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Thermoelectrics are a potentially transformative power generation technology because they possess the property to convert directly heat into an electric voltage. In addition, thermoelectrics are a pollution-free method for generating energy. Until last decade, efficiency of thermoelectric materials has remained low, but due to the study of nanostructured materials they are becoming promising for commercial use. In this work we will be introduced in the world of thermoelectric characterization. For this purpose we are going to perform thermal, transport, thermoelectric and magnetic measurements in bulk single crystal magnetite and polycrystalline bismuth.

A pesar de que el concreto convencional (elaborado con cemento Portland) es un material con gran versatilidad en cuanto a su funcionalidad y economía, presenta algunas limitaciones tales como: alta porosidad y baja resistencia a esfuerzos de flexión, tensión y a reactivos químicos altamente corrosivos. Algunas de estas limitaciones se han subsanado mediante la incorporación de fibras. Se han podido mejorar la resistencia a la tracción, compresión, durabilidad, resistencia a la fatiga, resistencia al impacto y a la abrasión, la contracción, la expansión, la estabilidad térmica, y resistencia al fuego. Sin embargo, muy pocas investigaciones ha abordado el efecto de fibras en concreto polimérico En el presente trabajo se estudian los efectos de la incorporación de fibras y de la radiación gamma en las propiedades mecánicas del concreto polimérico, en particular las resistencias a la compresión y a la flexión, la deformación mecánica y los módulos de elasticidad. Los concretos son elaborados con resina de poliéster insaturada, arena sílice y fibras de Luffa como agregados. CONACYT

[SPA] Este trabajo trata de explicar una metodología para adaptar las prácticas de laboratorio de la asignatura de “Ciencia de los materiales” al nuevo Espacio Europeo de Educación Superior (EEES) en carreras técnicas de ingeniería. Para ello se describen cómo eran las prácticas en el anterior plan de estudios y se propone una nueva metodología adaptada a los nuevos condicionantes ligados al EEES. La metodología propuesta no busca un cambio drástico en relación al sistema anterior, sino una mejora de aquellos aspectos que en la opinión de los autores pueden aumentar la calidad de la enseñanza. Así, la adaptación que se plantea se espera que permita al alumno futuro ingeniero desarrollar habilidades prácticas así como la capacidad de adaptarse a nuevas situaciones y de resolver problemas con iniciativa. [ENG]This work presents an adaptation of the laboratory work conducted in the module “Materials Science” to the new European Space of Higher Education (ESHS) in engineering degrees. This is done by describing how labs were performed previously and how they are planned to be developed in the future, following the constraints of ESHS. The proposed methodology does not intend to modify drastically the way the labs carried out, but rather, an improvement of those features that can improve the understanding of the undergraduate students of the subject. Accordingly, the adaptation herein described will hopefully allow the future engineer to develop practical abilities as well as a improved skills to tackle new situations and solve problems. Campus Mare Nostrum, Universidad Politécnica de Cartagena, Universidad de Murcia, Región de Murcia

Memoria ID-174. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2010-2011., El propósito de este proyecto ha sido el diseño e implantación en la plataforma Studium del “CmLab Laboratorio Virtual de Ciencia e Ingeniería de Materiales” donde el estudiante pueda conocer y comprender las prácticas y los ensayos realizados en un Laboratorio de Ciencia e Ingeniería de Materiales. En este laboratorio virtual se incluyen vídeos de prácticas y ensayos propios de este campo, abundantes fotografías y resultados de las propiedades mecánicas de diversos materiales elaborados a partir de los ensayos, además de un conjunto de actividades interactivas de repaso.

Descripción de cómo se realiza el ensayo de fluencia para la determinación de las propiedades mecánicas de los materiales a alta temperatura

Descripción de cómo se realiza el ensayo de rotura por impacto o resiliencia en caracterización mecánica de materiales

Explicación de las fórmulas de cálculo simplificadas para calcular ciertas propiedades en los materiales compuestos de fibra continua y alineada

Descripción de los mecanismos de polimerización más habituales para la síntesis de materiales compuestos: adición y condensación

Descripción de los ensayos de dureza más habituales utilizados en caracterización de materiales: Rockwell, Brinell, Vickers y Knoop

Descripción del fenómeno de cristalinidad aplicado a los materiales poliméricos y su influencia de en las propiedades.

Descripción de la técnica de difracción de rayos X aplicada a la determinación de las estructuras cristalinas más habituales en materiales metálicos: cúbicas centrada en caras, cúbica centrada en el cuerpo y hexagonal compacta

Descripción de cómo se determinan las propiedades mecánicas más importantes de los materiales a partir del diagrama tensión-deformación del ensayo de tracción

Descripción de los defectos más habituales que se pueden dar en estructuras cristalinas desde los defectos de punto (vacantes) a defectos de volumen.

Demostración mediante símil de esferas rígidas de las similitudes y diferencias en el ordenamiento atómico de las estructuras cristalinas cúbica centrada en caras y hexagonal compacta

Descripción de la estructura molecular de los materiales poliméricos y los factores de influencia de ésta en sus propiedades.

Definición y descripción de las familias más habituales de materiales compuestos y su clasificación.

Explicación de cómo determinar matemáticamente la relación entre el radio atómico y el parámetro de red (arista) en estructuras cúbicas

Descripción de cómo se realiza el ensayo de tracción para la determinación de las propiedades mecánicas más importantes de los materiales

Descripción de las estructuras cristalinas más habituales en materiales metálicos: cúbicas centrada en caras, cúbica centrada en el cuerpo y hexagonal compacta

Descripción del uso de aceros y uniones como materiales en la construcción

A detailed study about the synthesis, characterization and properties of poly(o-methylaniline)(PoMea)/maghnite nanocomposites has been performed. Changes in the characteristics of the nanocomposites, depending on the intercalated cation between the clay layers before the synthesis, have been observed. Intercalated morphology has been detected by TEM in nanocomposites containing copper-treated maghnite (Magh-Cu), while when maghnite treated with strong acids was used (Magh-H); an exfoliated material has been obtained. Also, remarkable differences in the properties of the polymers have been observed by TG-MS and FTIR, suggesting that the polymer produced with Magh-H has a higher degree of branching. The electrochemical behavior of the polymers extracted from the nanocomposites has been studied by cyclic voltammetry. Good electrochemical response has been observed for PoMea grown into Magh-Cu but not for the one polymerized into Magh-H. Ministerio de Educación y Ciencia (MAT2007- 60621 Project); Generalitat Valenciana (RED ARVIV2007/076); Algerian CNEPRU and FNR.

Chemical and electrochemical techniques have been used in order to asses surface functionalities of porous carbon materials. An anthracite has been chemically activated using both KOH and NaOH as activating agents. As a result, activated carbons with high micropore volume (higher than 1 cm3/g) have been obtained. These samples were oxidized with HNO3 and thermally treated in N2 flow at different temperatures in order to obtain porous carbon materials with different amounts of surface oxygen complexes. Thermal treatment in H2 was also carried out. The sample treated with H2 was subsequently treated in air flow at 450 ºC. Thus, materials with very similar porous texture and widely different surface chemistry have been compared. The surface chemistry of the resulting materials was systematically characterized by TPD experiments and XPS measurements. Galvanostatic and voltammetric techniques were used to deepen into the characterization of the surface oxygen complexes. The combination of both, chemical and electrochemical methods provide unique information, regarding the key role of surface chemistry in improving carbon wettability in aqueous solution and the redox processes undergone by the surface oxygen groups. Both contributions are of relevance to understand the use of porous carbons as electrochemical capacitors. Ministerio de Ciencia y Tecnología (PPQ2003-03884).

Aniline (ANI) and 2-aminoterephthalic acid (2ATA) copolymers, with different compositions, were prepared by chemical oxidative polymerization varying the feed ratio. The new materials have been characterized by techniques such as XPS, FTIR, Raman spectroscopies and thermal analysis. It has been checked that 2ATA units are included in the polymer backbone. Different properties have been studied as solubility, conductivity, optical absorption, fluorescence and electroactivity. The copolymers are soluble in aqueous alkaline medium and show clear electroactivity in aqueous acid medium. Ministerio de Ciencia y Tecnología (MAT2004-1479); Generalitat Valenciana (Grupos04/75); Programa Juan de la Cierva SECYT-UNRC, FONCYT y CONICET.

This paper assesses the impact that the introduction of scientific methods for materials characterisation (conventionally grouped under the label of Archaeometry) has had in the methodological configuration of Spanish archaeology over the last two decades. This is achieved through a bibliometric study of publications dealing with characterisation of archaeological ceramics from Andalucía (southern Spain). The variables handled in this study include aspects such as the number of sampled sites and items, their geographical provenance, the chronological and functional dimensions of the archaeological contexts they were taken from as well as the analytical techniques employed in their study.Este artículo intenta valorar el impacto que la introducción de métodos de caracterización de materiales procedentes de la física y la química (y agrupados habitualmente bajo la denominación genérica de Arqueometría) ha tenido en la configuración metodológica de la investigación arqueológica de nuestro país durante las últimas dos décadas. Para ello se realiza un análisis bibliométrico de un ámbito específico de la aplicación de las técnicas arqueométricas, cual es el de la caracterización de materiales cerámicos dentro de la Arqueología andaluza. Las variables tenidas en cuenta incluyen aspectos tales como la cantidad de sitios arqueológicos muestreados y de muestras analizadas, su procedencia geográfica, los contextos cronológicos y funcionales de los que las muestras fueron tomadas y las técnicas analíticas empleadas.

The electrochemical oxidation of the aniline dimers 2-aminodiphenylamine (2-adpa) and 4-aminodiphenylamine (4-adpa) has been performed in strongly acidic medium on platinum, graphite, and indium tin oxide electrodes. The resulting films have been characterized by a number of electrochemical, microscopic, and spectroscopic techniques in order to gain some insight on their respective chemical structures. Both poly(2-adpa) and poly(4-adpa) are electroactive species which differ significantly one from another. It was found that aged poly(4-adpa)displayed electrochemical, morphologic and spectroscopic characteristics similar to those shown by polyaniline. On the contrary, poly(2-adpa) is really a mixture of three oligomerization products. The two main oligomers contain both open-ring and cycled phenazine centers, although their chemical structures seem to differ in the cap-end of the chain growth. The third oligomer is a minor product which seems a highly symmetric macrocycle involving several 2-adpa molecules. This work has been cofinanced by the European Commission (ERDF funds) and the Spanish Ministerio de Educación y Cultura (MAT2004-01479). University of Alicante assisted in meeting the publication costs of this article.

The electrochemical oxidation of 2-aminodiphenylamine (2ADPA) was performed by cyclic scanning of the potential in aqueous HCl solutions. A mixture of oligomeric compounds, named poly(2ADPA), was deposited on the surface of the electrode. The chemical structures present in poly(2ADPA) containing phenazine units and open-ring units were assigned by 1H NMR spectroscopy. CV results revealed that the redox transformation of poly(2ADPA) from the fully reduced to the fully oxidized state occurs under a single voltammetric peak. The SEM images obtained for the polymer deposited on platinum substrates showed a “fallen leaves” morphology. In situ FTIR spectroscopy experiments carried out during the reversible oxidation of the polymer revealed that the conversion of aromatic rings (1500 cm−1) into quinoid structures (1524–1590 cm−1) is of major significance. Besides, the transformation of secondary aromatic amines (1301 cm−1) into fully oxidized imines and polaronic structures (1470, 1389, 1330 and 1250 cm−1) has been observed. Ministerio de Ciencia y Tecnlogía (MAT2004-1479); Comisión Europea (Fondos ERDF).

Hybrid material polypyrrole/PW12O-340 was electrosynthesised on carbon steel electrodes in acetonitrile medium. Passivation pretreatment of carbon steel in acetonitrile/perchlorate medium was used to avoid electrodissolution of electrode during the polymerisation. These hybrid coatings were evaluated against corrosion in chloride-containing 0.05 M NaOH and solutions obtained by filtering Portland cement slurries. Cyclic voltammetry, polarisation resistance(Rp), and Fe2+ concentrations measurements showed that the obtained coatings provide good protection against corrosion in chloride-containing media. Ministerio de Ciencia y Tecnología (MAT2001-1007) (REN 2001-2304-C02-02/TECNO)

The electrochemical homo-polymerization of o-, m- and p-aminobenzoic acids has been performed on Pt electrodes in perchloric acid aqueous medium by cyclic scanning of the potential. Different limit potentials were employed to obtain thin polymeric films. When the switching potential was extended beyond the respective monomer oxidation peak, a rather degraded material was obtained. In situ FTIR spectroscopy has been used to characterize the redox response of films synthesized at the lower potential limits. Characteristic absorption features related with benzenoid and quinoid rings and different types of C–N bonds suggest the presence of redox processes similar to those undergone by the parent compound polyaniline. In addition, the existence of a chemical interaction between –COOH and –NH– groups in the reduced state of the three homopolymers studied can be suggested. Carbon dioxide has been detected at potentials higher than 1.0 V (RHE) irrespective of the polymeric material, thus indicating its degradation. Ministerio de Ciencia y Tecnología (MAT2001-1007) (MAT2004-01479); Generalitat Valenciana (Grupos04/75)

The electrochemical oxidation of p-aminodiphenylamine (4ADPA) in the presence of aniline in phosphate medium of pH ranging from 1 to 10.5 has been investigated. Mixtures of both monomers can be co-polymerized to produce electroactive poly aniline-co-4ADPA (Pan-4adpa) films if the pH of the medium is kept, approximately, within 3 and 9 and the upper potential limit is lower than the oxidation potential of aniline. Pan-4adpa growth rates are pH dependent and are also affected by the amount of polymeric material deposited on the electrode surface. It has been suggested the existence of a certain inhibition effect of both H+ and OH− on the polymerization reaction. Contrary to what is observed for those films synthesized at pH 5 and 7, the growth of Pan-4adpa at pH 8 seems to be an autocatalytic process until the inhibition of the polymerization reaction takes place. Ministerio de Ciencia y Tecnología MAT2001-1007, MAT2004-01479 y REN2001-2304-C02-02/TECNO

Memoria para optar al grado de suficiencia investigadora del programa de doctorado “Ciencia de Materiales”. Tutores: José Luis Vázquez Picó y Emilia Morallón Núñez Resumen de los resultados obtenidos durante el estudio de la oxidación electroquímica de los isómeros del aminofenol, y la caracterización de los materiales poliméricos obtenidos. Ministerio de Ciencia y Tecnología (MAT 2001-1007); Generalitat Valenciana (GV01-313)

The adsorption and reactivity of citrate anions, cyanide anions, and the Au(I) and Au(III) cyanocomplexes (KAu(CN)2 and KAu(CN)4, respectively) on gold polycrystalline electrodes have been investigated by means of cyclic voltammetry and in situ FTIR spectroscopy in pH 7 sodium citrate medium. It was found that citrate anion adsorbs reversibly through the carboxylate groups from 0.4 V (RHE) on bare gold surfaces. However, the onset of this adsorption process is shifted by 600 mV in the positive direction when adsorbed cyanide species are present at the electrode surface. The Au(I) cyanocomplex produces a film on the gold electrode that inhibits the oxidation of both citrate anions and the gold surface. The reduction of the Au(III) cyanocomplex gives rise to the formation of the Au(I) cyanocomplex at potentials less negative than those required for gold deposition. Upon reduction, both cyanocomplexes release adsorbed cyanide on the gold electrode, which can be subsequently oxidized to cyanate at higher potentials. Generalitat Valenciana (GV01-313); Ministerio de Ciencia y Tecnología (MAT2001-1007).

The electrochemical oxidation of para-, meta- and ortho-aminophenols was carried out using a platinum electrode in aqueous acid medium. The spectroscopic results indicate that p-aminophenol suffers hydrolysis giving the formation of hydroquinone/p-benzoquinone. CO2 has been detected by in situ FTIR spectroscopy as the main soluble oxidation product. The m-aminophenol oxidation produces a blocking polymeric film on the platinum surface. The main oxidation products detected by in situ infrared spectroscopy were CO2 and quinone. Cyclic voltammetry and in situ FTIR spectroscopy were combined to study the redox processes of the conducting polymer obtained in the o-aminophenol oxidation. The spectroscopic results indicate that phenoxazine units are produced during the oxidation/reduction of poly(o-aminophenol). Generalitat Valenciana (GV01-313); Ministerio de Ciencia y Tecnología (MAT2001-1007); CONICET, SECYT-UNRC, Agencia Córdoba Ciencia, FONCYT, Fundación Antorchas.