Monodisperse ZnFe 2 O 4 nanoparticles were synthesized using a simple and low-cost polyol process based on thermal decomposition of the precursors of Fe(acac) 3 and Zn(acac) 2 in triethylene glycol without any surfactant. The as-prepared ZnFe 2 O 4 nanoparticles are highly crystalline, uniform in size, superparamagnetic and can be easily dispersed in aqueous media due to being coated by a layer of hydrophilic polyol ligands in situ. Magnetic study shown that the ZnFe 2 O 4 nanoparticles had a low magnetic anisotropy and low magnetic moment compared to the conventional Fe 3 O 4 nanoparticles. As a result, the as-prepared ZnFe 2 O 4 nanoparticles provide an optimized r 2 /r 1 ratio for T 1 -weighted magnetic resonance imaging (MRI) in the clinical field strength. A preliminary in vitro cytotoxicity test suggests that the zinc ferrite nanoparticles possess a good safety profile. Therefore, the as-prepared ZnFe 2 O 4 nanoparticles have great potential to serve as a novel non-lanthanide T 1 MRI contrast agent.
With the assistance of glucose and citrate, hollow micro-spheres of zinc citrate were prepared through low-temperature hydrothermal route, and then hollow micro-spheres of ZnO were obtained by calcinating the precursor at 500¡䟩n air. The composition, structures and morphologies of products were characterized by XRD, TG-DSC, SEM, TEM and IR. It was investigated that the precursor hollow micro-spheres with average diameter of 2 μm and thickness of 200 nm were prepared by the hydrothermal route. ZnO hollow micro-spheres prepared by calcinating the precursor with average diameter of 1 μm and thickness of 100 nm were composed of nanoparticles with diameter of 20–30 nm. The room-temperature photoluminescence property of the sample was studied. Under excitation wavelength of 325 nm, the as-prepared ZnO hollow micro-spheres possess excellent properties of blue emission, locating at 469 nm
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.