Preparation and magnetic properties of cobalt nanoparticles with dendrimers as templates

A series of cobalt (Co) nanoparticles were synthesized by employing dendrimers with a trimesyl core as templates and sodium borohydride as a reducing agent. Extensive characterizations of the produced materials were studied using TEM, selected area electron diffraction, energy-dispersive X-ray spectroscopy, FT-IR spectra, TGA, and XPS. And their magnetic properties, including hysteresis loop, field-cooled and zero-field-cooled curves, were investigated by superconducting quantum interference magnetometer. The nanoparticles exhibit supermagnetism at room temperature, accompanied by magnetic hysteresis below the blocking temperature. Co nanoparticles exhibited an excellent T1 MRI enhancement effect and can be a potential MRI contrast agent.