Preparation and characterization of cobalt-based nanostructured materials

Nano-sized cobalt clusters passivated by alkane-thiol molecules were obtained by the action of concentrated thiol solutions on micrometric cobalt particles. Thiol molecules caused an erosive process on the metal grains with the consequent formation of nano-sized metal debris and cobalt thiolate as by-product. The final material microstructure was composed by cobalt clusters embedded into a continuum cobalt thiolate matrix. Depending on the thiol molecule length, the material texture ranged from rubbery to waxy. These new types of nanocomposite materials were found to be crystalline, thermally stable up to ca. 300 °C, intensely red colored, and high hydrophobic. In addition, they generated polymeric structures when dissolved in non-polar solvents. © EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2003.