Grafito y grafeno

págs.: 109-137Capítulo incluido en el libro: Desarrollo y aplicaciones de materiales avanzados de carbón. Miguel Ángel Álvarez Merino, Francisco Carrasco Marín, Francisco José Maldonado Hódar (Editores). Sevilla: Univeridad Internacional de Andalucía, 2014. ISBN: 978-84-7993-247-3. Enlace: http://hdl.handle.net/10334

Enhancing the hydrogen transfer catalytic activity of hybrid carbon nanotube-based NHC–iridium catalysts by increasing the oxidation degree of the nanosupport

CVD-grown multiwalled carbon nanotubes were purified by applying four different treatments with increasing oxidation severity. The growing severity of the treatment results in progressive oxygen functionalization of the surface along with introduction of an increasing quantity of defects on the carbon nanotube walls. Iridium-N-heterocyclic carbene complexes were covalently anchored to those oxidized surfaces through their surface carboxylic acids via acetyl linkers. The carbon nanotube-based iridium-NHC hybrid materials developed are active in the hydrogen-transfer reduction of cyclohexanone to cyclohexanol with 2-propanol/KOH as hydrogen source but with rather different activity. The catalytic activity of the hybrid catalysts is strongly influenced by the type and amount of oxygenated functionalization resulting from the treatment applied to the support, being the most active and the most oxidized material.The authors thank the Spanish Ministry of Economy and Competitiveness (MINECO/FEDER) (Projects Consolider Ingenio 2010 CSD2009-00050 and CTQ2013-42532-P) and the Diputación General de Aragón (FSE-E07 and FSE-E69) for their financial support. Dr. P. A. thanks MINECO for a Ramón y Cajal contract. M. B. acknowledges his fellowship from MECD (AP2010-0025).Peer Reviewe

Método de obtención de oxido de material pregrafítico, oxido de grafeno o grafeno a partir de materiales pregrafíticos y productos obtenidos por dicho método

Método de obtención de óxido de material pregrafítico, óxido de grafeno o grafeno a partir de materiales pregrafíticos y productos obtenidos por dicho método. Método de obtención de un producto seleccionado del grupo que consiste en óxido de material pregrafítico, óxido de grafeno y grafeno, caracterizado porque comprende transformar al menos un material pregrafítico en el producto sin tratamiento de grafitización. Preferiblemente, el material pregrafítico es coque (comercial o preparado a partir de breas, tanto de petróleo como de carbón o sintéticas)Peer reviewedConsejo Superior de Investigaciones CientíficasB1 Patente sin examen previ

Supercapacitor modified with methylene blue as redox active electrolyte

MWCNT-based supercapacitors (SC) containing methylene blue (MB) as redox active electrolyte were studied. MWCNTs were employed as model of electrode active material due to their ideal double-layer behavior facilitates the investigation of the energy storage mechanisms involved. MB led to a cell capacitance enhancement equal to 4.5 times the original cell capacitance of MWCNTs in sulphuric acid with a capacitance reduction of only 12% after 6000 charge–discharge cycles. The potential evolution of each electrode during galvanostatic cycling revealed that MB redox reaction develops in both electrodes simultaneously in the voltage range of 0–0.104 V and that this is the main cause of cell capacitance enhancement. Beyond this voltage range, the Faradaic contribution from the MB redox reaction decreases because the anode behaves as a capacitative electrode with a rather reduced charge-capacity due to the small surface area of MWCNTs. By means of a modified assembly composed of a Nafion membrane and MB and sulfuric acid solutions located in the cathode and anode compartments, respectively, it was demonstrated the limiting role of the capacitative electrode in the cell charge-capacity in this type of hybrid devices.The authors acknowledge the financial support of the MICINN (Project MAT2010-20601-C02-01). Silvia Roldán thanks MICINN for a FPI predoctoral research grant.Peer reviewe

Catalytic activity of iridium NHC complexes covalently bonded to carbon nanotubes and graphene oxide

Trabajo presentado a la Annual World Conference on Carbon, celebrada en Dresden (Alemania) del 12 al 17 de julio de 2015.Carbon nanotubes and graphene have been extensively applied as proactive supports to generate heterogeneous catalysts. Both exhibit a carbon structure composed by carbon atoms with sp2 hybridization and both are used in similar applications, as in catalysis. However, the role of each particular substrate, determined by its structural peculiarities, can be differentvshould be studied for each particular catalytic reaction and in their structure.The aim of this work is to study the differences between oxidized carbon nanotubes (CNT) and graphene oxides (GO) as proactive supports of iridium Nheterocyclic carbene (NHC) catalyst. The effect of their inherent structure in the catalytic activity in hydrogen transfer reactions was studied in detail.The authors thank MINECO/MECD (Projects CONSOLIDER INGENIO 2010 CSD2009-00050, CTQ 2010-15221, Ramón y Cajal contract of P. Alvarez and fellowship of M. Blanco) and the Diputación General de Aragón (E07) for their financial support.Peer Reviewe

Grupos de ayuda mutua en personas con problemas severos de salud mental en el modelo de la recuperación. La inclusión del cuerpo.

El modelo de la recuperación se basa en la incorporación de las propias personas con trastornos mentales de naturaleza psicótica a su proceso de mejoría. Trabajando en este paradigma surge una experiencia denominada plataforma terapéutica que se desarrolla en un dispositivo de salud mental comunitaria pública y que incluye intervenciones múltiples, multidisciplinares e integradas con la intención de fomentar el uso de los recursos sanos de todas las dimensiones identificadas. Los factores referidos cristalizan en una propuesta desde los propios integrantes para iniciar una actividad grupal de baile liderada por uno de ellos en un contexto extra-sanitario con la intención de fomentar los aspectos sanos sociales y normalizar las actividades al margen de la vivencia de la experiencia psicótica. Se señalan las dificultades desde la institución y la propia clínica psicótica para llevar a cabo actividades en el paradigma de la recuperación en encuadres comunitarios y desde la sanidad pública.Recovery model is based on the implication of the people who suffer psychosis in their own improvement process. We propose a therapeutical experience in a Community Mental Health. Team in the Andalusian Health Service. It includes integrated interventions from different professional roles (Social worker, nursery and psychiatrist) to increase healthy areas. This article exposes a 3-year evolution including a self-promoted movement from the users. It includes bodily aspects and mutual self-help. This experience is set in a non-medical environment to promote healthy social aspects and increase experience out from the psychosis. We also remark institutional and clinical difficulties to develop recovery activities in comunnity environment from public health settings

Graphene materials with different structures prepared from the same graphite by the Hummers and Brodie methods

[EN] Graphene materials containing different functional groups were prepared from a natural graphite, by means of two different oxidation methods (Hummers and Brodie). It was observed that the differences in the structure of the resultant graphite oxides (GOs) greatly affect the structure of the graphenes resulting from their thermal exfoliation/reduction. Although the oxidation of the graphite was more effective with the modified Hummers method than with Brodie’s method (C/O of 1.8 vs 2.9, as determined by XPS), the former generated a lower residual oxygen content after thermal exfoliation/reduction and a better reconstruction of the 2D graphene structure (with fewer defects). This is explained by the presence of conjugated epoxy and hydroxyl groups in the GO obtained by Brodie’s method, which upon thermal treatment, lead to the incorporation of oxygen into the carbon lattice preventing its complete restoration. Additionally, graphene materials obtained with Brodie’s method exhibit, in general, smaller sheet size and larger surface area.The authors thank MICINN and European Union (CONSOLIDER INGENIO 2010, Ref. CSD2009-00050, MAT2010-16194) for their financial support. Dr. Patricia Alvarez thanks MICINN for her Ramon y Cajal contract.Peer reviewe

High dielectric constant in Barium titanate-graphene composites around the percolation threshold

Resumen del trabajo presentado a la 14th International Conference of the European Ceramic Society, celebrada en Toledo (España) del 21 al 25 junio de 2015.Peer Reviewe

Generation of a human control iPS cell line (ESi080‐A) from a donor with no rheumatic diseases

[Abstract] Here, we report the establishment of the human iPS cell line N1-FiPS4F#7 generated from skin cells of a patient with no rheumatic diseases, thus obtaining an appropriate control iPS cell line for researchers working in the field of rheumatic diseases. The reprogramming factors Oct4, Sox2, Klf4 and c-Myc were introduced using a non-integrating reprogramming strategy involving Sendai Virus.Instituto de Salud Carlos III; PI17/0219

Evaluating capacitive deionization for water desalination by direct determination of chloride ions

Ionic conductivity and capacitance measurements are widely used methods for evaluating the desalination efficiency in capacity deionization processes. In this study, these methods are revised and several problems associated to them are identified and evaluated. Furthermore, a new method based on the determination of the chloride ion concentration by means of a chloride selective electrode is proposed as a more reliable alternative for evaluating the desalination performance in these systems. This method has been shown not only to be precise in a wide range of salt concentrations but also to be independent of pH, one of the main limitations of the determinations based on ionic conductivity measurements.The authors thank MICINN and the European Union (project MAT2010-20601-C02-01) for the financial support provided. Patricia Díaz thanks MICINN for a FPI predoctoral research grant (FPI: BES-2011-045394).Peer reviewe