Cabrera-Lara, Lourdes I.; Somoza, Álvaro; Marco, J.F.; Serna Pereda, Carlos J.; Morales, M. P.
Cubic monodisperse MFe 2O 4 ferrite nanoparticles (M = Fe, Co, and Mn) with tunable sizes between 7 and 20 nm and a narrow size distribution have been achieved in a one step synthesis by thermal decomposition of Fe(III), Co (II), and Mn(II) oleates. These nanoparticles have been functionalized with dimercaptosuccinic acid (DMSA), 11-mercaptoundecanoic acid (MUA), and bis(carboxymethyl)(2-maleimidylethyl)ammonium 4-toluenesulfonate (MATS) to grant them aqueous stability and the possibility for further functionalization with different biomolecules. Their structural, magnetic, and colloidal properties have also been studied to determine their chemical and physical properties and the degree of stability under physiological conditions that...
Hernández-Velasco, Jorge; Cabrillo García, Carlos; Castellote, M.; Ruiz-Hervías, Jesús
1 pag.; VI Reunión de la Sociedad Española de Técnicas Neutrónicas (SETN), Segovia, 24-27 de junio de 2012
Sanz, Mikel; Oujja, M.; Rebollar, Esther; Marco, J.F.; Figuera, Juan de la; Monti, Matteo; Bollero, A.; Camarero, Jesús Julio; Pedrosa, Francisco J.; García-Hernández, M.; Castillejo, Marta
Pulsed laser deposition (PLD) is a versatile technique for the fabrication of nanostructures due to the possibilities it offers to control size and shape of nanostructured deposits by varying the laser parameters. Magnetite nanostructures are currently promising materials to be used in computing, electronic devices and spintronic applications. For all these uses the fabrication of uniform nanostructured pure magnetite thin films is highly advantageous. In PLD of magnetite, the laser irradiation wavelength and substrate temperature crucially affect the composition, crystallinity, surface structure and the magnetic properties of the grown samples. This work shows that the use of nanosecond IR laser...
Monti, Matteo; Sanz, Mikel; Oujja, M.; Rebollar, Esther; Castillejo, Marta; Bollero, A.; Camarero, Jesús Julio; Nemes, N. M.; Mompean, F. J.; García-Hernández, M.; McCarty, K. F.; Marco, J.F.; Figuera, Juan de la
5 páginas, 3 figuras.-- et al.
Castellón Elizondo, Erick; Chavarría, M.; Lorenzo, Víctor de; Zayat, Marcos; Levy, David
A reversible electro-optical light switching device is prepared by the combination of a biofilm created by a bacterial cell culture and its combination with a liquid crystal (LC). The macroporous structure of the biofilms, where the LC molecules are allocated, produces the required tridimensional orientational arrangement of the LC molecules that results in an opaque device. Upon application of a minor electric field, the LC molecules are reoriented and the device becomes transparent.
Reyes-Montero, Armando; Pardo, Lorena; López-Juárez, Rigoberto; González, Amador M.
Ba0.9Ca0.1Ti0.9Zr0.1O 3 (BCTZ) lead-free piezoelectric ceramics were successfully prepared by Pechini polymeric precursor method using low thermal treatments. XRD analysis shows single-phase perovskite type structure for powders synthesized at 700 C for 1 h. Dense ceramics were obtained from these reactive precursors using sintering temperatures below 1300°C (1200°C, 1250°C and 1275°C for 5 h). The ceramics sintered at 1275°C for 5 h exhibited the best ferro-piezoelectric properties: d33 = 390 pC/N, d31 = -143 pC/N, kp = 50%, ε33 T=2253 and tan δ = 0.06 (100 kHz) at room temperature, TC = 112°C, 2Pr = 24 μC/cm2 and 2EC =...
Palacios-Lidón, E.; Galisteo-López, J. F.; Juárez, Beatriz H.; López, Cefe
A method that allows the fabrication of opal slab heterostructures incorporating planar defects was discussed. The method is based on a multi-step process combining chemical vapor deposition and convective colloidal self assembly techniques. It allows precise control over the parameters that determine the optical properties of these systems, permitting their tuning. The optical properties of the fabricated structures were also discussed.
López-Sancho, María Pilar; Alvarez-Marrón, Joaquina; Pablo, Flora de; Masegosa, Josefa; Mayoral Gastón, María del Carmen; Molina, Elena; Pérez Sedeño, Eulalia; Puertas, Francisca; Sandalio, Luisa M.
Este es un artículo de acceso abierto distribuido bajo los términos de la licencia Creative Commons Attribution-Non Commercial (by-nc) Spain 3.0.
García-Ayuso, G.; Salvarezza, R. C.; Martínez Duart, J. M.; Sánchez, Olga; Vázquez, Luis
Azzaroni, O.; Fonticelli, Mariano; Benítez, G.; Schilardi, P. L.; Gago, Raúl; Caretti, Ignacio; Vázquez, Luis; Salvarezza, R. C.
The development of new methods for nanopatterning of metal surfaces is discussed. Self-assembled molecular films are used for the purpose. Patterned metallic surfaces can be modified by alkanethiolate self-assembled monolayers (SAM) to be used as a further mold for master replication. It is also demonstrated that the patterned metallic surfaces are excellent templates for producing nanopatterned metal-semiconductor hybrid surfaces by controlled chemical reactions.
Inorganic-organic composite systems (e.g. see figure) with controlled electrical and optoelectronic properties are of current interest for applications including electrochromic displays, batteries, membranes, and sensors. The various methods of intercalation of the organic guests into the inorganic hosts, and the property profiles of the materials based on the intercalation of conducting polymers in layered solids are reviewed.
Jiménez Riobóo, R. J.; Prieto, C.; Cuscó, Ramón; Artús, Lluís; Boney, C.; Bensaoula, A.; Yamaguchi, T.; Nanishi, Yasushi
Temperature-dependent surface acoustic wave (SAW) propagation velocity and temperature coefficient of frequency (TCF) have been determined for the first time in InxGa1-xN alloys by means of high-resolution Brillouin spectroscopy (HRBS). HRBS offers an alternative way of determining TCF. The obtained TCF values present a non-linear behavior with the In concentration. TCF of pure InN (-13.75 ppm/K) is similar to those of AlN and GaN (-19 and -17.7 ppm/K, respectively). InxGa1-xN samples exhibit frequency values that are very stable against temperature changes, which makes InxGa1-xN a good candidate for current SAW-based technological applications.
Gómez-Aleixandre, C.; Sánchez, Olga; Albella, J. M.; Santiso, José; Figueras, Albert
Chemical vapor deposition at high temperatures provided the deposited atoms with the necessary surface mobility to ensure crystallinity and epitaxial growth. The use of high-temperature CVD in the deposition of high-T-c superconducting ceramics and covalent materials such as diamond (see Figure) and boron nitride is reviewed, and, for example, the methods used to maintain the tetrahedral arrangement of neighboring atoms during deposition discussed.
González-Iglesias, Reinerio; Pajares, María A.; Ocal, Carmen; Espinosa, Juan Carlos; Oesch, Bruno; Gasset, M.
Several lines of evidence have shown glycosaminoglycans (GAGs) to be physiological ligands of the prion protein (PrP), but the molecular and regulatory aspects of the interaction remain unknown. Using full-length recombinant prion protein and low molecular mass heparin and heparan sulfate as glycosaminoglycans, we have found that the interaction occurs with the formation of oligomeric complexes. Within the protein-glycosaminoglycan complexes, PrP exhibited an enhanced fluorescence emission and a reduced solvent exposure. The pH and ionic strength-dependence of the interaction reveals His residues as the main binding sites at acid pH. A synthetic peptide consisting of four octarepeats is able to...
Martín-Luengo, María Ángeles; Yates Buxcey, Malcolm; Ramos Gómez, Milagros; Sáez Rojo, Eduardo; Martínez-Serrano, Alberto; González Gil, Lorena; Ruiz-Hitzky, Eduardo
Agricultural wastes are a source of renewable raw materials (RRM), with structures that can be tailored for the
use envisaged. Here, theyhave proved to be good replacement candidates for use as biomaterials for the growth
of osteoblasts in bone replacement therapies. Their preparation is more cost effective than that of materials
presentlyin use with the added bonus of converting a low-cost waste into a value-added product. Due to their
origin these solids are ecomaterials.
In this study, several techniques, including X-ray diffraction (XRD), chemical analysis, mercury intrusion
porosimetry(MIP), scanning electron microscopy(SEM), and bioassays, were used to compare the biocompatibilityand
cell growth of scaffolds produced from beer bagasse,...