Examinando por Autor "Rodríguez Montoro, Óscar"

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An introduction to High-Pressure Science and Technology
(CRC Press. Taylor Francis Group, 2016-01-01) Rodríguez Montoro, Óscar; Smith, Nadia Alexandra Sofia
To show the enormous potential of high-pressure technology, and its applications to different areas, focusing mainly on biotechnology and industrial applications.
Effects of high pressure on unsaturated fatty acids
(Taylor & Francis, 2014-09-24) Povedano, Isabel; Guignon, Berenguere; Rodríguez Montoro, Óscar; Sanz, Pedro Dimas; Taravillo Corralo, Mercedes; García Baonza, Mercedes
The objective of this study is to investigate the effects of high pressure processing on the molecular structure of some unsaturated fatty acids. Samples of elaidic acid, linoleic acid, ZE and EE conjugated linoleic acid are treated at 293 or 333 K at pressures up to 700 MPa. It is observed that the adiabatic heat generated from compression is able to bring the sample temperature above 373 K after 700 MPa. These relatively extreme conditions are of great interest for food sterilization, but they may induce undesirable change in fatty acid quality characteristics. To check for structural changes, Raman spectra of the samples are analysed after treatments. The comparison with Raman spectra of samples kept at atmospheric pressure shows that pressure induces some conformational changes at the hydrocarbon skeleton in solid samples, while the liquid ones remain unchanged. No cis/trans isomerization occurs, but gauche conformers are likely to be present.
Infrared spectroscopic study of the formation of fossil resin analogs with temperature using trans-communic acid as precursor
(Elsevier, 2018-05-21) Rodríguez Montoro, Óscar
For million years resin exudates have undergone chemical alterations by heat, pressure, radiation, water, oxygen, microorganisms, and have suffered processes of sedimentation and diagenesis. These agents have affected the organic functional groups present in the terpenes of the resins, giving rise to what we nowadays know as fossil resins. In this work, we try to get further insight in the chemical formation of fossil resins. As the simulation of the natural process is quite complex, we have focused on the temperature induced reactivity of the trans-communic acid, the main component of the Class I resins. Using this terpene derivate as a very basic model of a resin exudate, we have monitored their thermal changes by infrared spectroscopy, Differential Scanning Calorimetry and Thermogravimetric Analysis within the range of 25 to 340 °C. The temperature-induced transformation, both in presence and absence of inert atmosphere, is discussed on the basis of the reactivity of the conjugated double-bond, the exocyclic bond and the carboxylic acid group present in the trans-communic acid. The results obtained in these series of experiments agree with the maturation scheme accepted in the literature for natural resins, i.e. an initial cross-linked polymerization and a subsequent maturation reaction. From combined DSC/TGA and infrared spectroscopy results, we conclude that chemical changes produced in the trans-communic acid in the range 130–175 °C may mimic the initial polymerization-like process in the natural resins, whereas those produced between 180 and 340 °C seem to correspond to the maturation pathways described in the literature for fossil resins Class Ib. Spectral assignment of the most relevant infrared-active modes of the trans-communic acid at 25 °C is also provided with the aid of Density Functional Theory calculations.
OLIMPIADAS DE QUÍMICA 2016
(Real Sociedad Española de Química, 2019-11-27) Rodríguez Montoro, Óscar; Lobato Fernández, Álvaro; Rodríguez Renuncio, Juan Antonio
Olimpiadas de Química 2016. XXIX Olimpiada Nacional, IChO-Olimpiada Internacional 2016, OIAQ- Olimpiada Iberoamericana 2016
OLIMPIADAS DE QUÍMICA 2017
(Real Sociedad Española de Química, 2018-02-01) Rodríguez Montoro, Óscar; Lobato Fernández, Álvaro; Iza Cabo, Nerea; Rodríguez Renuncio, Juan Antonio
Olimpiadas de Química 2017. XXX Olimpiada Nacional, IChO-Olimpiada Internacional 2017, OIAQ- Olimpiada Iberoamericana 2017
OLIMPIADAS DE QUÍMICA 2018
(Real Sociedad Española de Química, 2019-02-01) Rodríguez Montoro, Óscar; Lobato Fernández, Álvaro; Rodríguez Renuncio, Juan Antonio
XXXI OLIMPIADA NACIONAL, ICHO - OLIMPIADA INTERNACIONAL 2018, OIQ - OLIMPIADA IBEROAMERICANA 2018
OLIMPIADAS DE QUÍMICA 2019
(Real Sociedad Española de Química, 2019-11-27) Rodríguez Montoro, Óscar; Muñoz San Martín, Crisitina; Rodríguez Renuncio, Juan Antonio; Arsuaga Ferreras, Jesús María
Olimpiadas de Química 2019. XXXII Olimpiada Nacional, IChO-Olimpiada Internacional 2019, OIAQ- Olimpiada Iberoamericana 2019
OLIMPIADAS DE QUÍMICA 2020
(Real Sociedad Española de Química, 2020-12-31) Rodríguez Montoro, Óscar; Ramírez de Arellano, Carmen; Arsuaga Ferreras, Jesús María
Olimpiadas de Química 2020. XXXIII Olimpiada Nacional de Química, IChO-Olimpiada Internacional 2020
Phase transitions and hindered rotation in dimethylacetylene at high pressures probed by Raman spectroscopy
(American Institute of Physics, 2004-12-08) García Baonza, Valentín; Rodríguez Montoro, Óscar; Taravillo Corralo, Mercedes; Cáceres Alonso, Mercedes; Núñez, Javier
We present Raman spectroscopy experiments in dimethylacetylene ~DMA! using a sapphire anvil cell up to 4 GPa at room temperature. DMA presents phase transitions at 0.2 GPa ~liquid to phase I! and 0.9 GPa, which have been characterized by changes in the Raman spectrum of the sample. At pressures above 2.6 GPa several bands split into two components, suggesting an additional phase transition. The Raman spectrum of the sample above 2.6 GPa is identical to that found for the monoclinic phase II (C2/m) at low temperatures, except for an additional splitting of the band assigned to the fourfold degenerated asymmetric methyl stretch. The global analysis of the Raman spectra suggests that the observed splitting is due to the loss of degeneracy of the methyl groups of the DMA molecule in phase II. According to the above interpretation, crystal phase II of DMA extends from 0.9 GPa to pressures close to 4 GPa. Between 0.9 and 2.6 GPa, the methyl groups of the DMA molecules rotate almost freely, but the rotation is hindered on further compression.
Polymerization at High Pressure of Dimethyl-Acetylene: Raman Microscopy, Vibrational
(Trans Tech Publications, 2002-01-01) Pérez Tejedor, francisco JAvier; Rodríguez Montoro, Óscar; Rodríguez Jiménez, Olga; García Baonza, Valentín; Núñez Delgado, Javier
We have measured the Raman spectrum of the dimethyl acetylene in the pressure range 0,1-62 kbar at room temperature. We have found three induced phase transitions at 0.1, 9 and 26 kbar. We have also found a massive polymerization reaction in this system which begins around 35 kbar. A force field treatment has been performed as a function of pressure, which allows analyzing the behaviour of the force constants with pressure for the dimethyl-acetylene.
La presencia de la Química en los billetes bancarios
(Real Sociedad Española de Química, 2020-10-05) Rodríguez Montoro, Óscar
La presencia de la Química en todo lo relacionado con la impresión de papel moneda, es muy significativa. Desde los pigmentos utilizados, tintas magnéticas de seguridad impresa, falsificaciones, microorganismos,… hasta las ilustraciones y los grandes científicos retratados. En el presente trabajo se hace una recopilación de todas ellas a la vez.
Pressure as driving force in the formation of Fossil Resins: Pressure Induced Changes in trans-Communic Acid studied by Raman Spectroscopy
(IOP PUBLISHING, 2017-01-01) Rodríguez Montoro, Óscar; Taravillo Corralo, Mercedes; Povedano, Isabel; Tortajada Pérez, José; García Baonza, Valentín
The main purpose of this study is to provide spectroscopic evidence of possible chemical pathways in the formation of fossil resins under high pressure conditions. In this work, we have studied trans-communic acid (majority precursor compound in resinites) under high pressure conditions by using a sapphire anvil cell. Raman spectra were measured at atmospheric pressure up to 8 GPa (at room temperature). Slight changes were observed in the spectra. Furthermore, the recovered sample after pressure release was analyzed by FTIR. Our results are not conclusive about a possible chemical pathway of polymerization induced by pressure.
Química a alta presión: transferencia tecnológica
(International Marketing Communication S. A. Editors: Instituto Tomás Pascual Sanz para la nutrición y la salud, 2010-06-01) Rodríguez Montoro, Óscar
Mostrar el enorme potencial de la tecnología de la química a alta presión, para dar una visión de conjunto de algunas de sus aplicaciones en diferentes disciplinas, centrándose particularmente en el sector de la Biotecnología.
La Química de las Finanzas
(Real Sociedad Española de Química, 2020-10-28) Rodríguez Montoro, Óscar
La Química y las Finanzas parecen ser en principio dos materias sin mucha relación y dispares una de otra. Pero si se hace una reflexión y se establecen una serie de paralelismos de la presencia de la Química en los diferentes activos financieros, tanto vetustos, como contemporáneos, estas diferencias se acortan enormemente.
Raman spectroscopic study of the formation of fossil resin analogues
(Wiley, 2014-08-25) Rodríguez Montoro, Óscar; Taravillo Corralo, Mercedes; San Andrés, Margarita; de la Roja de la Roja, José Manuel; Fernández Barrero, Alejandro; Arteaga; García Baonza, Valentín
The purpose of this work is to provide spectroscopic evidence of possible chemical pathways that took place in the formation of fossil resins Class I. The natural polymerization process is mimicked in the laboratory using pure communic acids (terpene derivatives) as reactants, which were subjected to controlled temperature treatment. We shall focus here on the trans-, cis- and iso-/ mirceo- communic acid isomers, and the temperature-induced reactivity is discussed on the basis of the different arrangements of the conjugated double-bonds moieties in the monomeric units. Transformations starting at 130, 90 and 127 °C, for trans-, cis- and iso-communic acids, respectively, led to the formation of intermediate products. The whole process was followed and analyzed by micro-Raman spectroscopy. The absence of several Raman signatures suggests conjugation loss in the side-chain of these intermediate compounds. With increasing temperature, the intermediate products suffer additional maturation reactions to form the final fossil resin analogues object of this work.
Theoretical (DFT) and experimental (Raman and FTIR) spectroscopic study on communic acids, main component of fossil resins
(Elsevier, 2019-07-19) Rodríguez Montoro, Óscar; Tortajada Pérez, José; Lobato Fernández, Álvaro; García Baonza, Valentín; Taravillo Corralo, Mercedes
The objective of this work is to establish a spectral assignment of several communic acids. The most significant vibrational modes of three stereoisomers of communic acids [trans-, cis-, and iso- (or mirceo-)] are presented. They are showed throughout experimental Raman and IR spectra, and on the basis on calculations with Density Functional Theory (DFT) and the assignment of the spectral bands of different resins found in the literature. These three communic acids studied are the most important isomers present in the scaffold of the fossil resins Class I, as monomers or co-polymerized according to several authors. These kinds of terpenes are used as starting material, for example, for the synthesis of the fungicide and compounds bioactives. In a novel way, it is reported jointly the assignment of the experimental Infrared and Raman modes together with theoretical modes, since normally the authors tend to focus on one or another spectroscopic technique only. These results can be used as a reference for distinguishing amber from less matured resins as copal, determining the local origin of archaeological fossilized resins. Moreover, they will serve as help to differentiate between real and imitation ambers.
U (VI) speciation studies by Raman spectroscopy technique in the production of nuclear fuel
(Elsevier, 2022-01-01) Jimenez Bonales, Laura; Rodríguez Villagrá, Nieves; Sánchez García, Iván; Rodríguez Montoro, Óscar
One key intermediate solid product in the industrial production of the U02 for fabrication of common nuclear fuel is the ammonium diuranate or ADU. Its composition and morphology are crucial for industrial operations since this determines the quality of U02 powder. In this work we demonstrate that Raman spectroscopy tech- nique is a power tool to characterize the precipitation of ADU and to monitor the precipitation reaction progress, being able to follow the U(VI) speciation and to correlate these results with the features of the obtained solid. Thereby, here we propose the use of the Raman spectroscopy technique in the production of nuclear fuel in order to monitor the speciation of U(VI) during the ADU precipitation with dual-purpose; in one hand, to improve the safety in the fuel management and on the other hand, for the quality control for the manufacturing.