PH control as a tool for the synthesis of Ag nanoparticles (NPs) aggregates with plasmonic applications

The degree of aggregation of nanoparticles (NPs) exerts an important influence on the physicochemical properties of a dispersion, like optical absorption and photothermal effect . Hence, the controlled tuning of aggregation can be a valuable tool for the synthesis of NPs systems with specific properties and potential technological applications. The stability and degree of aggregation of Ag NPs in a dispersion depend on the nature of the capping agent and also on the properties of the surrounding medium (pH, ionic strength, polarity, etc.). In this work, we analysed the effect of pH and concentration on the aggregation of silver NPs, capped with a ligand bearing carboxylic acid groups, in aqueous dispersions. We then determined the effect of the size of these aggregates on the optical absorption and photothermal effect of the dispersions.Fil: Cativa, Nancy Maribel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: dell’Erba, Ignacio E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Hoppe, Cristina Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Arenas, Gustavo F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Científicas y Tecnológicas en Electrónica. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones Científicas y Tecnológicas en Electrónica; ArgentinaXVI Simposio Latinoamericano de Polímeros y XIV Congreso Iberoamericano de PolímerosMar del PlataArgentinaUniversidad Nacional de Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiale

Hybrid Films Based on a Bridged Silsesquioxane Doped with Goethite and Montmorillonite Nanoparticles as Sorbents of Wastewater Contaminants

The synthesis and characterization of silsesquioxane (SSO) films with pendant dodecyl groups and doped with goethite (Gt) or montmorillonite (MMT) nanoparticles were carried out and the new materials tested as sorbents of diverse contaminants. The synthetic method used yielded SSO films with the inorganic substrates homogeneously distributed within the polymeric matrices. The new materials were characterized by SEM, FTIR, XRD, and DSC and tested to evaluate their capability for adsorbing metallic cations, organic dyes, and phosphate, frequent contaminants of industrial effluents. All films were found suitable for removing metallic cations. Results also showed that the SSO films undoped and doped with Gt are primarily apt for anionic compounds removal. Although the SSO films doped with MMT are capable of removing cationic contaminants from aqueous samples, the stiffness of the SSO matrix hinders MMT properties as an adsorbent. The possibility of dispersing nanoparticulate systems in the stable and chemically inert SSO matrices simplifies their application for contaminant removal, particularly because it makes the separation process of the absorbed pollutant from the treated medium easier