Preparation And Characterization Of Dual Responsive Magnetic Nanoparticles

In this study, dualfunctional iron oxide nanoparticles were synthesized via reversible addition-fragmentation chain transfer radical polymerization(RAFT),N-isopropylacrylamide (NIPAM) and6-(4’-methoxy-4-yloxy azobenzene)-hexyl methacrylate(AzoMA) as monomers, then the obtained diblock copolymers were successfully modified on the surface of iron oxide nanoparticles through the interaction between the chemical bonds. The diblock copolymers were characterized by FT-IR,1H NMR and gel permeation chromatography (GPC). The resulting polymers had a narrow range of polydispersity indexes1.06-1.20, and the molecular weight of the polymer exhibits linear growth trend with the increases of polymerization time and concentration of monomers, which showed that the process of RAFT was active and controllable.We obtained uniform Fe3O4@(PNIPAM-b-PAzoMA) particles with narrow distribution of30nm, which were characterized by scanning electron microscopy (SEM). The properties of temperature response were also studied by turbidimetric, the lower critical solution temperature(LCST) of dual responsive magnetic nanoparticles decreased with the increasement of the incorporated azobenzene. Dual responsive magnetic nanoparticles have potential applications in hyperthermia, artificial muscles, smart drug delivery systems and biomedical imaging.