Institute Microelectronica Of Madrid Imm Csic

Tres Cantos, Spain

Institute Microelectronica Of Madrid Imm Csic

Tres Cantos, Spain
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Heredia-Guerrero J.A.,University of Seville | San-Miguel M.A.,University of Seville | Luna M.,Institute Microelectronica Of Madrid Imm Csic | Dominguez E.,Estacion Experimental la Mayora CSIC | And 2 more authors.
Soft Matter | Year: 2011

Soft and spherical nanoparticles, named as cutinsomes, have been prepared from concentrated 9(10),16-dihydroxypalmitic acid (diHPA) in aqueous solution. After isolation, cutinsomes have been chemically and structurally characterized by ATR-FTIR, TEM and dynamic atomic force microscopy (dynamic AFM). The nanoparticle can be described as a lipidic, liquid-like and mostly esterified core surrounded by a polar shell of carboxylate/carboxylic acid molecules. Molecular dynamic (MD) simulations have been used to support this model. The structural stability of soft cutinsomes has been tested by deposition on both non-polar (HOPG) and polar (mica) flat substrates. It has been found that the magnitude of the interaction between the polar shell of cutinsomes and the support determines their structure conservation or its spreading or rupture and spill out of the liquid-like content. The structural consistence of these nanoparticles as a function of the polarity of substrate is of interest in elucidating the formation mechanism of cutin, the most abundant biopolyester in nature and a very interesting biomaterial to be mimetized. © 2011 The Royal Society of Chemistry.

Heredia-Guerrero J.A.,University of Seville | Dominguez E.,Estacion Experimental La Mayora | Luna M.,Institute Microelectronica Of Madrid Imm Csic | Benitez J.J.,University of Seville | Heredia A.,University of Malaga
Chemistry and Physics of Lipids | Year: 2010

In the present work, we report the physico-chemical properties and structural characteristics of special polyhydroxy fatty acid nanoparticles after their fusion by means of attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electronic microscopy (SEM), atomic force microscopy (AFM), and light microscopy. All the characteristics and properties investigated have an important degree of similarity to the native plant cutin, the main biopolymer present in the plant cuticles. The supramolecular organization of these polymerized prime nanoparticles after their interaction on cellulose substrate and isolated cuticle samples, simulating the in vivo conditions in epidermal plant cells, strongly suggests a growth of these nanoparticles after a self-assembly process. © 2010 Elsevier Ireland Ltd. All rights reserved.

Chevalier S.,University of Bordeaux 1 | Cuestas-Ayllon C.,University of Zaragoza | Grazu V.,University of Zaragoza | Luna M.,Institute Microelectronica Of Madrid Imm Csic | And 2 more authors.
Langmuir | Year: 2010

This manuscript describes a novel method for the biofunctionalization of glass surfaces with polyhistidine-tagged proteins. The main innovation of this methodology consists of the covalent binding between the nitrilotriacetic acid (NTA) moiety and the proteins, ensuring not only orientation, but also stability of the recombinant proteins on NTA-covered surfaces. In this work, as C-terminal polyhistidine tagged cadherin extracellular fragments have been used, this methodology guarantees the proper orientation of these proteins, by mimicking their insertion into cell plasma membranes. These biofunctionalized surfaces have been characterized by confocal microscopy, X-ray photoelectron spectroscopy, contact angle, and atomic force microscopy, showing a high density of cadherins on the glass surfaces and the stability of the linkage. The prepared materials exhibited a high tendency to promote cell spreading, demonstrating the functionality of the protein and the high utility of these biomaterials to promote cell adhesion events. Interestingly, differences in the cytoskeleton organization have been observed in cells adhering to surfaces with no cadherins or with nonoriented cadherins, in comparison to surfaces functionalized with well-oriented cadherins. This method, which allows the robust immobilization of polyhistidine tagged proteins due to their covalent binding and with a defined orientation, may also find particular usefulness in the making of protein biochips, for analysis of protein-protein interactions, as well as structural and single-molecule studies. © 2010 American Chemical Society.

Martin J.,Institute Microelectronica Of Madrid Imm Csic | Martin J.,Imperial College London | Martin-Gonzalez M.,Institute Microelectronica Of Madrid Imm Csic | Francisco Fernandez J.,CSIC - Institute of Ceramics and Glass | Caballero-Calero O.,Institute Microelectronica Of Madrid Imm Csic
Nature Communications | Year: 2014

Three-dimensional (3D) nanostructures combine properties of nanoscale materials with the advantages of being macro-sized pieces when the time comes to manipulate, measure their properties or make a device. However, the amount of compounds with the ability to self-organize in ordered 3D nanostructures is limited. Therefore, template-based fabrication strategies become the key approach towards 3D nanostructures. Here we report the simple fabrication of a template based on anodic aluminium oxide, having a well-defined, ordered, tunable, homogeneous 3D nanotubular network in the sub 100-nm range. The 3D templates are then employed to achieve 3D, ordered nanowire networks in Bi2 Te3 and polystyrene. Finally, we demonstrate the photonic crystal behaviour of both the template and the polystyrene 3D nanostructure. Our approach may establish the foundations for future high-throughput, cheap, photonic materials and devices made of simple commodity plastics, metals and semiconductors. © 2014 Macmillan Publishers Limited. All rights reserved.

Martin J.,Institute Microelectronica Of Madrid Imm Csic | Munoz M.,Institute Microelectronica Of Madrid Imm Csic | Encinar M.,Institute Microelectronica Of Madrid Imm Csic | Calleja M.,Institute Microelectronica Of Madrid Imm Csic | Martin-Gonzalez M.,Institute Microelectronica Of Madrid Imm Csic
Langmuir | Year: 2014

Polymers undergo severe low-dimensionality effects when they are confined to ultrathin films since most of the structural and dynamical processes involving polymer molecules are correlated to length scales of the order of nanometers. However, the real influence of the size limitation over such processes is often hard to identify as it is masked by interfacial effects. We present the fabrication of a new type of nanostructure consisting of poly[[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1, 3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl] (PCDTBT) thin film that is held up exclusively over tips of poly(ether-ether-ketone) (PEEK) nanopillars. The fabrication method exploits the nonwetting behavior of PCDTBT onto an ordered PEEK nanopillar array when the mobility of the PCDTBT molecules is enhanced by a solvent annealing process. We use this new configuration to characterize the mechanical behavior of free-standing thin film regions, thus in the absence of underlaying substrate, by means of an atomic force microscope (AFM) setup. First, we study how the finite thickness and/or the presence of the underlying substrate influences the mechanical modulus of the material in the linear elastic regime. Moreover, we analyze deep indentations up to the rupture of the thin film, which allow for the measurement of important mechanical features of the nanoconfined polymer, such as its yield strain, the rupture strain, the bending rigidity, etc., which are impossible to investigate in thin films deposited on substrates. © 2013 American Chemical Society.

Martin J.,Institute Microelectronica Of Madrid Imm Csic | Campoy-Quiles M.,CSIC - Institute of Materials Science | Nogales A.,CSIC - Institute for the Structure of Matter | Garriga M.,CSIC - Institute of Materials Science | And 4 more authors.
Soft Matter | Year: 2014

We study the structure of poly(3-hexylthiophene) (P3HT) subjected to nanoscale confinement in two dimensions (2D) as imposed by the rigid walls of nanopore anodic aluminum oxide (AAO) templates. P3HT nanowires with aspect ratios (length-to-diameter) above 1000 and diameters ranging between 15 nm and 350 nm are produced in the pores of the AAO templates via two processing routes. These are, namely, drying a solution or cooling from the melt. Our study focuses on the effects of nanoconfinement on the semicrystalline nature of the nanowires, the orientation of crystals, and the evolution of the structures that P3HT might develop under confinement, which we investigate by combining imaging (SEM), spectroscopic (FTIR, photoluminescence) and structural characterization (WAXS, DSC) techniques. Solution-processed P3HT nanowires are essentially amorphous and porous, whereas melt-processed nanowires are semicrystalline, and present a more compact morphology and smoother surfaces. In the latter case, the orientation of crystals was found to strongly depend on the pore diameter. In large diameter nanowires (250 nm and 120 nm), crystals are oriented laying the π-π stacking direction parallel to the nanowire axis. In contrast, in small diameter nanowires, the π-π stacking direction is mainly perpendicular to the nanowires, as crystals are likely to nucleate at pore walls. The structural evolution of P3HT upon heating into weakly (250 nm in diameter) and strongly (15 nm in diameter) confining pores has been studied. A complex set of structures is observed, i.e., crystals, a solid layered mesophase, a nematic/smectic mesophase, and the isotropic melt. Interestingly, a rare crystal polymorph (form II) is also observed under strong confinement conditions together with the usual lamellar crystal form I. Furthermore, we show that nanoconfinement stabilizes form II: such crystals are still present at 210 °C while in the bulk they get converted to form I crystals at around 50 °C. © 2014 the Partner Organisations.

Lopez-Garcia M.,CSIC - Institute of Materials Science | Galisteo-Lopez J.F.,CSIC - Institute of Materials Science | Blanco U.,CSIC - Institute of Materials Science | Lopez C.,CSIC - Institute of Materials Science | Garcia-Martin A.,Institute Microelectronica Of Madrid Imm Csic
Advanced Functional Materials | Year: 2010

The optical properties of two-dimensional hybrid photonic-plasmonic crystals are fine-tuned by modifying the dielectric component of the system. The filling fraction of the dielectric component in monolayers of spheres deposited on gold substrates is controlled by means of oxygen-plasma etching. Doing so enables spectral tuning of the optical modes of the system. Experiments are performed on both optically passive and active samples showing the possibility for strong modification of the emission properties of samples containing emitters distributed within the spheres. The change in sphere diameter needed to substantially modify the sample's optical response points to a potential use of these samples as sensors or tunable emitting devices if appropriate polymeric components are employed. The optical properties of two-dimensional hybrid photonic-plasmonic crystals are fine-tuned by employing oxygen plasma to modify the filling fraction of the lattice. Simulations and experiments agree in showing a high degree of spectral tunability of the modes of the system in a continuous manner. When applied to active samples a strong modification of the emission of internal sources is obtained. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lopez-Garcia M.,CSIC - Institute of Materials Science | Galisteo-Lopez J.F.,CSIC - Institute of Materials Science | Blanco A.,CSIC - Institute of Materials Science | Sanchez-Marcos J.,CSIC - Institute of Materials Science | And 2 more authors.
Small | Year: 2010

A hybrid photonic-plasmonic crystal structure comprising a close-packed monolayer of dielectric spheres deposited on plasmon-supporting gold substrate is investigated. The spontaneous emission of organic dyes embedded in the beads experiences a strong modification in intensity, polarization, and directionality. These facts are accounted for considering the hybridization of modes arising from the photonic and plasmonic components of the structure. © 2010 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim.

Bounioux C.,Ben - Gurion University of the Negev | Diaz-Chao P.,Institute Microelectronica Of Madrid Imm Csic | Campoy-Quiles M.,CSIC - Institute of Materials Science | Martin-Gonzalez M.S.,Institute Microelectronica Of Madrid Imm Csic | And 5 more authors.
Energy and Environmental Science | Year: 2013

Composite films of poly(3-hexylthiophene) and single- as well as multi-walled carbon nanotubes are demonstrated to offer a competitive thermoelectric performance. The power factor significantly exceeds values obtained with either constituent alone provided that the conjugated polymer is sufficiently p-doped. The use of single-walled carbon nanotubes consistently results in a higher electrical conductivity with a maximum value above 10 3 S cm-1 and thus gives rise to a power factor of 25 ± 6 μW m-1 K-2 for a filler content of only 8 wt% and a maximum 95 ± 12 μW m-1 K-2 for 42-81 wt%. Moreover, a carbon nanotube content of 8-10 wt% does not compromise the low bulk thermal conductivity of the polymer matrix, which promises a high figure of merit of at least ZT > 10-2 at room-temperature. All samples are cast on plastic substrates, emphasising their suitability for large-area, flexible thermoelectric applications. © 2013 The Royal Society of Chemistry.

PubMed | Coventry University and Institute Microelectronica Of Madrid Imm Csic
Type: | Journal: Scientific reports | Year: 2016

In this work, we measure the thermal and thermoelectric properties of large-area Si0.8Ge0.2 nano-meshed films fabricated by DC sputtering of Si0.8Ge0.2 on highly ordered porous alumina matrices. The Si0.8Ge0.2 film replicated the porous alumina structure resulting in nano-meshed films. Very good control of the nanomesh geometrical features (pore diameter, pitch, neck) was achieved through the alumina template, with pore diameters ranging from 2945nm down to 314nm. The method we developed is able to provide large areas of nano-meshes in a simple and reproducible way, being easily scalable for industrial applications. Most importantly, the thermal conductivity of the films was reduced as the diameter of the porous became smaller to values that varied from =1.540.27W K(-1)m(-1), down to the ultra-low =0.550.10W K(-1)m(-1) value. The latter is well below the amorphous limit, while the Seebeck coefficient and electrical conductivity of the material were retained. These properties, together with our large area fabrication approach, can provide an important route towards achieving high conversion efficiency, large area, and high scalable thermoelectric materials.

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