Conductive submicronic coatings of carbon black (CB)/silica composites have been prepared by a sol-gel process and deposited by spray-coating on glazed porcelain tiles. Stable CB dispersions with surfactant were rheologically characterized to determine the optimum CB-surfactant ratio. The composites were analyzed by Differential Thermal and Thermogravimetric Analysis and Hg-Porosimetry. Thin coatings were thermally treated in the temperature range of 300-500 °C in air atmosphere. The microstructure of the coatings was determined by scanning electron microscopy and the structure evaluated by confocal Raman spectroscopy. The electrical characterization of the samples was carried out using dc intensity-voltage curves. The coatings exhibit good adhesion, high density and homogeneous distribution of the conductive filler (CB) in the insulate matrix (silica) that protects against the thermal degradation of the CB nanoparticles during the sintering process. As consequence, the composite coatings show the lowest resistivity values for CB-based films reported in the literature, with values of ~7 x 10~5 fim.

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In this work we present a strategy for developing epitaxial incommensurate nanostructured-Au/oxide heterostructures with tuneable plasmonic response. Previously high quality single phase and oriented α-Fe2O3(0001) thin films were achieved, which have been used as a template for the noble metal epitaxial deposition. The complex systems have been grown by pulsed laser deposition on two different type of oxide substrates: α-Al2O3(0001) and SrTiO3(111). A one-step procedure has been achieved tailoring the isolated character and the morphological features of Au nanostructures through the substrate temperature during the Au growth, without altering the structural characteristics of the hematite layer that is identified as single iron oxide phase. The epitaxial character and the lattice coupling of Au/oxide bilayers are mediated through the sort of oxide substrate. Single oriented Au(111) islands are disposed with a rotation of 30º between their crystallographic axes and those of α-Fe2O3(0001). The Au(111) and SrTiO3(111) lattices are collinear while a rotation of 30º happens respect to the α-Al2O3(0001) lattice. The crystallographic domain size and crystalline order of hematite structure and Au nanostructured-layer are dependent on the substrate type and the Au growth temperature respectively. Besides, the functional character of the complex systems has been tested. The localized surface plasmons related to Au nanostructures are excited and controlled through the fabrication parameters, tuning the optical resonance with the degree of Au nanostructuring.

The photoluminescence of phosphorescent powders after a milling process depends extrinsically on the morphology of the particles such as size and intrinsically on the crystallinity.

The extensive range of applications where synthetic nanomaterials are nowadays used is causing a huge commercial market. An incipient use of these nanomaterials arises from the need to generate alternative antimicrobial agents, anticipating the development of resistant microorganisms. Here, we show a nanostructured ZnO with antimicrobial properties and low-cytotoxicity based on a nanoparticles arrangement by controlling the formation of sintering-neck into nanoporous spheres. The antimicrobial effectiveness of ZnO spheres is tested in a broad-spectrum of microorganisms such as fungi, Gram-negative and Gram-positive bacteria. The hierarchical structures show highly effective antimicrobial activity at low concentrations and in relatively short action times (24-72h). We demonstrate that the enhanced antimicrobial properties against microorganisms are ascribed to a combining of both physical and chemical interactions between microorganism and ZnO. The approximation mechanism between microorganism and ZnO is provided through electrostatic forces (physical interaction) which, thanks to the ZnO-microorganism proximity, promote a rapid release of zinc cations and the reactive oxygen species penetration into microorganisms (chemical interaction). We believe that this work provides insights on the mechanisms underlying the interactions ZnOmicroorganism and possess a combined action mechanism for which nanostructured ZnO is so effective to combat microorganisms.