Preparation of stable magnetic nanofluids containing Fe(3)O(4)@PPy nanoparticles by a novel one-pot route

Stable magnetic nanofluids containing Fe(3)O(4)@Polypyrrole (PPy) nanoparticles (NPs) were prepared by using a facile and novel method, in which one-pot route was used. FeCl(3)·6H(2)O was applied as the iron source, and the oxidizing agent to produce PPy. Trisodium citrate (Na(3)cit) was used as the reducing reagent to form Fe(3)O(4 )NPs. The as-prepared nanofluid can keep long-term stability. The Fe(3)O(4)@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 Fe(3+ )ions as the initiator, in which these Fe(3+ )ions remained in the solution adsorbed on the surface of the Fe(3)O(4 )NPs. Thus, the core-shell NPs of Fe(3)O(4)@PPy were obtained. The particle size of the as-prepared Fe(3)O(4)@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 Fe(3)O(4)@PPy NPs exhibit superparamagnetic behavior.