tailieunhanh - Zhao and Nan Nanoscale Research Letters 2011, 6:230

Zhao and Nan Nanoscale Research Letters 2011, 6:230 NANO EXPRESS Open Access Preparation of stable magnetic nanofluids containing Fe3O4@PPy nanoparticles by a novel one-pot route Baobao Zhao and Zhaodong Nan* Abstract Stable magnetic nanofluids containing Fe3O4@Polypyrrole (PPy) nanoparticles (NPs) were prepared by using a facile and novel method, in which one-pot route was used. FeCl3·6H2O was applied as the iron source, and the oxidizing agent to produce PPy. Trisodium citrate (Na3cit) was used as the reducing reagent to form Fe3O4 NPs. The asprepared nanofluid can keep long-term stability. The Fe3O4@PPy NPs can still keep dispersing well after the nanofluid has been standing for 1. | Zhao and Nan Nanoscale Research Letters 2011 6 230 http content 6 1 230 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Preparation of stable magnetic nanofluids containing Fe3O4@PPy nanoparticles by a novel one-pot route Baobao Zhao and Zhaodong Nan Abstract Stable magnetic nanofluids containing Fe3O4@Polypyrrole PPy nanoparticles NPs were prepared by using a facile and novel method in which one-pot route was used. FeCl3-6H2O was applied as the iron source and the oxidizing agent to produce PPy. Trisodium citrate Na3cit was used as the reducing reagent to form Fe3O4 NPs. The as-prepared nanofluid can keep long-term stability. The Fe3O4@PPy NPs can still keep dispersing well after the nanofluid has been standing for 1 month and no sedimentation is found. The polymerization reaction of the pyrrole monomers took place with Fe3 ions as the initiator in which these Fe3 ions remained in the solution adsorbed on the surface of the Fe3O4 NPs. Thus the core-shell NPs of Fe3O4@PPy were obtained. The particle size of the as-prepared Fe3O4@PPy can be easily controlled from 7 to 30 nm by the polymerization reaction of the pyrrole monomers. The steric stabilization and weight of the NPs affect the stability of the nanofluids. The as-prepared Fe3O4@PPy NPs exhibit superparamagnetic behavior. Introduction Nanofluids which contain nanoparticles dispersed in base fluids have been proposed as a new kind of heat transfer medium because they can improve the heat transport and energy efficiency and may have potential applications in the field of heat transfer enhancement 1 . Magnetic nanofluids suspension containing magnetic nanoparticles such as magnetite Fe3O4 iron Fe nickel Ni and cobalt Co show both magnetic and fluid properties and have important applications in industries 2 3 . Fe3O4 nanoparticles are always used to form magnetic nanofluids because of their broad potential and practical technological applications and .