Fabrication of core-shell Fe3O4/polypyrrole and hollow polypyrrole microspheres

A facile synthesis of highly-regulated core-shell Fe₃O₄/polypyrrole (PPy) microspheres is achieved using a surfactant directed chemical oxidation polymerization in aqueous solution. The thickness of the PPy layer can be tuned by the quantity of the pyrrole monomer. The formation of core-shell Fe₃O₄/PPy microspheres lies on the static interactions between the SO₃⁻ group in sodium dodecyl sulphate molecules and Fe₃O₄ microspheres. Other surfactants such as cetyltrimethylammonium bromide and polyoxyethylene (10) isooctylcyclohexyl ether (Triton X-100) directed polymerization cannot produce such highly-regulated core-shell Fe₃O₄/PPy microspheres. XPS spectra proved the core-shell structure of the composite microspheres. XRD, FTIR, and UV–vis spectra are used to characterize the chemical structure of the composite microspheres. The electrical and magnetic properties are also investigated. Moreover, the obtained core-shell Fe₃O₄/PPy microspheres can be converted to highly-regulated hollow PPy microspheres by dissolving the Fe₃O₄ core with acid solution. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers