can be obtained by varying the concentration of CTAB, molar ratio of An/Py and amount of Fe3O4. The resulting products were characterized by SEM, TEM, XRD, TG and measurements of their electrical conductivities and hysteresis loops. The complex permittivity and permeability of samples were measured on vector network analyzer in the range of 2～18 GHz, from which the reflection loss (R) curves of microwave vs frequency were calculated. The results showed that the PAn-co-PPy/Fe3O4 nanocomposites exhibit better microwave-absorbing properties than any single polymer or copolymer or PAn/Fe3O4 and PPy/Fe3O4 composites. It had a maximum reflection loss of –36.5 dB at 9.0 GHz with about 4.7 GHz bandwidth above -10 dB when the content of Fe3O4 in the composite was 12.4 wt%.

Key words: (PAn-co-PPy) polymer,ferroferric oxide,nanofiber composite,microwave-absorbing properties