Search

Here, we present a detailed description of the in situ isothermal crystallization of poly(trimethylene 2,5-furandicarboxylate)(PTF) as revealed by real-time Fourier transform infrared spectroscopy (FTIR) and grazing incidence wide-angle X-ray scattering (GIWAXS). From FTIR experiments, the evolution of hydrogen bonding with crystallization time can be monitored in real time, while from GIWAXS, crystal formation can be followed. Density functional theory (DFT) calculations have been used to simulate FTIR spectra for different theoretical structures, enabling a precise band assignment. In addition, based on DFT ab initio calculations, the influence of hydrogen bonding on the evolution with crystallization time can be understood. Moreover, from DFT calculations and comparison with both FTIR and GIWAXS experiments, a crystalline structure of poly(trimethylene 2,5-furandicarboxylate) is proposed. Our results demonstrate that hydrogen bonding is present in both the crystalline and the amorphous phases and its rearrangement can be considered as a significant driving force for crystallization of poly(alkylene 2,5-furanoate)s.

Understanding the intricate relationship between conductivity and polymer film microstructure is paramount to designing and developing high-performance conjugated-polymer-based electronic devices. Conjugated polymers are typically semicrystalline, and their films comprise both highly crystalline and amorphous regions with significant disparity between the conductivity of these regions. However, traditional conductivity measurements under steady-state conditions overlook the presence of the amorphous phase, offering an incomplete perspective on charge transport. Here, by employing isothermal dielectric measurements, we reveal that the amorphous phase plays a pivotal role and dominates the electrical conductivity at temperatures more pertinent to practical applications, while the crystalline fraction takes precedence at temperatures below room temperature. The conductivity mismatch between the amorphous and crystalline phases yields the Maxwell-Wagner-Sillars interfacial polarization (MWS-IP) effect. Here we demonstrated that the existence of MWS-IP ensues a universal scaling between the electrical conductivity, the relaxation time and the dielectric relaxation strength, for various conjugated polymers and their blends. Shedding light on the contribution of the amorphous phase in the conductivity of conjugated polymers can lead to the development of new polymers for applications in electronic devices with improved performance at operationally relevant temperatures.

Laser-induced periodic surface structures can be prepared on polymer thin films, despite the absence of light absorption at the wavelength of the irradiating laser, by using a bilayer approach. Nanostructuring of a poly(3-hexylthiophene-2,5-diyl) (P3HT) layer, by laser irradiation at 532 nm, covered by a thin layer of a non-absorbing polymer, in this case, the ferroelectric copolymer poly(vinylidene fluoride - trifluoro ethylene),P(VDF-TrFE), allows the development of a grating-like structure on the surface. The range of thicknesses of the upper layer, which leads to the formation of LIPSS, has been determined. It is verified that for a thickness larger than 40 nm, no periodic structures are formed, neither in the upper layer nor in the bottom P3HT one. This can be explained considering a mechanical restriction which prevents P3HT rearrangement. The upper nanostructured surface layer exhibits ferroelectric properties as proven by piezoresponse force microscopy measurements.

Bilayers of ferroelectric polymers [poly(vinylidene fluoride-trifluoroethylene), PVDF-TrFE] on semiconducting poly(3-hexylthiophene) (P3HT) substrates have been prepared by sequential spin coating. When creating thin layers of PVDF-TrFE from its solution in methyl ether ketone (MEK), they exhibit dewetting in the form of holes for thicker P3HT substrates, whereas they form continuous layers on thinner P3HT substrates. The dispersive and polar components of the surface tension of the different P3HT substrates were obtained through contact angle measurements. An estimation of the shape of the disjoining pressure as a function of thickness of a liquid film of MEK on top of the different P3HT substrates was obtained. Through these estimations, we observe that the stability region for continuous film formation shifts toward higher thicknesses for the samples where experimentally the holes are observed. This work provides understanding on the mechanism of stable film formation and effective tools to control the formation of holes, in functional polymer bilayers, of special importance in the fabrication of organic thin film-based devices.

Fused filament fabrication, commonly referred to as 3D printing, is an additive manufacturing method finding plenty of applications nowadays. In contrast, polymer nanopatterning by nanolithographic techniques plays an important role in obtaining functional surfaces and coatings for applications in different fields including micro- and nanoelectronics. In spite of their relevance, additive manufacturing and polymer nanolithography have not found yet a common niche to be developed. Although both approaches are oriented to achieve different types of objects, it is shown that the confluence of both technologies can be desirable and potentially convenient. Herein, it is demonstrated that by employing conventional 3D printing, it is possible to fabricate nanostructured polymer surfaces in a relatively simple way by using similar approaches as those used in nanoimprint lithography but without the need for clean room conditions. To do that, a printed-assisted nanoimprint lithography concept (3DPrANIL) has been tested for different types of polymer and silicon templates. It is demonstrated that a polymeric nanostructured hydrophilic template can be replicated accurately on another polymer rendering a nanostructured surface with enhanced hydrophobicity. The results support 3DPrANIL as novel method to obtain micro- and nanostructured surfaces with different functionalities like iridescence and hydrophobicity.

Our unsustainable use of nature is bringing the Earth system and its capacity to recover from global changes beyond the environmental boundaries that supported us as a society. Here, we discuss some urgent challenges that should be addressed for the human species to live with undesirable products resulting from its development : sustainable use of nitrogen, watersheds management for preserving water resources and their quality, environmental impact of plastics, increase of the resilience of marine ecosystems, restoration of the deteriorated marine coastal ecosystems, or the early detection of emergence of diseases. We advocate for the use of Nature based solutions to mitigate environmental problems, and also consider subjective wellbeing issues in the governance of societies for a future healthy planet.

Poly(alkylene 2,5-furanoate)s, (PAF)s, are fully biobased homopolyesters based on 2,5-furandicarboxylic acid that have recently emerged as promising alternative to petroleum based poly(alkylene terephthalate)s. In addition to a lower production carbon footprint poly(alkylene 2,5-furanoate)s have received significant attention due to their outstanding gas barrier properties in comparison to traditional poly aromatic esters [1]. The influence of chain dynamics on barrier properties has also devoted some attention. Dielectric spectroscopy experiments performed in poly(trimethylene 2,5-furanoate) revealed that the subambient relaxation, below its glass transition temperature, exhibited an inhibition of the mode corresponding to the ester oxygen linked to the aliphatic subunit which efficiently relaxes in the poly(trimethylene terephthalate) counterpart [2]. Fourier Transform Infrared (FT-IR) spectroscopy can provide precise information of intra-molecular motions at the molecular level [3]. By evaluating the vibrational frequencies and the corresponding oscillator, strength from the IR spectra information about the intra-molecular dynamics can be available. In this study, we present a combined IR spectroscopy and BDS study focused on the sub-glass temperature molecular dynamics of poly(trimethylene 2,5-furanoate) in comparison to that of poly(trimethylene terephthalate) in order to shed light on the influence the dynamics on the barrier properties of Poly(alkylene 2,5-furanoate)s.

This article presents an experimental study on the relaxation dynamics of a series of random copolymers based on bio-friendly comonomers with interesting gas barrier properties. We analyze the relaxation response in the glassy and ultraviscous regime of poly (trimethylene furanoate/sebacate) random copolymers via dielectric spectroscopy. We report lower values of dynamic fragility [a dimensionless index introduced in 1985 (Angell, Relaxations in Complex Systems, 1985)] in comparison to popular polyesters widely used in industry, such as poly (ethylene terephthalate), suggesting that the amorphous phase of these furanoate-based polyesters adopt an efficient chain packing. This is consistent with their low permeability to gases. We also discuss on different equations (phenomenological and theory-based approaches) for fitting the temperature-evolution of the alpha relaxation time.

We report on the preparation of micropatterned functional surfaces produced by inducing an out-of-plane deformation on elastic substrates and fixing these by creating a rigid oxidized top layer. Specifically, the elastic substrate used was Polydimethylsiloxane (PDMS) and the rigid layer on top was created by ozonation of this material. We evidenced that the surface pattern formed is directly dependent on the pressure applied, the mechanical properties of the elastic substrate and on the dimensions and shape of the mask employed to define the exposed and non-exposed areas. In addition to the pattern formed, another interesting aspect is related to the ozone diffusion within the material. Softer PDMS enables more efficient diffusion and produced a thicker oxidized layer in comparison to rigid PDMS. Finally, a simulation was carried out using the distribution of Von Misses stresses of a solid plate to understand the conditions in which the applied force resulted in the rupture of the rigid oxidized layer under a permanent deformation.

In this study, water-based functional polymer inks are prepared using different solvent displacement methods, in particular, polymer functional inks based on semiconducting polymer poly(3-hexylthiophene) and the ferroelectric polymer poly(vinylidene fluoride) and its copolymers with trifluoroethylene. The nanoparticles that are included in the inks are prepared by miniemulsion, as well as flash and dialysis nanoprecipitation techniques and we discuss the properties of the inks obtained by each technique. Finally, an example of the functionality of a semiconducting/ferroelectric polymer coating prepared from water-based inks is presented.

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.

This section is centered on the research actions addressed to increase efficiency in computation, to achieve low energy consumption, to reduce electronic material waste and to be less harmful to the environment. In order to achieve these objectives, the projected research strategies are addressed to combine disruptive technology with ground-breaking design innovations in devices and systems.

The growing demand for renewable energy sources has prompted the development of dielectric materials with the ability to store and efficiently recover electrical energy. Here, we correlate the structure and thermal conductivity of uniaxially oriented disentangled ultra-high molecular weight polyethylene (dis-UHMWPE) composites reinforced with gold nanoparticles with their electrical properties and potential application as electrical energy storage devices. Stretching increases the orientation of the polymer chains and thus the crystallinity and reduces the aggregation of gold nanoparticles while the thermal conductivity enhances significantly along the orientation axis. The structural changes driven by stretching result in two competing effects; on the one hand, the crystallinity increase reduces the permittivity of the composites and increases the resistivity, while on the other hand the recovery efficiency of oriented materials excels that of unstretched samples by up to 6 times at 5 s. Therefore, our work shows the structure–property relationship in electrical energy storage materials.

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.

La pandemia COVID-19, causada por el coronavirus SARS-CoV-2, se ha convertido durante este último año en una de las peores amenazas para la historia de la humanidad. Su impacto en todo el planeta ha planteado un desafío sin precedentes para la sociedad. El CSIC tomó la iniciativa en marzo de 2020 con el lanzamiento de la Plataforma Salud Global, orientada a buscar soluciones desde la ciencia ante la pandemia, y ha canalizado este esfuerzo contando desde el primer momento con el trabajo coordinado e ininterrumpido de nuestros investigadores y con el apoyo de la sociedad en su conjunto. La plataforma ha movilizado y coordina a más de 300 grupos de investigación de más de 90 centros del CSIC, en seis temáticas de trabajo, que tratan de cubrir con un enfoque interdisciplinar todos los aspectos de la pandemia: Prevención, Enfermedad, Contención y Diagnóstico, Tratamiento y Vacunas, Impacto social, y Comunicación. Gracias al apoyo recibido a través de nuestro ministerio, convocatorias y donaciones directas de entidades públicas y privadas, y de particulares, a quienes queremos agradecer la confianza depositada, el CSIC desarrolla más de 100 proyectos de investigación, que abarcan desde el desarrollo de antivirales, anticuerpos y antiinflamatorios, la monitorización de la transmisión, el estudio del genoma del virus y el impacto de las mutaciones, las características del microbioma intestinal y la genética de los pacientes, su respuesta inmune a la infección y a la vacunación, hasta la fabricación y puesta en el mercado de mascarillas, sistemas de diagnóstico y contención del virus, así como estudios realizados sobre la percepción social de las medidas, especialmente sobre el impacto en residencias de mayores. Los tres proyectos de desarrollo de vacunas que lidera el CSIC arrancaron también al comienzo de la pandemia, como una apuesta estratégica para demostrar la capacidad de desarrollar de principio a fin una vacuna propia en España. Los proyectos de investigación han da

In this study, water-based functional polymer inks are prepared using different solvent displacement methods, in particular, polymer functional inks based on semiconducting polymer poly(3-hexylthiophene) and the ferroelectric polymer poly(vinylidene fluoride) and its copolymers with trifluoroethylene. The nanoparticles that are included in the inks are prepared by miniemulsion, as well as flash and dialysis nanoprecipitation techniques and we discuss the properties of the inks obtained by each technique. Finally, an example of the functionality of a semiconducting/ferroelectric polymer coating prepared from water-based inks is presented.

In this article we explore the potential of synchrotron Grazing Incidence Small Angle X-ray Scattering (GISAXS) to evaluate the extension of a Photoinduced Resist-free Imprinting (PRI) effect for grating-like Laser Induced Periodic Surface Structures (LIPSS) on spin-coated thin films of the fullerene derivative [6,6]-phenyl C-butyric acid methyl ester (PCBM). Valuable information about the nature of both the original fullerene LIPSS and of the remaining resist-free nanostructure in terms of geometry, size distribution, lattice periodicity and degree of order can be achieved by simulations of the GISAXS patterns. One of the most interesting features provided by the GISAXS analysis is the estimation of the paracrystalline distortion factor, which can be useful to evaluate the level of order in the nanostructure. Data revealed that LIPSS in PCBM films can be described as one-dimensional paracrystalline lattices with levels of order in accordance with those typically observed in LIPSS of other materials. The PRI effect leaves a qualitatively similar nanostructure but about two times more disordered than the original LIPSS one. Our results show that GISAXS is a powerful tool to characterize Resist-free Imprinting procedures of potential relevance in nanotechnology.

The optical properties of poly(3-hexylthiophene-2,5-diyl) (P3HT) can be controlled by processing the polymer in the form of nanoparticles dispersed in aqueous mediums. Colloids of P3HT were prepared by two different methods: flash –or reprecipitation- and miniemulsion precipitation technique, which result in the latter case in a polymer-water system whose stability is mediated by an ionic surfactant. Both systems yield different color dispersions, thus different absorption spectra, that is explained to be caused by the influence of the surfactant on the structure of P3HT. Differential scanning calorimetry and synchrotron radiation X-ray diffraction experiments reveal the origin of these optical differences, showing evidences of the formation of a blended structure formed due to the interaction between P3HT and the ionic surfactant. This work evidences the potential use of techniques for preparing nanoparticles in water dispersions as a tool to manipulate the structure and thus, the optical properties of these materials.

Altres ajuts: the ICN2 is funded by the CERCA program/General-itat de Catalunya. The ICN2 is supported by the Severo Ochoa Centres of Excellence programme, funded by the Spanish Research Agency (AEI, grant No. SEV-2017-0706) (MINECO/FEDER, UE)., An accurate knowledge of the parameters governing the kinetics of block copolymer self-assembly is crucial to model the time- and temperature-dependent evolution of pattern formation during annealing as well as to predict the most efficient conditions for the formation of defect-free patterns. Here, the self-assembly kinetics of a lamellar PS-b-PMMA block copolymer under both isothermal and non-isothermal annealing conditions are investigated by combining grazing-incidence small-angle X-ray scattering (GISAXS) experiments with a novel modelling methodology that accounts for the annealing history of the block copolymer film before it reaches the isothermal regime. Such a model allows conventional studies in isothermal annealing conditions to be extended to the more realistic case of non-isothermal annealing and prediction of the accuracy in the determination of the relevant parameters, namely the correlation length and the growth exponent, which define the kinetics of the self-assembly.

Polymers occupy a central role in current society due to their utility and versatile properties. As part of the class of soft materials, polymers have also been employed in research through nanostructuration and functionalization, looking for the development of new metamaterials with wide applicability in science and society. A particular polymer, Polyethylene, has been widely used both in research and commodities, and new ways to nanostructure and improve its functionality should be considered. Here, we report on the nanostructuration of polyethylene for the fabrication of three-dimensional nanonetworks, by resorting to 3 different variants of polyethylene: low density, high density, and ultra-high molecular weight. Through the melt infiltration of these polymers into well-known three-dimensional interconnected anodic aluminum oxide templates (3D-AAO), a study can be performed to understand the effects of the chain length, structure, and chain-branching of the used polymers on the stability and integrity of the resulting polymeric nanonetworks. This was accomplished by performing infiltrations in the presence of excess bulk material and quenching the infiltration process to access transient infiltration stages. The morphology of these networks was analyzed through SEM and STEM-HAADF to understand the differences arising from polymer structure. The observed results are interpreted through the use of the Lucas-Washburn equation for capillary flow and the determination of the critical contact angle for spontaneous capillary infiltration. The resulting metamaterials also exhibit photonic responses, resulting from the replication of the periodic nature of the employed templates.

An accurate knowledge of the parameters governing the kinetics of block copolymer self-assembly is crucial to model the time- and temperature-dependent evolution of pattern formation during annealing as well as to predict the most efficient conditions for the formation of defect-free patterns. Here, the self-assembly kinetics of a lamellar PS-b-PMMA block copolymer under both isothermal and non-isothermal annealing conditions are investigated by combining grazing-incidence small-angle X-ray scattering (GISAXS) experiments with a novel modelling methodology that accounts for the annealing history of the block copolymer film before it reaches the isothermal regime. Such a model allows conventional studies in isothermal annealing conditions to be extended to the more realistic case of non-isothermal annealing and prediction of the accuracy in the determination of the relevant parameters, namely the correlation length and the growth exponent, which define the kinetics of the self-assembly.

This book presents new approaches that offer a better characterization of the interrelationship between crystalline and amorphous phases. In recent years, the use of dielectric spectroscopy has significantly improved our understanding of crystallization. The combination of modern scattering methods, using either synchrotron light or neutrons and infrared spectroscopy with dielectrics, is now helping to reveal modifications of both crystalline and amorphous phases. In turn, this yields insights into the underlying physics of the crystallization process in various materials, e.g. polymers, liquid crystals and diverse liquids. The book offers an excellent introduction to a valuable application of dielectric spectroscopy, and a helpful guide for every scientist who wants to study crystallization processes by means of dielectric spectroscopy.

Nanostructuring is one promising alternative to modify the functionalities of conducting polymers aiming atapplications in technologies like organic solar cells, organicfield-effect transistors and organic light-emittingdiodes. Nowadays, there is an increasing interest in alternative ways of nanostructuring more economic, quickerand reproducible, avoiding the necessity of stringent environmental conditions like clean rooms, high vacuum orcomplex mask fabrication. Here we prove that Laser Induced Periodic Surface Structures (LIPSS) can be formedinfilms of Poly(3,4-ethylenedioxythiophene) complexed with Poly(styrenesulfonate) (PEDOT:PSS) prepared byspin-coating on planar Indium Tin Oxide. PEDOT:PSS has been irradiated with the 4th harmonic of a Nd:YAGlaser resulting in LIPSS parallel to the laser polarization with a period close to the laser wavelength. LIPSSmorphology has been characterized by Atomic Force Microscopy (AFM) and synchrotron Grazing IncidenceSmall Angle X-ray Scattering while thefilm structure was studied by Grazing-Incidence Wide-Angle X-rayScattering and Raman spectroscopy. To analyze the impact of laser treatment on the electrical properties ofPEDOT:PSS, conductive AFM was employed showing that LIPSS partially preserve the original electrical con-ductivity. These results can be of interest for achieving functional polymer nanostructures by a quick and re-producible approach with no need for clean room conditions.

La pandemia COVID-19, causada por un nuevo coronavirus, el SARS-CoV-2, se ha convertido en pocos meses en una amenaza para la humanidad, desencadenando la peor crisis sanitaria de este siglo. Más de veinte millones de personas han sido ya infectadas por el virus y más de 700.000 han muerto en todo el mundo como resultado de esta infección. En el ámbito de la investigación, esta pandemia ha obligado a un esfuerzo extraordinario de colaboración nacional e internacional. El Consejo Superior de Investigaciones Científicas (CSIC) ha canalizado este esfuerzo creando una Plataforma Temática Interdisciplinar (PTI) denominada Salud Global/Global Health, con el objetivo de encontrar soluciones a corto, medio y largo plazo, para reducir el impacto de esta pandemia en nuestra sociedad. La plataforma ha movilizado y coordina a más de 300 grupos de investigación de más de 90 centros del CSIC, en seis grupos de trabajo temáticos, que tratan de cubrir con un enfoque interdisciplinar todos los aspectos de la pandemia: Prevención, Enfermedad, Contención y Diagnóstico, Tratamiento y Vacunas, Impacto social, y Comunicación. Este informe, elaborado desde esta plataforma, presenta por una parte el conocimiento actual a nivel global que tenemos en estas temáticas sobre la pandemia, basado en las publicaciones e informes científicos y técnicos publicados hasta el momento, y en paralelo los proyectos de investigación en desarrollo por los grupos de investigación del CSIC. Gracias al apoyo a través de convocatorias y donaciones directas de entidades públicas y privadas, y también de particulares, a quienes desde aquí queremos agradecer la confianza depositada, el CSIC ha puesto en marcha más de 80 proyectos y acciones de investigación, que abarcan desde el estudio del genoma del virus, la genética de los pacientes, su respuesta inmune, la gravedad de la infección, hasta el desarrollo de antivirales, vacunas, sistemas de diagnóstico, de monitorización, de protección, de desinfección, etc. Nue

Colloidal polymer nanoparticles have recently attracted great interest as a result of their use in a wide range of applications including drug delivery, biolabeling, advanced biological sensors, photonic crystals, etc. The large interfacial area of nanoparticles may induce profound changes in the properties of the polymers, a fact which is of utmost importance from both technological and fundamental viewpoints