Switchable surfactant-assisted carbon nanotube coatings: innovation through pH shift

The inner surface of fused-silica capillaries has been coated with a dense/homogeneous coating of commercial multi-wall carbon nanotubes (MWCNTs) using a stable ink as deposit precursor. Solubilization of the MWCNTs was achieved in water/ethanol/dimethylformamide by the action of a surfactant, which can switch between a neutral or an ionic form depending on the pH of the medium, which thus becomes the driving force for the entire deposition process. Careful control of the experimental conditions has allowed us to selectively deposit CNTs on the inner surface of insulating silica capillaries by a simple, reproducible, and easily adaptable method.

Análisis de la acción tutorial en ingeniería y arquitectura. Gestión eficaz del tiempo

En este trabajo expondremos un análisis exhaustivo de como se ha desarrollado la acción tutorial en la Escuela Politécnica Superior de la Universidad de Alicante en el curso 2014/2015. El marcado carácter de voluntariedad de la acción tutorial en nuestro centro por parte de estudiantes y tutores permite que el trabajo se realice más satisfactoriamente tanto por parte de tutores como por parte de los estudiantes, puesto que han decidido seguir el plan por ello mismos y no como una imposición. Además expondremos nuestras experiencias en el desarrollo del Taller de Gestión Eficaz del Tiempo, taller desarrollado en nuestro centro bajo la tutela de la experta Nuria Alberquilla, que tiene entre otros muchos objetivos el aprendizaje y puesta en práctica de técnicas para realizar una gestión eficaz del tiempo, con un mejor equilibrio entre la vida académica y personal y la identificación de los principales factores externos e internos que influyen en los resultados obtenidos, y cómo mejorarlos.

Grado en Química: coordinación y seguimiento del curso 2014-15

En la red docente "Seguimiento del grado en Química", formada por los coordinadores de las comisiones de semestre de la Facultad de Ciencias y la coordinadora del grado en Química, se ha analizado la información extraída de las reuniones periódicas (al menos dos por semestre) de las ocho comisiones de semestre (correspondientes a los cuatro cursos del grado en Química). El objetivo es conseguir una coherencia tanto en la distribución de contenidos, como en las metodologías docentes y de evaluación de las materias que componen el plan de estudios del Grado en Química de la Universidad de Alicante. Los resultados de este trabajo están permitiendo identificar problemas y plantear propuestas de mejora en la organización docente de la titulación. El trabajo realizado por la red se está utilizando para elaborar el autoinforme para la reacreditación del grado en Química.

Study on Electrochemical Capacitance using Templated Carbons

The template carbonization technique enables the production of porous carbons and carbon-based composites with precisely designed, controlled pore structures. The resulting templated carbons are therefore useful to investigate and understand the relation between carbon nanostructure and electrocapacitive properties. In this short review paper, we introduce our works on electrochemical capacitance using zeolite-templated carbons and carbon-coated anodic aluminum oxide.

Design of hybrid asymmetric capacitors in aqueous electrolyte using ZTC and ultraporous activated carbons

The use of two different materials as electrodes allows the construction of asymmetric and hybrid capacitors cells with enhanced energy and power density. This approach is especially well-suited for overcoming the limitations of pseudocapacitive materials that provide a huge capacitance boost, but in a limited potential window. In this work, we introduce the concepts and protocols that are required for a successful design of such systems, which is illustrated by the construction of an asymmetric hybrid cell where a zeolite-templated carbon and an ultraporous activated carbon have been combined.

Red de seguimiento y coordinación del Máster en Ciencia de Materiales

El Máster en Ciencia de Materiales se imparte en la Facultad de Ciencias de la Universidad de Alicante, consta de 60 créditos ECTS que se cursan durante 1 año académico. El máster está implantado desde el curso 2010-2011 por lo que durante el actual curso 2014-2015 tendremos la quinta promoción de egresados. La red docente está formada por la comisión académica del Máster en Ciencia de Materiales. Esta comisión (profesorado, alumno y personal de administración y servicios) lleva realizando un seguimiento de la titulación durante los 4 cursos anteriores. Por tanto la red tiene como objetivo principal el seguimiento, coordinación, evaluación y mejora de la planificación realizada con las experiencias recogidas a lo largo de estos años. Además, se realizará un estudio de los diferentes indicadores de calidad que utilizan las agencias de acreditación puesto que este año el Máster se someterá a la renovación de la acreditación.

Spectroscopic, calorimetric, and catalytic evidences of hydrophobicity on Ti-MCM-41 silylated materials for olefin epoxidations

Hydrophobic Ti-MCM-41 samples prepared by post-synthesis silylation treatment demonstrate to be highly active and selective catalysts in olefins epoxidation by using organic hydroperoxides as oxidizing agents in liquid phase reaction systems. Epoxide yields show important enhancements with increased silylation degrees of the Ti-mesoporous samples. Catalytic studies are combined and correlated with spectroscopic techniques (e.g. XRD, XANES, UV-Visible, 29Si MAS-NMR) and calorimetric measurements to better understand the changes in the surface chemistry of Ti-MCM-41 samples due to the post-synthesis silylation treatment and to ascertain the role of these trimethylsilyl groups incorporated in olefin epoxidation. In such manner, the effect of the organic moieties on solids, and both water and glycol molecules contents on the catalytic activity and selectivity are analyzed in detail. Results show that the hydrophobicity level of the samples is responsible for the decrease in water adsorption and, consequently, the negligible formation of the non-desired glycol during the catalytic process. Thus, catalyst deactivation by glycol poisoning of Ti active sites is greatly diminished, this increasing catalyst stability and leading to practically quantitative production of the corresponding epoxide. The extended use of these hydrophobic Ti-MCM-41 catalysts together with organic hydroperoxides for the highly efficient and selective epoxidation of natural terpenes is also exemplified.

Coordinación del Plan de Acción Tutorial en la Escuela Politécnica Superior

Al igual que en cursos anteriores en la Escuela Politécnica se desarrolla, promovido por el Vicerrectorado de Estudios, Formación y Calidad, coordinado desde el Instituto de Ciencias de la Educación, el Plan de Acción Tutorial (PAT) el cual está abierto a todos aquellos tutores que deseen formar parte del plan y también a todos los estudiantes, que, voluntariamente pueden marcar la opción de participar en el plan en la matrícula, y también a aquellos que, a pesar de no marcar la opción en la matrícula, finalmente han decidido seguir el plan de acción tutorial. Esta característica de participación e inscripción voluntaria permite que el trabajo se realice más satisfactoriamente tanto por parte de tutores como por parte de los estudiantes, puesto que han decidido seguir el plan por ello mismos y no como una imposición. Con este resumen nos proponemos presentar nuestras experiencias en el desarrollo del PAT de nuestro centro.

Terminology of metal–organic frameworks and coordination polymers (IUPAC Recommendations 2013)

A set of terms, definitions, and recommendations is provided for use in the classification of coordination polymers, networks, and metal–organic frameworks (MOFs). A hierarchical terminology is recommended in which the most general term is coordination polymer. Coordination networks are a subset of coordination polymers and MOFs a further subset of coordination networks. One of the criteria an MOF needs to fulfill is that it contains potential voids, but no physical measurements of porosity or other properties are demanded per se. The use of topology and topology descriptors to enhance the description of crystal structures of MOFs and 3D-coordination polymers is furthermore strongly recommended.

Materiales carbonosos nanoestructurados para la preparación de catalizadores híbridos mediante el sistema SILP

The main objective of this Doctoral thesis is the preparation of hybrid active catalysts using the SILP (Supported Ionic Liquid Catalysis) methodology and employing carbon materials as support. For that, in first place, SILP samples have been prepared and characterized. In second place, hybrid the SILP catalysts have been prepared, characterized and tested in some hydrogenation reactions, including an asymmetric hydrogenation. The investigated variables are mainly the amount and kind of ionic liquid and the physical, chemical and morphological properties of the support.

Galanet (Elche): análisis químico instrumental de los materiales de construcción

En el caso del yacimiento de Galanet sólo se han documentado 15 fragmentos de este tipo. Con estos condicionantes y a partir del análisis instrumental de tres de estos fragmentos intentaremos, dentro de los posible, responder a una serie de cuestiones que algunos autores (De Chazelles, Poupet, 1989, 10-11; Sánchez García, 1995, 350, Sánchez García, 1997, 142) han señalado como básicas para poder comprender el nivel técnico de una época o cultura y la evolución de sus técnicas constructivas, en este caso aplicadas al yacimiento de Galanet: -Determinar la procedencia del material utilizado. -Saber si la elección del material utilizado se debe a imperativos geológicos o prima en ella una decisión antrópica. -Si el material se ha usado en bruto o ha sufrido algún tratamiento previo. -Si la mayoría de las estructuras analizadas presentan una misma composición o por el contrario se utilizan diferentes composiciones en función del tipo de estructura. -Si la técnica utilizada es propia de una cronología, etapa cultural o área geográfica determinada con lo que se constituiría en un indicador cultural o por el contrario es inespecífica. -Si las soluciones técnicas empleadas son fruto del desarrollo interno de las fuerzas productivas o se deben a influencias foráneas. Es evidente que parte de estas cuestiones no se podrán contestar dado que solo contamos con unos pequeños fragmentos de material constructivo de apenas unos pocos centímetros y, sobre todo, que desconocemos cualquier detalle sobre el área de habitación del poblado de Galanet. Pero, al menos, intentaremos contribuir a conocerlo mejor.

Mesoporous Metal Complex–Silica Aerogels for Environmentally Friendly Amination of Allylic Alcohols

Two series of mesoporous hybrid iron(III) complex–silica aerogels were prepared in one-pot synthesis by using the sol–gel coordination chemistry approach. The use of the ligands 3-(2-aminoethylamino)propyltrimethoxysilane and 2-(diphenylphosphino)ethyltriethoxysilane, both with terminal triethoxysilyl groups, were used to incorporate metal complexes in situ into the framework of silica, through their co-condensation with a silicon alkoxide during the aerogel formation. This methodology yielded optically translucent hybrid mesoporous gels with homogeneous metal incorporation and excellent textural properties. The catalytic performance of these materials was tested in the direct amination of allylic alcohols in water as a target reaction, with activities comparable or even higher than those corresponding to the homogeneous iron(III) complex. Furthermore, these catalysts were stable and maintained their catalytic activity after six reaction cycles.

Mesostructured zeolites: bridging the gap between zeolites and MCM-41

Surfactant-templating is one of the most versatile and useful techniques to implement mesoporous systems into solid materials. Various strategies based on various interactions between surfactants and solid precursors have been explored to produce new structures. Zeolites are invaluable as size- and shape-selective solid acid catalysts. Nevertheless, their micropores impose limitations on the mass transport of bulky feed and/or product molecules. Many studies have attempted to address this by utilizing surfactant-assisting technology to alleviate the diffusion constraints. However, most efforts have failed due to micro/mesopore phase separation. Recently, a new technique combining the uses of cationic surfactants and mild basic solutions was introduced to synthesise mesostructured zeolites. These materials sustain the unique characteristics of zeolites (i.e., strong acidity, crystallinity, microporosity, and hydrothermal stability), including tunable mesopore sizes and degrees of mesoporosity. The mesostructured zeolites are now commercially available through Rive Technology, and show superior performance in VGO cracking. This feature article provides an overview of recent explorations in the introduction of mesoporosity into zeolites using surfactant-templating techniques. Various porous materials, preparation methods, physical and catalytic properties of mesostructured zeolites will be discussed.

Synthesis of palladium nanoparticles over graphite oxide and carbon nanotubes by reduction in ethylene glycol and their catalytic performance on the chemoselective hydrogenation of para-chloronitrobenzene

Pd nanoparticles have been synthesized over carbon nanotubes (CNT) and graphite oxide (GO) by reduction with ethylene glycol and by conventional impregnation method. The catalysts were tested on the chemoselective hydrogenation of p-chloronitrobenzene and the effect of the synthesis method and surface chemistry on their catalytic performance was evaluated. The catalysts were characterized by N2 adsorption/desorption isotherms at 77 K, TEM, powder X-ray diffraction, thermogravimetry, infrared and X-ray photoelectron spectroscopy and ICP-OES. It was observed that the synthesis of Pd nanoparticles employing ethylene glycol resulted in metallic palladium particles of smaller size compared to those prepared by the impregnation method and similar for both supports. The presence of oxygen groups on the support surface favored the activity and diminished the selectivity. It seems that ethylene glycol reacted with the surface groups of GO, this favoring the selectivity. The activity was higher over the CNT-based catalysts and both catalysts prepared by reduction in ethylene glycol were quite stable upon recycling.

Synthesis of palladium nanoparticles on carbon nanotubes and graphene for the chemoselective hydrogenation of para-chloronitrobenzene

We have studied the synthesis of palladium nanoparticles over carbon nanotubes (Pd/CNT) and graphene (Pd/G) and we have tested their catalytic performance in the liquid phase chemoselective hydrogenation of para-chloronitrobenzene at room temperature. The catalysts were characterized by N2 adsorption/desorption isotherms, TEM, X-ray diffraction, infrared and X-ray photoelectron spectroscopy and ICP-OES. The palladium particle size on Pd/G (3.4 nm) and Pd/CNT (2.8 nm) was similar though the deposition was higher on Pd/G. Pd/CNT was more active which can be ascribed to the different surface area and electronic properties of the Pd nanoparticles over CNT, while the selectivity was 100% to the corresponding haloaniline over both catalysts and they were quite stable upon recycling.