Water-to-PEG Variation: Morphology and Hyperthermic Behaviour of Iron Oxide

Magnetite (Fe₃O₄) nanoparticles (NPs) with various morphologies obtained by varying solvent (water)-to-surfactant (polyethylene glycol, PEG) ratios have been investigated for magnetic hyperthermia (MHT) application. The water-to-PEG ratio influenced the size, shape, and chemical composition of the NPs, which changes their magnetic properties and hyperthermia (HPT) response. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) studies reveal the formation of well crystalline inverse spinel structure of Fe₃O₄ with some Fe⁰ phases. Morphology of the NPs varies from nearly spherical to elongated to pseudohexagonal to cluster with an increased concentration of PEG. The NPs possess enhanced saturation magnetization ranging from 90 to 98 emu/g. The HPT studies indicated that the NPs show an enough specific absorption rate (SAR) under alternating magnetic field suitable for biological application with hexagonal Fe₃O₄ being more efficient.