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141 p., En nuestro planeta podemos ver agua en todas sus formas: gaseosa en las nubes, sólida en los glaciares, o líquida en ríos o mares. El agua es trascendental para la vida en la tierra ya que regula la temperatura del medio ambiente adecuadamente y, por lo tanto, se convierte en un factor que determina la supervivencia de la fauna y flora. En los seres humanos, el agua está directamente relacionada con el transporte de nutrientes, la eliminación de toxinas o la lubricación de tejidos participando en las reacciones químicas y en las reacciones metabólicas. Sin agua no podríamos además criar animales, cultivar, lavar los alimentos o mantener una buena higiene.Hasta el siglo XX el agua se ha considerado un recurso inagotable. Sin embargo, el crecimiento de la población mundial y el cambio climático han provocado que en el siglo XXI se haya convertido en un bien escaso. Además, el agua disponible está contaminada fundamentalmente por actividades humanas como la agricultura, ganadería, industria y, parcialmente por razones naturales como erupciones volcánicas. En este contexto se ha vuelto crucial disponer de metodologías o sistemas que permitan de una manera eficiente y económica descontaminar o remediar el agua que disponemos.Esta tesis se centrará en el desarrollo de adsorbentes para la remediación de agua dulce contaminada. Si bien existen muchos tipos de contaminantes diferentes, me concentraré en los llamados ¿contaminantes emergentes¿, una colección de moléculas presente en agua dulce que engloban los productos de cuidado personal, fármacos, plaguicidas y otros productos químicos industriales. De hecho, durante 2023 las regulaciones europeas y españolas del agua para consumo incluirán una extensa lista de estos contaminantes.Los metales pesados proceden de fuentes naturales (como la erosión de rocas compuestas por metales pesados o las erupciones volcánicas) o por actividad humana (la minería y los vertidos industriales). El consumo prolongado de agua contaminada por

209 p., This doctoral thesis was realized at the frontier between Liquid-Phase Transmission Electron Microscopy (LP-TEM) and Microfluidics. It contributes to the elevation of LP-TEM to a quantitative experimental technique for the study of nanoscale dynamics in liquid environments by applying concepts established in microfluidics.A workflow combining numeric modelling and experiments was elaborated. The workflow reveals and quantifies the effect of structural elements of microfluidic LP-TEM reactors on mass transport. Moreover, the effect of flow on the radiolysis reaction network was analysed. The acquired knowledge led to the development of customized LP-TEM mixing reactors with optimized mass transport.This manuscript derives general guidelines for LP-TEM flow experiments and showcases model experiments to demonstrate the progress towards quantitative LP-TEM studies.

125 p., Las proteínas son biopolímeros esenciales en todos los organismos vivos encargadas de un gran número de funciones. Tradicionalmente, el paradigma estructura-función dictaba que todas las proteínas debían encontrarse plegadas ya que solo así serían capaces de ejercer su función. Posteriormente, se ha descubierto un tipo de proteínas llamadas intrínsecamente desordenadas (o IDPs) que no se encuentran plegadas en su estado fisiológico. Debido a su desorden estructural, estas proteínas son capaces de adoptar diferentes configuraciones y unirse a diferentes proteínas. Esto les confiere una gran versatilidad funcional, y en consecuencia están muy presentes en vías de señalización y regulación celular. En esta tesis nos centraremos en el estudio de la unión de dos IDPs, HIF-1¿ y CITED2, a uno de los ocho dominios de la proteína de unión a CREB (CREB binding protein o CBP). Este dominio llamado TAZ1regula la activación del mecanismo de hipoxia en el organismo cuando la cantidad de oxígeno tisular es demasiado baja. En condiciones normales HIF-1 se hidroxila con la presencia de oxígeno y es degradado por el proteasoma, sin embargo cuando no hay oxígeno esta proteína no se puede hidroxilar,acumulándose y uniéndose a TAZ1. Esto provoca la activación de un gran número de genes relacionados con la supervivencia celular. Algunos de estos genes son utilizados por las células tumorales para sobrevivir, ya que al estar alejadas del torrente sanguíneo también tienen problemas similares a las células en condiciones hipóxicas. Por esta razón es que el bloqueo de la interacción de estas dos proteínas seria muy beneficioso.

232 p., Actualmente la producción de agua potable mediante la desalinización por membranas es un proceso eficiente pero que sufre una fuerte limitación: el ensuciamiento o ¿fouling¿ de membranas. La industria no puede detectar este problema con la suficiente anticipación como para poder planificar los procesos de limpieza de las membranas de forma anticipada y minimizar así los daños intrínsecamente asociados, como los residuos generados y el elevado coste energético. Las técnicas convencionales de detección y monitorización del fouling no tienen la sensibilidad suficiente como para poder dar una respuesta que permita tomar acciones y optimizar así el proceso de producción de agua. Es por ello, que el objetivo de este trabajo es investigar si las limitaciones de los métodos convencionales se pueden superar por combinar dos técnicas sensibles a fenómenos de superficie: la microbalanza de cristal de cuarzo con monitorización de la disipación (QCM-D) y la resonancia de plasmones superficiales multi-paramétrica (MP-SPR). Se pudo demostrar con éxito que la combinación QCM-D/MP-SPR permite caracterizar la acumulación de incluso las primeras capas de fouling a nivel nanométrico y por lo tanto, posee una sensibilidad lo suficientemente grande como para anticipar la necesidad de limpiar las membranas antes de que el flujo de agua del permeado disminuya. Estos métodos además permitieron testar diferentes estrategias de limpieza de membranas de forma eficiente tanto en términos de tiempo como de material. Finalmente, la tesis discute críticamente la aplicabilidad de un dispositivo basado en estas técnicas en un entorno industrial relevante.

152 p., Water, the most abundant molecule in our planet, is truly and empirically accepted as an essential component to sustain life on Earth. The extraordinary properties of this unique and universal "matrix of life" have served over this quarter century, as the driving force -for theoreticians and experimentalists- to perform novel research on the structural basis and molecular dynamics taking place in very different environments. Even today, scientists are still discovering new phenomena in water, especially at the nanoscale.When referred to bio-systems, water is usually seen as the liquid environment -or "matrix"- where physical and chemical processes take place. Here, the molecules of life are thought of being wet - this is, completely immersed in liquid water or, in other words, in fully hydrated conditions. While this is true for most living cells, a surprising number of processes require merely traces of water, which could be vapor or a layer as thin as nanometers. Indeed, this is observed in situations in which, because of extremes of either heat or cold, liquid water is scarce. Here, the hydration layer of the molecules - understood as an entity that differs from bulk water - should confer certain stability to keep the biomolecules still functional; and the processes taking place at the air interface should play a prominent role.In this direction, the transmission of many airborne viruses - through respiratory droplets (e.g. aerosols) - requires, actually, survival in dry conditions. Influenza A virus (IAV), is one of the best-known cases, for which the transmission and thus survival is tightly connected to seasonal factors. Seasonal epidemics generally occur during winter, when air temperature and humidity are low. Under these conditions, the respiratory droplets must confer some structural stability to the contained viruses; membrane collapse, for example, should be in principle avoided. However, this assumption is yet poorly understood and experimental data bas

Functional inks for light-based 3D printing are actively being searched for being able to exploit all the potentialities of additive manufacturing. Herein, a fast visible-light photopolymerization process is showed of conductive PEDOT:PSS hydrogels. For this purpose, a new Type II photoinitiator system (PIS) based on riboflavin (Rf), triethanolamine (TEA), and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is investigated for the visible light photopolymerization of acrylic monomers. PEDOT:PSS has a dual role by accelerating the photoinitiation process and providing conductivity to the obtained hydrogels. Using this PIS, full monomer conversion is achieved in less than 2 min using visible light. First, the PIS mechanism is studied, proposing that electron transfer between the triplet excited state of the dye (3Rf*) and the amine (TEA) is catalyzed by PEDOT:PSS. Second, a series of poly(2-hydroxyethyl acrylate)/PEDOT:PSS hydrogels with different compositions are obtained by photopolymerization. The presence of PEDOT:PSS negatively influences the swelling properties of hydrogels, but significantly increases its mechanical modulus and electrical properties. The new PIS is also tested for 3D printing in a commercially available Digital Light Processing (DLP) 3D printer (405 nm wavelength), obtaining high resolution and 500 µm hole size conductive scaffolds.

Waterborne polyurethane dispersions (WPUs) are environmentally friendly coatings since they present low amount of volatile organic compound amounts (VOCs). In the majority of the WPUs the dispersions are balanced with anionic groups and accordingly their stability at low pH is limited. In order to this drawback to be solved, in this work a tertiary amine containing chain extender (triethanolamine, TEOA) was introduced together with a conventional internal emulsifier (carboxylic acid) in acrylic end-capped polyurethane dispersions giving rise to amphoteric UV curable WPUs. After adding a radical photo-initiator and film formation, the coatings were cured under UV irradiation. The properties of amphoteric and anionic dispersions were compared. The best properties were obtained for the samples containing a 1/1 amine/acid molar ratio. Thus, while the anionic dispersions coagulated at low pH values, the 1/1 amphoteric dispersion showed high stability to pH changes. After curing this sample with UV irradiation, the gel content of the film was higher and the water vapour transmission rate was lower than that of the anionic polyurethane because of the strong acid/base interaction. The results showed that the amphoteric WPUs are promising for various applications, offering stability over a wider pH range than traditional formulations.

We reveal the feasibility of the localized surface plasmon resonance in a system of Bi nanoparticles embedded into an AlxGa1−xAs semiconductor matrix. With an ab initio determined dielectric function for bismuth and well-known dielectric properties of AlxGa1−xAs solid solution, we performed calculations of the optical extinction spectra for such metamaterial using Mie’s theory. The calculations demonstrate a strong band of the optical extinction using the localized surface plasmons near a photon energy of 2.5 eV. For the semiconducting matrices with a high aluminum content x > 0.7, the extinction by plasmonic nanoparticles plays the dominant role in the optical properties of the medium near the resonance photon energy

New material solutions are searched for the manufacturing and safety of current batteries. Herein, an extrusion printable polymer separator for lithium batteries based on single-ion polymer electrolytes is presented. The polymer electrolytes are based on methacrylic polymeric nanoparticles (NPs) functionalized with a lithium sulfonamide group combined with different organic plasticizers such as sulfolane and carbonates. The synthesis of the polymer NPs is carried out by emulsion copolymerization of methyl methacrylate and lithium sulfonamide methacrylate in the presence of a crosslinker, resulting in particle sizes of less than 30 nm, as shown by electron microscopy. Then polymer electrolytes are prepared by mixing polymer NPs with varying lithium sulfonamide content and different plasticizers such as carbonates and sulfolane. The polymer electrolytes show ionic conductivities between 2.9 × 10−4 and 2.3 × 10−5 S cm−1 at 85 °C with the highest values for the small-sized NPs with the highest lithium content. As a proof-of-concept application, layer-by-layer printing of a sulfolane-based polymer electrolyte is evaluated via direct ink writing directly onto classic battery electrodes. The electrochemical characterization of the printed solid electrolyte indicates favorable properties, ionic conductivity, lithium transfer number, electrochemical stability window, and cyclability in lithium symmetrical cells, to be used in lithium batteries.

Because the electronic properties of semiconducting polymers are inexorably linked to their solid-state microstructure, it is imperative to understand their complex crystallization processes fully. For example, poly(2,5-bis(3-alkylthiophen-2-yl)-thieno-[3,2-b]thiophene) (PBTTT), which is frequently considered a model system for highly ordered semicrystalline semiconducting polymers, can exhibit two distinct semi-crystalline thin film morphologies: the so-called terrace-phase, which features high charge carrier mobility (>1 cm2 V−1 s−1), and the ribbon-phase with much poorer properties. The achievement of one or the other depends on the temperature at which the polymer is thermally annealed. Our results evidence that PBTTT is in the liquid state at those “annealing temperatures” and, therefore, the achievement of the terrace- or ribbon phases depends, in fact, on the distinct structural configuration of liquid PBTTT chains at each temperature (before crystallization). Motivated by this observation, we investigate the complex crystallization kinetics of spun cast PBTTT thin films crystallized from those liquid states. We achieve this using a methodology that combines fast scanning calorimetry, X-ray scattering, and optical microscopy. We demonstrate that a preexisting smectic order enhances crystal nucleation rate, speeding up the crystallization kinetics at the early stages of phase transformation. More interestingly, our analysis reveals a complex crystallization kinetics in PBTTT, which differs from the typical crystallization behavior of commodity polymers. These results evidence that the crystallization of semiconducting polymers occurs quite differently to that of most commodity polymers, highlighting (once again) the necessity to conduct more fundamental investigations on the structure development of this important class of polymers.

Thermally activated delayed fluorescence (TADF) has emerged as one of the most promising strategies in the quest for organic light emitting diodes with optimal performance. This computational study dissects the mechanistic intricacies of the central photophysical step, reverse intersystem crossing (rISC) in N and B doped triangulenes as potential multi-resonance TADF compounds. Optimal molecular patterns conducive to efficient rISC, encompassing dopant atom size, number, and distribution, are identified. Additionally, we assess various electronic structure methods for characterizing TADF-relevant molecular systems. The findings identify the distinct role of the direct and mediated mechanisms in rISC, and provide insights into the design of advanced TADF chromophores for next-generation OLED technology.

An approach was proposed to control the displacement of domain walls in magnetic microwires, which are employed in magnetic sensors. The velocity of the domain wall can be altered by the interaction of two magnetic microwires of distinct types. Thorough investigations were conducted utilizing fluxmetric, Sixtus–Tonks, and magneto-optical techniques. The magneto-optical examinations revealed transformation in the surface structure of the domain wall and facilitated the determination of the mechanism of external influence on the movement of domain walls in magnetic microwires.

Solid polymer electrolytes that combine both a high lithium-ion transference number and mechanical properties at high temperatures are searched for improving the performance of batteries. Here, we show a salt-free all-polymer nanocomposite solid electrolyte for lithium metal batteries that improves the mechanical properties and shows a high lithium-ion transference number. For this purpose, lithium sulfonamide-functionalized poly(methyl methacrylate) nanoparticles (LiNPs) of very small size (20–30 nm) were mixed with poly(ethylene oxide) (PEO). The morphology of all-polymer nanocomposites was first investigated by transmission electron microscopy (TEM), showing a good distribution of nanoparticles (NPs) even at high contents (50 LiNP wt %). The crystallinity of PEO was investigated in detail and decreased with the increasing concentration of LiNPs. The highest ionic conductivity value for the PEO 50 wt % LiNP nanocomposite at 80 °C is 1.1 × 10–5 S cm–1, showing a lithium-ion transference number of 0.68. Using dynamic mechanic thermal analysis (DMTA), it was shown that LiNPs strengthen PEO, and a modulus of ≈108 Pa was obtained at 80 °C for the polymer nanocomposite. The nanocomposite solid electrolyte was stable with respect to lithium in a Li||Li symmetrical cell for 1000 h. In addition, in a full solid-state battery using LiFePO4 as the cathode and lithium metal as the anode, a specific capacity of 150 mAhg–1 with a current density of 0.05 mA cm–2 was achieved.

Magnetic microwires with amorphous structures can present a unique combination of excellent magnetic softness and giant magnetoimpedance (GMI) effects together with reduced dimensions and good mechanical properties. Such unique properties make them suitable for various technological applications. The high GMI effect, observed in as-prepared Co-rich microwires, can be further optimized by postprocessing. However, unexpected magnetic hardening and a transformation of the linear hysteresis loop into a rectangular loop with a coercivity on the order of 90 A/m were observed in several Co-rich microwires upon conventional annealing. Several routes to improve magnetic softness and GMI effect in Fe- and Co-rich magnetic microwires are provided. We observed that stress annealing could remarkably improve the magnetic softness and GMI ratio of Co-rich microwires. Thus, almost unhysteretic loops with a coercivity of 2 A/m and a magnetic anisotropy field of about 70 A/m are achieved in Co-rich microwires stress annealed at appropriate conditions. The observed change in hysteresis loops and the GMI effect is explained by stress-annealing-induced anisotropy, which is affected by the stresses applied during annealing and by the annealing temperature. While as-prepared Fe-rich amorphous microwires present a low GMI effect, appropriate postprocessing (annealing and stress annealing) allows for a remarkable GMI ratio improvement (an order of magnitude). The evaluated dependence of the maximum GMI ratio on frequency allows the identification of the optimal frequency band for the studied samples. The origin of stress-annealing-induced anisotropy and related changes in hysteresis loops and the GMI effect are discussed in terms of the relaxation of internal stresses, “back-stresses”, as well as structural anisotropy.

Transitioning to more ambitious electrode formulations facilitates developing high-energy density cells, potentially fulfilling the demands of electric car manufacturers. In this context, the partial replacement of the prevailing anode active material in lithium-ion cells, graphite, with silicon-based materials enhances its capacity. Nevertheless, this requires adapting the rest of the components and harmonizing the electrode integration in the cell to enhance the performance of the resulting high-capacity anodes. Herein, starting from a replacement in the standard graphite anode recipe with 22% silicon suboxide at laboratory scale, the weight fraction of the electrochemically inactive materials was optimized to 2% carbon black/1% dispersant/3% binder combination before deriving an advantage from including single-wall carbon nanotubes in the formulation. In the second part, the recipe was upscaled to a semi-industrial electrode coating and cell assembly line. Then, 1 Ah lithium-ion pouch cells were filled and tested with different commercial electrolytes, aiming at studying the dependency of the Si-based electrodes on the additives included in the composition. Among all the electrolytes employed, the EL2 excelled in terms of capacity retention, obtaining a 48% increase in the number of cycles compared to the baseline electrolyte formulation above the threshold capacity retention value (80% state of health).

425 p., Las tecnologías de fabricación han sido transformadas por los avances en la fabricación aditiva. Esta técnica revolucionaria minimiza el desperdicio, permite la producción de estructuras complejas y producción a medida. Esto mejora la eficiencia de recursos, reduce el inventario excesivo y promueve la sostenibilidad. Sin embargo, la fabricación aditiva basada en luz se enfrenta un desafío importante debido a la baja degradabilidad y reciclabilidad de los materiales utilizados en la fotopolimerización.Abordar este problema implica diversificar los materiales y formulaciones fotopolimerizables, el cual a sido el enfoque central de este estudio. En este sentido, se han introducido estrategias no radicalarias para la preparación de materiales poliméricos por medio de irradiación de luz con degradabilidad y reciclabilidad mejorada. Por ello, este trabajo incluye el estudio de varios de estos sistemas y su implementación en fotoimpresión en tanque exponiendo los limites y virtudes de los sistemas reportados.

Metalloenzymes are able to catalyze complex biochemical reactions in cellular (aqueous) media with high efficiency. In recent years, a variety of metal-containing single-chain nanoparticles (SCNPs) have been synthesized as simplified metalloenzyme-mimetic nano-objects. However, most of the metal-containing SCNPs reported so far contained complexed metal ions but not metal nanoclusters (NCs) with diameter <5 nm, which could be used as powerful, emerging catalysts. Herein, we report the synthesis of gold nanoclusters (Au-NCs) within SCNPs and the further use of Au-NCs/SCNPs as catalytic nanoreactors in water. We demonstrate that a common motif contained in several drugs (i.e., the aminophenyl–oxazolidinone fragment present in Rivaroxaban, Sutezolid, and Linezolid) can be efficiently prepared in water from a hydrophobic precursor compound by using the Au-NCs/SCNPs as efficient catalytic nanoreactors. In summary, this work paves the way forthe synthesis of metal–NCs/SCNPs for advanced catalysis in aqueous media.

Topologically non-trivial magnetization configurations in ferromagnetic materials on the nanoscale, such as hopfions, skyrmions, and vortices, have attracted considerable attention of researchers during the last few years. In this article, by applying the theory of micromagnetism, I demonstrate that the toroidal hopfion magnetization configuration is a metastable state of a thick cylindrical ferromagnetic nanodot or a nanowire of a finite radius. The existence of this state is a result of the competition among exchange, magnetostatic, and magnetic anisotropy energies. The Dzyaloshinskii–Moriya exchange interaction and surface magnetic anisotropy are of second importance for the hopfion stabilization. The toroidal hopfion metastable magnetization configuration may be reached in the process of remagnetizing the sample by applying an external magnetic field along the cylindrical axis.

257 p., The chemistry of the lithium salt employed plays a pivotal role in dictating the physico-chemical and electrochemical performance of any solid polymer electrolytes (SPEs), and thus also influences the performance of solid-state lithium metal batteries (SSLMBs). The lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt, first suggested as salt for SPEs in 1986, possesses low lattice energy and the TFSI' anion has a large structural flexibility, both due to the anion¿s highly delocalized negative charge and flexible center [e.g., ¿SO2¿N(¿)¿SO2¿] and has therefore been commonly used for SPE-based SSLMBs. However, low lithium-ion transference number (TLi+) and poor solid electrolyte interphase (SEI) creating properties, resulting in severe cell polarization and simultaneously notorious dendritic growth on the Li° anode. Therefore, in this thesis, several novel lithium salts were designed and synthesized to suppress anionic mobility and enhance TLi+, but without sacrificing significantly the ionic conductivity, and simultaneously with the aim of forming excellent SEI layers on the Li° anode to improve interfacial compatibility and stability towards Li° anode.

Capítuldo 5 confidencial pendiente de patente. Tesis completa 159 p. Tesis censurada 143, [ES]Las superficies expuestas al ambiente presentan una gran tendencia a atraer suciedad. Teniendo en cuenta que son éstas las que definen la mayor parte de las propiedades de los materiales, tanto la presencia como la acumulación de suciedad suponen un impacto negativo en numerosas aplicaciones ya que pueden generar importantes riesgos para la seguridad y la salud, así como, afectar negativamente al rendimiento, requiriendo costosas operaciones de mantenimiento. En los últimos años, la industria ha mostrado un gran interés en el desarrollo de soluciones capaces de preservar limpias las superficies. Tradicionalmente, las superficies repelentes se han obtenido mediante el efecto de la superhidrofobicidad. Sin embargo, su ineficacia para repeler líquidos de baja energía superficial y la fragilidad de ciertas micro/nanoestructuras necesarias pueden limitar su aplicación. En este contexto, el desarrollo de recubrimientos omnifóbicos de baja adhesión puede aportar numerosos beneficios en distintas aplicaciones de sectores muy diversos. Esta tesis persigue desarrollar nuevas estrategias para la obtención de superficies repelentes, focalizando el trabajo en alcanzar soluciones robustas con buenas prestaciones de durabilidad que sean capaces de responder a varias fuentes de contaminación simultáneamente. Para ello, el potencial que ofrece la nanotecnología se utiliza desde dos aproximaciones diferentes: a través de la estructuración superficial ymediante la incorporación de nanoobjetos como vectores para introducir nuevas funcionalidades, siendo el objetivo final desarrollar superficies omnifóbicas con propiedades diseñadas a medida que den respuesta a las necesidades de la industria.

150 p., Esta tesis se focaliza en el estudio del transporte eléctrico y térmico debido a electrones en el estado estacionario mediante la Teoría Funcional de la Densidad (DFT) desde un punto de vista teórico. Por un lado el estudio se centra en el desarrollo de un marco teórico (iq-DFT) el cual permite describir correctamente no solo la densidad, si no también la corriente eléctrica y la corriente de calor. Además, diferentes cantidades físicas como los coeficientes de transporte o la función espectral fuera del equilibrio se derivan de manera teórica en el formalismo propuesto. Por otro lado, esta tesis focaliza el estudio en sistemas fuertemente correlacionados. Generalmente, se ha considerado que estos sistemas no pueden ser correctamente descritos mediante DFT. En la presente tesis se estudian y construyen funcionales de intercambio y correlación de sistemas modelos Hamiltonianos que permiten describir correctamente el régimen de fuerte correlación.

Los capítulos: resumen, capítulo 4 y conclusiones están sujetos a confidencialidad por la autora. 277 p.

369 p., Desde hace millones de años los ácidos nucleicos son esenciales en todas las formas de vida conocidas, y desde hace unas décadas, su utilidad se amplía también a contextos no biológicos. La capacidad del ADN y del ARN para formar interacciones específicas entre sus bases o incluso otras moléculas ha posibilitado su integración en diversas aplicaciones y la creación de un área de investigación propia: la nanotecnología de ADN y ARN.Mediante diversos estudios fundamentales, en esta tesis se lleva el ADN sintético o de esperma de salmón a contextos no convencionales. De esta forma, se pretenden identificar mejor los factores que determinan su estructura, estabilidad y capacidad de reconocimiento. Además de crear nuevos entornos, se estudian también estructuras no convencionales de ADN, como pueden ser las nanoestructuras programables o los complejos entre ADN y ligando que se utilizan en reacciones catalíticas.

188 p., Single-layer (SL) transition metal dichalcogenide (TMD) materials possess a variety of collective electronic phases such as superconductivity (SC), charge density wave (CDW) order, and magnetic correlations, which exhibit fascinating properties in the confined space of two dimensions. In these layered materials electron-electron interactions are enhanced, which can trigger novel physical phenomena. In particular, the most fundamental properties and intrinsic parameters such as the critical temperatures (Tc) of these phases are strongly modified in most cases when reducing the dimension. Furthermore, the interplay of the electronic phases becomes crucial. Important questions on the pairing symmetry in 2D-TMD superconductors and the stability of these phases to external perturbations such as magnetic fields and doping atoms remain elusive.This thesis presents an atomic-scale study of the collective electronic states present in selected novel TMD materials in the ultimate single-layer limit. Molecular beam epitaxy is deployed to grow highly crystalline single-layer materials and more complex TMD heterostructures. By means of low temperature scanning tunneling microscopy and spectroscopy (STM/STS) under ultra-high vacuum conditions and high magnetic fields, we are able to study the electronic structure in depth and, therefore, the phase diagrams of these 2D materials. This thesis also benefits from other experimental techniques (AFM, ARPES, XMCD, XPS, SQUID, RHEED, LEED) and calculations that providecomplementary information to better understand the phenomenology of the physical systems under study.In the first part, we examine the quasi-particle density of states of a monolayer of NbSe2 to demonstrate the emergence of Leggett collective modes in the superconducting state, arising from the competition between the s-wave singlet ground state and a sub leading f-wave triplet component. Then, we study the impact of proximity effects on the electronic structure and collecti

256 p., Esta tesis explora los límites de la técnica de SMFS (Single-molecule force spectroscopy) AFM (atomicforce microscopy), estudiando la estabilidad mecánica de proteínas en todo su espectro, desde las lábiles proteínas de plegamiento rápido hasta las más resistentes, implicadas en procesos de infección microbianos. Utilizando este conocimiento, hemos diseñado un protocolo pionero basado en métodos de molecular docking y hight-throughput screening, utilizados habitualmente en la industria farmacéutica,para identificar moléculas con potencial mecano regulador. Estas moléculas nos permiten modular la estabilidad y el mecanismo de plegamiento de proteínas. En esta tesis también hemos iniciado el desarrollo de una técnica que combina MT (magnetic tweezers) y bioquímica de proteínas para estudiarlas etapas iniciales de la infección bacteriana. En esta tesis, se han examinado cuatro proteínas, desde la lábil EnHD, pasando por CD4 hasta las más mecánicamente resistentes como Caf1 o FnBPA. Estas proteínas están relacionadas con procesos de infección que originan enfermedades como SIDA, peste yendocarditis. El presente trabajo conecta la nanomecánica de proteínas con importantes preguntas biológicas, como los procesos de infección microbianos y alteraciones en la estabilidad de las proteínas.

Co-electrolysis of carbon oxides and nitrogen oxides promise to simultaneously help restore the balance of the C and N cycles while producing valuable chemicals such as urea. However, co-electrolysis processes are still largely inefficient and numerous knowledge voids persist. Here, we provide a solid thermodynamic basis for modelling urea production via co-electrolysis. First, we determine the energetics of aqueous urea produced under electrochemical conditions based on experimental data, which enables an accurate assessment of equilibrium potentials and overpotentials. Next, we use density functional theory (DFT) calculations to model various co-electrolysis reactions producing urea. The calculated reaction free energies deviate significantly from experimental values for well-known GGA, meta-GGA and hybrid functionals. These deviations stem from errors in the DFT-calculated energies of molecular reactants and products. In particular, the error for urea is approximately -0.25 ± 0.10 eV. Finally, we show that all these errors introduce large inconsistencies in the calculated free-energy diagrams of urea production via co-electrolysis, such that gas-phase corrections are strongly advised.

Epoxy/polycaprolactone (PCL) blends containing cationic photo-initiator were prepared by both solution and melt blending. These materials were processed by solvent casting, solution electrospinning (SE), melt electrowriting (MEW), and Fused Deposition Modeling (FDM) 3D printing. The final materials were obtained after UV curing at room temperature. FTIR, and gel content measurements showed that all the materials were crosslinked and that the PCL was part of the network. The shape memory abilities (measured by DMA experiments) depended on the processing technique. Thus, the fixity and recovery ratios were optimal for electrospun fibers, while the 3D printed sample was not able to recover any shape, probably because of the poor adhesion between the printed layers. According to AFM images, samples obtained by MEW and 3D printing produced materials with spherulitic morphology, while solution electrospinning rendered fibers with Shish-Kebab-type crystalline morphology. The latter was highly anisotropic, and many chains were oriented along the nanofiber axis interdispersed with amorphous regions where the epoxy resin formed covalent links with the PCL chains. This morphology conferred extraordinary solvent resistance and shape memory properties to the electrospun mats. The latter manifested a very high affinity towards chloroform, and accordingly, they displayed potential applications as chloroform sensors.

180 p., Esta tesis recoge los resultados obtenidos durante los primeros pasos en el desarrollo de un quemo-sensor de bario dicatión para el experimento NEXT. Su funcionamiento se basa en convertir propiedades químicas del analito en una señal detectable, como una señal eléctrica u óptica. Recientemente se ha explorado el uso de quemo-sensores fluorescentes como herramienta potencialmente única en el campo de la física de neutrinos. El experimento NEXT busca detectar la desintegración doble beta sin neutrinos del isótopo 136Xe. En esta desintegración se producen dos electrones y un dicatión 136Ba2+. Si el ión Ba2+se detectase en coincidencia con los electrones, el experimento NEXT funcionaría sin background. Para identificar el ión Ba2+ se ha propuesto utilizar quemo-sensores fluorescentes. El uso de esta técnica en el campo de física de partículas es completamente novedoso y requiere adaptar estos sensores al entorno extremadamente seco de una cámara de xenon gaseoso a alta presión. La fabricación del sensor requiere inmobilizar las moléculas en una superficie que preserve la sensibilidad de la señal fluorescente. Este enfoque requiere el uso de técnicas de deposición molecular y caracterización en superficies con precisión atómica y el desarrollo de un microscopio de fluorescencia adaptado a estas condiciones.

Electrolyzers can help in restoring the balance to the biogeochemical cycles of carbon and nitrogen while producing valuable chemical compounds. Before that happens on a global scale, various hurdles need to be overcome, some of which are related to the activity and selectivity of the materials used to catalyze electrolysis reactions. For instance, CO and NO are important electrolysis feedstocks and/or reaction intermediates and their hydrogenation is often energetically demanding. Here it is shown how the most favorable hydrogenation product among ∗CHO or ∗COH, and ∗NHO or ∗NOH on late transition metals can be ascertained by classification methods based on adsorption-energy scaling relations and “catalytic matrices”. In particular, late transition metals can be split into weak-binding and strong-binding and there is a noble-nonnoble energy gap between them. Such a simple categorization helps outline the metals and facets that selectively favor the making of O–H, C–H and N–H bonds.

This work compares for the first time the efficacy of using different ionic liquids (ILs) as epoxy hardeners in epoxy-based adhesives. Several phosphonium and imidazolium-based ionic liquids were tested as epoxy hardeners, and the thermal and mechanical properties and the lap shear strength of the cured epoxy resins were studied at different IL concentrations. Both the chemical structure and the concentration of ILs were found to impact the final properties of the epoxy resin, but among the ten different ILs studied, three of them cured the epoxy resin effectively and produced similar and even better mechanical properties and lap shear strength than those obtained with traditional amine-based curing agents. These results constitute an important step towards sustainability thanks to the non-volatility of ILs and the significantly lower amount needed for effectively curing epoxy resins.

269 p., En este trabajo se han estudiado varios sistemas basados en poliésteres con el objetivo de ampliar su conocimiento y difundir su uso. La familia de poliésteres más investigada en esta tesis es la de los polihidroxialcanoatos (PHAs), poliésteres biodegradables de origen bacteriana con excelentes propiedades ópticas y de barrera, ideales para aplicaciones en embalaje y en la industria biomédica pero con dos grandes defectos que limitaban su difusión: alta cristalinidad lo que implica malas propiedades mecánicas y altos puntos de fusión lo que implica una rápida degradación de los productos. Por tanto, este trabajo se encuadra en este contexto con el objetivo de estudiar nuevos sistemas sustitutivos de los clásicos; de hecho, diferentes sistemas basados en PHB se estudian con varias técnicas

We studied Ni2FeSi-, Co2FeSi-, and Co2MnSi-based full-Heusler alloy glass-coated microwires with the same geometric parameters, i.e., fixed nucleus and total diameters, prepared using the Taylor–Ulitovsky method. The fabrication of X2YZ (X = Co and Ni, Y = Fe and Mn, and Z = Si)-based glass-coated microwires with fixed geometric parameters is quite challenging due to the different sample preparation conditions. The XRD analysis showed a nanocrystalline microstructure for all the samples. The space groups Fm3¯m (FCC) and Im3¯m (BCC) with disordered B2 and A2 types are observed for Ni2FeSi and Co2FeSi, respectively. Meanwhile, a well-defined, ordered L21 type was observed for Co2MnSi GCMWs. The change in the positions of Ni, Co and Mn, Fe in X2YSi resulted in a variation in the lattice cell parameters and average grain size of the sample. The room-temperature magnetic behavior showed a dramatic change depending on the chemical composition, where Ni2FeSi MWs showed the highest coercivity (Hc) compared to Co2FeSi and Co2MnSi MWs. The Hc value of Ni2FeSi MWs was 16 times higher than that of Co2MnSi MWs and 3 times higher than that of Co2FeSi MWs. Meanwhile, the highest reduced remanence was reported for Co2FeSi MWs (Mr = 0.92), being about 0.82 and 0.22 for Ni2FeSi and Co2MnSi MWs, respectively. From the analysis of the temperature dependence of the magnetic properties (Hc and Mr) of X2YZ MWs, we deduced that the Hc showed a stable tendency for Co2MnSi and Co2FeSi MWs. Meanwhile, two flipped points were observed for Ni2FeSi MWs, where the behavior of Hc changed with temperature. For Mr, a monotonic increase on decreasing the temperature was observed for Co2FeSi and Ni2FeSi MWs, and it remained roughly stable for Co2MnSi MWs. The thermomagnetic curves at low magnetic field showed irreversible magnetic behavior for Co2MnSi and Co2FeSi MWs and regular ferromagnetic behavior for Ni2FeSi MWs. The current result illustrates the ability to tailor the structure and magnetic beha

We perform the conversion of a commodity plastic of common use in pipes, window frames, medical devices, flexible hoses, etc. like polyvinyl chloride (PVC) to single-chain nanoparticles (SCNPs). SCNPs are versatile, protein-mimetic soft nano-objects of growing interest for catalysis, sensing, and nanomedicine, among other uses. We demonstrate that the metamorphosis process -as induced through metal-free click chemistry- leads to well-defined, uniform SCNPs that are stable during storage in the solid state for months. All the conversion process (from PVC isolation to PVC-SCNPs synthesis) can be run in a green, dipolar aprotic solvent and involving, when required, a simple mixture of ethanol and water (1/1 vol.) as non-solvent. The resulting PVC-SCNPs are investigated as recyclable, metalloenzyme-mimetic catalysts for several representative Cu(II)-catalyzed organic reactions. The method could be valid for the metamorphosis and valorization of other commodity plastics in which it is feasible to install azide functional groups in their linear polymer chains.

In blends where polyethylene (PE) is the minor component dispersed in an isotactic-polypropylene (PP) matrix, an enhancement of the crystallization rate of PE was found when the crystallization temperature of the matrix phase is increased by means of a self-nucleation protocol. Such an effect is interpreted as the result of the epitaxial nucleation of PE droplet domains at the interface with the PP matrix (Macromolecules, 2021, 54, 19, 9100–9112). This study extends the findings on immiscible blends of a PP matrix and various industrially produced PE grades as the dispersed phase. Eight different PEs with varying molecular architecture, and thus density and melting temperatures, were mixed with PP in a 20/80 PE/PP weight ratio. The possible existence of surface nucleation was probed by applying a self-nucleation thermal protocol to the PP matrix and recording the concomitant variation of PE crystallization temperature (Tc). Different behaviours are observed for various PEs. In particular, those with relatively high density display a clear increase in crystallization temperature, over 3.0 °C, when the Tc of the matrix is increased (i.e., as PP lamellar thickness increased), indicating an efficient surface nucleation mechanism. Metallocene-made LLDPE also shows a small increase, about 1.7 °C, while PEs with lower densities, below 927 kg/m3, metallocene PEs or LDPE display no meaningful change in Tc with matrix self-nucleation. It was demonstrated that a threshold value of chain regularity is required to trigger the surface nucleation of PE on PP. Only polymers with a density above approximately 920 kg/m3 and melting temperatures exceeding about 115 °C can efficiently nucleate onto the PP substrate. It is postulated that the presence of a high amount of branches or comonomers along the PE chains hinders the epitaxial matching between PE and PP.

197 p., Nanofabrication encompasses processes and techniques used to create structures with features smaller than 100 nm, enabling precise design and manipulation of materials at the atomic and molecular level. Nanoscience and nanofabrication have made significant contributions to various industries, including electronics, materials science, and catalysis. A notable achievement in nanoscience has been the discovery and study of two-dimensional (2D) materials, which possess unique properties due to their weak atomic bonds and high surface-to-volume ratio. These materials offer flexibility, mechanical strength, high conductivity, and tunable optical properties. They have become essential tools for investigating optical phenomena at the atomic scale.This thesis focuses on optimizing sample preparation through controlled parameter modifications and subsequent characterization using techniques available at CIC nanoGUNE. The research combines fabrication techniques with 2D materials, primarily in the field of nanooptics, which explores the interaction between light and matter at the nanoscale. Techniques like mechanical exfoliation, atomic force microscopy, Raman spectroscopy, and various transfer methods are employed to obtain and manipulate thin layers of materials, including heterostructures. Sample fabrication involves lithographic techniques such as direct laser writing lithography and electronbeam lithography, allowing versatile and adaptable designs without the need for physical masks. Material deposition techniques like evaporation and sputtering, as well as material removal techniques like reactive ion etching and ion bombardment, are employed in the fabrication process.The potential of these techniques is demonstrated through the fabrication of samples on different substrates and exfoliated flakes, enabling detailed studies and collaborations. Challenges encountered in the fabrication process, such as the proximity effect in electron beam lithography and charge accumula

Hybrid nanocomposites (NCs) based on a bio-based thermoplastic polyurethane (TPU) with multi-walled carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) as nanofillers, were obtained using a simple melt-mixing method. The effects of a) the GNP:CNT ratio, b) the total nanofiller content, and c) the aspect ratio of the CNTs on both the nanostructure and the thermal, electrical, mechanical, and adhesive properties of the NCs were studied in depth. Synergies were observed in the mechanical and electrical properties of the hybrid NCs when compared to the corresponding binary TPU/GNP and TPU/CNT NCs, regardless of either the GNP:CNT ratio or the aspect ratio of the CNTs. This was attributed to the enhanced dispersion of the GNPs in the presence of CNTs, caused by the intercalation of the two-dimensional graphene nanoplatelets among the one-dimensional carbon nanotubes. Consequently, the resulting conductive network was more efficient, and the reinforcing efficiency of the single nanofillers was improved. The findings of our study show that electrically conductive NCs with improved mechanical properties were achieved when part of the CNTs in the formulation was replaced by cheaper GNPs. Furthermore, a synergy was also observed in the adhesive properties of the hybrid NCs through their significantly higher lap shear strength than that of the pure TPU or binary reference NCs. In other words, by replacing part of the CNTs with GNPs, we were able to obtain hybrid TPU NCs which were cheaper, more effective, and higher performing than binary TPU/CNT and TPU/GNP NCs, pointing to their potential use as electrically conductive hot-melt adhesives.

The unconventional bioorthogonal catalytic activation of anticancer metal complexes by flavin and flavoproteins photocatalysis has been reported recently. The reactivity is based on a two-electron redox reaction of the photoactivated flavin. Furthermore, when it comes to flavoproteins, we recently reported that site mutagenesis can modulate and improve this catalytic activity in the mini Singlet Oxygen Generator protein (SOG). In this paper, we analyze the reductive half-reaction in different miniSOG environments by means of density functional theory. We report that the redox properties of flavin and the resulting reactivity of miniSOG is modulated by specific mutations, which is in line with the experimental results in the literature. This modulation can be attributed to the fundamental physicochemical properties of the system, specifically (i) the competition of single and double reduction of the flavin and (ii) the probability of electron transfer from the protein to the flavin. These factors are ultimately linked to the stability of flavin‘s electron-accepting orbitals in different coordination modes.

The degradation of Pt-containing oxygen reduction catalysts for fuel cell applications is strongly linked to the electrochemical surface oxidation and reduction of Pt. Here, we study the surface restructuring and Pt dissolution mechanisms during oxidation/reduction for the case of Pt(100) in 0.1 M HClO4 by combining operando high-energy surface X-ray diffraction, online mass spectrometry, and density functional theory. Our atomic-scale structural studies reveal that anodic dissolution, detected during oxidation, and cathodic dissolution, observed during the subsequent reduction, are linked to two different oxide phases. Anodic dissolution occurs predominantly during nucleation and growth of the first, stripe-like oxide. Cathodic dissolution is linked to a second, amorphous Pt oxide phase that resembles bulk PtO2 and starts to grow when the coverage of the stripe-like oxide saturates. In addition, we find the amount of surface restructuring after an oxidation/reduction cycle to be potential-independent after the stripe-like oxide has reached its saturation coverage.

217 p., Metal species have a great impact on the biochemistry of living systems. It has been reported that polyoxomolybdates exhibit anti-tumor activity similar to that of commercial drugs. However, the mechanism by which these species are effective against cancer has been an elusive topic. It is believed that their activity is related to their interaction with phosphoester' containing biomolecules.Experimental studies have demonstrated that molybdenum species can cause cleavage in different model phosphoester molecules.However, the complex chemistry of molybdates has made these experimental studies difficult to interpret. We used computational methodologies to shed light on the phosphoesterase activity of molybdenum species in different reaction models. The study employed density functional theory to explore the mechanistic details of hydrolysis reactions of phosphate monoesters and diestersin the presence of different molybdenum species.The study results on the speciation of MoO2Cl2(DMF)2 supported the experimental findings that reported DMF release and Mo¿Clbond breakage. Two different NPP hydrolysis pathways were proposed depending on the complex concentration. Lower concentrations disfavoured the formation of polynuclear species, and the hydrolysis proceeded through less favourable mononuclear intermediates. With enough complex concentration, a nucleation process was favoured over the phosphate interaction. After theformation of dinuclear species, the incorporation of NPP and its consequent hydrolysis showed lower energetic barriers than theuncatalysed reaction. We also examined heptamolybdate as it was reported to hydrolyse NPP while its nuclearity decreased.Pentanuclear active species proposed by experimentals showed a higher activation barrier for its hydrolysis and cannot beconsidered as a catalyst. The study proposed a dinuclear compound resulting from heptamolybdate fragmentation as the catalytic species, which decreased the energetic barrier compared to the non¿

As-prepared Fe-rich microwires with perfectly rectangular hysteresis loops present magnetization reversal through fast domain wall propagation, while the giant magnetoimpedance (GMI) effect in Fe-rich microwires is rather low. However, the lower cost of Fe-rich microwires makes them attractive for magnetic sensors applications. We studied the effect of conventional (furnace) annealing and Joule heating on magnetic-propertied domain wall (DW) dynamics and the GMI effect in two Fe microwires with different geometries. We observed that magnetic softness, GMI effect and domain wall (DW) dynamics can be substantially improved by appropriate annealing. Observed experimental results are discussed considering the counterbalance between the internal stresses relaxation and induced magnetic anisotropy associated with the presence of an Oersted magnetic field during Joule heating.

In this article, we study the effect of annealing temperature and applied stress on the magnetic properties of Fe71.80B13.27Si11.02Nb2.99Ni0.92 and Co65.34Si12.00B10.20Cr8.48Fe3.90Mo0.08 microwires. An anomalous behavior of the coercive field is observed while applying stress, indicating nontrivial changes in the microwire magnetic anisotropy. The effect of applied stimuli on the magnetic anisotropy and magnetostriction constant in both microwires is also discussed.

127 p., En esta Tesis, estudiamos a escala nanométrica materiales con aplicabilidad en tecnologías cuánticas, centrándonos, principalmente, en sensores de radiación electromagnética basados en el efecto termoeléctrico gigante. Este efecto tiene lugar en heteroestructuras basadas en superconductores que se encuentran en contacto con un aislante ferromagnético, el cual crea un desequilibrio de espín en su densidad de estados, conocido como spin-splitting. Este efecto depende de muchos factores, entre los que se encuentran la calidad de la interfaz superconductor/aislante ferromagnético y las propiedades de todos los materiales que conforman la heteroestructura.Mediante una combinación de técnicas de caracterización en ultra alto vacío y ex-situ, hemos demostrado cómo las condiciones de preparación afectan a las propiedades estructurales, químicas y magnéticas de los materiales, pudiendo controlar y modificar esas propiedades de acuerdo a las necesidades del dispositivo en que se quieran incorporar. Además, hemos fabricado uniones de tipo túnel, estudiando también las condiciones de fabricación que tienen impacto en el transporte a través de dichas uniones.

147 p., In this thesis I studied the interaction of atomic and molecular magnetic impurities with superconductors. I deposited single Mn atoms on the surface of beta-Bi2Pd superconductor and manipulate them on the surface. The classical spin approximation green function approach allow me to describes the Yu-Shiba-Rusinov (YSR) states when the atoms are coupled on the surface in different structures. YSR states also arise close to iron porphyrin magnetic molecules with in-plane magnetic anisotropy due to the ligands that surround Fe. Here I switch to a full quantum spin model approach and describe the rich excitation spectrum. This comprehend a novel Cooper pair-excitation, possible when the magnetic impurity is strongly coupled with the superconductor. This study is done in proximitized Gold on vanadium, where I also characterize the proximity effect. I also studied a different proximity system where we couple Pb islands to graphene. The superconductivity is induced in graphene and the island manipulation allows the tuning and study of how proximity effect changes modifying confinement and island size.

154 p., En esta tesis, hemos investigado diferentes tipos de enlaces dinámicos como FLP-linker y las interacciones metal-ligando con propiedades mecánicas favorables para su incorporación en materiales poliméricos. Además de esto, se han estudiado las propiedades fotofísicas de los complejos metal-ligando para obtener materiales con propiedades complementarias además de las autoreparadoras. De esta manera, hemos podido entender algunos factores clave para diseñar materiales autoreparadores más eficientes que también podrían tener interesantes propiedades ópticas. Comprender la estructura electrónica e interacciones de estos enlaces es crucial para el desarrollo de nuevos enlaces dinámicos.Concretamente, la investigación involucra una caracterización detallada de las interacciones dinámicas delos linkers en cadenas poliméricas. Para estudiar estos sistemas y revelar los mecanismos de interacción subyacentes, hemos utilizado métodos computacionales como la teoría de la función de densidad (DFT). Además, hemos investigado las características fotofísicas de los materiales autoreparadores seleccionados basados en metal-ligando mediante la teoría de la función de densidad dependiente del tiempo (TDDFT),caracterizando de esta manera sus propiedades de absorción y emisión.

187 p., El fenómeno de las transiciones de fase termodinámicas (TPT, por sus siglas en inglés) en la materia, asociadas con un cambio abrupto en cierta cantidad física, son de una importancia fundamental, tanto en su comprensión teórica como en aplicaciones tecnológicas. Algunos ejemplos significativos de aplicaciones de las TPT incluyen la transición de fase en materiales superconductores, usados, por ejemplo, en la reducción del consumo energético en equipos de resonancia magnética, o los materiales de cambio de fase, empleados en la refrigeración de ordenadores o en almacenamiento térmico de energía.Los materiales ferromagnéticos (FM) son también un tipo de sistemas en los que pueden observarse TPTs. En estos materiales, un tipo de TPT está determinado por una temperatura especifica, llamada temperatura de Curie TC, por debajo de la cual el sistema exhibe una fase FM ordenada. A temperaturas inferiores a TC, el material presenta dos estados equivalentes en ausencia de campo magnético externo, también separados por otro tipo de TPT. Dichas TPT en materiales FM y sus estados magnéticos asociados son relevantes en aplicaciones tecnológicas ampliamente extendidas, como la refrigeración o las memorias magnéticas.En general, las tecnologías basadas en películas delgadas FM han considerado históricamente interfases abruptas entre capas principalmente. Dichos cambios abruptos inducen y/o amplifican efectos necesarios, por ejemplo, para la lectura y escritura de sus estados magnéticos. Sin embargo, cambiosgraduales en las propiedades físicas de las películas delgadas pueden mejorar su rendimiento, en determinadas circunstancias.En este contexto, es bien sabido que cambios graduales en la interacción de intercambio en películas delgadas FM influyen en el fenómeno de la TPT. En estas películas, pueden coexistir diferentes fases quasi-paramagneticas (PM)/FM. No solo eso, dicha separación de fases puede ser controlada con la temperatura, mediante el diseño del perfil de energía de in

Polymers and rheology were both born in the twenties of the last century, fruit of the disruptive and creative scientific atmosphere of this decade. The development of polymer science and technology in the last almost 100 years has been colossal, whereas rheology has been able to create its own route as a branch of Physics. In this review paper we describe the interactions between both scientific areas, demonstrating that many of the crucial aspects for the progress of one of them owes to contribution of the other and viceversa. This interrelationship is shown through a historical survey of the principal milestones, starting from the correlation of the molecular weight with the intrinsic viscosity. A pondered analysis of the contributions of rheology to polymer science and technology, lead us to assert that the role of the former is rather founded on 50 years old discoveries.

We report herein on a new platform for synthesizing stable, inert, and dispersible metal-free single-chain nanoparticles (SCNPs) via intramolecular metal-traceless azide–alkyne click chemistry. It is well known that SCNPs synthesized via Cu(I)-catalyzed azide–alkyne cycloaddition (CuAAC) often experience metal-induced aggregation issues during storage. Moreover, the presence of metal traces limits its use in a number of potential applications. To address these problems, we selected a bifunctional cross-linker molecule, sym-dibenzo-1,5-cyclooctadiene-3,7-diyne (DIBOD). DIBOD has two highly strained alkyne bonds that allow for the synthesis of metal-free SCNPs. We demonstrate the utility of this new approach by synthesizing metal-free polystyrene (PS)-SCNPs without significant aggregation issues during storage, as demonstrated by small-angle X-ray scattering (SAXS) experiments. Notably, this method paves the way for the synthesis of long-term-dispersible, metal-free SCNPs from potentially any polymer precursor decorated with azide functional groups.

New methodologies capable of extensively analyzing the cell-material interactions are necessary to improve current in vitro characterization methods, and proteomics is a viable alternative. Also, many studies are focused on monocultures, even though co-cultures model better the natural tissue. For instance, human mesenchymal stem cells (MSCs) modulate immune responses and promote bone repair through interaction with other cell types. Here, label-free liquid chromatography tandem mass spectroscopy proteomic methods were applied for the first time to characterize HUCPV (MSC) and CD14+ monocytes co-cultures exposed to a bioactive sol–gel coating (MT). PANTHER, DAVID, and STRING were employed for data integration. Fluorescence microscopy, enzyme-linked immunosorbent assay, and ALP activity were measured for further characterization. Regarding the HUCPV response, MT mainly affected cell adhesion by decreasing integrins, RHOC, and CAD13 expression. In contrast, MT augmented CD14+ cell areas and integrins, Rho family GTPases, actins, myosins, and 14-3-3 expression. Also, anti-inflammatory (APOE, LEG9, LEG3, and LEG1) and antioxidant (peroxiredoxins, GSTO1, GPX1, GSHR, CATA, and SODM) proteins were overexpressed. On co-cultures, collagens (CO5A1, CO3A1, CO6A1, CO6A2, CO1A2, CO1A1, and CO6A3), cell adhesion, and pro-inflammatory proteins were downregulated. Thus, cell adhesion appears to be mainly regulated by the material, while inflammation is impacted by both cellular cross-talk and the material. Altogether, we conclude that applied proteomic approaches show its potential in biomaterial characterization, even in complex systems.

The changes of properties and preferential interactions based on subtle energetic differences are important characteristics of organic molecules, particularly for their functionalities in biological systems. Only slightly energetically favored interactions are important for the molecular adsorption and bonding to surfaces, which define their properties for further technological applications. Here, prochiral tetracenothiophene molecules are adsorbed on the Cu(111) surface. The chiral adsorption configurations are determined by Scanning Tunneling Microscopy studies and confirmed by first-principles calculations. Remarkably, the selection of the adsorption sites by chemically different moieties of the molecules is dictated by the arrangement of the atoms in the first and second surface layers. Furthermore, we have investigated the thermal effects on the direct desulfurization reaction that occurs under the catalytic activity of the Cu substrate. This reaction leads to a product that is covalently bound to the surface in chiral configurations.

Electrocatalytic reduction of oxidized nitrogen compounds (NOx) promises to help rebalance the nitrogen cycle. It is widely accepted that nitrate reduction to NH4+/NH3 involves NO as an intermediate, and NO hydrogenation is the potential-limiting step of NO reduction. Whether *NO hydrogenates to *NHO or *NOH is still a matter of debate, which makes it difficult to optimize catalysts for NOx electroreduction. Here, “catalytic matrices” are used to swiftly extract features of active transition metal catalysts for NO electroreduction. The matrices show that active catalysts statistically stabilize *NHO over *NOH and have undercoordinated sites. Besides, square-symmetry active sites with Cu and other elements may prove active for NO electroreduction. Finally, multivariate regressions are able to reproduce the main features found by the matrices, which opens the door for more sophisticated machine-learning studies. In sum, catalytic matrices may ease the analysis of complex electrocatalytic reactions on multifaceted materials.