Electromagnetic composite films based on polypyrrole hydro-sponge and Fe3O4 ferrofluid

The preparation of free-standing electromagnetic composite films based on conductive polypyrrole (PPy) hydro-sponge and the Fe3O4 ferrofluid have been successfully accomplished via self-assembly in the presence of beta-cyclodextrin sulfate and under static condition. Transmission electron microscope (TEM). scanning electron microscope (SEM) and X-ray diffraction (XRD) are used to study the morphology of the PPy-Fe3O4 composite. Structural characterizations by Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA) have proved the interactions between Fe3O4 and PPy chains. As-prepared films possess high electrical conductivity, remarkable magnetic response as well as appropriate flexility. Both the conductivity and magnetization of the composite, the latter in particular, depend strongly on the Fe3O4 content and thus can be optimized by adjusting the relative content of Fe3O4 in the composite. The combination of both magnetic and conducting activities of the resulting composite makes it be a potential candidate as functional material in electromagnetic devices, such as magnetic-con trolled switches. (c) 2009 Elsevier B.V. All rights reserved.