FRD - CENES

Permanent URI for this communityhttp://48.217.138.120/handle/20.500.12272/1235

Browse

Author: search.filters.author.Scarpettini, Alberto FrancoSubject: search.filters.subject.Plasmonics

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Kinetic and plasmonic properties of gold nanorods adsorbed on glass substrates
    (2019-10-24) Gutiérrez, Marina V.; Scarpettini, Alberto Franco
    Monodisperse gold nanorods with different sizes were synthesized and adsorbed on chemically modified glass substrates. Influence of surfactant molar concentration on nanorod adsorption was studied and the optimum range was determined. During substrate coverages we monitored the growth of longitudinal localized surface plasmon resonances at short times due to density increase of isolated nanorods and, at longer times, their subsequent decrease and a concurrent growth of coupling resonances owing to nanoparticle surface mobility and aggregation. Temporal evolution of amplitudes of resonance peaks in extinction spectra and nanorod counting statistics in electron micrographs were used to model both coverage and aggregation processes, as exponentiallike functions of time. Their characteristic times and saturation values were analyzed and related to kinetic parameters, nanorod dimensions and extinction coefficients. This work can be used as a predictive tool to prepare plasmonic substrates with desired optical resonances.
  • Thumbnail Image
    Item
    Determination of nanoscale mechanical properties of polymers via plasmonic nanoantennas
    (2020-06-02) Boggiano, Hilario D.; Berté, Rodrigo; Cortés, Emiliano; Maier, Stefan A.; Bragas, Andrea V.; Scarpettini, Alberto Franco
    Nanotechnology and the consequent emergence of miniaturized devices are driving the need to improve our understanding of the mechanical properties of a myriad of materials. Here we focus on amorphous polymeric materials and introduce a new way to determine the nanoscale mechanical response of polymeric thin films in the GHz range, using ultrafast optical means. Coupling of the films to plasmonic nanoantennas excited at their vibrational eigenfrequencies allows the extraction of the values of the mechanical moduli as well as the estimation of the glass transition temperature via time-domain measurements, here demonstrated for PMMA films. This nanoscale method can be extended to the determination of mechanical and elastic properties of a wide range of spatially strongly confined materials.
  • Thumbnail Image
    Item
    Challenges on optical printing of colloidal nanoparticles.
    (2022-01-18) Violi, Ianina L.; Martínez, Luciana P.; Barella, Mariano; Zaza, Cecilia; Chvátal, Lukás; Zemánek, Pavel; Gutiérrez, Marina V.; Paredes, María Yanela; Scarpettini, Alberto Franco; Olmos-Trigo, Jorge; Pais, Valeria R.; Díaz Nóblega, Iván; Cortés, Emiliano; Sáenz, Juan José; Bragas, Andrea V.; Gargiulo, Julián; Stefani, Fernando D.
    While colloidal chemistry provides ways to obtain a great variety of nanoparticles with different shapes, sizes, material compositions, and surface functions, their controlled deposition and combination on arbitrary positions of substrates remain a considerable challenge. Over the last ten years, optical printing arose as a versatile method to achieve this purpose for different kinds of nanoparticles. In this article, we review the state of the art of optical printing of single nanoparticles and discuss its strengths, limitations, and future perspectives by focusing on four main challenges: printing accuracy, resolution, selectivity, and nanoparticle photostability.