Magnetically responsive polypyrrole nanotubes using Ce(III)-stabilized maghemite nanoparticles

Nanocomposites (NCs) that are made magnetically responsive in controlled conditions attract continuing interest for their added magnetic properties. In this study, we report on the preparation and full characterization of a multifunctional NC composed of magnetic γ-Fe₂O₃ nanoparticles (NPs) covalently attached to the surface of polyaminated (polyNH₂) poly(2,6-di-pyrrol-1-yl-hexanoic acid) (pDPL) nanotubes (NTs). Such a hybrid conducting polymer iron oxide maghemite γ-Fe ₂O₃@pDPL NC built specifically on covalent bonding has never been reported. The maghemite γ-Fe₂O₃ NPs were prepared using an innovative ultrasound-assisted Ce^{3 +} doping process, resulting in polycarboxylation of the NP surface useful for control of aggregation and derivatization of functionality. The second component of the NC, i.e. polyNH₂-modified pDPL NTs, was prepared from an acid functional pyrrole species followed by amine modification. The resulting innovative γ-Fe₂O₃@pDPL NC can be viewed as a multifunctional nanomaterial since it possesses both types of derivatization, i.e.polyCOOH (NPs) and polyNH₂ (NTs) combined with magnetic responsivity.