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    Synthesis and evaluation of a PVDF-PT3MA-Zn2SiO4:Mn hybrid polymeric composite for optical device applications  Open access

     Gomes, Alex Linardi; Lang, Rossano; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique; Sinezio De Carvalho Campos, Joao
    Journal of materials chemistry C
    Date of publication: 2014-01-01
    Journal article

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    A new hybrid organic/inorganic composite consisting of poly(3-thiophene methyl acetate) (PT3MA), poly(vinylidene fluoride) (PVDF) and manganese-doped zinc silicate (Zn2SiO4:Mn) has been synthesized and applied for the fabrication of an optical device. Recrystallized PVDF was used as a host matrix for the PT3MA polymer and Zn2SiO4:Mn inorganic compound. The active layer was deposited on an indium-tin-oxide (ITO)-coated glass substrate by the drop casting technique. A spin-coating method was also used for morphological comparison purposes. The synthesized material as well as the device (aluminium electrodes/PVDF-PT3MA-Zn2SiO4:Mn/ITO/glass) was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDX), dark current-voltage (I-V) characteristic curves, absorbance and photoluminescence (PL) spectroscopy. The results show spherical-and irregular-shaped microparticles both dispersed on and within the PVDF matrix, which correspond to PT3MA and Zn2SiO4:Mn, respectively. The hybrid composite shows strong luminescence at approximate to 525 nm superimposed by a broadband between 600 and 800 nm, originating from the Zn2SiO4:Mn radiative transitions and from the recombination of photogenerated carriers at PT3MA. At room temperature, the device presented semiconductor behaviour typically observed for photodetectors and a DC electrical conductivity of approximate to 0.37 mu S cm(-1).

    A new hybrid organic/inorganic composite consisting of poly(3-thiophene methyl acetate) (PT3MA), poly(vinylidene fluoride) (PVDF) and manganese-doped zinc silicate (Zn2SiO4:Mn) has been synthesized and applied for the fabrication of an optical device. Recrystallized PVDF was used as a host matrix for the PT3MA polymer and Zn2SiO4:Mn inorganic compound. The active layer was deposited on an indium-tin-oxide (ITO)-coated glass substrate by the drop casting technique. A spin-coating method was also used for morphological comparison purposes. The synthesized material as well as the device (aluminium electrodes/PVDF-PT3MA-Zn2SiO4:Mn/ITO/glass) was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDX), dark current-voltage (I-V) characteristic curves, absorbance and photoluminescence (PL) spectroscopy. The results show spherical-and irregular-shaped microparticles both dispersed on and within the PVDF matrix, which correspond to PT3MA and Zn2SiO4:Mn, respectively. The hybrid composite shows strong luminescence at approximate to 525 nm superimposed by a broadband between 600 and 800 nm, originating from the Zn2SiO4:Mn radiative transitions and from the recombination of photogenerated carriers at PT3MA. At room temperature, the device presented semiconductor behaviour typically observed for photodetectors and a DC electrical conductivity of approximate to 0.37 mu S cm(-1).

  • Measuring the proton conductivity of ion-exchange membranes using electrochemical impedance spectroscopy and Through-Plane cell

     Müller, Franciélli; Ferreira, Carlos A.; Azambuja, Denise S.; Aleman Llanso, Carlos Enrique; Armelin Diggroc, Elaine
    Journal of physical chemistry B
    Date of publication: 2014-01-30
    Journal article

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    The role of the incorporation of conducting polymer (CP), doped with different sulfonic acid organic molecules, in polystyrene (PS) and high-impact polystyrene (HIPS) with poly(styrene-ethylene-butylene) (SEBS) triblock copolymer has been investigated. Two factors associated with this model membrane system are addressed: (i) the influence of the presence of a low concentration of doped conducting polymer and (ii) the influence of the membrane preparation method. Membrane characterization and bulk conductivity measurements allowed the conclusion that proton conductivity has been promoted by the addition of CP; the best results were achieved for PAni-CSA, in either PS/SEBS or HIPS/SEBS blends. Additionally, the water uptake only decreased with the addition of PAni-doped molecules compared to the pure copolymer, without loss of ion-exchange capacity (IEC). Electrodialysis efficiency for HIPS/SEBS (before annealing) is higher than that for HIPS/SEBS (after annealing), indicating that membrane preparation method is crucial. Finally, through-plane cell arrangement proved to be an effective, quick, and time-saving tool for studying the main resistance parameters of isolating polymers, which is useful for application in industry and research laboratories working with membranes for electrodialysis or fuel cells.

  • Sol-gel hybrid films based on organosilane and montmorillonite for corrosion inhibition of AA2024

     Dalmoro, V.; Dos Santos, J.H.Z.; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique; Azambuja, Denise S.
    Journal of colloid and interface science
    Date of publication: 2014-07-15
    Journal article

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    The present work reports the production of films on AA2024-T3 composed of vinyltrimethoxysilane (VTMS)/tetraethylorthosilicate (TEOS) with incorporation of montmorillonite (sodium montmorillonite and montmorillonite modified with quaternary ammonium salt, abbreviated Na and 30B, respectively), generated by the sal-gel process. According to FT-IR analyses the incorporation of montmorillonite does not affect silica network. Electrochemical characterization was performed by electrochemical impedance spectroscopy measurement in 0.05 mol L-1 NaCl solution. Results indicate that montmorillonite incorporation improves the corrosion protection compared to the non-modified system. Scanning electron microscopy micrographs reveal that high concentrations of montmorillonite provide agglomerations on the metallic surface, which is in detriment of the anticorrosive performance. The VTMS/TEOS/30B films with the lowest concentration (22 mg L-1) of embedded clay provide the highest corrosion protection. (C) 2014 Elsevier Inc. All rights reserved.

    The present work reports the production of films on AA2024-T3 composed of vinyltrimethoxysilane (VTMS)/tetraethylorthosilicate (TEOS) with incorporation of montmorillonite (sodium montmorillonite and montmorillonite modified with quaternary ammonium salt, abbreviated Na and 30B, respectively), generated by the sal-gel process. According to FT-IR analyses the incorporation of montmorillonite does not affect silica network. Electrochemical characterization was performed by electrochemical impedance spectroscopy measurement in 0.05 mol L-1 NaCl solution. Results indicate that montmorillonite incorporation improves the corrosion protection compared to the non-modified system. Scanning electron microscopy micrographs reveal that high concentrations of montmorillonite provide agglomerations on the metallic surface, which is in detriment of the anticorrosive performance. The VTMS/TEOS/30B films with the lowest concentration (22 mg L-1) of embedded clay provide the highest corrosion protection. (C) 2014 Elsevier Inc. All rights reserved.

  • Electronic, electric and electrochemical properties of bioactive nanomembranes made of polythiophene:thermoplastic polyurethane

     Perez Madrigal, Maria Del Mar; Giannotti, Marina I.; Armelin Diggroc, Elaine; Sanz Carrasco, Fausto; Aleman Llanso, Carlos Enrique
    Polymer Chemistry
    Date of publication: 2014-02-21
    Journal article

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    The electronic, electric and electrochemical response of nanomembranes prepared by using spin-coating mixtures of a semiconducting polythiophene derivative (P3TMA) and thermoplastic polyurethane (TPU) has been exhaustively examined by UV-vis spectroscopy, conductive AFM, current/voltage measurements and cyclic voltammetry. TPU:P3TMA nanomembranes were reported to be good substrates for applications related to tissue engineering, acting as a cellular matrix for cell adhesion and proliferation. Both TPU:P3TMA and P3TMA nanomembranes show semiconductor behavior with very similar band gap energy (2.35 and 2.32 eV, respectively), which has been attributed to the influence of the fabrication process on the pi-conjugation length and packing interactions of P3TMA chains. This behavior is in opposition to the observations in THF solution, which indicates that the band gap energy of P3TMA is clearly lower than that of the mixture, independently of the concentration. The current and conductivity values determined for the nanomembranes, which range from 0.43 to 1.85 pA and from 2.23 x 10(-5) to 5.19 x 10(-6) S cm(-1), respectively, evidence inhomogeneity in the P3TMA-rich domains. This has been associated with the irregular distribution of the doped chains and the presence of insulating TPU chains. The voltammetric response of TPU:P3TMA and P3TMA nanomembranes is similar in terms of ability to store charge and electrochemical stability. Overall results indicate that TPU:P3TMA nanomembranes are potential candidates for the fabrication of bioactive substrates able to promote cell regeneration through electrical or electrochemical stimulation.

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    A rational design for the selective detection of dopamine using conducting polymers  Open access

     Fabregat Jove, Georgina; Casanovas Salas, Jordi; Redondo Negrete, Edurne; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique
    Physical chemistry chemical physics
    Date of publication: 2014-02-25
    Journal article

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    Poly(N-methylpyrrole) (PNMPy), poly(N-cyanoethylpyrrole) (PNCPy) and poly(3,4-ethylenedioxythiophene) (PEDOT) films have been prepared using both single and two polymerization steps for the selective determination of low concentrations of dopamine, ascorbic acid and uric acid in tertiary mixtures. Analysis of the sensitivity and resolution parameters derived from the electrochemical response of such films indicates that PEDOT is the most appropriate for the unambiguous detection of the three species. Indeed, the performance of PEDOT is practically independent of the presence of both gold nanoparticles at the surface of the film and interphases inside the film, even though these two factors are known to improve the electroactivity of conducting polymers. Quantum mechanical calculations on model complexes have been used to examine the intermolecular interaction involved in complexes formed by PEDOT chains and oxidized dopamine, ascorbic acid and uric acid. Results show that such complexes are mainly stabilized by C-H¿O interactions rather than by conventional hydrogen bonds. In order to improve the sensitivity of PEDOT through the formation of specific hydrogen bonds, a derivative bearing a hydroxymethyl group attached to the dioxane ring of each repeat unit has been designed. Poly(hydroxymethyl-3,4-ethylenedioxythiophene) (PHMeDOT) has been prepared and characterized by FTIR, UV-vis spectroscopy, cyclic voltammetry, scanning electron microscopy and atomic force microscopy. Finally, the performance of PHMeDOT and PEDOT for the selective detection of the species mentioned above has been compared. © 2014 the Partner Organisations.

    Poly(N-methylpyrrole) (PNMPy), poly(N-cyanoethylpyrrole) (PNCPy) and poly(3,4-ethylenedioxythiophene) (PEDOT) films have been prepared using both single and two polymerization steps for the selective determination of low concentrations of dopamine, ascorbic acid and uric acid in tertiary mixtures. Analysis of the sensitivity and resolution parameters derived from the electrochemical response of such films indicates that PEDOT is the most appropriate for the unambiguous detection of the three species. Indeed, the performance of PEDOT is practically independent of the presence of both gold nanoparticles at the surface of the film and interphases inside the film, even though these two factors are known to improve the electroactivity of conducting polymers. Quantum mechanical calculations on model complexes have been used to examine the intermolecular interaction involved in complexes formed by PEDOT chains and oxidized dopamine, ascorbic acid and uric acid. Results show that such complexes are mainly stabilized by C-H¿O interactions rather than by conventional hydrogen bonds. In order to improve the sensitivity of PEDOT through the formation of specific hydrogen bonds, a derivative bearing a hydroxymethyl group attached to the dioxane ring of each repeat unit has been designed. Poly(hydroxymethyl-3,4-ethylenedioxythiophene) (PHMeDOT) has been prepared and characterized by FTIR, UV-vis spectroscopy, cyclic voltammetry, scanning electron microscopy and atomic force microscopy. Finally, the performance of PHMeDOT and PEDOT for the selective detection of the species mentioned above has been compared. © 2014 the Partner Organisations.

  • Selective detection of dopamine combining multilayers of conducting polymers with gold nanoparticles

     Fabregat Jove, Georgina; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique
    Journal of physical chemistry B
    Date of publication: 2014-05-01
    Journal article

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    Electrodes based on the combination of three-layered films formed by two different conducting polymers and gold nanoparticles have been developed for the selective voltammetric determination of dopamine in mixtures with ascorbic acid and uric acid and human urine samples with real interferents. Voltammetric studies of solution mixtures indicate that electrodes formed by alternated layers of poly(3,4-ethylenedioxithiophene) (internal and external layer) and poly(N-methylpyrrole) (intermediate layer) show the best performance in terms of sensitivity and resolution. Furthermore, the sensitivity of such three-layered electrodes increases only slightly after coating its surface with gold nanoparticles (AuNPs), indicating that the catalytic effect typically played by AuNPs in the oxidation of dopamine is less effective in this case. Electrochemical pretreatments based on the application of consecutive oxidation-reduction cycles to electrodes before the detection process have been found to improve the selectivity without altering the sensitivity. On the other hand, the flux of dopamine to the three-layered surface increases linearly with the scan rate. The detection limit for these electrodes is around 10 µM DA in mixtures with uric acid, ascorbic acid, and cetaminophen, decreasing to 2-3 µM in the absence of such interferents. The utility of three-layered electrodes as sensors has also been demonstrated by determining DA in human samples with real interferents.

    Electrodes based on the combination of three-layered films formed by two different conducting polymers and gold nanoparticles have been developed for the selective voltammetric determination of dopamine in mixtures with ascorbic acid and uric acid and human urine samples with real interferents. Voltammetric studies of solution mixtures indicate that electrodes formed by alternated layers of poly(3,4-ethylenedioxithiophene) (internal and external layer) and poly(N-methylpyrrole) (intermediate layer) show the best performance in terms of sensitivity and resolution. Furthermore, the sensitivity of such three-layered electrodes increases only slightly after coating its surface with gold nanoparticles (AuNPs), indicating that the catalytic effect typically played by AuNPs in the oxidation of dopamine is less effective in this case. Electrochemical pretreatments based on the application of consecutive oxidation-reduction cycles to electrodes before the detection process have been found to improve the selectivity without altering the sensitivity. On the other hand, the flux of dopamine to the three-layered surface increases linearly with the scan rate. The detection limit for these electrodes is around 10 µM DA in mixtures with uric acid, ascorbic acid, and cetaminophen, decreasing to 2-3 µM in the absence of such interferents. The utility of three-layered electrodes as sensors has also been demonstrated by determining DA in human samples with real interferents.

  • Detection of dopamine using chemically synthesized multilayered hollow microspheres

     Fabregat Jove, Georgina; Estrany Coda, Francisco; Casas Becerra, M. Teresa; Aleman Llanso, Carlos Enrique; Armelin Diggroc, Elaine
    Journal of physical chemistry B
    Date of publication: 2014-05-01
    Journal article

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    Microspheres made of alternating layers of two different conducting polymers, poly(3,4-ethylenedioxythiophene) and poly(N-methylpyrrole), have been found to be sensitive to dopamine (DA) oxidation, presenting a very well-defined and linear response in the range of DA concentrations from 0.5 to 2 mM. The novelty of the present study is the use of doped multilayered hollow microspheres, which are prepared by successive oxidative chemical polymerizations in FeCl3 aqueous solution. The multilayered microspheres were characterized by FTIR and UV-visible spectroscopies, scanning and transmission electron microscopies, and atomic force microscopy. The UV-visible bands confirm that the multilayered system is not well doped with FeCl4 - counterions. Therefore, the doping level was increased by further oxidation with LiClO4 before DA electrochemical detection. Despite that the range of concentration detection was limited from 0.5 mM to 2 mM, doped hollow multilayered microspheres show a very good anodic peak current response compared to single-layer films fabricated with an individual conducting polymer and activated by gold nanoparticles.

  • Hybrid nanofibers from biodegradable polylactide and polythiophene for scaffolds

     Llorens Domenjo, Elena; Perez Madrigal, Maria Del Mar; Armelin Diggroc, Elaine; Del Valle Mendoza, Luis Javier; Puiggali Bellalta, Jorge; Aleman Llanso, Carlos Enrique
    RSC Advances
    Date of publication: 2014-01-01
    Journal article

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    Hybrid scaffolds constituted of polylactide (PLA) as a biodegradable polymer and poly(3-thiophene methyl acetate) (P3TMA) as an electroactive polymer were prepared and studied. Both polymers had a similar solubility and consequently could be easily electrospun using a common solvent. Electrospinning operational parameters were optimized to get continuous micro/nanofibers with a homogeneous diameter that ranged between 600 and 900 nm depending on the PLA-P3TMA ratio. Electrospinning was only effective when the P3TMA content was at maximum 50 wt%. The incorporation of P3TMA slightly decreased the fibre diameter, led to smoother fibre surfaces and gave rise to some heterogeneous clusters inside the fibers. PLA was highly oriented inside the electrospun fibers and able to easily cold crystallize by heating. Thermal degradation was not highly influenced by the presence of P3TMA, although the onset temperature slightly increased since the first decomposition step of PLA was prevented. New scaffolds had promising electrochemical properties and even provided a good substrate for cell adhesion and cell proliferation. Therefore, these hybrid materials are suitable to improve the cellular response towards physiological processes.

  • Conducting polymers and hybrid derivates with specific applications as sensors and bioactive platforms

     Fabregat Jove, Georgina
    Defense's date: 2014-06-06
    Universitat Politècnica de Catalunya
    Theses

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    El propósito de la presente tesis es el desarrollo y diseño de nanocompuestos híbridos basados ??en polímeros conductores para su posterior aplicación en el campo de la biotecnología y la biomedicina. Las principales líneas de investigación se resumen de la siguiente manera; 1) Preparación , caracterización y evaluación de derivados N-sustituidos de polipirrol y poli(3,4-etilendioxitiofeno ) (PEDOT) para la detección electroquímica de la dopamina, uno de los neurotransmisores asociados a trastornos neurológicos. Para examinar este propósito, diferentes estrategias han sido consideradas, tales como; el método de polimerización empleando polímeros individuales o combinados, la incorporación de nanopartículas de oro, la utilización de templates, etc. 2) Diseño de aminoácidos sintéticos unidos covalentemente con un grupo EDOT y posterior desarrollo de materiales híbridos (péptido - PEDOT). Los materiales híbridos han demostrado conservar las propiedades eléctricas y electroquímicas del polímero base, siendo posibles candidatos para el desarrollo de plataformas bioactivas y bioelectrocompatible. 3) Preparación y caracterización de materiales híbridos orgánicos formados por una cadena principal de politiofeno y cadenas injertadas de polietilenglicol (PEG), los cuales tienen una elevada aplicabilidad como superficies activas para la adsorción selectiva de proteínas y como plataformas bioactivas. 4) Preparación y caracterización de nuevos bionanocomposites formados por PEDOT y CREKA, el cual es un pentapéptido lineal biológicamente activo. La incorporación de CREKA en una matriz de PEDOT se ha llevado a cabo en diferentes condiciones experimentales, y ha demostrado tener un efecto positivo sobre las propiedades electroquímicas del polímero conductor como también proporcionar una mejora en la proliferación celular debido a la capacidad de éste para unirse a la fibrina. Algunos resultados obtenidos en la presente Tesis han sido publicados o aceptados para su publicación en revistas científicas: 1.An electroactive and biologically responsive hybrid conjugate based on chemical similarity. G. Fabregat, G. Ballano, E. Armelin, L. J. del Valle, C. Cativiela and C. Alemán, Polym. Chem., 2013, 4, 1412.2.Hybrid materials consisting of an all-conjugated polythiophene backbone and grafted hydrophilic poly(ethylene glycol) chains. A.-D. Bendrea, G. Fabregat, L. Cianga, F. Estrany, L. J. del Valle, I. Cianga and C. Alemán, Polym. Chem., 2013,4, 2709.3.Polythiophene-g-poly(ethylene glycol) graft copolymers for electroactive scaffolds.A.-D. Bendrea, G. Fabregat, J. Torras, S. Maione, L. Cianga, L. J. del Valle, I. Cianga and C. Alemán, J. Mater. Chem. B, 2013,1, 4135.4.Design of hybrid conjugates based on chemical similarity.G. Fabregat, G. Ballano, J. Casanovas, A. D. Laurent, E. Armelin, Luis J. del Valle, C. Cativiela, D. Jacquemin and C. Alemán, RSC Adv., 2013, 3, 21069.5.Controlling the morphology of poly(N -cyanoethylpyrrole).G. Fabregat, M. T. Casas, C. Alemán and E. Armelin, J. Phys. Chem. B, 2012, 116, 5064.7.Ultrathin Films of Polypyrrole Derivatives for Dopamine Detection. G. Fabregat, E. Córdova-Mateo, E. Armelin, O. Bertran and C. Alemán. J. Phys. Chem. C, 2011, 115,14933.8.Nanostructured conducting polymer for dopamine detection.M. Martí, G. Fabregat, F. Estrany, C. Alemán and E. Armelin, J. Mater. Chem., 2010, 20, 10652.

  • Novel epoxy coating based on DMSO as a green solvent, reducing drastically the volatile organic compound content and using conducting polymers as a nontoxic anticorrosive pigment

     Martí Barroso, Mireia; Molina Pérez, Laura; Aleman Llanso, Carlos Enrique; Armelin Diggroc, Elaine
    ACS Sustainable Chemistry & Engineering
    Date of publication: 2013-12-02
    Journal article

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    This work reports novel anticorrosive epoxy coatings based on safer dimethyl sulfoxide solvent and free of zinc anticorrosive pigment. The latter was replaced by conducting polymers, as nontoxic anticorrosive pigments. The procedure used for their formulation, spectroscopic characterization, thermal and mechanical properties have been discussed and compared with those of conventional epoxy coatings. Furthermore, accelerated and long-term corrosion assays have evidenced that the new epoxy coatings protect steel from chlorine aggressive medium for 2880 h and for 2 years in atmospheric corrosive medium. Therefore, the results evidenced an excellent corrosion resistance, excellent application, and aesthetic appearance of the new coatings. © 2013 American Chemical Society.

    This work reports novel anticorrosive epoxy coatings based on safer dimethyl sulfoxide solvent and free of zinc anticorrosive pigment. The latter was replaced by conducting polymers, as nontoxic anticorrosive pigments. The procedure used for their formulation, spectroscopic characterization, thermal and mechanical properties have been discussed and compared with those of conventional epoxy coatings. Furthermore, accelerated and long- term corrosion assays have evidenced that the new epoxy coatings protect steel from chlorine aggressive medium for 2880 h and for 2 years in atmospheric corrosive medium. Therefore, the results evidenced an excellent corrosion resistance, excellent application, and aesthetic appearance of the new coatings.

  • A synergistic combination of tetraethylorthosilicate and multiphosphonic acid offers excellent corrosion protection to AA1100 aluminum alloy

     Dalmoro, Viviane; dos Santos, João Henrique Zimnoch; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique; Azambuja, Denise S.
    Applied surface science
    Date of publication: 2013-05-15
    Journal article

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    This work describes a new mechanism for the incorporation of organophosphonic acid into silane self-assembly monolayers, which has been used to protect AA1100 aluminum alloy. The protection improvement has been attributed to the fact that phosphonic structures promote the formation of strongly bonded and densely packed monolayer films, which show higher surface coverage and better adhesion than conventional silane systems. In order to evaluate the linking chemistry offered by phosphonic groups, two functionalized organophosphonic groups have been employed, 1,2-diaminoethanetetrakis methylenephosphonic acid (EDTPO) and aminotrimethylenephosphonic acid (ATMP), and combined with tetraethylorthosilicate (TEOS) films prepared by sol¿gel synthesis. Results suggest that phosphonic acids may interact with the surface through a monodentate and bidentate coordination mode and, in addition, form one or more strong and stable linkages with silicon through non-hydrolysable bonds. Therefore, the incorporation of a very low concentration of phosphonic acids on TEOS solutions favors the complete coverage of the aluminum substrate during the silanization process, which is not possible using TEOS alone. The linking capacity of phosphonic acid has been investigated by FTIR-RA spectroscopy, SEM and EDX analysis, X-ray photoelectron spectroscopy (XPS), and quantum mechanical calculations. Finally, electrochemical impedance spectroscopy has been used to study the corrosion protection revealing that EDTPO-containing films afforded more protection to the AA1100 substrate than ATMP-containing films.

    This work describes a new mechanism for the incorporation of organophosphonic acid into silane self-assembly monolayers, which has been used to protect AA1100 aluminum alloy. The protection improvement has been attributed to the fact that phosphonic structures promote the formation of strongly bonded and densely packed monolayer films, which show higher surface coverage and better adhesion than conventional silane systems. In order to evaluate the linking chemistry offered by phosphonic groups, two functionalized organophosphonic groups have been employed, 1,2-diaminoethanetetrakis methylenephosphonic acid (EDTPO) and aminotrimethylenephosphonic acid (ATMP), and combined with tetraethylorthosilicate (TEOS) films prepared by sol–gel synthesis. Results suggest that phosphonic acids may interact with the surface through a monodentate and bidentate coordination mode and, in addition, form one or more strong and stable linkages with silicon through non-hydrolysable bonds. Therefore, the incorporation of a very low concentration of phosphonic acids on TEOS solutions favors the complete coverage of the aluminum substrate during the silanization process, which is not possible using TEOS alone. The linking capacity of phosphonic acid has been investigated by FTIR-RA spectroscopy, SEM and EDX analysis, X-ray photoelectron spectroscopy (XPS), and quantum mechanical calculations. Finally, electrochemical impedance spectroscopy has been used to study the corrosion protection revealing that EDTPO-containing films afforded more protection to the AA1100 substrate than ATMP-containing films

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    Sensitive thermal transitions of nanoscale polymer samples using the bimetallic effect: Application to ultra-thin polythiophene  Open access

     Ahumada Heredero, Óscar; Perez Madrigal, Maria Del Mar; Ramírez García, Jorge; Curcó Cantarell, David; Esteves, Carina; Armelin Diggroc, Elaine; Luongo, Giovanni; Puiggali Bellalta, Jorge; Aleman Llanso, Carlos Enrique; Salvador Matar, Antonio
    Review of scientific instruments
    Date of publication: 2013-06-15
    Journal article

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    A sensitive nanocalorimetric technology based on microcantilever sensors is presented. The tech- nology, which combines very short response times with very small sample consumption, uses the bimetallic effect to detect thermal transitions. Specifically, abrupt variations in the Young¿s modu- lus and the thermal expansion coefficient produced by temperature changes have been employed to detect thermodynamic transitions. The technology has been used to determine the glass transition of poly(3-thiophene methyl acetate), a soluble semiconducting polymer with different nanotechno- logical applications. The glass transition temperature determined using microcantilevers coated with ultra-thin films of mass = 10 - 13 gis5.2 ¿ C higher than that obtained using a conventional differential scanning calorimeter for bulk powder samples of mass = 5 × 10 - 3 g. Atomistic molecular dynamics simulations on models that represent the bulk powder and the ultra-thin films have been carried out to provide understanding and rationalization of this feature. Simulations indicate that the film-air in- terface plays a crucial role in films with very small thickness, affecting both the organization of the molecular chains and the response of the molecules against the temperature.

    A sensitive nanocalorimetric technology based on microcantilever sensors is presented. The tech- nology, which combines very short response times with very small sample consumption, uses the bimetallic effect to detect thermal transitions. Specifically, abrupt variations in the Young’s modu- lus and the thermal expansion coefficient produced by temperature changes have been employed to detect thermodynamic transitions. The technology has been used to determine the glass transition of poly(3-thiophene methyl acetate), a soluble semiconducting polymer with different nanotechno- logical applications. The glass transition temperature determined using microcantilevers coated with ultra-thin films of mass = 10 − 13 gis5.2 ◦ C higher than that obtained using a conventional differential scanning calorimeter for bulk powder samples of mass = 5 × 10 − 3 g. Atomistic molecular dynamics simulations on models that represent the bulk powder and the ultra-thin films have been carried out to provide understanding and rationalization of this feature. Simulations indicate that the film-air in- terface plays a crucial role in films with very small thickness, affecting both the organization of the molecular chains and the response of the molecules against the temperature.

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    Nanomembranes and nanofibers from biodegradable conducting polymers  Open access

     Llorens Domenjo, Elena; Armelin Diggroc, Elaine; Perez Madrigal, Maria Del Mar; Del Valle Mendoza, Luis Javier; Aleman Llanso, Carlos Enrique; Puiggali Bellalta, Jorge
    Polymers
    Date of publication: 2013-09-01
    Journal article

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    This review provides a current status report of the field concerning preparation of fibrous mats based on biodegradable (e. g., aliphatic polyesters such as polylactide or polycaprolactone) and conducting polymers (e. g., polyaniline, polypirrole or polythiophenes). These materials have potential biomedical applications (e. g., tissue engineering or drug delivery systems) and can be combined to get free-standing nanomembranes and nanofibers that retain the better properties of their corresponding individual components. Systems based on biodegradable and conducting polymers constitute nowadays one of the most promising solutions to develop advanced materials enable to cover aspects like local stimulation of desired tissue, time controlled drug release and stimulation of either the proliferation or differentiation of various cell types. The first sections of the review are focused on a general overview of conducting and biodegradable polymers most usually employed and the explanation of the most suitable techniques for preparing nanofibers and nanomembranes (i.e., electrospinning and spin coating). Following sections are organized according to the base conducting polymer (e. g., Sections 4-6 describe hybrid systems having aniline, pyrrole and thiophene units, respectively). Each one of these sections includes specific subsections dealing with applications in a nanofiber or nanomembrane form. Finally, miscellaneous systems and concluding remarks are given in the two last sections.

    This review provides a current status report of the field concerning preparation of fibrous mats based on biodegradable (e. g., aliphatic polyesters such as polylactide or polycaprolactone) and conducting polymers (e. g., polyaniline, polypirrole or polythiophenes). These materials have potential biomedical applications (e. g., tissue engineering or drug delivery systems) and can be combined to get free-standing nanomembranes and nanofibers that retain the better properties of their corresponding individual components. Systems based on biodegradable and conducting polymers constitute nowadays one of the most promising solutions to develop advanced materials enable to cover aspects like local stimulation of desired tissue, time controlled drug release and stimulation of either the proliferation or differentiation of various cell types. The first sections of the review are focused on a general overview of conducting and biodegradable polymers most usually employed and the explanation of the most suitable techniques for preparing nanofibers and nanomembranes (i.e., electrospinning and spin coating). Following sections are organized according to the base conducting polymer (e. g., Sections 4-6 describe hybrid systems having aniline, pyrrole and thiophene units, respectively). Each one of these sections includes specific subsections dealing with applications in a nanofiber or nanomembrane form. Finally, miscellaneous systems and concluding remarks are given in the two last sections.

  • Bioactive nanomembranes of semiconductor polythiophene and thermoplastic polyurethane: Thermal, nanostructural and nanomechanical properties

     Perez Madrigal, Maria Del Mar; Giannotti, Marina I.; Oncins Marco, Gerard; Franco Garcia, Maria Lourdes; Armelin Diggroc, Elaine; Puiggali Bellalta, Jorge; Sanz Carrasco, Fausto; Del Valle Mendoza, Luis Javier; Aleman Llanso, Carlos Enrique
    Polymer Chemistry
    Date of publication: 2013-02-07
    Journal article

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  • Electroactive nanofibers for drug release devices and cellular substrates

     Perez Madrigal, Maria Del Mar; Llorens Domenjo, Elena; Armelin Diggroc, Elaine; Del Valle Mendoza, Luis Javier; Puiggali Bellalta, Jorge; Aleman Llanso, Carlos Enrique
    International Conference on Materials Chemistry
    Presentation's date: 2013-07-08
    Presentation of work at congresses

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  • Transport of ions inside polymeric cation exchange membranes: Experimental and theoretical studies

     Armelin Diggroc, Elaine; Cordova Mateo, Ester; Müller, Franciélli; Bertran Cànovas, Oscar; Ferreira, Carlos Arthur; Aleman Llanso, Carlos Enrique
    Frontiers in Polymer Science
    Presentation's date: 2013-05-21
    Presentation of work at congresses

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  • Smart electroactive hybrid materials as platforms for tissue engineering

     Armelin Diggroc, Elaine; Fabregat Jove, Georgina; Ballano Ballano, María Gema; Bendrea, Anca-Dana; Cianga, Luminita; Del Valle Mendoza, Luis Javier; Cativiela, Carlos; Cianga, Ioan; Aleman Llanso, Carlos Enrique
    Frontiers in Polymer Science
    Presentation's date: 2013-05-21
    Presentation of work at congresses

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  • Efecto de la agitación en la electrogeneración del PEDOT en medios con baja concentración de monómero: mejora en la electroactividad de los depósitos

     Estrany Coda, Francisco; Sanchez Jimenez, Margarita; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique
    Reunión Bienal de la Real Sociedad Española de Química
    Presentation's date: 2013-07-16
    Presentation of work at congresses

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  • Membranas Poliméricas Íon Seletivas Aniônicas e Catiônicas Para Uso Em Eletrodiálise  Open access

     Müller, Franciélli
    Defense's date: 2013-09-27
    Universitat Politècnica de Catalunya
    Theses

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    El objetivo principal de la presente Tesis Doctoral es el desarrollo de membranas poHméricas aniónicas y catiónicas para el tratamiento de soluciones que contienen iones metálicos utilizando el proceso de electrodiáHsis. En este trabajo fueron sintetizadas membranas catiónicas a partir de palies ti reno cristal (PS), poliestireno de alto impacto (HIPS) con copolímero en bloque de poli(etileno-butileno-estireno) (SEBS) y de polianilina (PAni) dopada con ácido canforsulfónico (CSA). Después de la sulfonación, fueron utilizadas las mezclas de los polímeros para producir las membranas selectivas de iones por evaporación del disolvente con posterior tratamiento térmico. Las membranas aniónicas fueron sintetizadas a partir de poli(alcohol vinílico) (PVA), con la inserción de grupos cuaternario de amonio en la matriz del polímero y posterior reticulación con glutaraldehído y anhídrido maleico. Diferentes membranas fueron sintetizadas con el propósito de comparar y evaluar la combinación de propiedades mecánica, química, electroquímica y del transporte de iones. La morfología y estructura de las membranas fueron analizadas por microscopía electrónica de barrido, microscopfa de fuerza atómica y espectroscopia de infrarrojos. La estabilidad y las transiciones térmicas de todas las membranas fueron caracterizadas utilizando las técnicas calorimétricas y se compararon con todos los polímeros individuales. Las propiedades físicas (por ejemplo, la conductividad iónica, capacidad de intercambio de iones, la absorción de agua, estabilidad dimensional, propiedades mecánicas, etc.) mostraron que la performance de las membranas catiónicas que contienen PS es generalmente más alta que las membranas que contienen HIPS. Los ensayos de electrodiálisis para la determinación del desempeño de las membranas en el transporte de iones sodio, níquel, cromo, cloruros e nitratos fueron realizados en una celda de laboratorio con tres compartimientos. Membranas comerciales Selemion® CMT (catiónica) y AMV(aniónica) fueron utilizadas para comparar los resultados de la extracción porcentual de los iones indicados.Todos los resultados obtenidos en la presente tesis han sido aceptados o han sido enviados para publicación en revistas internacionales; además, algunos resultados han sido divulgados recientemente en congresos internacionales, tal y como se describe abajo.[1] "Transport ofMeta!lic lons through Polyaniline-Containing Composite Membranas". Carlos A Ferreira, Jordi Casanova, Marco A S. Rodrigues, Franciélli Müller. Elaine Armelin. Carlos Alemán. J. Chem. Eng. Sci. 2010, 55.4801-4807.[2] "Desenvolvimento de Membranas e Filmes Auto-Suportados a partir de Polianilina: Síntese, Caracterizac;áo e Aplicac;áo". Franciélli Müller, Franco D. R. Amado, Marco A S. Rodrigues, Carlos A Ferreira. Polímeros. 2011, 21, 1-6.[3] "New Sulfonated Polystyrene and Styrene Ethylene/Butylene Styrene Block Copolymers for Applications in Electrodialysis'". Franciélli Müller, Carlos A Ferreira, Lo urdes Franco, Jordi Puiggali, Carlos Alemán, Elaine Arme!in. J. Phys. Che m. B. 2012,116.11767-11779.[4] "Eiectrochemicallmpedance Spectroscopyemployed in the studyofthe conductivity properties in membranas forelectrodialysis". Franciélli Müller, Carlos A Ferreira, Elaine Armelin, Carlos Alemán. Manuscrito em preparayao, 2013.Congresos:1. ANQUEnCCE -lnternational Congress in Chemical Engineering, 24-27 Junho, 2012, Sevilla, Espanha. ION-EXCHANGEMEMBRANES BASED ON SULFONATED POL YSTYRENEAND STYRENE-ETHYLENE/BUTYLENE-STYRENE BLOCKCOPOL YMERS FOR APPLICATIONS IN ELECTRODIAL YSIS. F. Müller et al.2. Frontier in polymers science, 21-23 Malo, 2013, Sitges (Barcelona), Espanha. TRANSPORT OF IONS IN S IDE POL YMERICCATION EXCHANGE MEMBRANES: EXPERIMENTAL ANO THEORETICAL STUDIES. F. Müller et al.

    Tesi realitzada en co-tutela (Universidade Federal do Rio Grande do Sul -Brasil- i Universtitat Politécnica de Catalunya)

    The main objective of this Thesis is the development of anionic and cationic polymeric membranes for treatment of solution containing metallic ions using electrodialysis process. In this work were synthesized cationic membranes from crystal polystyrene (PS), high impact polystyrene (HIPS), poly(styrene-ethylene-butylene-) triblock copolymer (SEBS) and polyaniline (PAni) doped with camphorsulfonic acid (CSA). After sulfonation, blends of polymers were used to produce ion exchange membranes by solvent-casting and subsequent thermal treatment. The anionic membranes were synthesized from poly (vinyl alcohol) (PVA), with insertion of quaternary ammonium groups in the polymeric matrix and subsequent crosslinking with glutaraldehyde and maleic anhydride. Different membranes were synthesized in order to view and evaluate the combination of mechanical, chemical, electrochemical and ionic transport. The morphology and structure of the membranes were investigated by scanning electron microscopy, atomic force microscopy and infrared spectroscopy. The thermal transitions and stability of all the membranes were characterized using calorimetric techniques and compared with those of the individual polymers. The physical properties (i.e., ionic conductivity, ion exchange capacity, water absorption, dimensional stability, mechanical properties, etc.) showed that the performance of cationic membranes containing PS is generally better than membranes containing HIPS. The tests for determining of performance electrodialysis membranes in the transport of sodium, nickel, chromium, chloride and nitrate ions were performed in a three compartments laboratory cell. Selemion CMT® (cationic) and AMV (anionic) commercial membranes were used to compare the results of the extraction percentage of indicated ions. All the results derived from the present thesis have been accepted or have been sent for publication in international journals and also reported in some international congresses,

    O objetivo principal da presente Tese de Doutorado é o desenvolvimento de membranas poliméricas aniônicas e catiônicas para tratamento de soluções que contenham íons metálicos utilizando o processo de eletrodiálise. Neste trabalho foram sintetizadas membranas catiônicas a partir de poliestireno cristal (PS) ou poliestireno de alto impacto (HIPS) com copolímero em bloco de estireno-etileno/butileno-estireno (SEBS) e polianilina (PAni) dopada com ácido canforsulfônico (CSA). Após sulfonação, as combinações dos polímeros foram usadas para produzir membranas íon seletivas por evaporação do solvente com subsequente tratamento térmico. As membranas aniônicas foram sintetizadas a partir de poli(álcool vinílico) (PVA), com inserção de grupos quaternários de amônio na matriz polimérica e posterior reticulação com glutaraldeído e anidrido maleico. Diferentes membranas foram sintetizadas com o propósito de avaliar a combinação de propriedades mecânicas, químicas, eletroquímicas e de transporte iônico. A morfologia e a estrutura das membranas foram analisadas por microscopia eletrônica de varredura, microscopia de força atômica e espectroscopia de infravermelho. As transições térmicas e estabilidade de todas as membranas foram caracterizadas usando técnicas calorimétricas e comparadas com todos os polímeros individuais. Análises das propriedades físicas (ex. condutividade iônica, capacidade de troca iônica, absorção de água, estabilidade dimensional, propriedades mecânicas, etc.) mostraram que o desempenho das membranas catiônicas que contém PS, é em geral, melhor do que as membranas que contem HIPS. Os ensaios de eletrodiálise para determinação do desempenho das membranas no transporte de íons sódio, níquel, cromo, cloreto e nitrato foram realizados em células de bancada de três compartimentos e mostraram que as membranas produzidas podem ser utilizadas com êxito neste processo de separação. Membranas comerciais Selemion® CMT (catiônica) e AMV (aniônica) foram utilizadas para comparar as extrações percentuais dos íons indicados com as membranas produzidas

    El objetivo principal de la presente Tesis Doctoral es el desarrollo de membranas poliméricas aniónicas y catiónicas para el tratamiento de soluciones que contienen iones metálicos utilizando el proceso de electrodiálisis. En este trabajo fueron sintetizadas membranas catiónicas a partir de poliestireno cristal (PS) o poliestireno de alto impacto (HIPS) con copolímero en bloque de estireno-etileno-/butileno-estireno (SEBS) y de polianilina (PAni) dopada con ácido canforsulfónico (CSA). Después de la sulfonación, fueron utilizadas las mezclas de los polímeros para producir las membranas iones selectivas por evaporación del disolvente con posterior tratamiento térmico. Las membranas aniónicas fueron sintetizadas a partir de poli(alcohol vinílico) (PVA), con la inserción de grupos cuaternario de amonio en la matriz del polímero y posterior reticulación con glutaraldehído y anhídrido maleico. Diferentes membranas fueron sintetizadas con el propósito de evaluar la combinación de propiedades mecánica, química, electroquímica y del transporte de iones. La morfología y estructura de las membranas fueron analizadas por microscopía electrónica de barrido, microscopía de fuerza atómica y espectroscopía de infrarrojo. La estabilidad y las transiciones térmicas de todas las membranas fueron caracterizadas utilizando las técnicas calorimétricas y se compararon con todos los polímeros individuales. Las propiedades físicas (por ejemplo, la conductividad iónica, capacidad de intercambio de iones, la absorción de agua, estabilidad dimensional, propiedades mecánicas, etc.) mostraron que la performance de las membranas catiónicas que contienen PS es generalmente más alta que las membranas que contienen HIPS. Los ensayos de electrodiálisis para la determinación del desempeño de las membranas en el transporte de iones sodio, níquel, cromo, cloruro y nitrato fueron realizados en una celda de laboratorio con tres compartimientos y mostraron que las membranas producidas pueden ser utilizadas con éxito en este proceso de separación. Membranas comerciales Selemion® CMT (catiónica) y AMV (aniónica) fueron utilizadas para comparar las extracciones porcentuales de los iones indicados con las membranas producidas

  • Formulation of anticorrosive paints employing conducting polymers  Open access

     Martí Barroso, Mireia
    Defense's date: 2013-07-08
    Universitat Politècnica de Catalunya
    Theses

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    El propósito de la presente tesis es preparar una serie de recubrimientos protectores empleando polímeros conductores(CPs) como inhibidores de la corrosión. El uso de pinturas orgánicas es el método más empleado para la prevención de lacorrosión. Los recubrimientos anticorrosivos forman una clase de sistemas de alto rendimiento con una amplia variedad deaplicaciones y pueden ser clasificados en dos grandes grupos: recubrimientos de altas prestaciones y recubrimientos desuaves prestaciones. El primero de ellos es el que se emplea en estructuras expuestas a ambientes muy agresivos, talescomo: plataformas petrolíferas, puentes, plantas industriales químicas, contenedores, barcos, entre otros; y el último es elque se suele emplear en el exterior de ambientes industriales, ambientes urbanos, casas, oficinas, entre otros.La presente tesis consiste en un compendio de las siguientes etapas del trabajo y resultados:1. Preparación de CPs nanoestructurados para inhibición de la corrosión: Estudio de la habilidad del Poli(N-metilpirrol) paraformar estructuras nanoestructuradas y la actuación de éstas como aditivo anticorrosivo en recubrimientos orgánicos.2. Sustitución parcial del zinc metálico en polvo habitualmente empleado en pinturas de altas prestaciones, por unapequeña cantidad de CP: Estudio del uso de pequeñas concentraciones de polianilina sal emeraldina (PAni-EB), comosustituto parcial del zinc metálico en polvo, en pinturas de imprimación epoxi marinas, con el objetivo de mantener lainhibición a la corrosión.3. Evaluación de pigmentos anticorrosivos amigables con el medio ambiente para pinturas de imprimación alquídicas:Estudio de la sustitución de una elevada concentración de fosfato de zinc, generalmente empleado en recubrimientos desuaves prestaciones, por una concentración muy baja de PAni-EB (forma no-dopada), PAni-ES (forma dopada) y un derivadodel politiofeno (parcialmente dopado) en un recubrimiento alquídico, y el estudio de sus capacidades protectorasempleando ensayos de corrosión acelerados.4. Preparación de una nueva pintura epoxi, basada en DMSO como disolvente ecológico y libre de pigmento anticorrosivo dezinc, y su aplicación para la protección de acero al carbono: Formulación y evaluación de una nueva pintura epoxi basada enDMSO como solvente y empleando PAni-EB y poli[2, 2¿-(3-metilacetato)tiofeno] como nuevos pigmentos anticorrosivos.Todos los resultados obtenidos en la presente tesis han sido aceptados o han sido enviados para publicación en revistasinternacionales; además, algunos resultados han sido divulgados recientemente en congresos internacionales, tal y comose describe abajo:1. M. Martí, G. Fabregat, F. Estrany, C. Alemán, E. Armelin, ¿Nanostructured conducting polymer for dopamine detection¿, J.Mater. Chem., 2010, 20, 10652-10660.2. E. Armelin, M. Martí, F. Liesa, J.I. Iribarren, C. Alemán, ¿Partial replacement of metallic zinc dust in heavy duty protectivecoatings by conducting polymer¿, Prog. Org. Coat., 2010, 69, 26-30.3. M. Martí, G. Fabregat, D.S. Azambuja, C. Alemán, E. Armelin, ¿Evaluation of an environmentally friendly anticorrosivepigment for alkyd primer¿, Prog. Org. Coat., 2012, 73, 321¿329.4. M. Martí, L. Molina, C. Alemán, E. Armelin, ¿Replacement of toxic solvents and anticorrosive pigments used in solvent-borneepoxy coatings by safer functional organic compounds¿, enviado para publicación en Journal of Hazardous Materials, 2013.5. M. Martí, E. Armelin, J. Iribarren, C. Alemán. Soluble polythiophenes as anticorrosive additives for marine epoxy paints¿,enviado para publicación en Materials and Corrosion, 2013.6. G. Fabregat, M. Martí, F. Estrany, C. Alemán, E. Armelin, E-MRS 2010 Spring Meeting. 2010, Strasbourg, France.7. E. Armelin, M. Martí, F. Estrany, C. Alemán, 12th Mediterranean Congress of Chemical Engineering: shaping the future ofchemical engineering. 2011, Barcelona, Spain

    The intention and purpose of the present thesis is to prepare a series of protective coatings using some conducting polymers (CPs) as corrosion inhibitors. The use of organic paints is the most common method for corrosion prevention. Anticorrosive coatings form a class of high-performance systems with a very wide range of applications and being classified in two broad groups: heavy-duty coatings, for high performance, and light-duty coatings, for medium performance. The first class being required for highly aggressive medium, like oil platforms, bridges, chemical industry plants, containers, shipping, and others; the late being employed mainly for outside industrial environments, urban environments, houses, offices, and others. This thesis consists of an overview and a compendium of the following work stages and results: 1. Preparation of nanostructured CPs for corrosion inhibition: Study of the ability of poly(N-methylpyrrole) to form nanostructures and the performance of such nanostructures when act as anticorrosive additive of organic coatings. 2. Partial replacement of metallic zinc dust usually employed in heavy duty protective coatings, by a small concentration of CPs: Study of the use of a small amount of polyaniline emeraldine salt as a partial substitute of metallic zinc dust in marine epoxy primers in order to maintain corrosion inhibition. 3. Evaluation of an environmentally friendly anticorrosive pigment for alkyd priming: Study of the substitution of a high concentration of zinc phosphate, commonly employed in light-duty coatings, by a very low concentration of polyaniline emeraldine base (undoped form), polyaniline emeraldine salt (doped form) and an eco-friendly polythiophene derivative (partially oxidized) in an alkyd coatings and the study of their protective performance using accelerated corrosion assays. 4. Preparation of a novel epoxy coating, based on DMSO as green solvent and free of zinc anticorrosive pigment, and its application on carbon steel protection: Formulation and evaluation of a novel anticorrosive epoxy coating based on DMSO solvent and free of zinc, using polyaniline emeraldine base and poly[2,2’-(3-methylacetate)thiophene] as anticorrosive pigments. All the results derived from the present thesis have been accepted or have been sent for publication in international journals and also reported in some international congresses, as we point below: 1. M. Martí, G. Fabregat, F. Estrany, C. Alemán, E. Armelin, “Nanostructured conducting polymer for dopamine detection”, J.Mater. Chem., 2010, 20, 10652-10660. 2. E. Armelin, M. Martí, F. Liesa, J.I. Iribarren, C. Alemán, “Partial replacement of metallic zinc dust in heavy duty protective coatings by conducting polymer”, Prog. Org. Coat., 2010, 69, 26-30. 3. M. Martí, G. Fabregat, D.S. Azambuja, C. Alemán, E. Armelin, “Evaluation of an environmentally friendly anticorrosive pigment for alkyd primer”, Prog. Org. Coat., 2012, 73, 321–329. 4. M. Martí, L. Molina, C. Alemán, E. Armelin, “Replacement of toxic solvents and anticorrosive pigments used in solvent-borne epoxy coatings by safer functional organic compounds”, submitted for publication in Journal of Hazardous Materials, 2013. 5. M. Martí, E. Armelin, J. Iribarren, C. Alemán. Soluble polythiophenes as anticorrosive additives for marine epoxy paints”, submitted for publication in Materials and Corrosion, 2013. 6. G. Fabregat, M. Martí, F. Estrany, C. Alemán, E. Armelin, “Nanostructured Poly(N-Methylpyrrole) and Its Application in Dopamine Detection”, E-MRS 2010 Spring Meeting. 2010, Strasbourg, France. 7. E. Armelin, M. Martí, F. Estrany, C. Alemán, “Environmentally friendly anticorrosive additive to replace zinc and its compounds in alkyd and epoxy primers”, 12th Mediterranean Congress of Chemical Engineering: shaping the future of chemical engineering. 2011, Barcelona, Spain

    El propósito de la presente tesis es preparar una serie de recubrimientos protectores empleando polímeros conductores (CPs) como inhibidores de la corrosión. El uso de pinturas orgánicas es el método más empleado para la prevención de la corrosión. Los recubrimientos anticorrosivos forman una clase de sistemas de alto rendimiento con una amplia variedad de aplicaciones y pueden ser clasificados en dos grandes grupos: recubrimientos de altas prestaciones y recubrimientos de suaves prestaciones. El primero de ellos es el que se emplea en estructuras expuestas a ambientes muy agresivos, tales como: plataformas petrolíferas, puentes, plantas industriales químicas, contenedores, barcos, entre otros; y el último es el que se suele emplear en el exterior de ambientes industriales, ambientes urbanos, casas, oficinas, entre otros. La presente tesis consiste en un compendio de las siguientes etapas del trabajo y resultados: 1. Preparación de CPs nanoestructurados para inhibición de la corrosión: Estudio de la habilidad del Poli(N-metilpirrol) para formar estructuras nanoestructuradas y la actuación de éstas como aditivo anticorrosivo en recubrimientos orgánicos. 2. Sustitución parcial del zinc metálico en polvo habitualmente empleado en pinturas de altas prestaciones, por una pequeña cantidad de CP: Estudio del uso de pequeñas concentraciones de polianilina sal emeraldina (PAni-EB), como sustituto parcial del zinc metálico en polvo, en pinturas de imprimación epoxi marinas, con el objetivo de mantener la inhibición a la corrosión. 3. Evaluación de pigmentos anticorrosivos amigables con el medio ambiente para pinturas de imprimación alquídicas: Estudio de la sustitución de una elevada concentración de fosfato de zinc, generalmente empleado en recubrimientos de suaves prestaciones, por una concentración muy baja de PAni-EB (forma no-dopada), PAni-ES (forma dopada) y un derivado del politiofeno (parcialmente dopado) en un recubrimiento alquídico, y el estudio de sus capacidades protectoras empleando ensayos de corrosión acelerados. 4. Preparación de una nueva pintura epoxi, basada en DMSO como disolvente ecológico y libre de pigmento anticorrosivo de zinc, y su aplicación para la protección de acero al carbono: Formulación y evaluación de una nueva pintura epoxi basada en DMSO como solvente y empleando PAni-EB y poli[2, 2’-(3-metilacetato)tiofeno] como nuevos pigmentos anticorrosivos. Todos los resultados obtenidos en la presente tesis han sido aceptados o han sido enviados para publicación en revistas internacionales; además, algunos resultados han sido divulgados recientemente en congresos internacionales, tal y como se describe abajo: 1. M. Martí, G. Fabregat, F. Estrany, C. Alemán, E. Armelin, “Nanostructured conducting polymer for dopamine detection”, J. Mater. Chem., 2010, 20, 10652-10660. 2. E. Armelin, M. Martí, F. Liesa, J.I. Iribarren, C. Alemán, “Partial replacement of metallic zinc dust in heavy duty protective coatings by conducting polymer”, Prog. Org. Coat., 2010, 69, 26-30. 3. M. Martí, G. Fabregat, D.S. Azambuja, C. Alemán, E. Armelin, “Evaluation of an environmentally friendly anticorrosive pigment for alkyd primer”, Prog. Org. Coat., 2012, 73, 321–329. 4. M. Martí, L. Molina, C. Alemán, E. Armelin, “Replacement of toxic solvents and anticorrosive pigments used in solvent-borne epoxy coatings by safer functional organic compounds”, enviado para publicación en Journal of Hazardous Materials, 2013. 5. M. Martí, E. Armelin, J. Iribarren, C. Alemán. Soluble polythiophenes as anticorrosive additives for marine epoxy paints”, enviado para publicación en Materials and Corrosion, 2013. 6. G. Fabregat, M. Martí, F. Estrany, C. Alemán, E. Armelin, E-MRS 2010 Spring Meeting. 2010, Strasbourg, France. 7. E. Armelin, M. Martí, F. Estrany, C. Alemán, 12th Mediterranean Congress of Chemical Engineering: shaping the future of chemical engineering. 2011, Barcelona, Spain.

  • POLIMEROS CONDUCTORES Y SUS DERIVADOS HIBRIDOS CON APLICACIONES AVANZADAS

     Estrany Coda, Francisco; Armelin Diggroc, Elaine; Zanuy Gomara, David; Iribarren Laco, Jose Ignacio; Sanchez Jimenez, Margarita; Aleman Llanso, Carlos Enrique
    Participation in a competitive project

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  • An electroactive and biologically responsive hybrid conjugate based on chemical similarity

     Fabregat Jove, Georgina; Ballano Ballano, María Gema; Armelin Diggroc, Elaine; Del Valle Mendoza, Luis Javier; Cativiela, Carlos; Aleman Llanso, Carlos Enrique
    Polymer Chemistry
    Date of publication: 2012-11-20
    Journal article

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    Synthetic amino acids have become very important tools for the design of new materials. In this work, an electroactive polymer¿amino acid hybrid material has been synthesized by conjugating poly(3,4-ethylenedioxythiophene) (PEDOT), a well known conducting polymer, with a synthetic amino acid bearing 3,4-ethylenedioxythiophene, which has been explicitly designed and prepared for such a purpose. Nanometric films have been electrochemically generated using a two-step procedure to evaluate the properties and potential applications of the resulting hybrid material. The successful incorporation of the amino acid as end-capping of the PEDOT chains has been proved by FTIR, energy dispersive X-ray and X-ray photoelectron spectroscopies. The fabrication of the hybrid material using an engineered tissue has allowed us to preserve not only morphological and structural characteristics of the conducting polymer but also, and most importantly, to preserve the electrical conductivity, electroactivity, electrochemical stability and specific capacitance. Finally, the behavior of the hybrid material as a cellular matrix has been compared with that of PEDOT using cellular adhesion and proliferation assays. Results obtained in this work represent the success of a new strategy for the preparation of peptide-conducting polymer hybrid materials, which is currently being improved upon by transforming the 3,4-ethylenedioxythiophene-containing amino acid into a cell adhesive peptide

  • Bioactive and electroactive response of flexible polythiophene:Polyester nanomembranes for tissue engineering

     Perez Madrigal, Maria Del Mar; Armelin Diggroc, Elaine; Del Valle Mendoza, Luis Javier; Estrany Coda, Francisco; Aleman Llanso, Carlos Enrique
    Polymer Chemistry
    Date of publication: 2012-04
    Journal article

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  • Preparation and characterization of semiconducting polymeric blends. Photochemical synthesis of poly(3-alkylthiophenes) using host microporous matrices of poly(vinylidene fluoride)

     Gomes, Alex Linardi; Pinto Zakia, Maria Beny; Armelin Diggroc, Elaine; Filho, Jose Godoy; Aleman Llanso, Carlos Enrique; Sinezio De Carvalho Campos, Joao
    Polymer Chemistry
    Date of publication: 2012-05
    Journal article

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    Chemical and electrochemical synthesis techniques have been the principal methods of obtaining polymers in industry and scientific research laboratories. However, during the last two decades, photochemical synthesis, although poorly studied, has been reported to present several advantages, in that it is a fast and cheap technique, and it is not aggressive to the environment. The technique has been applied to the production of some conducting polymers. In this study, semiconducting polymeric blends composed of PT3AA-K¿PVDF and PT3MA¿PVDF were respectively obtained by photochemical polymerization in aqueous solutions of 3-thiophene acetic acid and 3-thiophene methyl acetate monomers using PVDF microporous matrices and potassium dichromate as catalyst. The percentage of products and by-products incorporated in the host matrix was obtained by gravimetric analysis. The chemical structures of the polymers synthesized were analyzed by FTIR, UV-vis and 1H NMR. GPC analysis indicated the formation of oligomers composed of 5¿6 mers. The morphology of the matrices and polymeric blends was observed by SEM-EDS and their electric behavior evaluated by measures of electric conductivity. The SEM images show the presence of polythiophene in the pores of the PVDF microporous membrane. The thermal properties of the polymers and their blends were evaluated by DSC and TGA. Thermal analysis by DSC demonstrated an increase in melting temperature of the blends, attributed to the confinement of PVDF crystalline phases for the polymer photosynthesized. The results of volumetric conductivity measurements of polymeric blends show an increase in conductivity in the matrices from 10-15 to 10-11 S cm-1.

  • Controlling the morphology of poly(N -cyanoethylpyrrole)

     Fabregat Jove, Georgina; Aleman Llanso, Carlos Enrique; Casas Becerra, M. Teresa; Armelin Diggroc, Elaine
    Journal of physical chemistry B
    Date of publication: 2012-04-26
    Journal article

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    The morphology of poly(N-cyanoethylpyrrole) has been controlled through the polymerization process. This polymer has been prepared by anodic polymerization, chemical oxidative polymerization in emulsion medium, and layer-by-layer templating polymerization. Anodic polymerization using LiClO4 as supporting electrolyte provides compact films, in which the oxidation degree is controlled through the thickness, useful for the microdetection of dopamine. Chemical polymerization using FeCl3 as oxidant agent results in very well-defined microspheres with porous internal structure, which may be useful in molecular loading and transport processes. Finally, the layer-by-layer templating technique produces core−shell particles of controlled size and thickness. Moreover, these core−shell particles can be easily converted in hollow microspheres by removing the template

  • Evaluation of an environmentally friendly anticorrosive pigment for alkyd primer

     Martí Barroso, Mireia; Fabregat Jove, Georgina; Azambuja, Denise S.; Aleman Llanso, Carlos Enrique; Armelin Diggroc, Elaine
    Progress in organic coatings
    Date of publication: 2012-04
    Journal article

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    An alkyd formulation containing zinc phosphate (10 wt.%) was prepared and subsequently modified replacing the latter anticorrosive additive by a very low concentration of conducting polymer. Specifically, three modified paints, which contain polyaniline emeraldine base (undoped form), polyaniline emeraldine salt (doped form) and an eco-friendly polythiophene derivative (partially oxidized), were formulated. The properties and corrosion resistance of the four alkyd coatings have been characterized. Among the three modified paints, the one containing polythiophene shows the best adherence and the highest corrosion resistance. This has been attributed to the fact that the miscibility of the polythiophene derivative with the alkyd formulation is better than that of polyaniline. Furthermore, accelerated corrosion assays and electrochemical impedance spectroscopy measurements revealed that the corrosion resistance of the paint with polythiophene is several orders of magnitude higher than that with zinc phosphate. The polythiophene derivative has been found to induce the formation of a passivating and well-adhered layer between the coating and the surface, preventing the access of chloride anions and oxygen to the substrate.

  • Ultraporous poly(3,4-ethylenedioxythiophene) for nanometric electrochemical supercapacitor

     Aradilla Zapata, David; Estrany Coda, Francisco; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique
    Thin solid films
    Date of publication: 2012-04-30
    Journal article

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  • New Sulfonated Polystyrene and Styrene¿Ethylene/Butylene¿Styrene Block Copolymers for Applications in Electrodialysis

     Müller, Franciélli; Ferreira, Carlos Arthur; Franco Garcia, Maria Lourdes; Puiggali Bellalta, Jorge; Aleman Llanso, Carlos Enrique; Armelin Diggroc, Elaine
    Journal of physical chemistry B
    Date of publication: 2012-09
    Journal article

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  • Phosphonic acid/silica-based films: A potential treatment for corrosion protection

     Dalmoro, Viviane; dos Santos, João Henrique Zimnoch; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique; Azambuja, Denise S.
    Corrosion science
    Date of publication: 2012-07
    Journal article

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    Films of tetraethyl orthosilicate (TEOS) and 1,2-diaminoethanetetrakis methylenephosphonic acid (EDTPO) were evaluated as a anticorrosive treatment against corrosion for AA2024-T3 in a 0.05 mol L−1 NaCl solution. The electrochemical behavior was investigated using electrochemical impedance spectroscopy. The chemical composition of the silanization bath and films were analyzed by infrared spectroscopy. The effect of hydrolysis time on sol–gel TEOS/EDTPO was monitored, being obtained the best performance after 72 h of hydrolysis at 25 °C. The optimal concentration of EDTPO within the TEOS matrix was 3.75 × 10−4 mol L−1. Improved barrier properties of these films were achieved by the addition of silica nanoparticles.

  • Biodegradable free-standing nanomembranes of conducting polymer:polyester blends as bioactive platforms for tissue engineering

     Armelin Diggroc, Elaine; Gomes, Alex Linardi; Perez Madrigal, Maria Del Mar; Puiggali Bellalta, Jorge; Franco Garcia, Maria Lourdes; Del Valle Mendoza, Luis Javier; Rodriguez Galan, Rafael Alfonso; Campos, J.S.D.C.; Ferrer Anglada, Nuria; Aleman Llanso, Carlos Enrique
    Journal of materials chemistry B
    Date of publication: 2012-01-14
    Journal article

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  • Aplicación de los compuestos multicapa de polímeros conductores para la preparación de supercapacitores simétricos

     Estrany Coda, Francisco; Aradilla Zapata, David; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique
    Reunión del Grupo de Electroquímica de la Real Sociedad Española de Química
    Presentation's date: 2012-07-02
    Presentation of work at congresses

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  • Ion-exchange membranes based on sulfonated polystyrene and styrene-ethylene/butylene-styrene block copolymers for applications in electrodialysis

     Müller, Franciélli; Ferreira, Carlos Arthur; Iribarren Laco, Jose Ignacio; Aleman Llanso, Carlos Enrique; Armelin Diggroc, Elaine
    International Congress of Chemistry Engineering
    Presentation's date: 2012-06-24
    Presentation of work at congresses

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  • Novel epoxy coating based on green solvent and free of zinc anticorrosive pigment

     Iribarren Laco, Jose Ignacio; Aleman Llanso, Carlos Enrique; Liesa Mestres, Francisco; Armelin Diggroc, Elaine
    International Congress of Chemistry Engineering
    Presentation's date: 2012-06-24
    Presentation of work at congresses

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  • Conducting polymer:thermoplastic blends for the fabrication of flexible free-standing ultra-thin membranes: nanomeasures and biomedical applications

     Perez Madrigal, Maria Del Mar; Armelin Diggroc, Elaine; Giannotti, Marina I.; Sanz Carrasco, Fausto; Del Valle Mendoza, Luis Javier; Aleman Llanso, Carlos Enrique
    E-MRS Spring Meeting
    Presentation's date: 2012-05-14
    Presentation of work at congresses

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  • Elaboració de material per a l'avaluació d'assignatures de química

     Cadenato Matia, Ana Maria; Morillo Cazorla, Margarita; Alvarez Del Castillo, M. Dolores; Gorchs Altarriba, Roser; Martínez Martínez, María R.; Armelin Diggroc, Elaine; Farran Marsa, Adriana; Cortes Izquierdo, M. Pilar; Grau Vilalta, Maria Dolors; Guaus Guerrero, Ester; Molins Duran, Gemma; Baquero Navarro, Maria Teresa; Almajano Pablos, Maria Pilar; Calvet Tarragona, Aurelio; Rodriguez Galan, Rafael Alfonso; Salán Ballesteros, Mª Núria; Folch Pérez, Joaquim; Macanás de Benito, Jorge; Pallares Andreu, Marc
    Jornada d'Innovació Docent UPC
    Presentation of work at congresses

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  • Microstructures of poly(N-methylpyrrole) and their interaction with morphine

     da Cruz Teixeira Dias, Bruno José; Aleman Llanso, Carlos Enrique; Estrany Coda, Francisco; Azambuja, Denise S.; Armelin Diggroc, Elaine
    Electrochimica acta
    Date of publication: 2011-06-30
    Journal article

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    Microstructures of poly(N-methylpyrrole) have been generated by direct electrochemical oxidation of N-methylpyrrole with poly(styrenesulfonic acid) in aqueous solution, using a micelle formation mechanism with gas bubble templates. These microstructures present a “doughnut”-like morphology with diameters ranging from 20 to 100μm. Other anionic surfactants, such as camphorsulfonic acid and β-naphthalenesulfonic acid, have been also employed, results evidencing that the morphology of the microstructures depends on the nature of the surfactant electrolytes. The dimensions, abundance and texture of the microstructures have been modulated by varying the surfactant molecules, the electrochemical technique, and the distance between the working and counter-electrode. The generated microstructures have been characterized using electrochemical techniques, Raman and infrared spectroscopies, scanning electron microscopy and atomic force microscopy. Hollow microstructures-containing films made of poly(N-ethylpyrrole)/poly(styrenesulfonic acid), which present remarkable electroactivity and electrostability, has been proved to interact with morphine molecules. Thus, systems based on this prominent material show a high ability to capture the drug molecules and to retain them for a long period of time.

  • 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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    Ultrathin films of poly[N-(2-cyanoethyl)pyrrole] and poly(N-methylpyrrole) and their composites with Au nanoparticles were used for the electrochemical detection of small concentrations (10 mM-100 µM) of dopamine, a neurotransmitter related with neurological disorders. Results indicated that Au nanoparticles improve the sensing abilities of the two polymers, even though they are not essential to obtain effective and fast responses toward the presence of dopamine. Furthermore, although both polymers have been found to be highly sensitive to low concentrations of dopamine, the response of poly[N-(2-cyanoethyl)pyrrole] is better and more effective than the response of poly(N-methylpyrrole). Experimental results were corroborated with quantum mechanical calculations on model systems, which also indicated that the interaction of oxidized dopamine with poly[N-(2-cyanoethyl)pyrrole] is stronger than that with poly(N-methylpyrrole). This behavior has been attributed to two different factors: (i) the flexibility of the cyanoethyl groups, which allows maximize the number of attractive van der Waals interactions, and (ii) the dipole of the cyano group, which interacts favorably with the dipole of the C-O bonds of oxidized dopamine. Finally, theoretical results were used to propose an atomistic model that explains the interaction behavior between the oxidized dopamine and the conducting polymers.

  • 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 Salas, 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)

  • Free-standing nanomembranes of conducting polymer and biodegradable polyester

     Armelin Diggroc, Elaine; Gomes, Álex Linardi; Pérez, Mar; Del Valle Mendoza, Luis Javier; Puiggali Bellalta, Jorge; Aleman Llanso, Carlos Enrique
    International Conference on Multifunctional, Hybrid and Nanomaterials
    Presentation's date: 2011-03-06
    Presentation of work at congresses

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  • Nanostructures, morphology and properties of poly[N-(2-cyanoethyl)pyrrole]

     Fabregat Jove, Georgina; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique
    European Polymer Congress
    Presentation's date: 2011-06-26
    Presentation of work at congresses

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  • Nanotechnology for detection of biomolecules and fabrication of bioactives platforms

     Aleman Llanso, Carlos Enrique; Perez Madrigal, Maria Del Mar; Fabregat Jove, Georgina; Armelin Diggroc, Elaine
    Mediterranean Congress of Chemical Engineering
    Presentation's date: 2011-11-15
    Presentation of work at congresses

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  • Influencia de polímeros convencionais e condutor em membranas cátion-seletivas: Síntese e caracterizaçao

     Müller, Franciélli; Ferreira, Carlos Arthur; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique; Schramm, Juliana
    Congresso Brasileiro de Polímeros
    Presentation's date: 2011-10-16
    Presentation of work at congresses

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  • Environmentally friendly anticorrosive additive to replace zinc and its compounds in alkyd and epoxy primers

     Armelin Diggroc, Elaine; Martí Barroso, Mireia; Estrany Coda, Francisco; Aleman Llanso, Carlos Enrique
    Mediterranean Congress of Chemical Engineering
    Presentation's date: 2011-11-15
    Presentation of work at congresses

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  • ENVIRONMENTAL ANTI-CORROSIVE ADDITIVES BASED ON POLY(ALKYL THIOPHENE ACETATES) EASILY DISPERSIBLE IN PRIMING PAINTS FOR METAL SURFACES

     Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique; Iribarren Laco, Jose Ignacio; Liesa Mestres, Francisco; Estrany Coda, Francisco
    Date of request: 2011-10-25
    Invention patent

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  • Nanostructured conducting polymer for dopamine detection

     Martí Barroso, Mireia; Fabregat Jove, Georgina; Estrany Coda, Francisco; Aleman Llanso, Carlos Enrique; Armelin Diggroc, Elaine
    Journal of materials chemistry B
    Date of publication: 2010
    Journal article

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  • Access to the full text
    Transport of Metallic Ions through Polyaniline-containing composite membranes  Open access

     Ferreira, Carlos Arthur; Casanovas Salas, Jordi; Rodrigues, Marco A. S.; Müller, Franciélli; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique
    Journal of chemical and engineering data
    Date of publication: 2010-09-30
    Journal article

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    The extraction of Na+, Ni2+, and Cr3+ using six different membranes made of polyaniline composited with high-impact polystyrene, which differ in the doping agent and/or the preparation method, has been investigated. The swelling and ion-exchange capacities of the six polyaniline composited with high-impact polysterene (HIPS/PAni) membranes have been determined and compared with that of the commercial Selemion membrane. Electrodialysis tests using a five-compartment cell evidenced that the extraction of ions depends on the electronic structure of the SO3 - groups, which is modulated by the doping agent, and on both microstructure and electrical resistance of the membrane, which are regulated by the preparation method. The transport of ions through HIPS/PAni and Selemion membranes was found to be comparable. Quantum mechanical calculations on model complexes have been performed to characterize the electronic structure of the dopants. Results indicate that the strength of the interaction between the different doping agents and the polyaniline is inversely proportional to the concentration of negative charge in the SO3 - group of the former. Moreover, both the binding energy and the distribution of charges calculated for dopant · · · PAni complexes have been compared with those predicted for dopant · · · metallic ion complexes.

  • Characterization and Properties of Poly[N-(2-cyanoethyl)pyrrole]

     Aradilla Zapata, David; Estrany Coda, Francisco; Armelin Diggroc, Elaine; Oliver, R.; Iribarren Laco, Jose Ignacio; Aleman Llanso, Carlos Enrique
    Macromolecular chemistry and physics
    Date of publication: 2010-08-02
    Journal article

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  • Partial replacement of metallic zinc dust in heavy duty protective coatings by conducting polymer

     Armelin Diggroc, Elaine; Martí Barroso, Mireia; Liesa Mestres, Francisco; Iribarren Laco, Jose Ignacio; Aleman Llanso, Carlos Enrique
    Progress in organic coatings
    Date of publication: 2010-09
    Journal article

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    The aim of this work is to show that the high concentration of metallic zinc dust typically used in marine epoxy primers may be reduced by introducing a small concentration of conducting polymer as auxiliary anticorrosive additive. Specifically, in this work we compare the protection imparted by an epoxy coating with 79 wt.% of anticorrosive pigment with that obtained using the same formulation but reducing such concentration to 60 wt.% and adding 0.3 wt.% of polyaniline emeraldine salt. Initially, the influence of this modification in the structural, thermal and mechanical properties of the coating has been examined. After this, accelerated corrosion assays in an aggressive solution medium have been developed. The protection imparted by the unmodified and modified paint formulations has been determined using the standard method ASTM D 1654-79.

  • Influence of the doping level on the interactions between poly(3,4-ethylenedioxythiophene) and plasmid DNA

     da Cruz Teixeira Dias, Bruno José; Zanuy Gomara, David; Del Valle Mendoza, Luis Javier; Estrany Coda, Francisco; Armelin Diggroc, Elaine; Aleman Llanso, Carlos Enrique
    Macromolecular chemistry and physics
    Date of publication: 2010-05-17
    Journal article

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    The influence of the doping level in the formation of specific interactions between plasmid DNA and PEDOT is investigated using experimental assays and theoretical calculations. Electrochemical methods are used to prepare polymer samples with oxidation degrees ranging from 0.14 to 1.05 positive charges per repeating unit. A combination of experimental and theoretical results are used to propose a mechanism for the formation of DNA/conducting polymer complexes, which consists of the initial stabilization of the adducts through non-specific interactions followed by small structural re-arrangements that allow to be established specific hydrogen bonds involving the polar groups of the conducting polymer and selected DNA bases.