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Faradaic deionization (FDI) is an emerging and promising electrochemical technology for stable and efficient water desalination. Battery-type energy storage materials applied in FDI have demonstrated to achieve higher salt removal capacities than carbon-based conventional capacitive deionization (CDI) systems. However, most of the reported FDI systems are based on inorganic intercalation compounds that lack cost, safety and sustainability benefits, thereby curtailing the development of a feasible FDI cell. In this work, we introduce an all-polymer rocking chair practical FDI cell, with a symmetric system composed by a redox-active naphthalene-polyimide (named as PNDIE) buckypaper organic electrodes. First, electrochemical performance of PNDIE in 0.05 M NaCl under open-air conditions is evaluated in both three-electrode half- and symmetric FDI full-cell using typical lab-scale electrode dimensions (1.6 mgPNDIE; 0.78 cm2), revealing promising specific capacity (115 mAh g-1) and excellent cycle stability for full-cell experiments (77 % capacity retention over 1000 cycles). Then, all-polymer rocking chair FDI flow cell was constructed with practical PNDIE electrodes (92.2 mgPNDIE; 9.6 cm2) that delivered large desalination capacity (155.4 mg g-1 at 0.01 A g-1) and high salt removal rate and productivity (3.42 mg g-1 min-1 at 0.04 A g-1 and 62 L h-1 m-2, respectively). In addition, long-term stability (23 days) experiments revealed salt adsorption capacity (SAC) retention values over 95% after 100 cycles. The overall electrochemical and deionization performances of the reported technology is far superior than the state-of-the-art CDI and FDI techniques, making it a competitive choice for robust and sustainable “water-energy” electrochemical applications.

Unformatted post-print version of the accepted article, There has been considerable interest in the nucleation and crystallization of polymers in the presence of nanoparticles (NPs, or nanofillers in general, NFs). Most of the extensive work in this area has focused on anisotropic, non-Brownian NFs (e.g., clay sheets, carbon nanotubes) whose spatial dispersion state in these nanocomposites is controlled by the process by which they are formed. While NF spatial dispersion is thus generally poor, or poorly characterized, in many works, thermodynamic handles that can be used to control NF dispersion state in the polymer melt include (a) favorable interactions between the polymer chains and the bare NP surfaces, or (b) the density and length of the chains, with the same chemistry as the matrix, grafted to the NP surface. These relatively large NFs merely act as immovable objects that affect the kinetics of nucleation by providing heterogeneous sites, and the crystallization rate by confining the polymer in the melt state. The dispersion state of the NFs can dramatically 2 affect the nucleation and crystallization of the matrix, but in most cases reported, the NFs increase nucleation efficiency relative to the neat polymer. At higher NF loadings, the effect of polymer confinement by the NFs dominates, leading to a decrease in crystal growth rates. In this review, we first describe the most important lessons learned from these commonly studied systems and then use this knowledge to understand the results obtained when small, mobile spherical NPs (typically smaller than 100 nm in size) are used as the nanofillers. The role of NP mobility, which provides for dynamic confinement of the polymer melt, on the kinetics of polymer crystallization (nucleation, growth, and overall crystallization) and how this behavior is mostly consistent with the case of immobile NF is a second important focus of our review. In addition to the role of NFs on crystallization kinetics, we discuss recently reported nanoparticle ordering phenomena, i.e.

279 p., En esta Tesis, además de estudiar los NLOP, también investigamos las características topológicas de algunos sistemas moleculares con NLOP grandes tales como los electruros moleculares. Los electruros son unos nuevos compuestos iónicos donde los electrones actúan como aniones. En este trabajo, utilizando métodos de primeros principios, tratamos de responder una pregunta fundamental relacionada con los electruros: ¿Podemos asignar un número entero de electrones a las regiones del espacio que identificamos como responsables del carácter electrúrico? Para ello, evaluamos varios indicadores de localización electrónica y cuantificamos el número de electrones aislados y calculamos directamente las funciones de distribución de electrones (EDF)que están relacionadas con la probabilidad de tener un número específico de electrones aislados. Además, con el uso de herramientas de la química cuántica, asignamos estados de oxidación efectivos formales (EOS) a tales electrones aislados. El análisis de EOS y los EDFs nos permiten clasificar los electrones aislados de los electruros moleculares estudiados.Los hallazgos presentados en esta Tesis amplían el conocimiento actual sobre varios aspectos cruciales de las simulaciones de propiedades ópticas no lineales, que pueden ser de gran interés para el desarrollo de DFA más eficientes y precisos.

Single-ion lithium conducting polymer electrolytes based on delocalized borate groups have been designed and synthesized by rapid UV-photopolymerisation. For this purpose, three different functional lithium boron sp3 anionic monomers, containing fluorinated, ethoxy, or a blend of both functionalities have been synthesized. These monomers were photopolymerized in the presence of a PEG-di-acrylate crosslinker and tetraglyme as plasticizer. By this method, gel polymer electrolytes (SIPEs) endowed with lithium single-ion conduction were prepared. The impact generated by the different functionalities of the borate groups and the addition of plasticizer on the electrochemical and ion conducting properties of the synthesized polymer electrolytes are analyzed in detail. These polymer electrolytes showed high ionic conductivity (1.71·10 -4 S·cm-1 at 25 °C) and high lithium transference number values (up to 0.85). Finally, they were investigated as solid electrolytes in lithium metal symmetrical cells showing good performance (<0.85 V at ±0.2 mA·cm-2 for 175 h).

243 p., Los G-quadruplex han suscitado un gran interés en los últimos años para desarrollar terapias contra el cáncer. Estas estructuras de ADN pueden encontrarse en los telómeros y/o promotores de oncogenes, y se ha observado que la estabilización de tales G-quadruplexos puede alterar el crecimiento de células tumorales. Sin embargo, los mecanismos que conducen a la formación y estabilización de estos G-quadruplexos aún no están bien establecidos y son el foco de muchos trabajos actuales en este campo. En esta tesis se ha estudiado la interacción de dos isómeros, ecuatorial y axial, del complejo metálico [Mo(¿3-C3H5)Br(CO)2(phen)] con diferentes estructuras de ADN, prestando especial interés en el ADN G-quadruplexo, mediante métodos computacionales para conocer su citotoxicidad ya encontrada previamente mediante métodos experimentales. Entre todos los métodos utilizados, la Teoría del Funcional de la Densidad de Escalamiento Lineal (LS-DFT) tiene una especial relevancia a lo largo de este trabajo, pero también se han realizado cálculos con métodos como el semi-empírico, el DLPNO-CCSD(T), y el QM/MM, complementados con EDA, así como el uso de herramientas computacionalespara el análisis de enlaces débiles, QTAIM y NCI. Las energías de formación calculadas, el análisis de descomposición de energía, las energías de solvatación y el análisis de interacciones no covalentes explican la afinidad y la selectividad del complejo metálico por el ADN G-quadruplexo sobre el ADN de doble hélice. También se ha observado que, entre los dos isómeros complejos metálicos estudiados, el complejo Axial es favorable para la interacción con el ADN G-quadruplexo debido a la disposición que adopta el complejo, completamente insertado en la cavidad de la estructura del G-quadruplexo, dispuesto entre tétradas, favoreciendo la creación de interacciones débiles estabilizadoras. Las interacciones débiles más relevantes son las relacionadas con el apilamiento ¿- ¿ debido a que la superficie aromática pl

Solid composite electrolytes combining an ionic molecular phase to facilitate ion transport with a polymeric component to provide mechanical strength are promising material for solid state batteries. However, the structure-property relationships of these complex composites are not fully understood. Herein we study composites combining the non-flammability and thermal stability of the organic ionic plastic crystal (OIPC) N-methyl-N-ethylpyrrolidinium bis(trifluoromethanesulfonyl) amide [C2mpyr][TFSI] with the mechanical strength of acrylic polymer nanoparticles functionalised with sulphonamide groups having lithium counter-cations. The effect of the formation of interfaces and interfacial regions between the OIPC and polymer nanoparticle on the thermal stability, ion transport, morphology and ion dynamics were studied. It was found that the composites where an interphase was formed by local mixing of the polymer with the OIPC upon heating showed higher local disorder in the OIPC phase and enhanced ion transport in comparison with the as-prepared composites. In addition, doping the composite with LiTFSI salt led to further structural disorder in the OIPC and a selective increase in lithium-ion mobility. Such an improved fundamental understanding of structure, dynamics and interfacial regions in solid electrolyte composites can inform the design of OIPC-polymer nanoparticle composites with enhanced properties for application as solid electrolyte in batteries.

Underwater recording remains a critical challenge in bioelectronics because traditional flexible electrodes can not fulfill essential requirements such as stability and steady conductivity in aquatic environments. Herein, we show the use of elastic gels made of hydrophobic natural deep eutectic solvents as water-resistant electrodes. These eutectogels are designed with tailorable mechanical properties via one-step photopolymerization of acrylic monomers in different eutectic mixtures composed of fatty acids and menthol. The low viscosity of the eutectics turns the formulations into suitable inks for 3D printing, allowing fast manufacturing of complex objects. Furthermore, the hydrophobic nature of the building blocks endows the eutectogels with excellent stability and low water uptake. The obtained flexible eutectogel electrodes can record real-time electromyography (EMG) signals with low interference in the air and underwater.

Deep Eutectic Solvents (DES) are a new class of ionic conductive compounds attracting significant attention as greener alternatives to costly ionic liquids. Herein, we developed novel mixed ionic-electronic conducting materials by simple mixing of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) and various DES as additives. The DES addition induces the supramolecular assembly and gelification of PEDOT:PSS triggered by extensive hydrogen bonding and charge stabilization. The DES gels also known as eutectogels feature boost the mixed ionic-electronic conductivity of PEDOT:PSS up to 368 S·cm-1, unveiling great potential as flexible bioelectronics. All the PEDOT:PSS/DES gels showed shear-thinning behavior and viscosity values ranging from 100 to 1000 Pa·s. The eutectogels show good injectability with almost instantaneous elastic recovery, making them ideal materials for direct ink writing (DIW). As proof of that, PEDOT:PSS/DES (choline chloride: lactic acid) was 3D printed in different patterns, annealed at high temperature, and assembled into adhesive electrodes. This way tattoos-like electrodes, denoted as Eutecta2 were fabricated and placed in-vivo on the forearm and the thumb of human volunteers for electromyography measurements. Eutecta2 hexagonal patterns showed excellent conformability, and their signal-to-noise ratio (SNR) was higher than Ag/AgCl commercial electrodes for thumb motion measurements. Furthermore, forearm motion was measured after 14 days with similar values of SNR, demonstrating long-term stability and reusability. All in all, our findings revealed that DES could be used as inexpensive and safe additives to direct the self-assembly of PEDOT: PSS into supramolecular eutectogels inks for flexible bioelectronics.

149 p., La liberación controlada de fármacos es una de las aplicaciones más atractivas del uso de los nanomateriales en la biomedicina puesto que el hecho de transportar un agente terapéutico de forma controlada a un órgano o tejido concreto minimiza posibles efectos adversos que ese agente pueda tener sobre tejidos sanos.A pesar de los esfuerzos, la traslación de los nanomateriales a la medicina es limitada. Los nanomateriales pueden sufrir transformaciones durante su circulación y en los diferentes procesos de translocación a nivel de tejido, órgano o células que conducen a su agregación, degradación o pérdida de integridad, lo cual compromete su eficacia terapéutica.En esta tesis, nos hemos propuesto avanzar en la comprensión de las propiedades físico-químicas y la transformación de nanomateriales en el ambiente celular y en medios biológicos relevantes. Se ha trabajado con diferentes nanomateriales como hidrogeles, nanopartículas metálicas modificadas con cepillos poliméricos, nanopartículas de oro y nanopartículas poliméricas supramoleculares. Cada material considerado, nos permite resolver diferentes aspectos de la interacción de los nanomateriales con el ambiente celular. Para ello se han utilizado técnicas como microscopía confocal, microscopía confocal Raman, resonancia magnética nuclear de lapso de tiempo, espectroscopia de fluorescencia de correlación o espectroscopia de fluorescencia de correlación cruzada.

Unformatted post-print version of the accepted article, There has been considerable interest in the nucleation and crystallization of polymers in the presence of nanoparticles (NPs, or nanofillers in general, NFs). Most of the extensive work in this area has focused on anisotropic, non-Brownian NFs (e.g., clay sheets, carbon nanotubes) whose spatial dispersion state in these nanocomposites is controlled by the process by which they are formed. While NF spatial dispersion is thus generally poor, or poorly characterized, in many works, thermodynamic handles that can be used to control NF dispersion state in the polymer melt include (a) favorable interactions between the polymer chains and the bare NP surfaces, or (b) the density and length of the chains, with the same chemistry as the matrix, grafted to the NP surface. These relatively large NFs merely act as immovable objects that affect the kinetics of nucleation by providing heterogeneous sites, and the crystallization rate by confining the polymer in the melt state. The dispersion state of the NFs can dramatically 2 affect the nucleation and crystallization of the matrix, but in most cases reported, the NFs increase nucleation efficiency relative to the neat polymer. At higher NF loadings, the effect of polymer confinement by the NFs dominates, leading to a decrease in crystal growth rates. In this review, we first describe the most important lessons learned from these commonly studied systems and then use this knowledge to understand the results obtained when small, mobile spherical NPs (typically smaller than 100 nm in size) are used as the nanofillers. The role of NP mobility, which provides for dynamic confinement of the polymer melt, on the kinetics of polymer crystallization (nucleation, growth, and overall crystallization) and how this behavior is mostly consistent with the case of immobile NF is a second important focus of our review. In addition to the role of NFs on crystallization kinetics, we discuss recently reported nanoparticle ordering phenomena, i.e.

Understanding the chemico-physical properties of colloidal semiconductor nanocrystals (NCs) requires exploration of the dynamic processes occurring at the NC surfaces, in particular at the ligand-NC interface. Classical molecular dynamics (MD) simulations under realistic conditions are a powerful tool to acquire this knowledge because they have good accuracy and are computationally cheap, provided that a set of force-field (FF) parameters is available. In this work, we employed a stochastic algorithm, the adaptive rate Monte Carlo method, to optimize FF parameters of cesium lead halide perovskite (CsPbBr3) NCs passivated with typical organic molecules used in the synthesis of these materials: oleates, phosphonates, sulfonates, and primary and quaternary ammonium ligands. The optimized FF parameters have been obtained against MD reference trajectories computed at the density functional theory level on small NC model systems. We validated our parameters through a comparison of a wide range of nonfitted properties to experimentally available values. With the exception of the NC-phosphonate case, the transferability of the FF model has been successfully tested on realistically sized systems (>5 nm) comprising thousands of passivating organic ligands and solvent molecules, just as those used in experiments.

Unformatted postprint, Bio-based plastics that can supplant petroleum-derived materials are necessary to meet the future demands of sustainability in the life cycle of plastic materials. While there are significant efforts to develop protein-based plastic materials for commercial use, their application is limited by poor processability and limitations in mechanical performance. Here, we present a bovine serum albumin (BSA)-based resin for stereolithographic apparatus (SLA) 3D printing that affords bioplastic objects with shape memory behavior. We demonstrate that the native conformation of these globular proteins is largely retained in the 3D printed constructs, and that each protein molecule possesses a “stored length” that could be revealed during mechanical deformation (extension or compression) of the 3D bioplastic objects. While the plastically deformed objects could retain this state for an indefinite period of time, heating the object or submerging in water allowed it to return to its original 3D printed shape.

We show that properties of molecules with low-frequency modes calculated with density functional approximations (DFAs) suffer from spurious oscillations along the nuclear displacement coordinate due to numerical integration errors. Occasionally, the problem can be alleviated using extensive integration grids that compromise the favorable cost-accuracy ratio of DFAs. Since spurious oscillations are difficult to predict or identify, DFAs are exposed to severe performance errors in IR and Raman intensities and frequencies or vibrational contributions to any molecular property. Using Fourier spectral analysis and digital signal processing techniques, we identify and quantify the error due to these oscillations for 45 widely used DFAs. LC-BLYP and BH&H are revealed as the only functionals showing robustness against the spurious oscillations of various energy, dipole moment, and polarizability derivatives with respect to a nuclear displacement coordinate. Given the ubiquitous nature of molecules with low-frequency modes, we warrant caution in using modern DFAs to simulate vibrational spectroscopies.

Single-ion lithium conducting polymer electrolytes based on delocalized borate groups have been designed and synthesized by rapid UV-photopolymerisation. For this purpose, three different functional lithium boron sp3 anionic monomers, containing fluorinated, ethoxy, or a blend of both functionalities have been synthesized. These monomers were photopolymerized in the presence of a PEG-di-acrylate crosslinker and tetraglyme as plasticizer. By this method, gel polymer electrolytes (SIPEs) endowed with lithium single-ion conduction were prepared. The impact generated by the different functionalities of the borate groups and the addition of plasticizer on the electrochemical and ion conducting properties of the synthesized polymer electrolytes are analyzed in detail. These polymer electrolytes showed high ionic conductivity (1.71·10 -4 S·cm-1 at 25 °C) and high lithium transference number values (up to 0.85). Finally, they were investigated as solid electrolytes in lithium metal symmetrical cells showing good performance (<0.85 V at ±0.2 mA·cm-2 for 175 h).

The use of plastic waste to develop high added value materials, also known as upcycling, is a useful strategy towards the development of more sustainable materials. More specifically, the use of plastic waste as a feedstock for synthesising new materials for energy storage devices can not only provide a route to upgrading plastic waste but can also help in the search for sustainable materials. This perspective describes recent strategies for the use of plastic waste as a sustainable, cheap and abundant feedstock in the production of new materials for electrochemical energy storage devices such as lithium batteries, sodium batteries and supercapacitors. Two main strategies are described, the development of conducting carbons by combustion of plastic waste and the depolymerization of plastics into new chemicals and materials. In both cases, catalysis has been key to ensuring high efficiency and performance. Future opportunities and challenges are highlighted and hypotheses are made on how the use of plastic waste could enhance the circularity of current energy storage devices.

The crystallization kinetics of semicrystalline polymers is often studied with isothermal experiments and analyzed by fitting the data with analytical expressions of the Avrami and Lauritzen and Hoffman (LH) theories. To correctly carry out the analysis, precautions both in experiments and data fitting should be taken. Here, we systematically discussed the factors that influence the validity of the crystallization kinetics study. The basic concepts and fundamentals of the Avrami and LH theories were introduced at first. Then, experimental protocols were discussed in detail. To clarify the impact of various experimental parameters selected common polymers, i.e., polypropylene and polylactide, were studied using various experimental techniques (i.e., differential scanning calorimetry and polarized light optical microscopy). Common mistakes were simulated under conditions when non-ideal experimental parameters were applied. Furthermore, from a practical point of view, we show how to fit the experimental data to the Avrami and the LH theories, using an Origin ® App developed by us.

Unformatted preprint version of the submitted article, Successive self-nucleation and annealing (SSA) can thermally fractionate semi-crystalline polymers, thus detecting the characteristic structural features that lead to specific melting point distributions (corresponding to the lamellar thickness distribution in the sample). SSA has been employed to investigate the structural evolution of polyamide 1012 (PA1012) when it is submitted to thermal treatments in the solid-state (below the melting point, Tm) as well as in the liquid-state (above Tm), as a function of the molecular weight of the sample. Below Tm, mainly chemical crosslinking occurred, thus provoking the decrease in the melting enthalpy of the highest temperature SSA melting fraction. The structural evolution was limited primarily by crystallization, and the high crystallinity of the low molecular weight samples led to low crosslinking rates. Above Tm, the structural evolution was correlated with the melt viscosity and the end group concentration. The concentration and diffusion ability of end groups was inversely proportional to the initial melt viscosities, therefore linear chain growing rate increased with the decrease in initial melt viscosities. Crosslinking reaction rate increased with the increase in initial melt viscosities. This work has determined the structural evolution differences of PA1012 depending on different initial states. This work can provide guidance for studies of thermal structural evolution of all AABB-type polyamides and subsequent design of high-performance materials with various structures according to their application requirements.

Unformatted post-print version of the accepted article, A series of aliphatic polyethers with different chain lengths (nCH2= 6 to 12, and 16) is studied employing differential scanning calorimetry and X-rays scattering. The calorimetric and structural behavior of samples crystallized from the melt is divided into the odd-even and saturation regions. In the odd-even region (nCH2 = 6 to 10), the odd samples (nCH2 = 7, and 9) show enhanced calorimetric properties (e.g., higher transition temperatures) and faster crystallization kinetics than the even ones (nCH2 = 6, 8 and 10). The odd samples crystallize in orthorhombic unit cells and the even ones in monoclinic unit cells. In the saturation region (nCH2 = 11 to 16), the calorimetric properties increase as nCH2 increases without alternation. However, unexpectedly, the nCH2 = 12 displayed a mixed structure (monoclinic + orthorhombic) instead of an orthorhombic one. Thus, a structural saturation effect (i.e., an orthorhombic unit cell) is not reached. This particular structural feature was investigated under varied thermal histories, induced by different cooling rates. The samples as synthesized (i.e., crystallized during precipitation from solution) exhibited a structural saturation effect since both nCH2 = 10 and 12 display an orthorhombic unit cell. But, the nCH2 = 10 exhibits a monoclinic unit cell, and the nCH2 = 12 a mixed structure when the samples crystallize from the melt at different rates. Only the nCH2 = 16 crystallizes in an orthorhombic unit cell, independently of the thermal history. Thus, the complex odd-even effects in these aliphatic polyethers are a function of the cooling rate from the melt and sample preparation procedures (solution or melt crystallization).

Unformatted postprint, Mixed conducting polymer electrodes built from poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS) are attracting a great deal of interest in healthcare monitoring. However, the widespread application of this organic conductor in wearable devices is seriously restricted by toxic additives used to enhance its electrical conductivity. Herein, we explored a family of biocompatible ionic liquids (ILs), based on the cholinium cation and different carboxylated anions, as dopants and gelators for PEDOT:PSS to formulate safe bioelectrodes for long-term cutaneous recording. We examined the effect of the IL anion on the ionic-electronic conductivities and physicochemical properties of these soft conductors. Among the different ILs tested, cholinium lactate ([Ch][Lac]) afforded the greatest increase in the materials' electronic conductivity (≈30 S/cm vs. 0.2 S/cm for non-formulated PEDOT:PSS). Moreover, the PEDOT:PSS/IL mixtures formed gels due to supramolecular intereactions. The gels showed a rheological behavior associated to gels with excellent injectability properties. Finally, the performance of PEDOT:PSS/[Ch][Lac] as biocompatible electrodes for electrocardiogram recording is discussed. All in all, the obtained results unveil the effectiveness of cholinum-based ILs as non-toxic dopants of PEDOT:PSS, paving the way to explore novel bioderived electrolytes.

Unformatted postprint, Iongels are soft ionic conducting materials, usually comprised of polymer networks swollen with ionic liquids (ILs), which are being investigated for applications ranging from energy to bioelectronics. The employment of iongels in bioelectronic devices such as bioelectrodes or body sensors has been limited by the lack of biocompatibility of the ILs and/or polymer matrices. In this work, we present iongels prepared from solely biocompatible materials: i) a biobased polymer network containing tannic acid as a crosslinker in a gelatin matrix, and ii) three different biocompatible cholinium carboxylate ionic liquids. The resulting iongels are flexible and elastic with Young’s modulus between 11.3 and 28.9 kPa. The morphology of the iongels is based on a dual polymer network system formed by both chemical bonding due to the reaction of the gelatin’s amines with the polyphenol units and physical interactions between the tannic acid and the gelatin. These biocompatible iongels presented high ionic conductivity values, from 0.003 and up to 0.015 S*cm-1 at room temperature. Furthermore, they showed excellent performance as conducting gel in electrodes for electromyography recording as well as muscle stimulation.

The application of physical stimuli to cell cultures has shown potential to modulate multiple cellular functions including migration, differentiation and survival. However, the relevance of these invitro models to future potential extrapolation invivo depends on whether stimuli can be applied "externally", without invasive procedures. Here, we report on the fabrication and exploitation of dynamic additive-manufactured Janus scaffolds that are activated on-command via external application of ultrasounds, resulting in a mechanical nanovibration that is transmitted to the surrounding cells. Janus scaffolds were spontaneously formed via phase-segregation of biodegradable polycaprolactone (PCL) and polylactide (PLA) blends during the manufacturing process and behave as ultrasound transducers (acoustic to mechanical) where the PLA and PCL phases represent the active and backing materials, respectively. Remote stimulation of Janus scaffolds led to enhanced cell proliferation, matrix deposition and osteogenic differentiation of seeded human bone marrow derived stromal cells (hBMSCs) via formation and activation of voltage-gated calcium ion channels

An undecamer oligonucleotide probe based on a pair of deoxythymidines flanked by several modified nucleotides is a specific and highly efficient biosensor for micrococcal nuclease (MNase), an endonuclease produced by Staphylococcus aureus. Herein, the interaction mode and cleavage process on such oligonucleotide probes are identified and described for the first time. Also, we designed truncated pentamer probes as the minimum-length substrates required for specific and efficient biosensing. By means of computational (virtual docking) and experimental (ultra-performance liquid chromatography-mass spectrometry and matrix-assisted laser desorption ionization time-of-flight) techniques, we perform a sequence/structure-activity relationship analysis, propose a catalytically active substrate-enzyme complex, and elucidate a novel two-step phosphodiester bond hydrolysis mechanism, identifying the cleavage sites and detecting and quantifying the resulting probe fragments. Our results unravel a picture of both the enzyme-biosensor complex and a two-step cleavage/biosensing mechanism, key to the rational oligonucleotide design process.

Role of dispersion interactions in Endohedral TM@(ZnS)(12) structures, [EN] II−VI semiconducting materials are gaining attention due to their optoelectronic properties. Moreover, the addition of transition metals, TMs, might give them magnetic properties. The location and distance of the TM are crucial in determining such magnetic properties. In this work, we focus on small hollow (ZnS)12 nanoclusters doped with TMs. Because (ZnS)12 is a cage-like spheroid, the cavity inside the structure allows for the design of endohedral compounds resembling those of C60. Previous studies theoretically predicted that the first-row TM(ZnS)12 endohedral compounds were thermodynamically unstable compared to the surface compounds, where the TM atom is located at the surface of the cluster. The transition states connecting both structure families were calculated, and the estimated lifetimes of these compounds were predicted to be markedly small. However, in such works dispersion effects were not taken into account. Here, in order to check for the influence of dispersion on the possible stabilization of the desired TM(ZnS)12 endohedrally doped clusters, several functionals are tested and compare to MP2. It is found that the dispersion effects play a very important role in determining the location of the metals, especially in those TMs with the 4s3d shell half-filled or completely filled. In addition, a complete family of TM doped (ZnS)12 nanoclusters is explored using ab initio molecular dynamics simulations and local minima optimizations that could guide the experimental synthesis of such compounds. From the magnetic point of view, the Cr(7S)@(ZnS)12 compound is the most interesting case, since the endohedral isomer is predicted to be the global minimum. Moreover, molecular dynamics simulations show that when the Cr atom is located at the surface of the cluster, it spontaneously migrates toward the center of the cavity at room temperature.

We investigate the magnetic nanoparticles hyperthermia in a non-adiabatic and radiating process through the calorimetric method. Specifically, we propose a theoretical approach to magnetic hyperthermia from a thermodynamic point of view. To test the robustness of the approach, we perform hyperthermia experiments and analyse the thermal behavior of magnetite and magnesium ferrite magnetic nanoparticles dispersed in water submitted to an alternating magnetic field. From our findings, besides estimating the specific loss power value from a non-adiabatic and radiating process, thus enhancing the accuracy in the determination of this quantity, we provide physical meaning to a parameter found in literature that still remained not fully understood, the effective thermal conductance, and bring to light how it can be obtained from experiment. In addition, we show our approach brings a correction to the estimated experimental results for specific loss power and effective thermal conductance, thus demonstrating the importance of the heat loss rate due to the thermal radiation in magnetic hyperthermia.

Unformatted preprint version of the submitted article, A thermoplastic bio-polyurethane from renewable sources (TPU) and the nanocomposite developed by mixing it with carbon nanotubes (CNT) are investigated as potentially adequate for Material Extrusion-based Additive Manufacturing (EAM). Thermal and rheological features are studied from the perspective of their liaisons with printing adequacy and conditions. As predicted by rheology, both samples show good performance in filament elaboration and flow in the nozzle. Warpage is observed for TPU, but not for the nanocomposite, which is due to the effect of CNT nanoparticles on polymer chains dynamics. At the studied printing velocities, interlayer adhesion strength is independent of printing velocity implying that there is no significant chain orientation which can induce changes in the TPU entanglements. The nanocomposite shows a lower welding strength, notwithstanding both have the same chain entanglements density. This is explained by considering that the higher viscosity of TPU/CNT, as compared to TPU, reduces the melt diffusion coefficient.

We present single-shot electron velocity-map images of nanoplasmas generated from doped helium nanodroplets and neon clusters by intense near-infrared and mid-infrared laser pulses. We report a large variety of signal types, most crucially depending on the cluster size. The common feature is a two-component distribution for each single-cluster event: a bright inner part with nearly circular shape corresponding to electron energies up to a few eV, surrounded by an extended background of more energetic electrons. The total counts and energy of the electrons in the inner part are strongly correlated and follow a simple power-law dependence. Deviations from the circular shape of the inner electrons observed for neon clusters and large helium nanodroplets indicate non-spherical shapes of the neutral clusters. The dependence of the measured electron energies on the extraction voltage of the spectrometer indicates that the evolution of the nanoplasma is significantly affected by the presence of an external electric field. This conjecture is confirmed by molecular dynamics simulations, which reproduce the salient features of the experimental electron spectra.

Unformatted preprint version of the submitted article, In this work, we studied the composition-dependent miscibility of polyamide 6 and biobased polyamide 4,10 (PA6/PA410) blends, as triggered by crystallization driven phase segregation. The blends were prepared by extrusion melt blending in a wide composition range and studied by Differential Scanning Calorimetry (DSC), X-ray diffraction (both in-situ and ex-situ SAXS/WAXS), and Polarized Light Optical Microscopy (PLOM) during non-isothermal crystallization. The blends were found to be miscible in the amorphous state, as demonstrated by a single Tg that follows the Fox equation as a function of composition. The blends were also considered to be miscible in the melt, as no evidence of phase segregation was found by SAXS or phase contrast microscopy in the melt. The miscibility of the blends in the crystalline state is a strong function of composition. When only 10 or 20% PA6 is present in the blends, co-crystallization was evidenced by DSC and WAXS and the blends exhibited a single PA410 rich crystalline phase. On the other hand, as 30% or more PA6 is added to PA410, crystallization driven phase segregation occurs and progressively increased with PA6 content in the blends. Hence double crystalline blends are formed with both PA6 rich and PA410 rich crystalline phases. Clear evidence of either one or two crystalline phases was demonstrated by temperature-dependent measurements employing DSC, PLOM, WAXS and SAXS. Both the single and double crystalline PA6/PA410 blends exhibited good mechanical properties in view of the excellent compatibility displayed by the blends. The mechanical properties are in line with those exhibited by miscible blends following a simple rule of mixtures.

Unformatted preprint version of the submitted article, The crystallization of heterogeneously nucleated bulk polymers typically occurs in a single exothermic process, within a narrow temperature range, i.e., a single exothermic peak is detected by Differential Scanning Calorimetry when the material is cooled from the melt. However, when a bulk semicrystalline polymer is subdivided or dispersed into a multitude of totally (or partially) isolated microdomains (e.g., droplets or cylinders), in number comparable to that of commonly available nucleating heterogeneities, several separated crystallization events are typically observed, i.e., fractionated crystallization. This situation is often found for the minor crystallizable component in immiscible blends. When the bulk polymer is dispersed into a number of microdomains that is several orders of magnitude higher than the available number of heterogeneities within it, most microdomains will be heterogeneity-free. In these clean microdomains the nucleation can occur by contact with the interfaces (i.e., surface nucleation) or by homogeneous nucleation inside the microdomain volume. These cases can be easily encountered in cylinders or spheres within strongly segregated block copolymers, or in infiltrated polymers within nanopores of alumina templates. In this work, a comprehensive review of the known cases of fractionated crystallization is provided. The changes upon decreasing microdomain sizes from a dominant single heterogeneous nucleation, through fractionated crystallization, to surface or homogeneous nucleation are critically reviewed. Emphasis is placed on the common features of the phenomenon across the different systems, and thus on the general conclusions that can be drawn from the analysis of representative semicrystalline polymers. The origin of the fractionated crystallization effects and their dramatic consequences on the nucleation and crystallization kinetics of semicrystalline polymers are also discussed.

Laser-based methods have demonstrated to be effective in the fabrication of surface micro- and nanostructures, which have a wide range of applications, such as cell culture, sensors or controlled wettability. One laser-based technique used for micro- and nanostructuring of surfaces is the formation of laser-induced periodic surface structures (LIPSS). LIPSS are formed upon repetitive irradiation at fluences well below the ablation threshold and in particular, linear structures are formed in the case of irradiation with linearly polarized laser beams. In this work, we report on the simple fabrication of a library of ordered nanostructures in a polymer surface by repeated irradiation using a nanosecond pulsed laser operating in the UV and visible region in order to obtain nanoscale-controlled functionality. By using a combination of pulses at different wavelengths and sequential irradiation with different polarization orientations, it is possible to obtain different geometries of nanostructures, in particular linear gratings, grids and arrays of nanodots. We use this experimental approach to nanostructure the semiconductor polymer poly(3-hexylthiophene) (P3HT) and the ferroelectric copolymer poly[(vinylidenefluoride-co-trifluoroethylene] (P(VDF-TrFE)) since nanogratings in semiconductor polymers, such as P3HT and nanodots, in ferroelectric systems are viewed as systems with potential applications in organic photovoltaics or non-volatile memories.

Cu100−xCox thin films have been obtained by sputtering (x = 3, 9) and sputter gas aggregation (x = 2.5, 7.5) and subsequent annealing at 400 °C for 1 h. We have studied their structural, magnetic, and magnetotransport properties, both for the as-deposited and annealed samples, confirming the important role of the fabrication method in the properties. The magnetic measurements and the fitting of the hysteresis loops evidence that as-deposited samples consist of superparamagnetic (SPM) and/or ferromagnetic clusters, but in the samples obtained by gas aggregation the clusters are greater (with ferromagnetic behavior at room temperature) whereas in the samples obtained by sputtering, the clusters are smaller and there are also diluted Co atoms in the Cu matrix. The annealing affects negligibly the samples obtained by gas aggregation, but the ones obtained by sputtering are more affected, appearing greater clusters. This behavior is also reflected in the magnetoresistance (MR) measurements of the samples, with different shapes of the MR curves depending on the preparation method: more lineal in the whole range for sputtering, saturation at low fields (about 10 kOe) for gas aggregation. Finally, a Kondo-like minimum in the resistance versus temperature is found in the samples obtained by sputtering, affected by the magnetic field and the annealing. The observed Kondo-like behavior and the influence of annealing on a Kondo-like minimum in sputtered thin films have been attributed to the presence of diluted Co atoms in the Cu matrix and the Co precipitations from the Co–Cu solid solution upon annealing respectively.

The folding of certain proteins (e.g., enzymes) into perfectly defined 3D conformations via multi-orthogonal interactions is critical to their function. Concerning synthetic polymers chains, the “folding” of individual polymer chains at high dilution via intra-chain interactions leads to so-called single-chain nanoparticles (SCNPs). This review article describes the advances carried out in recent years in the folding of single polymer chains into discrete SCNPs via multi-orthogonal interactions using different reactive chemical species where intra-chain bonding only occurs between groups of the same species. First, we summarize results from computer simulations of multi-orthogonally folded SCNPs. Next, we comprehensively review multi-orthogonally folded SCNPs synthesized via either non-covalent bonds or covalent interactions. Finally, we conclude by summarizing recent research about multi-orthogonally folded SCNPs prepared through both reversible (dynamic) and permanent bonds.

Carbon nanomaterials (CNMs) and conjugated polymers (CPs) are actively investigated in applications such as optics, catalysis, solar cells, and tissue engineering. Generally, CNMs are implemented in devices where the relationship between the active elements and the micro and nanostructure has a crucial role. However, they present some limitations related to solubility, processibility and release or degradability that affect their manufacturing. CPs, such as poly(3,4-ethylenedioxythiophene) (PEDOT) or derivatives can hide this limitation by electrodeposition onto an electrode. In this work we have explored two different CNMs immobilization methods in 2D and 3D structures. First, CNM/CP hybrid 2D films with enhanced electrochemical properties have been developed using bis-malonyl PEDOT and fullerene C60. The resulting 2D films nanoparticulate present novel electrochromic properties. Secondly, 3D porous self-standing scaffolds were prepared, containing carbon nanotubes and PEDOT by using the same bis-EDOT co-monomer, which show porosity and topography dependence on the composition. This article shows the validity of electropolymerization to obtain 2D and 3D materials including different carbon nanomaterials and conductive polymers.

This communication reports a family of single-ion lithium conducting polymer electrolytes based on highly delocalized borate groups is reported. The effect of the nature of the substituents on the boron atom on the ionic conductivity of the resultant methacrylic polymers was analyzed. To the best of our knowledge the lithium borate polymers endowed with flexible and electron-withdrawing substituents presents the highest ionic conductivity reported for a lithium single-ion conducting homopolymer (1.65×10−4 S cm−1 at 60 °C). This together with its high lithium transference number tLi+= =0.93 and electrochemical stability window of 4.2 V vs Li0/Li+ show promise for application in lithium batteries. To illustrate this, a lithium borate monomer was integrated into a single-ion gel polymer electrolyte which showed good performance on lithium symmetrical cells (<0.85 V at ±0.2 mA cm−2 for 175 h).

Hybrid solid electrolytes which combine the properties of inorganic and polymeric ion conductors are being investigated for lithium batteries which use lithium metal anodes. The number of inorganic/polymer compositions and their synergy in ion-conducting properties are limited by the hybrid fabrication method and the limited compatibility between both types of materials. Here we report a hybrid solid electrolyte formed by a poly(ethylene glycol) type single-ion polymer network and ceramic garnet-type nanoparticles of Li7−3XAlXLa3Zr2O12 (LLZO) with very high lithium conductivity. The combination of a lithium-single ion polymer matrix with LLZO inorganic particles results in flexible free-standing films by using a fast UV-photopolymerization process with facile control of its composition. This methodology showed excellent dispersion of the LLZO nanoparticles within the gel polymer network with up to 50 wt% ceramic content, as shown in the enviromental ESEM images. These hybrid electrolytes have high ionic conductivity values (1.4 × 10−4 S cm−1 at 25 °C) and high lithium transference number as compared to previous hybrid electrolytes. The effect of LLZO nanoparticle content on the lithium transport was investigated in detail using solid-state nuclear magnetic resonance spectroscopy (NMR). Finally, determination of the critical current density (CCD) before lithium dendrites are initiated has been carried out on both pristine and hybrid electrolytes, so as to assess their potential as solid electrolytes for lithium metal batteries.

Unformatted postprint, Conducting polymers (CPs) have been attracting great attention in the development of (bio)electronic devices. Most of current devices are rigid 2D systems and possess uncontrollable geometries and architectures that lead to poor mechanical properties presenting ion/electronic diffusion limitations. The goal of the article is to provide an overview about the additive manufacturing (AM) of conducting polymers, which is of paramount importance for the design of future wearable 3D (bio)electronic devices. Among different 3D printing AM techniques, inkjet, extrusion, electrohydrodynamic and light-based printing have been mainly used. This review article collects examples of 3D printing of conducting polymers such as poly(3,4-ethylene-dioxythiophene) (PEDOT), polypyrrole (PPy) and polyaniline (PANi). It also shows examples of AM of these polymers combined with other polymers and/or conducting fillers such as carbon nanotubes, graphene and silver nanowires. Afterwards, the foremost application of CPs processed by 3D printing techniques in the biomedical and energy fields, i.e., wearable electronics, sensors, soft robotics for human motion, or health monitoring devices, among others, will be discussed.

Unformatted post-print version of the accepted article, Crystallization of polymeric materials under nanoscopic confinement is highly relevant for nanotechnology applications. When a polymer is confined within rigid nanoporous anodic aluminum oxide (AAO) templates, the crystallization behavior experiences dramatic changes as the pore size is reduced, including nucleation mechanism, crystal orientation, crystallization kinetics, and polymorphic transition, etc. As an experimental prerequisite, exhaustive cleaning procedures after infiltrations of polymers in AAO pores must be performed to ensure producing an ensemble of isolated polymer-filled nanopores. Layers of residual polymers on the AAO surface percolate nanopores and lead to the so-called “fractionated crystallization”, i.e., multiple crystallization peaks during cooling. As the density of isolated nanopores in a typical AAO template exceeds the density of heterogeneities in bulk polymers, the majority of nanopores will be heterogeneity-free. This means that the nucleation will proceed by surface or homogeneous nucleation. As a consequence, a very large supercooling is necessary for crystallization, and its kinetics is reduced to a first-order process that is dominated by nucleation. Self-nucleation is a powerful method to exponentially increase nucleation density. However, when the diameter of the nanopores is lower than a critical value, confinement prevents the possibility to self-nucleate the material. Because of the anisotropic nature of AAO pores, polymer crystals inside AAO also exhibit anisotropy, which is determined by thermodynamic stability and kinetic selection rules. For low molecular weight poly(ethylene oxide) (PEO) with extended chain crystals, the orientation of polymer crystals changes from the “chain perpendicular to” to “chain parallel to” AAO pore axis, when the diameter of AAO decreases to the contour length of the PEO, indicating the effect of thermodynamic stability. When the thermodynamic requirement is satisfied, the orientation is determi

Unformatted post-print version of the accepted article, Self-nucleation and annealing (SSA) is an efficient way to thermally fractionate semi-crystalline polymers. The thermal fractions produced by SSA have distinct melting points that correspond to different average lamellar thickness. In this research, SSA was adopted to investigate the in-situ evolution of lamellar thickness of polyamide 1012 (PA1012), which was affected by high temperature thermal treatments. SSA successfully fractionated PA1012 into 4 thermal fractions with different average lamellar thicknesses. The integrated area of the first or second SSA fraction against the total endothermic integrated area was plotted as a function of thermal treatment time to study the kinetics of lamellar thickness changes. Two opposing structural effects, chain growth and crosslinking, occurred during the applied thermal treatment (which consisted in thermally treating the material by holding it isothermally at temperatures in the range of 140-250 ºC) and they were detected as a function of time by SSA, rheology and dissolution behavior. The structural changes increased the viscosity and Tg and decreased the overall crystallization rate. Based on the construction of a master curve of “time-temperature superposition” at a reference temperature (T0) of 190 oC, the mechanism for lamellar thickness evolution was divided into three stages: (a) Stage I: Initially, PA1012 end groups reacted rapidly with active sites to generate chemically crosslinked structures. (b) Stage II: As the number of end groups rapidly increased, amidation reactions between carboxylic end groups and amine end groups resulted in linear chain growth. Linear chain growth and crosslinking occurred simultaneously, and there was no change in lamellar thickness or its distribution. (c) Stage III: Eventually, an increasing number of end groups was formed in the system, most of which led to linear chain growth via chain end-group reactions. These structural changes during the applied thermal treatments enhanced t

Unformatted post-print version of the accepted article, The self-nucleation behavior of a polybutene-1/ethylene random copolymer, P(B1-ran-E), which undergoes a complex crystal-crystal transition behavior, has been studied in detail. Similar to PE random copolymers, this material shows a strong melt memory effect even above equilibrium melting point of PB-1 homopolymer. Different polymorphic forms can be obtained when P(B1-ran-E) is cooled from different self-nucleation Domains. The trigonal form I' could only be nucleated in the presence of remaining form I crystals via self-seeding, while the melt memory in Domain IIa could only act as self-nuclei for kinetically favored form II. Furthermore, observations from optical microscopy illustrated that melt memory is able to enhance nucleation density but it does not affect the spherulitic growth rate.

Unformatted postprint, Solid-state lithium batteries are considered one of the most promising battery systems due to their high volumetric energy density and safety. Poly(ethylene oxide) (PEO) is the most commonly used solid polymer electrolyte in solid-state batteries. In this article, we introduce new polyphosphoester polymer electrolytes, which show improved flame retardant properties in comparison with PEO. For this purpose, new polyphosphoester copolymers were synthesized, including phosphoester, poly(ethylene glycol) (PEG) and UV cross-linkable vinyl units. Solid polymer electrolytes films based on polyphosphoesters copolymers and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) were prepared by curing under UV-light. The crystallinity present in the copolymers due to the PEG segmentdecreases with the amount of salt in the electrolyte, as seen by DSC. Solid polymer electrolytes based on polyphosphoester copolymers show ionic conductivity values as high as 2·10-4 S cm-1 at 70 °C. FTIR analysis showed that lithium cations complexed with phosphoester groups provoked an increase in the lithium transference number to 0.26 as compared to that of PEO 0.17. Pyrolysis flow combustion calorimetry (PCFC) or microcalorimetry results demonstrated the improved flame retardancy of the polyphosphoesters in comparison to a reference PEO based polymer electrolyte. The selected polyphosphoester solid electrolyte was investigated in a solid-state lithium cell Li0/Polymer electrolyte/LFP battery showing a specific capacity retention close to 80% and coulombic efficiency greater than 98% among 100 cycles at 70 °C.

Unformatted postprint, Mixed conductors having both high ionic and electronic conductivity are needed in membrane electrode assemblies (MEA) present in electrochemical devices from fuel cells, to supercapacitors and all battery chemistries. Typically, carbon black, binders and redox active materials are combined to make an electrode assembly into which a liquid electrolyte can 2 impregnate. Solid state devices require the ionic conduction built into the MEA. In this case, a material which can provide both electronic and ionic conduction as well as a redox functionality is described based on PEDOT-Cl as both the electronic conductor and the redox active component whilst an organic ionic plastic crystal [C2mpyr][FSI] is present as both binder and ionic conductor. Surprisingly, both the electronic and ionic conductivity of the composite are enhanced relative to the pure components by a factor of ×9 for electronic and ×180 for ionic. The mixed conducting composites are demonstrated to retain their redox activity in aqueous electrolytes, and, in the optimum case, 103 F g-1 and 296 mF cm-2 capacitance values are obtained for low and high mass loading electrodes. These materials demonstrate an innovative approach to prepare electrode assemblies where all three functionalities are incorporated into the materials. ie. electronic, ionic and redox activity for future energy devices.

Unformatted post-print version of the accepted article, A series of hetero-arm amphiphilic molecular brushes (AMBs) with poly(ethylene glycol) (PEG) and long chain n-alkyl side chains were synthesized via conventional free radical polymerization (FRP) of mainly 4-vinyl benzyl-PEG methyl ether and N-alkylmaleimide macromonomers. By varying PEG side chain degree of polymerization (D.P. = 12, 16 and 20) and n-alkyl chain lengths (C16 and C20), AMBs with varying combinations of side chain lengths were produced. This enabled the elucidation of the effect of side chain length on AMB phase behavior, semicrystalline morphologies and crystallization kinetics, via differential scanning calorimetry, polarized light optical microscopy and x-ray diffraction experiments. Calculations of segregation strength together with SAXS measurements indicate that all materials are probably phase segregated structure in the melt. Most of the AMB materials prepared were double crystalline, i.e., contained crystals from alkyl and PEG chains. AMB crystallization was constrained by AMB architecture, the frustration being most evident in AMBs with combinations of either low D.P.PEG, or short alkyl chain lengths. Large, well-developed spherulites, implying break-out crystallization from a weakly segregated melt, were only observed for the AMBs with the combination of the longest PEG chain (D.P. = 20) and longest alkyl chain length (C20). A peculiar behavior was found when spherulitic growth rates and overall crystallization rates of the PEG chains, within this particular AMB sample, were determined as a function of crystallization temperature. In both cases, a distinct minimum with decreasing temperature was observed, probably caused by the challenges encountered in crystal packing of the PEG side chains, tethered to an amorphous backbone, which also contained already crystallized C20 chains. This minimum is analogous to that observed in the crystallization of long chain n-alkanes, or high molar mass polyethylenes with bromine pendant groups that has b

Epoxy/Polycaprolactone (PCL) blends cured with a conventional diamine (4,4′-diaminodiphenylmethane, DDM) and with different amounts of a disulfide containing diamine (4, 4´-dithioaniline, DSS) were prepared through melting. The curing process was studied by FTIR and differential scanning calorimetry (DSC) and the mechanical behavior of the networks was studied by DMA. The shape memory properties and the recyclability of the materials were also analyzed. All blends showed a very high curing degree and temperature activated shape memory effect, related to the glass transition of the epoxy resin. The PCL plasticized the mixture, allowing tailoring of the epoxy glass transition. In addition, in the blends cured with DSS, as a consequence of the disulfide exchange reaction, the permanent shape could be erased and a new shape could be reprogrammed. Using this strategy, reprogrammable permanent shape memory materials were obtained.

Las páginas 156 a 173 están sujetas a confidencialidad por la autora. 182 p., La creciente demanda de dispositivos para la detección y monitorización de sustancias bio(químicas) ha llevado al estudio y desarrollo de nuevas plataformas para cubrir estas necesidades. En el ámbito de la salud, los biosensores representan la herramienta más sensible y eficaz con una amplia variedad de aplicaciones, sobre todo para su uso en el punto de medida (point-of-care). Estos dispositivos deben ser robustos, portables, sensibles y de fácil manejo. Entre las diferentes metodologías, los inmunoensayos son los más utilizados por su sensibilidad y selectividad frente a un gran número de biomarcadores de interés médico. A pesar de los ejemplos en el mercado basados en flujo lateral, todavía su integración en plataformas portables y el incremento de la sensibilidad no se han conseguido satisfactoriamente. Para abordar esta problemática, en la presente tesis doctoral se propone el estudio de la amplificación de la señal mediante el uso de reacciones enzimáticas, y su integración en una plataforma microfluídica para la fabricación de un inmunosensor fotoelectroquímico como plataforma ¿lab-on-a-chip¿. Por un lado, se estudiaron diferentes estrategias de detección y amplificación de la señal mediante la modulación enzimática de nanopartículas de sulfuro de plata y sulfuro de cadmio. Aquí, se desarrollaron tres sistemas enzimáticos para la detección de analitos de interés mediante fotoelectroquímica, fluorescencia, absorbancia y electroquimioluminiscencia. Se seleccionó la fotoelectroquímica como método de detección debido a las ventajas en cuanto a facilidad de integración en sistemas portables y alta sensibilidad. Por otro lado, se estudiaron diferentes métodos de inmovilización de anticuerpos en poliestireno para mejorar la orientación y el proceso de biorreconocimiento. Estos sustratos son transparentes y permiten su uso en dispositivos donde esté involucrada la luz. Finalmente, se diseñó una plataforma microfluídica donde se integró el poliestireno seleccionado y

Plasmonic nanoparticles exhibit excellent light-harvesting properties in the visible spectral range, which makes them a convenient material for the conversion of light into useful chemical fuel. However, the need for using surface ligands to ensure colloidal stability of nanoparticles inhibits their photochemical performance due to the insulating molecular shell hindering the carrier transport. We show that cellulose fibers, abundant in chemical functional groups, can serve as a robust substrate for the immobilization of gold nanorods, thus also providing a facile way to remove the surfactant molecules. The resulting functional composite was implemented in a bioinspired photocatalytic process involving dehydrogenation of sodium formate and simultaneous photoregeneration of cofactor molecules (NADH, nicotinamide adenine dinucleotide) using visible light as an energy source. By systematic screening of experimental parameters, we compare photocatalytic and thermocatalytic properties of the composite and evaluate the role of palladium cocatalyst.

Unformatted post-print version of the accepted article, The effect of confinement on the crystallization, crystal orientation, and polymorphic crystal transition of bulk and infiltrated polybutene-1 (PB-1) within nanoporous alumina templates (AAO) were studied. After cooling from the melt, PB-1 within AAO templates crystallized into the tetragonal Form II directly. The nucleation process inside the AAO pores was probably homogeneous when pore sizes were below 200 nm. The crystal orientation of Form II was investigated by grazing angle X-ray scattering. Form II to I transition was investigated as a function of time and modeled with the Avrami equation. The rate of Form II to I transition for infiltrated PB-1 within 400 nm AAO was unexpectedly higher than that of the bulk. The stress generated due to the mismatch of the thermal expansion coefficients between PB-1 and AAO greatly enhanced the nucleation of Form I within the Form II matrix. A slower Form II to I transition was observed when the pore diameter of AAO decreased. The transition degree decreased with decreasing pore diameter and was completely inhibited for PB-1 infiltrated within the 30 nm AAO template. A stable Form II interfacial layer with a thickness of ~ 12 nm was postulated to account for this phenomenon.

Unformatted post-print version of the accepted article, We have characterized a series of aliphatic polycarbonates synthesized by organocatalysis containing a variable number of methylene groups (nCH2) in their repeat units ranging from nCH2 = 6 to 12. The melting and crystallization behavior and crystalline structures were studied by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), and wide-angle X-ray scattering (WAXS). We found a clear even-odd effect in terms of thermal properties and crystalline structure, for nCH2 = 6 to 9, and a saturation of the even-odd effect, for nCH2 = 10 to 12. These results were independent of the crystallization conditions employed: non-isothermal, isothermal and successive self-nucleation and annealing (SSA). The even-odd region showed that the even samples had higher melting temperatures than the odd ones, and a monoclinic unit cell. On the other hand, the odd samples showed an orthorhombic unit cell. Both even and odd samples exhibited a trans-conformation, with a dilution of the impact of carbonyl group as evidenced by the weakening of the crystalline memory effect as nCH2 increases, independently of the even or odd nature of the samples. In the saturation region, the methylene instead of the carbonyl groups dominated the behavior, resulting in thermal properties that changed almost linearly with nCH2. The unit cells were all orthorhombic and the strength of memory effect was similar, as nCH2 increased. Accordingly, the samples showed a shift of the FTIR bands towards a PE-like dominated conformation.

Unformatted preprint version of the submitted article, In this work, we provide a detailed description of the tri-lamellar nanoscale morphology of a triple crystalline PEO-b-PCL-b-PLLA triblock terpolymer obtained by Hot-Stage Atomic Force microscopy (AFM) imaging and Wide Angle X-ray scattering (WAXS) analysis for the first time. The precursor PCL-b-PLLA diblock copolymer has also been included in the study for comparison purposes. A two-step crystallization protocol has been applied to create a distinct lamellar morphology. Both WAXS and AFM revealed the double crystalline nature of the diblock copolymer. However, the identification of multiple crystalline phases in the triblock terpolymer by AFM and WAXS at room temperature is not straightforward. The advantages of hot-stage AFM allowed following the evolution of the lamellar morphology and the successive melting of the tricrystalline PEO-b-PCL-b-PLLA sample during heating. Taking into account the melting temperature of each crystalline block, the existing lamellar populations were clearly identified. At 45 °C, the thinnest lamellae disappeared, due to the melting of PEO crystals. The medium size lamellae disappeared at 60 °C when PCL crystals melt. At that temperature, the only remaining crystals are those of the PLLA block. AFM mechanical modulus images provide further evidence of the lamellar self-assembly of the triblock terpolymer. The nanoscale arrangement includes lamellae of PCL, PEO, or both in between the PLLA lamellae. Hot-Stage AFM is a valuable technique to elucidate the morphological features of complex multi-crystalline systems.

Nanoconfined ions have dramatically different local environments compared to the bulk, which profoundly affects the ion solvation and transport properties taking place in the confined space. Herein, we investigate the rotational and translation mobility of both cation and anions of an OIPC (diethyl)(methyl)(isobutyl)phosphonium hexafluorophosphate) confined in 40 and 180 nm straight-through Al2O3 pores. The results revealed that the nanoconfined OIPC exhibit 44 times higher ionic conductivity than the bulk material at 30 degrees C. This enhancement is attributed to both the reduced tortuosity and the increased population of mobile species. More interestingly, the Al2O3 nanochannels were found to selectively enhance the rotation and translational motion of [P-122i4] cation at elevated temperatures, whilst leaving that of the [PF6] anion less affected

Strong synthetic and engineering efforts have taken the efficiency of non-fullerene acceptor (NFA) based organic solar cells above 18% in a few years. Nonetheless, a deep understanding of the fundamental properties of this class of molecules is still missing. Here, we systematically investigated the morphological properties of two high efficient indacenodithienothiophene-based NFAs - namely ITIC and ITIC-4F - in order to correlate the hydrogen/fluorination substitutions with the materials structural and stability properties. We confirm that each NFA structurally evolves with increasing temperature into several polymorphs, identifying through spectroscopy their corresponding narrow temperature ranges. We demonstrate that the materials' response to accelerated stress tests (ASTs) is both substitution and polymorph dependent. ASTs underlined that the most vulnerable molecular segment corresponds to the thienothiophene C?C bond along the central backbone, together with the C?C linkage between the electron-rich donor and the electron-deficient acceptor moieties, with a degradation process triggered by oxygen and light. ITIC-4F showed lower oxidation capability and a higher bond strength retaining effect compared to ITIC. Lastly, the AST approach employed here allowed for the extrapolation of morphological and stability-related features within a high-throughput framework, and can be considered as a valuable methodological tool for future stability-related studies

Unformatted post-print version of the accepted article, Although the study of melt memory has attracted much interest, the effect of polymer chemical structure on its origin has not been fully elucidated. In this work, we study melt memory effects by Differential Scanning Calorimetry employing a self-nucleation protocol. We use homologous series of homopolymers containing different polar groups and different number of methylene groups in their repeating units: polycarbonate, polyesters, polyethers and polyamides. We show that melt memory in homopolymers is generally controlled by the strength of the intermolecular interactions. The incorporation of methylene groups reduces melt memory effects by decreasing the strength of segmental chain interactions, which is reflected by the decrease in dipolar moments and solubility parameters. This work presents for the first time a unified view of the melt memory effects in different homopolymers.