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Magnetically separable core/shell Fe3O4/ZnO heteronanostructures (MSCSFZ) were synthesized by a facile approach, and their application for enhanced solar photodegradation of RhB was studied.

Cobalt ferrite nanoparticles (CFNPs) are emerging as a potential candidate for biomedical applications, such as magnetic hyperthermia therapy (MHT), due to their high saturation magnetisation (M S) and effective magnetic anisotropy constant (K eff) at the nanoscale. For MHT, heating efficiency depends considerably on applied AC magnetic field, particle diameter, and inter-particle interaction. Our study is aimed at developing a superparamagnetic nanosystem based on CFNPs with enhanced specific absorption rate (SAR) for advanced MHT. The CFNPs were synthesised using thermal decomposition of organometallic precursors. Transmission electron microscopy reveals a narrow size distribution of the CFNPs, with average particle sizes of 8 and 11 nm. Magnetic measurements showed high values of M S (~70 emu g−1) and K eff (2–3 × 106 erg cm−3). The ferromagnetic behaviour and strong interaction between particles at room temperature are also observed. Large SAR values of the CFNPs are achieved, which are superior to those reported previously in the literature. The high heating efficiencies of the present CFNPs make them a promising candidate for advanced MHT.

In this work the synthesis of thermo-sensitive polymer coated magnetic nanoparticles and their inductive heating have been studied. Poly (N-isopropylacrylamide-co-acrylic acid) (NA) polymers were first synthesized by emulsion polymerization of poly(N-isopropylacrylamide) (NIP) in water and followed by encapsulating magnetic nanoparticles (MNPs). As increasing the concentration of acrylic acid (AA), the lower critical solution temperature (LCST) increased, so that with 150% of AA (molar ratio) the LCST reached 42 °C, which is close to the temperature of hyperthermia treatment. Magnetization and ac susceptibility measurements were conducted to depict some characteristics of the NIP-MNPs and NA-MNPs that are related with the loss power. Attempts to analyze the rate of magnetic inductive heating were performed to show the Brownian relaxation origin of additional heat source created by the magnetite nanoparticles capped with thermosensitive polymers. Our results suggest that these thermo-sensitive polymer-coated magnetic nanoparticles show a potential for hyperthermia and drug delivery application.

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