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  • Mineralization of DNA into nanoparticles of hydroxyapatite

     Bertran Cànovas, Oscar; Del Valle Mendoza, Luis Javier; Revilla Lopez, Guillermo; Chaves Barboza, Gustavo Adolfo; Cardus Andreu, Lluis; Casas Becerra, M. Teresa; Casanovas Salas, Jordi; Turon, Pau; Puiggali Bellalta, Jorge; Aleman Llanso, Carlos Enrique
    Dalton transactions
    Date of publication: 2014-01-07
    Journal article

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    Encapsulation of DNA into hydroxyapatite (HAp) has been investigated using a rational approach that involves computer simulation and experimental techniques. The temporal evolution of the radial distribution functions derived from atomistic molecular dynamics simulations of Ca2+, PO 4 3- and OH--containing aqueous solutions in the presence and absence of B-DNA has been used to conclude that the backbone of the double helix acts as a template for HAp growth. More specifically, results reveal the formation of calcium phosphate clusters at the first stages of the simulations, which subsequently re-organize to nucleate HAp. This effect is produced in the absence and, especially, presence, of DNA indicating that the biomolecules do not inhibit but even promote mineral growth. Furthermore, computer simulations suggest that the diffusion of the OH- anions through the inorganic solution is the limiting step for the nucleation of the biomineral. Nanocapsules and crystalline nanorods of HAp containing DNA molecules inside have been prepared by mixing solutions containing Ca 2+ and PO4 3- ions with fish sperm DNA at high pH. The dimensions and morphology of such nanostructures have been examined by transmission electron microscopy, while the characterization of the biomineral has been focused on the identification of DNA inside HAp using infrared, X-ray photoelectron and UV-vis spectroscopies, as well as gel electrophoresis. The biominerals reported in this work are important for biomedical applications requiring the protection of DNA from aggressive environmental conditions. © 2014 The Royal Society of Chemistry.

  • Interactions in dendronized polymers: intramolecular dominates intermolecular

     Cordova Mateo, Ester; Bertran Cànovas, Oscar; Zhang, Baozhong; Vlassopoulos, Dimitris; Pasquino, Rossana; Schlüter, A. Dieter; Kröger, Martin; Aleman Llanso, Carlos Enrique
    Soft matter
    Date of publication: 2014
    Journal article

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    In an attempt to relate atomistic information to the rheological response of a large dendritic object, inter- and intramolecular hydrogen bonds and pi,pi-interactions have been characterized in a dendronized polymer (DP) that consists of a polymethylmethacrylate backbone with tree-like branches of generation four (PG4) and contains both amide and aromatic groups. Extensive atomistic molecular dynamics simulations have been carried out on (i) an isolated PG4 chain and (ii) ten dimers formed by two PG4 chains associated with different degrees of interpenetration. Results indicate that the amount of nitrogen atoms involved in hydrogen bonding is similar to 11% while similar to 15% of aromatic groups participate in pi,pi-interactions. Furthermore, in both cases intramolecular interactions clearly dominate over intermolecular ones, while exhibiting markedly different behaviors. Specifically, the amount of intramolecular hydrogen bonds increases when the interpenetration of the two chains decreases, whereas intramolecular pi,pi-interactions remain practically insensitive to the amount of interpenetration. In contrast, the strength of the corresponding two types of intermolecular interactions decreases with interpenetration. Although the influence of complexation on the density and cross-sectional radius is relatively small, interpenetration affects significantly the molecular length of the DP. These results support the idea of treating DPs as long colloidal molecules.

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    Modeling biominerals formed by apatites and DNA  Open access

     Revilla Lopez, Guillermo; Casanovas, Jordi; Bertran Cànovas, Oscar; Turon, Pau; Puiggali Bellalta, Jorge; Aleman Llanso, Carlos Enrique
    Biointerphases: an open access journal for the biomaterials interface community
    Date of publication: 2013-04-08
    Journal article

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    Different aspects of biominerals formed by apatite and DNA have been investigated using computer modeling tools. Firstly, the structure and stability of biominerals in which DNA molecules are embedded into hydroxyapatite and fluoroapatite nanopores have been examined by combining different molecular mechanics methods. After this, the early processes in the nucleation of hydroxyapatite at a DNA template have been investigated using molecular dynamics simulations. Results indicate that duplexes of DNA adopting a B double helix can be encapsulated inside nanopores of hydroxyapatite without undergoing significant distortions in the inter-strand hydrogen bonds and the intra-strand stacking. This ability of hydroxyapatite is practically independent of the DNA sequence, which has been attributed to the stabilizing role of the interactions between the calcium atoms of the mineral and the phosphate groups of the biomolecule. In contrast, the fluorine atoms of fluoroapatite induce pronounced structural distortions in the double helix when embedded in a pore of the same dimensions, resulting in the loss of its most relevant characteristics. On the other hand, molecular dynamics simulations have allowed us to observe the formation of calcium phosphate clusters at the surface of the B-DNA template. Electrostatic interactions between the phosphate groups of DNA and Ca 2+ have been found to essential for the formation of stable ion complexes, which were the starting point of calcium phosphate clusters by incorporating PO34 from the solution

  • Computer simulation of fifth generation dendronized polymers: impact of charge on internal organization

     Bertran Cànovas, Oscar; Zhang, Baozhong; Schlüter, A. Dieter; Kröger, Martin; Aleman Llanso, Carlos Enrique
    Journal of physical chemistry B
    Date of publication: 2013-05-16
    Journal article

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    The internal organization of a fifth-generation dendronized polymer (PG5) has been investigated by atomistic molecular dynamics simulations in a vacuum. This study reveals an exceptional behavior of PG5 within the homologous series of g-generation PGg polymers. Three molecular configurations, which present a heterogeneous distribution of dendrons and an amount of backfolding lower than PG4 and PG6, have been obtained for PG5. The highest stability and closest agreement with available experimental data corresponds to a helical conformation characterized by a pitch of about 30 A, thickness of 105 A, and average density of 0.861 g/cm3. While small angle neutron scattering studies of PG5 in solution show a constant radial density distribution around the backbone, we here in our vacuum studies find a cylindrical volume element of sharply reduced density reminiscent of a pore. This neutral PG5 was compared with its charged deprotected analogue, dePG5 in water, to see in as much the positive charges in the periphery of this macromolecule would affect its conformational behavior. During deprotection of PG5, the tert-butyloxycarbonyl protected amine groups are converted into ammonium, mimicking the experimental situation during a divergent synthesis procedure. The repulsive interactions among the positively charged ammonium groups are responsible for a huge (30%) reduction of the average density and a small (1%) increase of elongation of the helical backbone, which results in a structure with a spongy appearance. Also here, we find a reduced dendron density near the backbone which is compensated for by the pore being filled with water. 2013 American Chemical Society

  • Computer simulation of dendronized polymers: organization and characterization at the atomistic level

     Bertran Cànovas, Oscar; Zhang, Baozhong; Schlüter, A. Dieter; Halperin, Avraham; Kröger, Martin; Aleman Llanso, Carlos Enrique
    RSC Advances
    Date of publication: 2013
    Journal article

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  • Atomistic organization and characterization of tube-like assemblies comprising peptide-polymer conjugates: computer simulation studies

     Bertran Cànovas, Oscar; Curcó Cantarell, David; Zanuy Gomara, David; Aleman Llanso, Carlos Enrique
    FARADAY DISCUSSIONS
    Date of publication: 2013
    Journal article

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    The structure and stability of the nanotube obtained by assembling peptide-polymer conjugates consisting of two poly(n-butyl acrylate) blocks coupled to the cyclic (D-alt-L)-octapeptide cyc[(L-Gln-D-Ala-L-Lys-D-Ala)(2)], have been investigated at the molecular level using atomistic molecular dynamics simulations. The effect of the wrapping polymer shells in the tube-like core, which consists of stacked beta-sheet cyclopeptides, has been examined by simulating assemblies of both unsubstituted cyclopeptides, and conjugates in chloroform and N,N-dimethylformamide solutions. Furthermore, the influence of the environment has been investigated by comparing conjugate assemblies in solution with those deposited on mica. In addition, nanotubes stabilized by beta-sheet-like hydrogen bonds between both parallel and antiparallel oriented cyclopeptides have been considered in all cases. The results, which have been analysed in terms of energy contributions, partial radial distribution functions, inter-subunit distances, shape of the cyclopeptide ring, internal van der Waals diameters, and both height and width of the nanostructures deposited on mica, have provided important microscopic insights. For example, analysis of both the energy terms and the structural dynamics obtained for the different assemblies indicate that the mica surface interacts more favourably with the parallel assembly than with the antiparallel ones, whereas the only configuration that is structurally stable in solution is the latter. Furthermore, adsorption onto the solid substrate produces a small deformation of the cylindrical molecular system.

  • Transport of hydronium ions inside poly(styrene-co-divinyl benzene) cation exchange membranes

     Cordova Mateo, Ester; Bertran Cànovas, Oscar; Ferreira, Carlos Arthur; Aleman Llanso, Carlos Enrique
    Journal of membrane science
    Date of publication: 2013-02-01
    Journal article

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  • Properties of oligothiophene dendrimers as a function of molecular architecture and generation number

     Cordova Mateo, Ester; Rodriguez Ropero, Francisco; Bertran Cànovas, Oscar; Aleman Llanso, Carlos Enrique
    Chemphyschem
    Date of publication: 2012-04-10
    Journal article

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  • Thermodynamic and stereochemical aspects of the polymerizability of glycolide and lactide

     Aleman Llanso, Carlos Enrique; Bertran Cànovas, Oscar; Houk, K.N.; Padias, Anne Buyle; Hall, H.K.
    Theoretical chemistry accounts
    Date of publication: 2012-03-01
    Journal article

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    The ring-opening polymerizations of the dilactones glycolide and the S,S- and S,R-stereoisomers of lactide were studied using quantum mechanical methods. The ring strain and the conformational distribution of these cyclic monomers and of the polymers were calculated, and the effect of the medium on the polymerization was predicted, for both bulk and solution. The polymerizability of the three monomers in the gas phase, that is, nonpolar medium, is much greater than that of d-valerolactone or 1,4-dioxan-2-one. This difference vanishes in the polar medium chloroform, which is attributed to the fact that, while all of these monomers possess polar cis-lactone bonds, the three dilactones possess small dipole moments. The data are combined to give polymerization enthalpy and free energy values. The four stereoregular lactide polymers did not differ significantly in energy. Accordingly, the ability to synthesize any one of these rests on catalyst specificity (‘‘polymer chain-end control’’). Although introduction of sterically demanding methyl groups into glycolide is expected to favor coiled conformations and decrease polymerizability, this was not found to be the case. Good agreement of calculated values with experimental data from the literature was achieved.

  • Linear viscoelastic response of dendronized polymers

     Pasquino, Rossana; Zhang, Baozhong; Sigel, Reinhard; Yu, Hao; Ottiger, M.; Bertran Cànovas, Oscar; Aleman Llanso, Carlos Enrique; Schlüter, A. Dieter; Vlassopoulos, Dimitris
    Macromolecules
    Date of publication: 2012-11-13
    Journal article

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    On the modeling of aggregates of an optically active regioregular polythiophene  Open access

     Torras Costa, Juan; Sanchez Navas, Cristina; Bertran Cànovas, Oscar; Aleman Llanso, Carlos Enrique
    Physical chemistry chemical physics
    Date of publication: 2012-02-14
    Journal article

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    The conformational properties of the optically active regioregular poly[(R)-3-(4-(4-ethyl-2-oxazolin-2-yl) phenyl) thiophene] (PEOPT) were explored by molecular dynamics on a single chain using several solvents of increasing polarity. Furthermore, their aggregate formation was studied over a wide range of temperatures using a replica exchange molecular dynamics simulation providing simulation data representative of the equilibrium behaviour of their aggregates. Results show a clear tendency of PEOPT to keep a syn–gauche conformation between continuous backbone thiophene rings favouring a bent chain structure in solvent. After studying their aggregation behaviour in acetonitrile, a strong tendency to pack stabilizing structures that reinforce the chirality of the polymer, in concordance with experimental data, was found. Two different aggregated structures were observed depending on oligomer length, a self-assembled helical aggregate based on stacked octamers and a bent double helix aggregate in large oligomers.

  • Ultrathin Films of Polypyrrole Derivatives for Dopamine Detection

     Fabregat Jove, Georgina; Cordova Mateo, Ester; Armelin Diggroc, Elaine; Bertran Cànovas, Oscar; Aleman Llanso, Carlos Enrique
    The journal of physical chemistry. Part C, nanomaterials and interfaces
    Date of publication: 2011-08-04
    Journal article

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  • Avances tecnológicos en la detección de neurotransmisores

     Bertran Cànovas, Oscar; Fabregat Jove, Georgina; Cordova Mateo, Ester; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique
    Química e industria (Madrid)
    Date of publication: 2011-06-01
    Journal article

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    La combinación de los resultados que proporcionan los experimentos realizados en el laboratorio y el ordenador es una de las claves para conseguir avances científicos importantes en la investigación de la química aplicada del siglo XXI. En este trabajo se presenta, en síntesis, cómo la combinación de técnicas electroanalíticas y de simulación molecular ha permitido diseñar detectores de dopamina, un neurotransmisor que afecta a las funciones motoras y cognitivas, en concentraciones similares a las que se encuentran en las sinapsis neuronales

  • Electronic properties of poly(thiophene-3-methyl acetate)  Open access

     Gomes, Alex Linardi; Casanovas, Jordi; Bertran Cànovas, Oscar; Sinezio de Campos, Joao; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique
    Journal of polymer research
    Date of publication: 2011-11-04
    Journal article

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    The electronic structure of poly(thiophene-3- methyl acetate) has been investigated using UV–vis absorption spectroscopy and quantum mechanical calculations. Experimental measures in chloroform solution indicate that the π-conjugation length increases with the polymer concentration, which is reflected by the red shift of the absorbance peak of the π-π* transition. On the other hand, the energy required for the π-π* transition has been found to decrease with the volatility of the solvent for concentrated polymer solutions, even though the influence of the solvent is very small for dilute solutions. Quantum mechanical calculations indicate that the interactions between the π-conjugated backbone and the methyl acetate side groups are very weak. On the other hand, the lowest energy transition predicted for an infinite polymer chain that adopts the anti-gauche and all-anti conformations is 2.8 and 1.9 eV, respectively. Finally, measurements on spincasted nanofilms reflect that the π-π* transition energy increases with the thickness, which has been attributed to the distortion of the molecular conformation. In spite of this, the energy gap obtained for the thinnest film (1.52 eV) is significantly smaller than that determined for dilute and concentrated chloroform solutions (2.56 and 2.09 eV, respectively)

  • Parameterization of the torsional potential for calix[4]arene-substituted poly(thiophene)s

     Preat, Julien; Rodriguez Ropero, Francisco; Torras Costa, Juan; Bertran Cànovas, Oscar; Zanuy Gomara, David; Aleman Llanso, Carlos Enrique
    Journal of computational chemistry
    Date of publication: 2010-06
    Journal article

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    Three different strategies have been followed to develop the torsional force-field parameters of the interring dihedral angles for calix[4]arene-substituted poly(thiophene)s, a family of highly sensitive ion receptors. These procedures, which are based on the rotational profiles calculated using quantum mechanical methods, differ in the complexity of the model compounds and the processing applied to the quantum mechanical energies before the fitting. The performance of the three sets of developed parameters, which are essentially compatible with the General Amber Force Field, has been evaluated by computing the potential of mean forces for the inter-ring rotation of 2,2'-bithiophene, and its substituted analog bearing a calix[4]arene group in different environments. Finally, the ability of the new sets of torsional parameters to describe a calix[4]arene-substituted poly(thiophene) in tetrahydrofuran solution has been checked using Molecular Dynamics simulations. Specifically, the molecular shape, the polymer conformation, and the effects of the Na+ ions trapped in the cavity of the receptor have been examined. Although the potential derived from unsubstituted 2,2'-bithiophene is able to reproduce the experimental free energies of the minima, the overall results indicate that the parameters derived from the analog bearing a calix[4]arene group provide the best description of the systems under study. This should be attributed to the strong constraints found in complex substituted poly(thiophene)s, which require parameterization strategies able to capture all the interactions and phenomena involved in their inter-ring rotations.

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    Field-Induced Transport in Sulfonated Poly(styrene-co-divinylbenzene) Membranes  Open access

     Bertran Cànovas, Oscar; Curcó, David; Torras Costa, Juan; Ferreira, Carlos Arthur; Aleman Llanso, Carlos Enrique
    Macromolecules
    Date of publication: 2010-12-06
    Journal article

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    Atomistic simulations have been carried to investigate electric field induced transport of hydronium ions in a sulfonated poly(styrene-co-divinylbenzene) membrane. In order to provide a good description of this cross-linked material, a methodology has been explicitly designed to construct a reliable model of the hydrated membrane. This model has been used to carry out molecular dynamics simulations in presence of electric fields, which varied from 0.001 to 3.0 V3 nm-1. Results show that the electric field affects the structure of the membrane producing both a redistribution of the unoccupied volume, which modifies the heterogeneity of the resin, and a rearrangement of the negatively charged sulfonate groups, which undergo a systematic alignment along the electric field direction. As was expected, the mobility of hydronium ions is enhanced with the strength of the electric field. Moreover, the electric field induces a significant rearrangement of the sulfonate groups, which is evidenced by the alignment of theC-S bonds along the direction of the field. The membrane has been found to behave as a spring, in which the force exerted by the electric field acts in opposite sense to the force exerted by the internal structure of the cross-linked material.

  • Incorporation of deMon2k as a new parallel quantum mechanical code for the PUPIL system  Open access

     Bertran Cànovas, Oscar; Trickey, Samuel; Torras Costa, Juan
    Journal of computational chemistry
    Date of publication: 2010-11-15
    Journal article

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    The PUPIL system is a combination of software and protocols for the systematic linkage and interoperation of molecular dynamics and quantum mechanics codes to perform QM/MD (sometimes called QM/MM) calculations. The Gaussian-03 and Amber packages were added to the Pupil suite recently. However, efficient parallel QM codes are critical because calculation of the QM forces is the overwhelming majority of the computational load. Here we report details of incorporation of the deMon2k density functional suite as a new parallel QM code. An additional motivation is to add a highly optimized, purely DFT code. We illustrate with a demonstration study of the influence of perchlorate as a dopant ion of the poly(3,4-ethylenedioxythiophene) conducting polymer in explicit acetonitrile solvent using Amber and deMon2k. We discuss unanticipated requirements for use of a scheme for semi-empirical correction of Kohn-Sham eigenvalues to give physically meaningful one-electron gap energies. We provide comparison of both geometric parameters and electronic properties for non-doped and doped systems. We also present results comparing deMon2k and Gaussian03 calculation of forces for a short sequence of steps. And we discuss briefly some difficult problems of quantum zone scf convergence for the anionically doped system. The difficulties seem to be caused by well-know deficiencies in simple approximate exchange-correlation functionals.

  • Poly(2-thiophene-3-yl-malonic acid), a Polythiophene with Two Carboxylic Acids Per Repeating Unit

     Bertran Cànovas, Oscar; Armelin Diggroc, Elaine; Estrany Coda, Francisco; Gomes, Alex Linardi; Torras Costa, Juan; Aleman Llanso, Carlos Enrique
    Journal of physical chemistry B
    Date of publication: 2010-04-22
    Journal article

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    A new substituted polythiophene derivative bearing malonic acid, poly(2-thiophen-3-yl-malonic acid), has been prepared and characterized using a strategy that combines both experimental and theoretical methodologies. The chemical structure of this material has been investigated using FTIR and 1H NMR, and its molecular conformation has been determined using quantum mechanical calculations. Interestingly, the arrangement of the inter-ring dihedral angles was found to depend on the ionization degree of the material, that is, on the pH, which has been found completely soluble in aqueous base solution. Thus, the preferred anti-gauche conformation changes to syn-gauche when the negatively charged carboxylate groups transforms into neutral carboxylic acid. UV−vis experiments and quantum mechanical calculations on model systems with a head-to-tail regiochemistry showed that the lowest π−π* transition energy is 2.25 and 2.39 eV for the negatively charged and the neutral polymer, respectively. These values are slightly larger than those previously reported for other polythiophenes with bulky polar side groups. The polymer presents a good thermal stability with a decomposition temperature above 215 °C and an electrical conductivity of 10−5 S/cm, which is characteristic of semiconductor materials. Scanning electron microscopy micrographs showed that, after doping, the surface of this material displays regular distribution pores with irregular sizes. This surface suggests that poly(2-thiophen-3-yl-malonic acid) is a candidate for potential applications such as selective membranes for electrodialysis, wastewater treatment, or ion-selective membranes for biomedical uses.

  • Modeling the structural and electronic properties of an optically active regioregular polythiophene

     Bertran Cànovas, Oscar; Torras Costa, Juan; Aleman Llanso, Carlos Enrique
    The journal of physical chemistry. Part C, nanomaterials and interfaces
    Date of publication: 2010-06-03
    Journal article

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    A comprehensive theoretical study about the structural and electronic molecular properties of the optically active regioregular poly[(R)-3-(4-(4-ethyl-2-oxazolin-2-yl)phenyl)thiophene] and its model oligomers has been developed with use of quantum mechanical calculations. Results show two stable arrangements for the investigated oligomers. The first one consists of a plain structure with all the inter-ring dihedral angles arranged in a syn-gauche+ conformation rather than the anti-gauche+ typically found in substituted polythiophenes. This produces a reduction of the steric repulsions allowing the formation of a π-stacking alignment between phenyl groups of adjacent monomers. The second is a helical structure with six repeating units per turn that is constructed by alternating the syn-gauche+ and syn-gauche- conformations. The lowest π-π* transition energy predicted for an idealized polymer chain, which was derived from Density Functional Theory calculations, is in agreement with the reported experimental values obtained by UV-vis spectroscopy.

  • APLICACIONES DE LOS POLÍMEROS CONDUCTORES EN INGENIERÍA Y BIOTECNOLOGÍA

     Bertran Cànovas, Oscar; Torras Costa, Juan; Estrany Coda, Francisco; Armelin Diggroc, Elaine; Iribarren Laco, Jose Ignacio; Liesa Mestres, Francisco; Zanuy Gomara, David; Revilla Lopez, Guillermo; Canales Gabriel, Manel; Aleman Llanso, Carlos Enrique
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  • Thermodynamic Control of the Polymerizability of Five-, Six-, and Seven-Membered Lactones

     Aleman Llanso, Carlos Enrique; Bertran Cànovas, Oscar; Casanovas, Jordi; Hall, H.K.; Houk, K.N.
    Journal of organic chemistry
    Date of publication: 2009-08
    Journal article

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  • Controlled Isomerization of a Light-Driven Molecular Motor: A Theoretical Study

     Torras Costa, Juan; Rodriguez Ropero, Francisco; Bertran Cànovas, Oscar; Aleman Llanso, Carlos Enrique
    The journal of physical chemistry. Part C, nanomaterials and interfaces
    Date of publication: 2009
    Journal article

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  • Characterization and properties of a polythiophene with a malonic acid dimethyl ester side group

     Armelin Diggroc, Elaine; Bertran Cànovas, Oscar; Estrany Coda, Francisco; Salvatella, Roser; Aleman Llanso, Carlos Enrique
    European polymer journal
    Date of publication: 2009-05-27
    Journal article

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  • INNOVACIO, MODELITZACIÓ I ENGINYERIA EN BIOMATERIALES (IMEM)

     Liesa Mestres, Francisco; Torras Costa, Juan; Bertran Cànovas, Oscar; Estrany Coda, Francisco; Zanuy Gomara, David; Armelin Diggroc, Elaine; Iribarren Laco, Jose Ignacio; Revilla Lopez, Guillermo; Aleman Llanso, Carlos Enrique
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  • Structural and electronic properties of poly(thiaheterohelicene)s

     Torras Costa, Juan; Bertran Cànovas, Oscar; Aleman Llanso, Carlos Enrique
    Journal of physical chemistry B
    Date of publication: 2009-10-26
    Journal article

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    Quantum chemical methods have been applied on model oligomers of poly(thiaheterohelicene)s to investigate the structural and electronic properties of these systems. Specifically, the properties of the helical structures found for poly(heterohelicene) and poly(methyl-sulfonium), which were calculated using density functional theory calculations, are in good agreement with available experimental data. The geometrical parameters obtained for poly(methyl-sulfonium) reflect the enlargement of the inner carbon-carbon bond lengths at the thiophene rings, which are those closer to the helical screw axes, and lead to reduce their aromaticity of such heterocycles. On this basis, a relationship between the aromaticity and the lowest π-π* transition energy has been established. Finally, the lowest π-π* transitions have been extrapolated for infinite polymer chains of poly(heterohelicene) and poly(methyl-sulfonium) using different theoretical approaches.

  • Cross-linking in polypyrrole and poly(N-methylpyrrole): comparative experimental and theoretical studies

     Aleman Llanso, Carlos Enrique; Casanovas, J; Torras Costa, Juan; Bertran Cànovas, Oscar; Armelin Diggroc, Elaine; Oliver Pujol, Ramon; Estrany Coda, Francisco
    Polymer
    Date of publication: 2008-02
    Journal article

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  • Structural and electronic properties of poly(3-thiophen-3-yl-acrylic acid)

     Bertran Cànovas, Oscar; Armelin Diggroc, Elaine; Torras Costa, Juan; Estrany Coda, Francisco; Mireia, Codina; Aleman Llanso, Carlos Enrique
    Polymer
    Date of publication: 2008-04
    Journal article

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  • Correlation between symmetry breaker position and the preferences of conformationally constrained homopeptides: a molecular dynamics investigation

     Torras Costa, Juan; Zanuy Gomara, David; Crisma, Marco; Toniolo, Claudio; Bertran Cànovas, Oscar; Aleman Llanso, Carlos Enrique
    Biopolymers
    Date of publication: 2008-10
    Journal article

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  • Hydrogen bonding interactions in 2-thiophen-2-ylmalonic acid

     Casanovas, Jordi; Bertran Cànovas, Oscar; Armelin Diggroc, Elaine; Torras Costa, Juan; Estrany Coda, Francisco; Aleman Llanso, Carlos Enrique
    Journal of physical chemistry A
    Date of publication: 2008-10
    Journal article

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  • Modelling organic molecular crystals by hybrid quantum mechanical/molecular mechanical embedding

     Torras Costa, Juan; Bromley, Stefan; Bertran Cànovas, Oscar; Francesc, Illas
    Chemical physics letters
    Date of publication: 2008-05
    Journal article

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  • On the structural and electronic properties of poly(3-thiophen-3-yl-acrylic acid methyl ester)

     Bertran Cànovas, Oscar; Pfeifer, Peter; Torras Costa, Juan; Armelin Diggroc, Elaine; Estrany Coda, Francisco; Aleman Llanso, Carlos Enrique
    Polymer
    Date of publication: 2007-11
    Journal article

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  • Primeras pruebas de impresión fotográfica sobre piel curtida

     Damga, Selmin; Bertran Cànovas, Oscar
    55 Congreso AQEIC
    Presentation's date: 2006-05-06
    Presentation of work at congresses

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  • Apunts de fonaments de física

     Bertran Cànovas, Oscar; Riba Ruiz, Jordi Roger
    Date of publication: 2006-06-30
    Book

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  • Apunts de fonaments matemàtics i

     Riba Ruiz, Jordi Roger; Bertran Cànovas, Oscar
    Date of publication: 2006-06-30
    Book

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  • Desarrollo de polímeros conductores con aplicaciones en ingeniería y biotecnología mediante simulación molecular y técnicas electroquímicas

     Aleman Llanso, Carlos Enrique; Iribarren Laco, Jose Ignacio; Armelin Diggroc, Elaine; Estrany Coda, Francisco; Torras Costa, Juan; Bertran Cànovas, Oscar; Zanuy Gomara, David; Liesa Mestres, Francisco
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  • Single conductor DC magnetic field reduction

     Riba Ruiz, Jordi Roger; Bertran Cànovas, Oscar
    Date of publication: 2005-05-01
    Book chapter

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  • Mesura del cicle d'histèresi dinàmic d'un material ferromagnètic

     Riba Ruiz, Jordi Roger; Bertran Cànovas, Oscar
    Revista de física
    Date of publication: 2005-01
    Journal article

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  • Comprovació experimental de la llei de Coulomb per a pols magnètics

     Bertran Cànovas, Oscar; Riba Ruiz, Jordi Roger
    Revista de física
    Date of publication: 2004-06
    Journal article

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  • Single conductor DC magnetic field reduction

     Riba Ruiz, Jordi Roger; Bertran Cànovas, Oscar
    1st International Meeting on Applied Physics
    Presentation of work at congresses

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  • La Escuela Superior de Tenería de Igualada, un centro al servicio de las empresas de curtidos

     Rius Carrasco, Antoni; Puig Vidal, Rita; Riba Ruiz, Jordi Roger; Bertran Cànovas, Oscar; Olle Otero, Luis; Morera Prat, Josep Maria; Canals Parelló, Trini; Font Vallès, Joaquim; Cantero Gómez, Maria Rosa
    XXVII IULTCS Congress
    Presentation's date: 2003-05-31
    Presentation of work at congresses

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  • Aportación al apantallamiento del campo magnético que genera un conductor único que transporta corriente alterna

     Riba Ruiz, Jordi Roger; Bertran Cànovas, Oscar; Alabern Morera, Francesc Xavier
    Eléctrica'2002
    Presentation of work at congresses

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  • Leather roghness characterisation by fractal geometry

     Bertran Cànovas, Oscar; Manich Bou, Albert M.; Ussman, Mohamed; Bacardit Dalmases, Anna; Bosch, Teresa; Morera Prat, Josep Maria
    XXVI IULTCS Congress in Cape Town
    Presentation of work at congresses

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  • Estudio previo sobre la curtición con ultrasonidos

     Soler Solé, Jaume; Morera Prat, Josep Maria; Bertran Cànovas, Oscar; Borràs Fillat, Maria Dolors; Bartolí Soler, Esther
    Symposium AIICA sobre tecnologías limpias
    Presentation's date: 1995-10-05
    Presentation of work at congresses

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