NASA Langley Research Center has developed new methods for fabricating hollow nanoparticles using dendrimer molecules. Dendrimers are used as templates to control the size, stability, and solubility of these metallic nanoparticles ranging in metal lining thicknesses from less than 5 nm to several tens of nm.
Further, the diameter of the void is controlled by the dendrimer generation used. An important advantage of this technique is that highly monodisperse particles with a variety of shapes, sizes, and chemical compositions can be prepared.
Controlling the diameter of gold or other metal, which has historically been challenging, is done via the use of amines. Amine groups on the dendrimer molecules display a capability to generate sites for transition metal ion complexation and the dendrimers act as both nanoscale templates and void generators.
Hollow nanoparticles prepared this way are expected to show advantages for use as void generators with metal lining due to phonon scattering of non-conductive dendrimer molecules. Monolithic ceramic and polymeric templates have also been used for preparing nanomaterials. In many cases, the template can be removed chemically or thermally, leaving behind the hollow nanomaterials.