Development of photonic gas sensors based on porphyrin-metal oxide nanostructured thin films obtained by glancing angle deposition

Programa de Doctorado en Biotecnología y Tecnología QuímicaHoy en día existe un gran interés tecnológico y científico por el estudio y desarrollo de nuevos materiales nanoestructurados en los que podemos predecir y controlar sus propiedades para su uso en una aplicación tecnológica. Un ejemplo muy interesante de materiales compuestos nanoestructurados o 'nanocomposites' son aquellos fabricados mediante una estrategia denominada 'host-guest' (huésped-anfitrión) compuestos de matrices de óxidos en los cuales se incorpora el material activo para obtener la funcionalidad requerida, ya sean nanopartículas metálicas, colorantes orgánicos, puntos cuánticos, etc, a escala nanométrica. Esto materiales presentan grandes posibilidades de aplicación en campos tales como microelectrónica, sensórica, ingeniería química y bioquímica, etc. Materiales híbridos son aquellos que se componen de dos sustancias, normalmente una orgánica y otra inorgánica. Estos materiales híbridos son muy versátiles en cuanto a su composición, procesado y propiedades ópticas y mecánicas. De las interacciones superficiales entre las matrices de óxido y el material incorporado se derivan características singulares que dependen en gran medida de la presencia de defectos, gradientes composicionales, rugosidad y microestructura, que juegan un papel vital en la funcionalidad de estos nuevos materiales. El hecho de poder fabricar materiales nanoestructurados altamente porosos supone maximizar el área superficial accesible, lo que conduce a la posibilidad de poder incorporar materiales activos en el interior de los poros. Esta propiedad ha sido muy útil en catálisis, absorción, purificación y almacenamiento de gases, en el desarrollo de materiales aislantes en la industria de los semiconductores y en aplicaciones ópticas. Las películas delgadas matrices de óxido se prepararán mediante técnicas de Evaporación Electrónica a Ángulos Rasantes (GLAD-PVD) o Magnetron Sputtering (MS) en la configuración Ángulo Rasante. Estas dos técnicas de fabricación de películas micrométricas de alto vacío permiten la obtención de capas delgadas nanoestructuradas de espesor controlado. Una vez preparadas las películas anfitrionas según se ha indicado anteriormente se procede a la incorporación de un determinado material activo o material huesped. Los materiales activos que se estudiaran en esta tesis son moléculas orgánicas de la familia de las porfirinas. Dentro de la gran cantidad de las aplicaciones que dan lugar estos materiales híbridos nanoestructurados, el presente trabajo se centra en el desarrollo de sensores de gases fotónicos basados en una matriz porosa de óxido metálico, donde los poros están abiertos, que actúa de material anfitrión o matriz y un material huésped activo que se incorpora a los poros de la matriz.Universidad Pablo de Olavide. Departamento de Sistemas Físicos, Químicos y Naturale

A transparent TMPyP/TiO2 composite thin film as an HCl sensitive optochemical gas sensor

Tetracationic porphyrin (TMPyP) molecules were incorporated into an optically transparent TiO2 thin film, prepared by Glancing Angle Physical Vapour Deposition (GAPVD), by simple infiltration (at pH 6.4). The preparation of optically transparent TMPyP/TiO2 composite thin films provides a method for the integration of the porphyrin molecules into photonic devices for direct monitoring of gases. Previously, UV-visible and fluorescence spectral techniques have been used to study the reversible protonation of TMPyP in aqueous solution. The optical spectrum of TMPyP shows an intense Soret band at 423 nm with a 22 nm red shift upon protonation by HCl. The experimental conditions for monitoring the concentration of HCl gas by absorption spectroscopy have been optimized. The maximum absorbance change was observed at the Soret band wavelength. A selected temperature of 80 °C and a 300 s recovery period were found to be the optimum operating parameters (response time t50 = 16.8 ± 0.7 s). The composite with smaller surface concentration of TMPyP (¿ = 0.3 × 10-9 mol cm -2) presented the best detection limit (0.1 ppm). The response of the composite sensor was highly stable for several months.Ministerio de Educación y Ciencia PET2007 0363 01/ 02, TEC201021830C0201, CSD20070000

Optical Gas Sensing of Ammonia and Amines Based on Protonated Porphyrin/TiO2 Composite Thin Films

Open porous and transparent microcolumnar structures of TiO2 prepared by physical vapour deposition in glancing angle configuration (GLAD-PVD) have been used as host matrices for two different fluorescent cationic porphyrins, 5-(N-methyl 4-pyridyl)-10,15,20-triphenyl porphine chloride (MMPyP) and meso-tetra (N-methyl 4-pyridyl) porphine tetrachloride (TMPyP). The porphyrins have been anchored by electrostatic interactions to the microcolumns by self-assembly through the dip-coating method. These porphyrin/TiO2 composites have been used as gas sensors for ammonia and amines through previous protonation of the porphyrin with HCl followed by subsequent exposure to the basic analyte. UV–vis absorption, emission, and time-resolved spectroscopies have been used to confirm the protonation–deprotonation of the two porphyrins and to follow their spectral changes in the presence of the analytes. The monocationic porphyrin has been found to be more sensible (up to 10 times) than its tetracationic counterpart. This result has been attributed to the different anchoring arrangements of the two porphyrins to the TiO2 surface and their different states of aggregation within the film. Finally, there was an observed decrease of the emission fluorescence intensity in consecutive cycles of exposure and recovery due to the formation of ammonium chloride inside the film.We thank the Junta de Andalucía (Project: FQM-2310), the European Regional Development Funds program (EU-FEDER) and the Spanish Ministry of Economy and Competitiveness (Projects: MAT2013-40852-R, MAT2013-42900-P, MAT2014-57652-C2-2-R, MAT2015-69035-REDC, MINECO-CSIC 201560E055, PCIN-2015-169-C02-02 under a 2014 M-Era.Net project and RECUPERA 2020), for financial support. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)

Differences in n-type doping efficiency between Al- and Ga-ZnO films

A careful and wide comparison between Al and Ga as substitutional dopants in the ZnO wurtzite structure is presented. Both cations behave as n-type dopants and their inclusion improves the optical and electrical properties of the ZnO matrix, making it more transparent in the visible range and rising up its electrical conductivity. However, the same dopant/Zn ratio leads to a very different doping efficiency when comparing Al and Ga, being the Ga cation a more effective dopant of the ZnO film. The measured differences between Al- and Ga-doped films are explained with the hypothesis that different quantities of these dopant cations are able to enter substitutionally in the ZnO matrix. Ga cations seem to behave as perfect substitutional dopants, while Al cation might occupy either substitutional or interstitial sites. Moreover, the subsequent charge balance after doping appear to be related with the formation of different intrinsic defects that depends on the dopant cation. The knowledge of the doped-ZnO films microstructure is a crucial step to optimize the deposition of transparent conducting electrodes for solar cells, displays, and other photoelectronic devices.Ministerio de Ciencia e Innovación TEC2007-60996, MAT2008-06858-C02-02, MAT2008- 06330, TEC2010-16700FUNCOAT CSD2008-00023- CONSOLIDER INGENIOSonderforschungsbereich SFB 76

Complete Revascularization of Stable STEMI Patients Offers a Significant Benefit if Done During the Index PCI, but Not if It\u27s Done as a Staged Procedure

Background: Complete revascularization (CR) of hemodynamically stable STEMI improves outcomes when compared to culprit-only PCI. However, the optimal timing for CR (CR during index PCI [iCR] versus staged PCI [sCR]) is unknown. sCR is defined as revascularization of non-culprit lesions not done during the index procedure (mean 31.5±24.6 days after STEMI). Our goal was to determine whether iCR was the superior strategy when compared to sCR. Methods: A systematic review of Medline, Cochrane, and Embase was performed for RCTs reporting outcomes of stable STEMI patients who had undergone CR. Only RCTs with a clearly defined timing of CR, for the classification into iCR and sCR, and a follow-up of at least 12 months were included. Seven RCTs comprising 6647 patients (mean age:62.9±1.4 years, male sex:79.4%) met these criteria and were included. Results: After a mean follow-up of 25.1±9.4 months, iCR was associated with a significant reduction in cardiovascular mortality (risk ratio [RR] 0.48, 95% confidence interval [CI] 0.26-0.90, p=0.02, relative risk reduction [RRR] 52%) and non-fatal reinfarctions (RR 0.42, 95% CI 0.25-0.70, p=0.001, RRR: 58%). sCR showed a significant reduction in non-fatal reinfarctions only (RR 0.68, 95% CI 0.54-0.85, p=0.0008, RRR: 32%). There was no difference in the safety outcome of contrast-induced nephropathy between groups. Conclusion: iCR of stable STEMI patients is associated with a significant reduction in cardiovascular death and a trend towards reduction in all-cause mortality. These benefits are not seen in sCR. Both strategies are associated with a reduction in non-fatal reinfarctions

Optical gas sensing of ammonia and amines based on protonated porphyrin/TiO2 composite thin films

Open porous and transparent microcolumnar structures of TiO2 prepared by physical vapour deposition in glancing angle configuration (GLAD-PVD) have been used as host matrices for two different fluorescent cationic porphyrins, 5-(N-methyl 4-pyridyl)-10,15,20-triphenyl porphine chloride (MMPyP) and meso-tetra (N-methyl 4-pyridyl) porphine tetrachloride (TMPyP). The porphyrins have been anchored by electrostatic interactions to the microcolumns by self-assembly through the dip-coating method. These porphyrin/TiO2 composites have been used as gas sensors for ammonia and amines through previous protonation of the porphyrin with HCl followed by subsequent exposure to the basic analyte. UV–vis absorption, emission, and time-resolved spectroscopies have been used to confirm the protonation–deprotonation of the two porphyrins and to follow their spectral changes in the presence of the analytes. The monocationic porphyrin has been found to be more sensible (up to 10 times) than its tetracationic counterpart. This result has been attributed to the different anchoring arrangements of the two porphyrins to the TiO2 surface and their different states of aggregation within the film. Finally, there was an observed decrease of the emission fluorescence intensity in consecutive cycles of exposure and recovery due to the formation of ammonium chloride inside the film.Junta de Andalucía FQM-2310EU-FEDERMinisterio de Economía y Competitividad MAT2013-42900-P MAT2014-57652-C2-2-R MAT2015-69035-REDC MINECO-CSIC 201560E055 PCIN-2015-169-C02-0

New World Civitas, Contested Jurisdictions and Intercultural Conversation in the Construction of the Spanish Monarchy

Jurisdictional frontiers were created, contested, and negotiated among a wide range of actors, including native Americans and Europeans, with reference to the cities founded in Castilla del Oro (roughly present-day Panama). This research deals, first, with the reshaping of the concept of a city in the New World, based on its inhabitants' sense of civitas. It analyses, secondly, the creation and redefinition of jurisdiction during political conflicts and, third, the construction and maintenance of jurisdiction through local relations with indigenous populations described as "conversation". The analysis of the creation and preservation of local jurisdictions allows for an interpretation of the complexities involved in the configuration of political power and political space from below in the territories claimed by the Spanish Monarchy.Art Empir

Anàlisi i disseny d'un conversor analògic digital Sigma-Delta

[ES] El objetivo de este Trabajo de Fin de Grado es analizar el diseño y la caracterización de un modulador de un convertidor Sigma-Delta en dos tecnologías diferentes. El convertidor sigma delta es un tipo de conversor analógico-digital utilizado en diversas aplicaciones, como comunicaciones, audio y sensores. El modulador es una parte esencial de este convertidor, encargado de realizar la conversión de señales analógicas a digitales. En este estudio, se ha comparado dos tecnologías de diseño de moduladores Sigma-Delta, explorando sus ventajas y desventajas en términos de rendimiento, velocidad y consumo de energía. Se llevó a cabo un análisis detallado de cada tecnología, incluyendo aspectos como el diseño de circuitos y sus topologías, diseño de circuitos de caracterización y análisis temporal y frecuencial. Además, se ha realizado una caracterización exhaustiva de los moduladores implementados, evaluando su desempeño y prestaciones en conjunto. Se realizó adicionalmente una mejora sobre los diseñados caracterizándolos y estudiando cómo se realiza dicha mejora con nuevas topologías como la expuesta en este documento. El estudio de esta práctica, permitirán comprender mejor las características y el rendimiento de los moduladores Sigma Delta además de ayudar a entender como funciona dentro de un sistema como el de un conversor analógico digital..[EN] The objective of this document is to analyze the design and characterization of the modulator of a Sigma-Delta converter in two different technologies. The Sigma-Delta converter is a type of analog-to-digital converter used in various applications such as communications, audio, and sensors. The modulator is an essential part of this converter, responsible for converting analog signals to digital. In this study, two Sigma-Delta modulator design technologies will be compared, exploring their advantages and disadvantages in terms of performance, speed, and power consumption. A detailed analysis of each technology will be conducted, including circuit design and topologies, circuit characterization design, and temporal and frequency analysis. Furthermore, a comprehensive characterization of the implemented modulators will be performed, evaluating their performance and overall capabilities. Improvement will be made by characterizing and studying how it is achieved using new topologies as presented in this document. Studying this practice will provide a better understanding of the characteristics and performance of Sigma-Delta modulators, as well as help understand their functioning within an analog-to-digital converter system.Castillero Perea, PA. (2023). Análisis y diseño de un conversor analógico digital Sigma-Delta. Universitat Politècnica de València. http://hdl.handle.net/10251/19639

A transparent TMPyP/TiO2 composite thin film as an HCl sensitive optochemical gas sensor

Tetracationic porphyrin (TMPyP) molecules were incorporated into an optically transparent TiO2 thin film, prepared by Glancing Angle Physical Vapour Deposition (GAPVD), by simple infiltration (at pH 6.4). The preparation of optically transparent TMPyP/TiO2 composite thin films provides a method for the integration of the porphyrin molecules into photonic devices for direct monitoring of gases. Previously, UV-visible and fluorescence spectral techniques have been used to study the reversible protonation of TMPyP in aqueous solution. The optical spectrum of TMPyP shows an intense Soret band at 423 nm with a 22 nm red shift upon protonation by HCl. The experimental conditions for monitoring the concentration of HCl gas by absorption spectroscopy have been optimized. The maximum absorbance change was observed at the Soret band wavelength. A selected temperature of 80 °C and a 300 s recovery period were found to be the optimum operating parameters (response time t50 = 16.8 ± 0.7 s). The composite with smaller surface concentration of TMPyP (¿ = 0.3 × 10-9 mol cm -2) presented the best detection limit (0.1 ppm). The response of the composite sensor was highly stable for several months. © 2010 Elsevier B.V.Peer Reviewe