Effects of Fabrication Methods on the Performance of Luminescent Solar Concentrators Based on Doped Polymer Optical Fibers

In this work, we detail two types of fabrication processes of four polymer optical fibers doped with lumogen dyes. The fiber preforms have been manufactured with two different methods: extrusion and casting. We have compared the performance of the two types of fibers as luminescent solar concentrators by calculating their optical efficiencies and concentration factors. The obtained results show better performance for those fibers manufactured by the casting process. We have also studied the photostability of the two types of fibers doped with the dye lumogen red under solar light radiation. A high thermal stability of the doped fibers has been observed.This work was funded in part by the Fondo Europeo de Desarrollo Regional (FEDER), in part by the Ministerio de Ciencia, Innovación y Universidades under projects RTC2019-007194-4, RTI2018-094669-B-C31 and MAT2014-5742-R and in part by the GobiernoVasco/Eusko Jaurlaritza IT933-16, ELKARTEK KK-2019/00101 (μ4Indust), and ELKARTEK KK-2019/00051 (SMARTRESNAK)

Smart hybrid materials. Structural design and applications

The field of multifunctional nanohybrid materials is one of the most promising and rapidly emerging research areas in materials chemistry. The sinergy between inorganic and organic components¿ properties, in a single material, provides vast opportunities to develop novel advanced materials in catalysis, sensing, coating, optical and electronic materials, biomedicine, and energy storage. A stimuli-responsive polymer can significantly change according to the environment it is in. The nonlinear response of these polymers makes them so unique and effective in combination with inorganic nanoparticles. In this talk, we will highlight our recent development in the area of multifunctional hybrid nanostructures, laying focus on the improved, optical, electronic and catalytic properties of organic-inorganic nanomaterials as a response to chemical signals conversions derived from the impact of pH and temperature external stimuli. Actually, a polymer-stabilized NPs in organic and aqueous solvents offer a great chemical playground for directed self-assembly, by simply changing composition of the solvent, hydrophobicity of monomers; which expands their potential applications. This research requires a good understanding of structure-property relationships that guide the design and generation of novel smart materials with well-controlled physical and assembly features for specific applications

Research methodology in physics and chemistry of surfaces and interfaces

This book covers a selection of recent research studies and new developments in physics and chemistry in micro and nanoscale materials. It brings together research contributions from eminent experts in the field from both academic and industry, providing the latest developments in advanced materials chemical domains

Influence of Polymethylmethacrylate microstructure on its conductive properties at high temperature

The influence of a set of tacticity-governed microstructures on the conductive properties of poly(methyl methacrylate) has been studied at high temperatures. Those structures are specially the mmmr and the mmmmrx (x = m or r), which occur when an isotactic sequence breaks-off, and also the rrrm-based termini of syndiotactic sequences. The electrical properties have been studied at the electrical modulus level, assuming a dispersive conductivity to explain conduction processes and Havriliak-Negami equation to evaluate dipolar contribution. A good agreement between experimental data and the model is observed, and some considerations about the conductive processes can be concluded. Conductivity is thermally activated at the temperature range considered, and ac regime can be associated with a correlated ion hopping of carrier process, which does not reacha strongly correlated regime, what we associate with a high relaxation time of carriers at high temperatures that do allow carriers to follow processes associated to a.c. regime.Interestingly, conductivity is shown to be dependent on the mmmrm-based stereosequences longer than one heptad. These stereosequences have been shown to exhibit enhanced free volume and rotational motion, what may explain the conductivity-mmmrm structure correlations as found on this work.MM thanks the Agència de Gestió d'Ajuts Universitaris i de Recerca de la Generalitat de Catalunya for financial support (2009SGR1168)..Peer ReviewedPostprint (published version

Antitags: SERS-encoded nanoparticle assemblies that enable single-spot multiplex protein detection

Simultaneous detection of multiple proteins on a single spot can be efficiently achieved by using multiplexed surface-enhanced Raman spectroscopy (SERS)-encoded nanoparticle 'antitags' consisting of poly(ethylene glycol) (PEG)-protected silver dimers (and higher aggregates) and antibody-tagging entities. The effective SERS-based multivariate deconvolution approach guarantees an accurate and successful distinguishable identification of single and multiple proteins in complex samples. Their potential application in multiplexed SERS bioimaging technology can be easily envisaged. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Peer Reviewe

Synthesis of Au@polymer nanohybrids with transited core-shell morphology from concentric to eccentric Emoji-N or Janus nanoparticles

Abstract The combination of multifunctionality and synergestic effect displayed by hybrid nanoparticles (NPs) has been revealed as an effective stratagem in the development of advanced nanostructures with unique biotechnology and optoelectronic applications. Although important work has been devoted, the demand of facile, versatile and efficient synthetic approach remains still challenging. Herein, we report a feasible and innovative way for polymer-shell assembling onto gold nanoparticles in competitive conditions of hydrophobic/hydrophilic feature and interfacial energy of components to generate core-shell nanohybrids with singular morphologies. The fine control of reaction parameters allows a modulated transformation from concentric to eccentric nanostructure-geometries. In this regard, a rational selection of the components and solvent ratio guarantee the reproducibility and efficiency on hybrid-nanoassembly. Furthermore, the simplicity of the synthetic approach offers the possibility to obtain asymmetric Janus NPs and new morphologies (quizzical-aspheric polymer-shell, named Emoji-N-hybrids) with adjustable surface-coating, leading to new properties and applications that are unavailable to their symmetrical or single components

Design of Nanostructured Surfaces Based on Metal NP Precipitation Strategy and their Catalytic Application

The fabrication of functional surfaces based on arrangements of metallic nanoparticles (MNPs) is challenging for biomedical, optoelectronic, and catalytic applications. Herein, the fabrication of 3D nanostructured microfibers is reported by the controlled cooperative precipitation of MNPs on electrospun polymer fiber mats, at the critical solution temperature of a thermoresponsive copolymer coating the MNPs surface. To obtain the metallic decorated surfaces, several factors must be taken into consideration, such as the previous functionalization of the metallic nanoparticle surface and the selection of a suitable polymer concentration, pH, and temperature. The results show that the plasmonic properties of the prepared surfaces depend on the solution temperature. Among potential applications, the high specific area of the resulting Au@polymer@fiber nanocomposites is ideal to be exploited for catalytic applications. Thus, the reduction of 4¿nitrophenol has been studied as a model.The authors gratefully acknowledge the financial support provided by Ministerio de Economía y Competitividad of Spain (Grants MAT2014- 57429-R and MAT2015-65184-C2-2-R). The authors thank David Gómez Vargas assistance with the SEM measurementsPeer Reviewe

On a novel tentative stereochemical microstructure based explanation of b relaxation of poly(vinylchloride) (PVC)

A set of PVC samples with various stereochemical microstructures, especially the mmmr and the mmmmrx (x = m or r placement) repeating stereosequences, termini of isotactic sequences, has been prepared whether by changing the tem- perature of polymerization or by SN2 substitution reaction which was demonstrated to occur through a highly stereo- specific mechanism. The stereochemical microstructures were accurately analysed by 13C NMR spectroscopy. For purposes of stating the microstructure/b relaxation relationship, the mechanical behaviour of all samples was studied by a dynamic mechanical thermal analyser (DMTA). The results are discussed on the ground of earlier fundamental contributions within the framework of the property/stereochemical microstructure relationships as abundantly studied in our laboratory. Basically it is shown that b relaxation decreases in both temperature and intensity with the content of the aforementioned microstructures, thereby suggesting that relaxation to stem from the enhanced free volume and favoured rotational motion facilities of the mmmr pentad under GTGTTG TT conformation.We are grateful to the Comisión Interministerial de Ciencia y Tecnología (C.I.C.Y.T.) for financial support (MAT2002-00250) of this research.Peer reviewe

Optical and Swelling Stimuli-Response of Functional Hybrid Nanogels: Feasible Route to Achieve Tunable Smart Core@Shell Plasmonic@Polymer Nanomaterials

This work focuses on achieving the modulation of optical and swelling properties of nanomaterials based on the self-assembly of thermostimuli polymers around metallic nanoparticles (NPs) for the obtention of functional plasmonic-polymer core/shell nanohybrids. Moreover, an important effort is made for understanding the role of the polymer assembly, molecule interactions, and contributing effect of each nanohybrid’s single component (i.e., polymer and NP) in the final temperature-tune optical properties. In this regard, a two-step route for building-up uniform core/shell hybrid nanogels with tunable thermoresponsive and plasmonic properties is considered as the key vehicle to get a better knowledge of the processes governing the synthesis, behavior, and properties of these materials. These plasmonic nanohybrids are made of gold NPs coated with poly­(2-(2-methoxyethoxy)­ethyl methacrylate) P­(MEO₂MA) nanogels with tunable shell thickness by surfactant (SDS) participation. Thereby, this controlled methodology was probed with spherical AuNPs of 22, 58, and 101 nm diameters, and the hybrid NPs showed size change at the temperature induced volume phase transition (VPTT) of the polymer shell and a red shift of the Localized Surface Plasmon Resonance (LSPR) maximum with increasing temperature. This approach paves the way to new strategies of design and research of temperature induced tunable optically active nanostructures (smart nanomaterials)