Counter-Ion Induced Morphological Control of Polypyrrole/Fe3O4 Nanocomposites in the Presence of Surfactant CTAB
We report a facile and novel route to in-situ growth of conducting polypyrrole (PPy)/Fe3O4 nanocomposites via a counter-ion induced method, in which the cationic surfactant CTAB was used as a soft template, ammonium persulfate (APS) or FeCl3 was used as an oxidant, and organic acids were used as a configuration “directing” agent. The as-synthesized nanocomposites were characterized by TEM, XRD and the measurements of their electromagnetic properties. Experimental results show that both the kind of oxidant and the size of counter-ions in the polymerization system play the key roles in the fabrication of the morphologies of the final PPy/Fe3O4 nanocomposites. A uniform core-shell spherical nanostructure was formed when FeCl3 was used as the oxidant, whereas the string-bead nanostructure could be obtained when APS was used instead. The size of the counter-ions during the connection of micellar molecules could directly induce the formation of the PPy/Fe3O4 composites with various morphologies from spherical nanoparticles, nanofibers or string-bead nano-network to microtube structures. Meanwhile the loading amount of Fe3O4 ferrofluid would not only determine the diameter size of the string-bead nanostructures, but also the electromagnetic properties such as the microwave absorbing capacity of the resulting nanocomposites.
Zhong Cao, Xueqiang Cao, Lixian Sun, Yinghe He
C. M. Yang et al., "Counter-Ion Induced Morphological Control of Polypyrrole/Fe3O4 Nanocomposites in the Presence of Surfactant CTAB", Advanced Materials Research, Vols. 239-242, pp. 1552-1557, 2011