Institute Nanociencia Of Aragon Ina

Zaragoza, Spain

Institute Nanociencia Of Aragon Ina

Zaragoza, Spain
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Armao IV J.J.,Charles Sadron Institute | Nyrkova I.,Institute Charles SadronCNRS | Fuks G.,Charles Sadron Institute | Osypenko A.,Charles Sadron Institute | And 6 more authors.
Journal of the American Chemical Society | Year: 2017

The study of supramolecular polymers in the bulk, in diluted solution, and at the solid-liquid interface has recently become a major topic of interest, going from fundamental aspects to applications in materials science. However, examples of supramolecular polymers at the liquid-liquid interface are mostly unexplored. Here, we describe the supramolecular polymerization of triarylamine molecules and their light-triggered organization at a chloroform-water interface. The resulting interfacial nematic layer of these 1D supramolecular polymers is further used as a template for the precise alignment of spherical gold nanoparticles coming from the water phase. These hybrid thin films are spontaneously formed in a single process, without chemical prefunctionalization of the metallic nanoparticles, and their ordering is improved by centrifugation. The resulting polymer chains and strings of nanoparticles can be co-aligned with high anisotropy over very large distances. By using a combination of experimental and theoretical investigations, we decipher the full sequence of this oriented self-assembly process. In such a highly anisotropic configuration, electron energy loss spectroscopy reveals that the self-assembled nanoparticles behave as plasmonic waveguides. © 2017 American Chemical Society.

Bellido E.,Catalan Institute of Nanoscience and Nanotechnology | De Miguel R.,Institute Nanociencia Of Aragon Ina | Ruiz-Molina D.,Catalan Institute of Nanoscience and Nanotechnology | Lostao A.,Institute Nanociencia Of Aragon Ina | Maspoch D.,Catalan Institute of Nanoscience and Nanotechnology
Advanced Materials | Year: 2010

(figure presented)Desired numbers of proteins can be positioned on surfaces by using dip-pen nanolithography (DPN). Ferritin nanoarrays are fabricated by direct-writing nanodroplets of a ferritin solution on transmission electron microscopy surfaces. After the contact-angle value of these droplets Is determined, the concentration of the inking protein solution and the diameter of the dot-like feature can be modulated to position a single ferritin particle on a surface (see figure). © 2010 WILEY-VCH Verlag GmbH & Co. KCaA.

Picher M.,CNRS Charles Coulomb Laboratory | Navas H.,CNRS Charles Coulomb Laboratory | Arenal R.,ONERA | Arenal R.,Institute Nanociencia Of Aragon Ina | And 3 more authors.
Carbon | Year: 2012

The influence of the temperature and precursor pressure on the defect density of single-walled carbon nanotubes (SWCNTs) grown by catalytic chemical vapor deposition was studied for several catalyst-precursor couples. The SWCNT defect density was assessed by studying the Raman D band. In situ Raman monitoring was used to determine experimental conditions allowing the preparation of samples free of pyrolytic carbon and not altered by air exposure. The most striking feature is that the Arrhenius plots of the I G/I D ratio systematically display a convex shape, i.e. the apparent activation energy decreases with increasing temperature. From HRTEM observations and oxidation experiments, this evolution of the D band features is ascribed to the catalytic growth of long SWCNTs with few defects at high temperature and of short and defective SWCNTs and carbon structures at low temperature. The convex Arrhenius behavior is well accounted by two kinetic models: (i) a model considering a change of intermediate states as a function of the temperature (for instance due to a phase transition of the catalyst particle or a change of intermediate carbon species) and (ii) a model considering a high-temperature process of defect creation (for instance by reaction with reactive gas species). © 2012 Elsevier Ltd. All rights reserved.

Marcos-Campos I.,Institute Nanociencia Of Aragon Ina | Marcos-Campos I.,Hospital Universitario Lozano Blesa | Asin L.,Institute Nanociencia Of Aragon Ina | Torres T.E.,Institute Nanociencia Of Aragon Ina | And 8 more authors.
Nanotechnology | Year: 2011

In this work, the capability of primary, monocyte-derived dendritic cells (DCs) to uptake iron oxide magnetic nanoparticles (MNPs) is assessed and a strategy to induce selective cell death in these MNP-loaded DCs using external alternating magnetic fields (AMFs) is reported. No significant decrease in the cell viability of MNP-loaded DCs, compared to the control samples, was observed after five days of culture. The number of MNPs incorporated into the cytoplasm was measured by magnetometry, which confirmed that 1-5pg of the particles were uploaded per cell. The intracellular distribution of these MNPs, assessed by transmission electron microscopy, was found to be primarily inside the endosomic structures. These cells were then subjected to an AMF for 30min and the viability of the blank DCs (i.e.without MNPs), which were used as control samples, remained essentially unaffected. However, a remarkable decrease of viability from approximately 90% to 2-5% of DCs previously loaded with MNPs was observed after the same 30min exposure to an AMF. The same results were obtained using MNPs having either positive (NH2 +) or negative (COOH-) surface functional groups. In spite of the massive cell death induced by application of AMF to MNP-loaded DCs, the number of incorporated magnetic particles did not raise the temperature of the cell culture. Clear morphological changes at the cell structure after magnetic field application were observed using scanning electron microscopy. Therefore, local damage produced by the MNPs could be the main mechanism for the selective cell death of MNP-loaded DCs under an AMF. Based on the ability of these cells to evade the reticuloendothelial system, these complexes combined with an AMF should be considered as a potentially powerful tool for tumour therapy. © 2011 IOP Publishing Ltd.

Rivas-Murias B.,University of Santiago de Compostela | Lucas I.,University of Zaragoza | Jimenez-Cavero P.,University of Zaragoza | Magen C.,University of Zaragoza | And 3 more authors.
Nano Letters | Year: 2016

We report the effect of interface symmetry-mismatch on the magnetic properties of LaCoO3 (LCO) thin films. Growing epitaxial LCO under tensile strain on top of cubic SrTiO3 (STO) produces a contraction along the c axis and a characteristic ferromagnetic response. However, we report here that ferromagnetism in LCO is completely suppressed when grown on top of a buffer layer of rhombohedral La2/3Sr1/3MnO3 (LSMO), in spite of identical in-plane and out-of-plane lattice deformation. This confirms that it is the lattice symmetry mismatch and not just the total strain, which determines the magnetism of LCO. On the basis of this control over the magnetic properties of LCO, we designed a multilayered structure to achieve independent rotation of the magnetization in ferromagnetic insulating LCO and half-metallic ferromagnet LSMO. This is an important step forward for the design of spin-filtering tunnel barriers based on LCO. © 2016 American Chemical Society.

Gomez V.,Institute Nanociencia Of Aragon Ina | Alguacil F.J.,CSIC - National Center for Metallurgical Research | Alonso M.,CSIC - National Center for Metallurgical Research
Aerosol and Air Quality Research | Year: 2012

Experimental characterization of a mixed screen-type diffusion battery has been made by using monodisperse neutral particles with diameter below 10 nm. The diffusion battery contained two "composite" grids, each of them consisting of a gold screen sandwiched between two Aluminium screens. The equivalent fiber diameter of the composite grid was obtained by fitting the experimental penetration data for uncharged particles to the Cheng-Yeh model. Once the equivalent or effective fiber diameter is known, the fan filter model of Cheng and Yeh allows accurate prediction of particle penetration through the mixed-screen type diffusion battery. © Taiwan Association for Aerosol Research.

Alonso M.,CSIC - National Center for Metallurgical Research | Alguacil F.J.,CSIC - National Center for Metallurgical Research | Gomez V.,Institute Nanociencia Of Aragon Ina
Journal of Aerosol Science | Year: 2013

This work presents the results of a theoretical investigation aimed at the determination of the relationship between applied voltage V and mobility Z for highly diffusive particles classified in a concentric cylindrical differential mobility analyzer (DMA). Based on knowledge of the mean of the first passage time probability distribution, the expression V / V n d= 1 - 2πk T L Z / p eQ s h has been obtained (Vnd=classification voltage for non-diffusing particles; k=Boltzmann's constant; T=absolute temperature; L=DMA length; p=number of elementary charges on the particle; e=electron's charge; Qsh=sheath air flow rate). Numerical simulations of particle trajectories have shown that the above expression is only approximate and that the last term, accounting for the effect of diffusion, has to be multiplied by a geometrical factor which is approximately given by the fitting expression 2.49ln-0.66(R2/R1), where R1 and R2 are the inner and outer electrode radii, respectively. The V/Vnd ratio departs from one only in extreme cases, namely, classification of particles with very high mobility in a quite long DMA operated at relatively low flow rates. For other situations the difference between V and Vnd is negligible. © 2013 Elsevier Ltd.

Arutyunyan N.R.,RAS A.M. Prokhorov General Physics Institute | Arenal R.,ONERA | Arenal R.,Institute Nanociencia Of Aragon Ina | Obraztsova E.D.,RAS A.M. Prokhorov General Physics Institute | And 4 more authors.
Carbon | Year: 2012

The presence of hexagonal boron nitride in the initial C:BN:Ni:Y 2O 3 mixture in the arc-discharge process leads to the modification of carbon nanostructures and to the creation of B xC yN z entities. BN-incorporation into these carbon nanostructures (single-wall nanotubes and carbon flakes) has been analyzed by high resolution transmission electron microscopy and electron energy loss spectroscopy. The optical absorption spectroscopy measurements have revealed a monotonous increase of the bandgap value of the synthesized nanotubes with the increase of the content of BN phase in the initial mixture of the synthesis compounds. Furthermore, a narrowing of the nanotube diameter distribution in favor of small diameters takes place in the presence of BN during the synthesis process. © 2011 Elsevier Ltd. All rights reserved.

Lacroix L.-M.,INSA Toulouse | Gatel C.,CEMES | Arenal R.,Institute Nanociencia Of Aragon Ina | Garcia C.,INSA Toulouse | And 6 more authors.
Angewandte Chemie - International Edition | Year: 2012

A platinum star performance: Quasi-single-crystalline Pt nanoparticles with peculiar morphologies cubic dendrites, planar tripods, and fivefold stars were synthesized in high yield. Shape selectivity was achieved by finely tuning the growth kinetics under a dihydrogen atmosphere. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Picher M.,Montpellier University | Anglaret E.,Montpellier University | Arenal R.,ONERA | Arenal R.,Institute Nanociencia Of Aragon Ina | Jourdain V.,Montpellier University
ACS Nano | Year: 2011

Single-walled carbon nanotubes are grown by catalytic chemical vapor deposition in various conditions of temperature and carbon precursor pressure. Systematic analyses of the Raman radial breathing modes at two laser wavelengths are used to monitor the evolution of the diameter distribution. Two distinct domains with opposite influences of the temperature and the precursor pressure on the diameter distribution are evidenced. Thanks to specially designed experiments made of two successive growths, three processes are identified to influence the diameter distribution during the nanotube growth: (i) at too low precursor pressure, nanotube nucleation cannot occur on the smallest catalyst particles; (ii) at low temperature and high precursor pressure, small catalyst particles are preferably encapsulated by disordered carbon structures; (iii) at high temperature, catalyst coarsening causes the disappearance of the smallest catalyst particles. © 2011 American Chemical Society.

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