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San Juan de la Rambla, Spain

Zubizarreta L.,Instituto Tecnologico Of La Energia Ite | Iserte R.,Instituto Tecnologico Of La Energia Ite | Llovera P.,Polytechnic University of Valencia | Gil-Agusti M.,Instituto Tecnologico Of La Energia Ite
Microporous and Mesoporous Materials | Year: 2011

A series of different carbon materials have been obtained by self-assembly method under different conditions in order to study the effect of the nature of carbon precursor, pore forming agent and catalyst concentration on the textural, chemical and structural properties of carbon materials. Results show that using hexadecanol as pore forming agent produces mesoporous carbon materials with controlled mesopore size by varying the amount of pore forming agent. Specific surface areas up to 314 m2 g-1 can be reached. The microporosity of the samples decreases with the amount of the catalyst used during the synthesis from 0.12 to 0.01 cm3 g-1. On the other hand, the use of ethylene glycol as pore forming agent gives highly microporous carbon materials independently on the synthesis conditions (i.e. 0.19 cm3 g-1). The influence of pore forming agent nature and synthesis conditions on the chemical and structural properties of carbon materials is lower. The obtained samples present an amorphous structure with a slightly higher order degree than typical activated carbons. Results show that self-assembly is a promising method to obtain carbon materials for applications, in which a control of the textural properties is required, such as energy storage applications. © 2011 Elsevier Inc. All rights reserved.

Brana G.O.,Instituto Tecnologico Of La Energia Ite | Segovia P.L.,Polytechnic University of Valencia | Magraner F.,Instituto Tecnologico Of La Energia Ite | Quijano A.,Instituto Tecnologico Of La Energia Ite
Journal of Physics: Conference Series | Year: 2011

Cellular polymers have recently attracted attention for their property of exhibiting a piezoelectric constant when they are electrically charged. The electrostatic charge generated in the voids by the internal discharges creates and internal macrodipole which is responsible for the piezoelectric effect. Charging by corona discharge is the most used method for cellular polymers. Many works has been published on polypropylene and polyethylene films mainly focused on the required expansion process or on the results obtained for raw cellular materials electrically activated. Our work is based on commercial polyethylene cellular films which have been physically characterized and electrically activated. The effect of thermal treatment, physical uniaxial or biaxial stretching and corona charging was investigated. The new method of corona charging improved the piezoelectric constant under other activation conditions.

Munar A.,Jaume I University | Andrio A.,Jaume I University | Iserte R.,Instituto Tecnologico Of La Energia Ite | Compan V.,Instituto Tecnologico Of La Energia Ite | Compan V.,Polytechnic University of Valencia
Journal of Non-Crystalline Solids | Year: 2011

Ionic conductivity, diffusion coefficients, mobility and ionic concentration for lithium salts dissolved in polymer electrolytes are determined by the modeling of the dielectric loss and spectra. Cation and anion diffusion coefficients are quantified using the Trukhan model depending on the assumed ratio of the cation to anion diffusion coefficients. Measurements are performed for polymer electrolytes consisting of polyethylene oxide (PEO) with dissolved LiClO4 salts for different sample thicknesses and temperatures ranging from 5 to 105 °C, which comprises both the crystalline and amorphous phases of the composite electrolyte. A good phenomenological description of the dielectric loss spectra is obtained for both the semi-crystalline and amorphous phases. The fraction of mobile ions is estimated to vary from 0.002% at 25 °C (semi-crystalline phase) up to 0.05% at 80 °C (amorphous phase). © 2011 Elsevier B.V. All rights reserved.

Vlascici D.,West University of Timisoara | Fagadar-Cosma E.,Romanian Academy of Sciences | Popa I.,Romanian National Institute for Research for Electrochemistry and Condensed Matter | Chiriac V.,West University of Timisoara | Gil-Agusti M.,Instituto Tecnologico Of La Energia Ite
Sensors (Switzerland) | Year: 2012

Three A3B porphyrins with mixed carboxy-, phenoxy-, pyridyl- and dimethoxysubstituent functionalization on the meso-phenyl groups were obtained by multicomponent synthesis, fully characterized and used as ionophores for preparing PVC-based membrane sensors selective to iron(III). The membranes have an ionophore:PVC:plasticizer composition ratio of 1:33:66. Sodium tetraphenylborate was used as additive (20 mol% relative to ionophore). The performance characteristics (linear concentration range, slope and selectivity) of the sensors were investigated. The best results were obtained for the membrane based on 5-(4-carboxyphenyl)-10,15,20-tris(4-phenoxyphenyl)-porphyrin plasticized with bis(2-ethylhexyl)sebacate, in a linear range from 1 × 10-7-1 × 10-1 M with a slope of 21.6 mV/decade. The electrode showed high selectivity with respect to alkaline and heavy metal ions and a response time of 20 s. The influence of pH on the sensor response was studied. The sensor was used for a period of six weeks and the utility has been tested for the quantitative determination of Fe(III) in recovered solutions from spent lithium ion batteries and for the quantitative determination of Fe(III) in tap water samples. © 2012 by the authors; licensee MDPI, Basel, Switzerland.

Ruiz D.,Aplicaciones Tecnologicas S.A. | Llovera-Segovia P.,Instituto Tecnologico Of La Energia Ite | Pomar V.,Aplicaciones Tecnologicas S.A. | Quijano A.,Instituto Tecnologico Of La Energia Ite
Journal of Electrostatics | Year: 2013

The influence of many parameters on the electric discharges at U50% can only be correlated by means of an analysis of a large amount of experimental data. The 50% probability of breakdown is considered a random process. We have investigated how to find relevant statistical differences leading to breakdown or withstanding during an impulse voltage test under the same conditions for a plane high voltage electrode and a grounded electrode configuration. An analysis based on Neural Network discrimination has been developed which indicates that measurements do contain some relevant information test at early stages in a reduced time frame. © 2012 Elsevier B.V.

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