Nanoparticles fabrication



The control of the morphology and size at the nanoscale is a hot topic because of the spectacular effects that small changes produce on a variety of physical (optical, magnetic, electronic…) properties of a material. Colloidal synthesis has proven extremely useful to prepare a wide variety of nanoparticles with tight control of size and shape. Still, much of the knowledge in this area is empirical and no general rules can be provided for a rational nanomaterial design. We are particularly interested in understanding and control the nucleation and growth, crucial steps occurring during the synthesis of a nanocrystal. Though eminently fundamental, this research is required for the design of nanoparticle with tailored properties that can be used for practical applications. Thus, our group has developed different strategies to fabricate different type of metal nanoparticles, mainly plasmonic, with different configurations (single-component, core-shell, alloys, dimers, etc.).

In the case of plasmonic nanoparticles, we fully analyze their optical properties, which originate from the so-called localized surface plasmon resonance (LSPRs). It can be described as the collective coherent oscillation of electrons from conduction band with respect to a positive metallic lattice, occurring when a metal nanoparticle is stimulated by the electromagnetic field of an incident light beam. In the case of Au, Ag and Cu the optical properties typically lie in the visible-NIR range and can be easily modulated by tuning particle size and shape, as well as interparticle distance and the refractive index of the surrounding medium.

Moreover, we are also interested in combining metal nanoparticles with other materials (metal, silica, polymer, macrocycles, etc.) in order to fabricate hybrids materials with define composition and configurations with multifunctionality or enhanced properties.