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  • 1.
    Aasmundtveit, K.E.
    et al.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., N-7491 Trondheim, Norway.
    Samuelsen, E.J.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., N-7491 Trondheim, Norway.
    Guldstein, M.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., N-7491 Trondheim, Norway.
    Steinsland, C.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., N-7491 Trondheim, Norway.
    Flornes, O.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., N-7491 Trondheim, Norway.
    Fagermo, C.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., N-7491 Trondheim, Norway.
    Seeberg, T.M.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskapelige U., N-7491 Trondheim, Norway.
    Pettersson, Lars
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Inganäs, Olle
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Feidenhans'l, R.
    Forskningscenter Risø, DK-4000 Roskilde, Denmark.
    Ferrer, S.
    Europ. Synchrt. Radiation Facility, BP 220, F-38043 Grenoble Cedex, France.
    Structural anisotropy of poly(alkylthiophene) films2000Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 33, nr 8, s. 3120-3127Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The structural anisotropy of various poly(alkylthiophene) films have been studied by X-ray diffraction, using both conventional methods and synchrotron radiation at grazing incidence. Solution-cast films orient with the side chains preferably normal to the film surface, whereas spin-cast films of nonstereoregular material orient with both the main and the side chains in the film plane. For thick (10-50 µm) solution-cast films, the degree of orientation depends strongly on the solvent used for casting, and on the stereoregularity of the polymer, films of stereoregular materials being more oriented than those of nonregular materials. The most oriented nonregular films are those cast from mixtures of chloroform and tetrahydrofuran. Thin (50-500 nm) solution-cast films are more oriented than the thicker ones, and the effects of different stereoregularity or different casting solvents are small. For spin-cast films, the degree of orientation is independent of substrate and solvent. Spin-cast films of stereoregular material have two different phases: One with the side chains normal to the substrate, and another where they are parallel to the substrate. The diffraction peaks of spin-cast poly(octylthiophene) narrow considerably upon heating.

  • 2.
    Aasmundtveit, K.E.
    et al.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskaplige U., N-7491 Trondheim, Norway.
    Samuelsen, E.J.
    Institutt for Fysikk, Norges Tekn.-Naturvitenskaplige U., N-7491 Trondheim, Norway.
    Mammo, W.
    Institutionen för Organisk Kemi, Chalmers Tekniska Hôgskola, S-412 96 Göteborg, Sweden.
    Svensson, M.
    Institutionen för Organisk Kemi, Chalmers Tekniska Hôgskola, S-412 96 Göteborg, Sweden.
    Andersson, M.R.
    Institutionen för Polymerteknik, Chalmers Tekniska Hôgskola, S-412 96 Göteborg, Sweden.
    Pettersson, Lars
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Inganäs, Olle
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Structural ordering in phenyl-substituted polythiophenes2000Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 33, nr 15, s. 5481-5489Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Various substituted poly(phenylthiophene)s have been studied by X-ray diffraction. They are semicrystalline, with very different degrees of crystallinity. Those with para-substituted phenyl groups have a low degree of crystallinity, whereas those with ortho-substituted phenyl groups are more crystalline. The most crystalline materials in this study have two equally long substituents on the phenyl ring, one at the ortho position and the other at the ortho or meta position on the opposite side of the phenyl ring. Poly(3-(2,5-dioctylphenyl)thiophene) (PDOPT) was most thoroughly studied, and a structural model is proposed. The structure of PDOPT is quite different from previously studied substituted polythiophenes in that the octyl side chains are directed normal to the thiophene planes. In this way, the conjugated polymer chains are kept separated from each other. Solution-cast and spin-cast PDOPT films are anisotropic, with the octyl side chains oriented normal to the film surface in both cases. This is contrary to the situation for poly(3-alkylthiophene)s, where solution-cast and spin-cast films orient in different ways.

  • 3.
    Andersson, Mats R.
    et al.
    Chalmers Tekniska Högskola.
    Berggren, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Gustafsson, Göran
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Gustafsson-Carlberg, J. C.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Selse, D.
    Chalmers Tekniska Högskola.
    Hjertberg, T.
    Chalmers Tekniska Högskola.
    Wennerström, O.
    Chalmers Tekniska Högskola.
    Electroluminescence from Substituted Poly(thiophenes): From Blue to Near-Infrared1995Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 28, nr 22, s. 7525-7529Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report a systematic approach to the control of the conjugation length along the poly(thiophene) backbone. The planarity of the main chain can be permanently modified by altering the pattern of substitution and character of the substituents on the poly(thiophene) chain, and the conjugation length is thus modified. We obtain blue, green, orange, red, and near-infrared electroluminescence from four chemically distinct poly(thiophenes). The external quantum efficiencies are in the range of 0.01-0.6%.

  • 4.
    Andersson, Mats R.
    et al.
    Chalmers Tekniska Högskola.
    Selse, D.
    Chalmers Tekniska Högskola.
    Berggren, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Järvinen, H.
    Neste Chemicals, Poruoo, Finland.
    Hjertberg, T.
    Chalmers Tekniska Högskola.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Wennerström, Olof
    Chalmers Tekniska Högskola.
    Österholm, J.-E.
    Neste Chemicals, Poruoo, Finland.
    Regioselective polymerization of 3-(4-octylphenyl)thiophene with FeCl31994Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 27, nr 22, s. 6503-6506Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We have shown that it is possible to regioselectively polymerize 3-(4-octylphenyl) thiophene with FeCl3. Adding FeCl3 slowly to the monomer leads to a soft and therefore regioselective polymerization. The head-to-tail content was determined by H-1 NMR to be 94 +/- 2%. Thin films of the polymer treated with chloroform vapor have an absorption maximum at 602 nm (2.06 eV) with clear vibronic fine structure. Free standing films have a conductivity of 4 S/cm, which is 100 times higher than for earlier prepared poly(3-(4-octylphenyl)thiophene). A mechanism for the regioregular polymerization is also proposed.

  • 5.
    Aronsson, Christopher
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Selegård, Robert
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Zinc-Triggered Hierarchical Self-Assembly of Fibrous Helix-Loop-Helix Peptide Superstructures for Controlled Encapsulation and Release2016Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 49, nr 18, s. 6997-7003Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We demonstrate a novel route for hierarchical self-assembly of sub-micrometer-sized peptide superstructures that respond to subtle changes in Zn2+ concentration. The self-assembly process is triggered by a specific folding-dependent coordination of Zn2+ by a de novo designed nonlinear helix-loop-helix peptide, resulting in a propagating fiber formation and formation of spherical superstructures. The superstructures further form larger assemblies that can be completely disassembled upon removal of Zn2+ or degradation of the nonlinear peptide. This flexible and reversible assembly strategy of the superstructures enables facile encapsulation of nanoparticles and drugs that can be released by means of different stimuli.

  • 6.
    Barrau, Sophie
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Andersson, Viktor
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Zhang, Fengling
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Masich, Sergej
    Karolinska Institutet, Stockholm.
    Bijleveld, Johan
    Chalmers University of Technology, Göteborg.
    Andersson, Mats R
    Chalmers University of Technology, Göteborg.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Nanomorphology of Bulk Heterojunction Organic Solar Cells in 2D and 3D Correlated to Photovoltaic Performance2009Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 42, nr 13, s. 4646-4650Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Control of the nanoscale morphology of the donor-acceptor material blends inorganic solar Cells is critical for optimizing the photovoltaic performances. The influence of intrinsic (acceptor materials) and extrinsic (donor:acceptor weight ratio, substrate, solvent) parameters was investigated, by atomic force microscopy (AFM) and electron tomography (ET), on the nanoscale phase separation of blends of a low-band-gap alternating polyfluorene copolymers (APFO-Green9) with [6,6]-phenyl-C-71-butyric acid methyl ester ([70]PCBM). The photovoltaic performances display an optimal efficiency for the device elaborated with a 1:3 APFO-Green polymer:[70][PCBM weight ratio and spin-coated from chloroform solution. The associated active layer morphology presents small phase-separated domains which is a good balance between as a large interfacial donor-acceptor area and Continuous paths of the donor and acceptor phases to the electrodes.

  • 7. Bredas, JL
    et al.
    Marder, SR
    Salaneck, William R
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi.
    Alan J. Heeger, Alan G. MacDiarmid, and Hideki Shirakawa - Tribute2002Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 35, nr 4, s. 1137-1139Annet (Annet vitenskapelig)
  • 8.
    Busson, P
    et al.
    Royal Institute of Technology.
    Ortegren, J
    Royal Institute of Technology.
    Ihre, H
    Royal Institute of Technology.
    Gedde, UW
    Royal Institute of Technology.
    Hult, A
    Royal Institute of Technology.
    Andersson, G
    Chalmers University of Technology.
    Eriksson, A
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Lindgren, M
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Preparation of mesogen-functionalized dendrimers for second-order nonlinear optics2002Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 35, nr 5, s. 1663-1671Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Liquid crystalline dendrimers with peripheral mesogen-containing units have been prepared. Multistep synthesis with several selective reactions was used in the preparation of the mesogen-containing molecules, 4"-[10-(hydroxycarbonyl)decyloxy]phenyl 4-[4-(2-(R)-octyloxy)-3-nitrophenyl]benzo ate and 4"-[10-(hydroxycarbonyl)decyloxy]biphenyl 4-[4-(2-(R)-octyloxy)-3-nitrophenyl]benzoate. Both molecules possessed an electron-accepting nitro group placed perpendicular to the long axis of the molecules in order to enhance the nonlinear optical activity. A second generation hydroxyl functional aliphatic dendrimer based on the dihydroxy acid, 2,2-bis(hydroxymethyl)propionic acid, was used as dendritic scaffold and was subsequently functionalized with the aforementioned groups. The purity and structure of the two liquid crystalline dendrimers were determined by H-1 NMR spectroscopy, size exclusion chromatography, and elemental analysis. The synthesis of both the mesogen-containing units and the liquid crystalline dendrimers is described in detail. Investigation of the liquid crystalline properties of the materials by differential scanning calorimetry and optical microscopy showed that they exhibited different mesophases, including the chiral smectic C phase. Ferroelectric switching was observed in this tilted phase, and electrooptical properties, including tilt angle and spontaneous polarization measurements, were investigated. Finally, the nonlinear optical properties of one of the materials were preliminary characterized.

  • 9.
    Doherty, Walter J
    et al.
    University of Arizona.
    Wysocki, R.J.
    Department of Chemistry, University of Arizona, Tucson, AZ 85721-0041.
    Armstrong, N.R.
    Department of Chemistry, University of Arizona, Tucson, AZ 85721-0041.
    Saavedra, S.S.
    Department of Chemistry, University of Arizona, Tucson, AZ 85721-0041.
    Electrochemical copolymerization and spectroelectrochemical characterization of 3,4-ethylenedioxythiophene and 3,4-ethylenedioxythiophene-methanol copolymers on indium-tin oxide2006Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 39, nr 13, s. 4418-4424Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This work describes the electrochemical copolymerization and spectroelectrochemical characterization of 3,4-ethylenedioxythiophene (EDOT) with a commonly used EDOT derivative: 2,3-dihydrothieno[3,4b]-l,4-dioxyn-2-yl methanol (EDTM), on indium-tin oxide (ITO) electrodes, as a function of the EDTM/EDOT comonomer feed ratio. The potential of initial polymerization and the degree of optical contrast between reduced and oxidized states increased steadily with increasing proportions of EDTM. Reactivity ratios were determined by spectroscopic characterization of the copolymer film and by monitoring the depletion of monomer from the starting solution by liquid chromatography, following the formation of relatively thick PEDOT/PEDTM films. Average reactivity ratios of 1.5 ±0.2 and 0.4 ±0.3 were obtained for EDOT and EDTM, respectively, demonstrating preferential deposition of EDOT on ITO electrode surfaces. Significant differences were noted at low and high degrees of conversion, indicating changes in copolymer composition with film thickness. These results have real significance for the characterization of electron-transfer rates for the first monolayer of PEDOT/ PEDTM on ITO, determined by a new mode of potential-modulated attenuated total reflectance spectroelectrochemistry. © 2006 American Chemical Society.

  • 10.
    Du, Chun
    et al.
    Chinese Academy of Science.
    Li, Cuihong
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Li, Weiwei
    Chinese Academy of Science.
    Chen, Xiong
    Chinese Academy of Science.
    Bo, Zhishan
    Beijing Normal University.
    Veit, Clemens
    Fraunhofer Institute for Solar Energy Systems ISE.
    Ma, Zaifei
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Wuerfel, Uli
    Fraunhofer Institute for Solar Energy Systems ISE.
    Zhu, Hongfei
    Chinese Academy of Science.
    Hu, Wenping
    Chinese Academy of Science.
    Zhang, Fengling
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    9-Alkylidene-9H-Fluorene-Containing Polymer for High-Efficiency Polymer Solar Cells2011Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 44, nr 19, s. 7617-7624Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A novel donor-acceptor copolymer containing 9-alkylidene-9H-fluorene unit in the main chain, poly[9-(1-hexylheptylidene)-2,7-fluorene-alt-5, 5-(4,7-di-2-thienyl-5,6-dialkoxy-2,1,3-benzothiadiazole)] (PAFDTBT), has been synthesized and evaluated in bulk heterojunction polymer solar cells (BHJ PSCs). The polymer possesses a low band gap of 1.84 eV, a low-lying HOMO energy level (5.32 eV), and excellent solubility in common organic solvents. PSCs based on PAFDTBT and (6,6)-phenyl-C(71)-butyric add methyl ester (PC(71)BM) demonstrate a power conversion efficiency (PCE) of 6.2% with a high fill factor (FF) of 0.70, which indicates that 9-alkylidene-9H-fluorene can be a very useful building block for constructing narrow band gap conjugated polymers for high-efficiency BHJ PSCs.

  • 11. Gillissen, S
    et al.
    Jonforsen, M
    Kesters, E
    Johansson, Tomas
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Theander, M
    Andersson, MR
    Inganäs, Olle
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Lutsen, L
    Vanderzande, D
    Synthesis and characterization of poly(pyridine vinylene) via the sulfinyl precursor route2001Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 34, nr 21, s. 7294-7299Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The synthesis and characterization of poly(pyridine vinylene) (PPyV) via the nonionic sulfinyl precursor route is presented. Starting from an unsymmetrical monomer, precursor polymers were prepared in various solvents, which led to polymers with variable molecular weights. The thermal conversion to the conjugated structure, as well as its stability, was studied with different techniques such as FT-IR, UV-vis, TGA, and direct insertion probe mass spectroscopy (DIP-MS). From these results we were able to derive the most suitable conditions to perform the conversion. The fully conjugated PPyV was further characterized with photoluminescence (PL) and cyclic voltammetry (CV) measurements. The PL efficiency was found to be as high as 14%. The CV measurements showed that the polymer can be reduced (n-doped).

  • 12.
    Hynynen, Jonna
    et al.
    Chalmers University of Technology, Sweden.
    Kiefer, David
    Chalmers University of Technology, Sweden.
    Yu, Liyang
    Chalmers University of Technology, Sweden.
    Kroon, Renee
    Chalmers University of Technology, Sweden.
    Munir, Rahim
    King Abdullah University of Science and Technology KAUST, Saudi Arabia; King Abdullah University of Science and Technology KAUST, Saudi Arabia.
    Amassian, Aram
    King Abdullah University of Science and Technology KAUST, Saudi Arabia; King Abdullah University of Science and Technology KAUST, Saudi Arabia.
    Kemerink, Martijn
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Komplexa material och system. Linköpings universitet, Tekniska fakulteten.
    Mueller, Christian
    Chalmers University of Technology, Sweden.
    Enhanced Electrical Conductivity of Molecularly p-Doped Poly(3-hexylthiophene) through Understanding the Correlation with Solid-State Order2017Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 50, nr 20, s. 8140-8148Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Molecular p-doping of the conjugated polymer poly(3-hexylthiophene) (P3HT) with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane (F4TCNQ) is a widely studied model system. Underlying structure property relationships are poorly understood because processing and doping are often carried out simultaneously. Here, we exploit doping from the vapor phase, which allows us to disentangle the influence of processing and doping. Through this approach, we are able to establish how the electrical conductivity varies with regard to a series of predefined structural parameters. We demonstrate that improving the degree of solid-state order, which we control through the choice of processing solvent and regioregularity, strongly increases the electrical conductivity. As a result, we achieve a value of up to 12.7 S cm(-2) for P3HT:F4TCNQ, We determine the F4TCNQ anion concentration and find that the number of (bound + mobile) charge carriers of about 10(-4) mol cm(-3) is not influenced by the degree of solid-state order. Thus, the observed increase in electrical conductivity by almost 2 orders of magnitude can be attributed to an increase in charge-carrier mobility to more than 10(-1) cm(2) V-1 s(-1). Surprisingly, in contrast to charge transport in undoped P3HT, we find that the molecular weight of the polymer does not strongly influence the electrical conductivity, which highlights the need for studies that elucidate structure property relationships of strongly doped conjugated polymers.

  • 13.
    Johansson, D.M.
    et al.
    Department of Organic Chemistry, Chalmers University of Technology, S-412 96 Göteborg, Sweden.
    Srdanov, G.
    UNIAX Corporation, 6780 Cortona Drive, Santa Barbara, CA 93117, United States.
    Yu, G.
    UNIAX Corporation, 6780 Cortona Drive, Santa Barbara, CA 93117, United States.
    Theander, M.
    Inganäs, Olle
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Andersson, M.R.
    Department of Polymer Technology, Chalmers University of Technology, S-412 96 Göteborg, Sweden.
    Synthesis and characterization of highly soluble phenyl-substituted poly(p-phenylenevinylenes)2000Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 33, nr 7, s. 2525-2529Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present the synthesis and characterization of soluble, high molecular weight phenyl-substituted poly(p-phenylenevinylenes). The studied polymers are poly(2-(2',5'-bis(2?-ethylhexyloxy)phenyl)- 1,4-phenylenevinylene) (BEHP-PPV) and copolymers of BEHP-PPV and poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV). Their photoluminescence and electroluminescence have been examined as well as their stability to air and light. The polymers emitted green and yellow light. Stability measurements showed increased stability compared to some previously known substituted PPVs.

  • 14. Johansson, DM
    et al.
    Theander, M
    Chalmers Univ Technol, Dept Polymer Technol, SE-41296 Gothenburg, Sweden Chalmers Univ Technol, Dept Organ Chem, SE-41296 Gothenburg, Sweden Linkoping Univ, IFM, Dept Phys, SE-58183 Linkoping, Sweden.
    Granlund, T
    Chalmers Univ Technol, Dept Polymer Technol, SE-41296 Gothenburg, Sweden Chalmers Univ Technol, Dept Organ Chem, SE-41296 Gothenburg, Sweden Linkoping Univ, IFM, Dept Phys, SE-58183 Linkoping, Sweden.
    Inganäs, Olle
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Andersson, MR
    Synthesis and characterization of polyfluorenes with light-emitting segments2001Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 34, nr 6, s. 1981-1986Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Two new polymers consisting of poly(9-(2'-ethylhexyl)-9-hexylfluorene) (EHH-PF) with a small amount of substituted poly(p-phenylenevinylene) (PPV) segments have been synthesized and characterized. The synthetic route was designed to allow the incorporation of only one (or zero) PPV segments per polymer chain. Photoluminescence measurements showed that energy transfer from the PF segments to the more narrow band-gap PPV segments did occur, both in solution and in film. In the solid state, all emissions were detected from the PPV segments with photoluminescence quantum yields up to 68%. One of the polymers has been used as the active material in a microcavity laser device. The threshold for lasing is 2 muJ/cm(2).

  • 15. Johansson, DM
    et al.
    Theander, M
    Chalmers Univ Technol, Dept Polymer Technol, SE-41296 Gothenburg, Sweden Chalmers Univ Technol, Dept Organ Chem, SE-41296 Gothenburg, Sweden Linkoping Univ, Dept Phys IFM, SE-58183 Linkoping, Sweden UNIAX Corp, Goleta, CA 93117 USA.
    Srdanov, G
    Chalmers Univ Technol, Dept Polymer Technol, SE-41296 Gothenburg, Sweden Chalmers Univ Technol, Dept Organ Chem, SE-41296 Gothenburg, Sweden Linkoping Univ, Dept Phys IFM, SE-58183 Linkoping, Sweden UNIAX Corp, Goleta, CA 93117 USA.
    Yu, G
    Chalmers Univ Technol, Dept Polymer Technol, SE-41296 Gothenburg, Sweden Chalmers Univ Technol, Dept Organ Chem, SE-41296 Gothenburg, Sweden Linkoping Univ, Dept Phys IFM, SE-58183 Linkoping, Sweden UNIAX Corp, Goleta, CA 93117 USA.
    Inganäs, Olle
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Andersson, MR
    Influence of polymerization temperature on molecular weight, photoluminescence, and electroluminescence for a phenyl-substituted poly(p-phenylenevinylene)2001Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 34, nr 11, s. 3716-3719Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present the synthesis and characterization of poly(2-(2",5'-bis(2"-ethylhexyloxy)phenyl)-1,4-phenylenevinylene) (BEHP-PPV) polymerized at different temperatures. The photoluminescence efficiencies in the solid state of BEHP-PPV obtained at 144 and 0 degreesC are 28% and 60%, respectively. H-1 NMR measurements showed a lower concentration of structural defects for BEHP-PPV obtained at lower temperatures, which can explain the increased photoluminescence efficiencies for these polymers. Polymerization temperatures below 0 degreesC decrease the molecular weight without changing the photoluminescence efficiency to any large extent. The electroluminescence efficiencies follow the trend in the photoluminescence efficiencies.

  • 16. Johansson, DM
    et al.
    Wang, XJ
    Johansson, Tomas
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Inganäs, Olle
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Yu, G
    Srdanov, G
    Andersson, MR
    Synthesis of soluble phenyl-substituted poly(p-phenylenevinylenes) with a low content of structural defects2002Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 35, nr 13, s. 4997-5003Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The synthesis and characterization of two new soluble poly(p-phenylenevinylenes) (PPVs) are reported. The polymers are poly(2-2',5'-bis(octyloxy)benzene)-1,4-phenylenevinylene) (BOP-PPV) and poly(2-(2',5'-bis(octyloxy)benzene)-5-methoxy-1,4-phenylenevinylene) (BOPM-PPV). Both polymers have been polymerized at high and low temperatures to study the formation of structural defects. It is shown that both methoxy groups as side chains and low polymerization temperatures decrease the content of defects in the final polymer. As a consequence, the polymers with lower concentration of defects exhibit higher electroluminescence yields in light-emitting diodes. In addition to this, the polymers with a low content of defects exhibited longer operational lifetimes in these devices. The highest photoluminescence quantum yield in the solid state and electroluminescence efficiency were found to be 72% and 1.74%, respectively.

  • 17. Jonforsen, M
    et al.
    Johansson, Tomas
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Inganäs, Olle
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Andersson, MR
    Synthesis and characterization of soluble and n-dopable poly(quinoxaline vinylene)s and poly(pyridopyrazine vinylene)s with relatively small band gap2002Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 35, nr 5, s. 1638-1643Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Synthesis and characterization of poly(quinoxaline vinylene)s and poly(pyridopyrazine vinylene)s with linear and branched aliphatic side chains are reported. The electron affinity of the polymers was measured with cyclic voltammetry (CV) and found to be highest for the pyridopyrazine vinylene polymers, Compared to CN-MEH-PPV, the pyridopyrazine vinylene polymers were easier to reduce, while the quinoxaline derivatives were harder. UV-vis absorption measurements showed that the polymers have relatively small band gaps.

  • 18.
    Jonkheijm, P
    et al.
    Eindhoven University of Technology, Netherlands.
    van Duren, JKJ
    Eindhoven University of Technology, Netherlands.
    Kemerink, Martijn
    Eindhoven University of Technology, Netherlands.
    Janssen, RAJ
    Eindhoven University of Technology, Netherlands.
    Schenning, APHJ
    Eindhoven University of Technology, Netherlands.
    Meijer, EW
    Eindhoven University of Technology, Netherlands.
    Control of film morphology by folding hydrogen-bonded oligo(p-phenylenevinylene) polymers in solution2006Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 39, nr 2, s. 784-788Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The film morphology of pi-conjugated oligomers has been controlled by self-assembly in solution. To this end supramolecular hydrogen-bonded systems of oligo(p-phenylenevinylene) (OPV) carrying ureido-s-triazine hydrogen-bonding groups are used. Neutron scattering experiments in dodecane solutions show that columnar stacks are formed. Films with thicknesses on the order of 100 nm are made that have a supramolecular organization resembling the organization present in solution. Uniform rodlike morphological domains range over several hundreds of nanometers as shown by atomic force microscopy. The rodlike morphology of the OPVs was also preserved when blended with a C-60 derivative, producing stable photovoltaic devices.

  • 19.
    Kemerink, Martijn
    et al.
    Eindhoven University of Technology, Netherlands.
    van Duren, JKJ
    Eindhoven University of Technology, Netherlands.
    van Breemen, AJJM
    Eindhoven University of Technology, Netherlands.
    Wildeman, J
    Eindhoven University of Technology, Netherlands.
    Wienk, MM
    Eindhoven University of Technology, Netherlands.
    Blom, PWM
    Eindhoven University of Technology, Netherlands.
    Schoo, HFM
    Eindhoven University of Technology, Netherlands.
    Janssen, RAJ
    Eindhoven University of Technology, Netherlands.
    Substitution and preparation effects on the molecular-scale morphology of PPV films2005Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 38, nr 18, s. 7784-7792Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The morphology of spin-cast films of poly(p-phenylenevinylene) (PPV) derivatives is studied as a function of the substitution pattern of the conjugated backbone. Moreover, the influence of concentration in the casting solution, annealing, the choice of solvent, and the role of defects are addressed. By using a recently developed scanning-probe technique, we are able to visualize individual polymer chains and aggregates on the surface of spin-cast films. We find that a symmetric substitution pattern strongly promotes interchain aggregation in the surface layer, whereas an unsymmetric pattern in some cases leads to intrachain or self-aggregation. The nature of these intrachain aggregates is further investigated using molecular dynamics simulations. The observed molecular morphologies can in most cases be qualitatively related to macroscopic electrooptical properties. Therefore, our results strongly suggest that the surface morphology may be regarded as indicative of the morphology of the entire film.

  • 20.
    Laiho, Ari
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Tran Nguyen, Ha
    University of Mons, Belgium.
    Sinno, Hiam
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Engquist, Isak
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Dubois, Philippe
    University of Mons, Belgium.
    Coulembier, Olivier
    University of Mons, Belgium.
    Crispin, Xavier
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Amphiphilic Poly(3-hexylthiophene)-Based Semiconducting Copolymers for Printing of Polyelectrolyte-Gated Organic Field-Effect Transistors2013Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 46, nr 11, s. 4548-4557Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Polyelectrolytes are promising electronically insulating layers for low-voltage organic field effect transistors. However, the polyelectrolyte–semiconductor interface is difficult to manufacture due to challenges in wettability. We introduce an amphiphilic semiconducting copolymer which, when spread as a thin film, can change its surface from hydrophobic to hydrophilic upon exposure to water. This peculiar wettability is exploited in the fabrication of polyelectrolyte-gated field-effect transistors operating below 0.5 V. The prepared amphiphilic semiconducting copolymer is based on a hydrophobic regioregular poly(3-hexylthiophene) (P3HT) covalently linked to a hydrophilic poly(sulfonated)-based random block. Such a copolymer is obtained in a three-step strategy combining Grignard metathesis (GRIM), atom transfer radical polymerization (ATRP) processes, and a postmodification method. The structure of the diblock copolymer was characterized using FT-IR, 1H NMR spectroscopy, and gel permeation chromatography (GPC).

  • 21.
    Müller, Christian
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Andersson, Mattias
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Pena-Rodriguez, Ovidio
    Esfera UAB, Spain .
    Garriga, Miquel
    Esfera UAB, Spain .
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Campoy-Quiles, Mariano
    Esfera UAB, Spain .
    Determination of Thermal Transition Depth Profiles in Polymer Semiconductor Films with Ellipsometry2013Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 46, nr 18, s. 7325-7331Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Geometric confinement and interface effects can significantly alter the thermodynamic properties of thin polymer films. Phase transition temperatures have been shown to strongly depend on film thickness below a critical thickness threshold. It has been suggested that this behavior is due to an interface-induced continuous variation in phase transition 200 temperatures throughout the depth of the films. Here we employ variable-temperature spectroscopic ellipsometry to demonstrate the existence of these depth profiles. We examine four different polymer semiconductors that are of interest for organic light-emitting diodes, solar cells, and field-effect transistors. In contrast to insulating polymers, these light-absorbing materials provide detailed information about structural changes as a function of depth due to wavelength-dependent attenuation. This concept enables us to investigate a broad range of thermodynamic processes including the glass transition, crystallization as well as crystalline and liquid-crystalline melting. In general, for the here investigated systems, higher transition temperatures are found at the free surface. Finally, the deduced profiles are used to predict the thickness dependence of the mean phase transition temperature.

  • 22.
    Nilsson, Peter
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Optical emission of a conjugated polyelectrolyte: calcium-induced conformational changes in calmodulin and calmodulin-calcineurin interactions2004Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 37, nr 24, s. 9109-9113Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Electronic polymers in aqueous media offer bioelectronic detection of biomolecular processes. Here we report fluorometric detection of calcium-induced conformational changes in calmodulin based on noncovalent assembly of calmodulin to a water-soluble zwitterionic polythiophene derivative. Assembly with calmodulin will induce a planar geometry and aggregation of the polymer chains, detected as a decrease of the intensity and a red shift of the fluorescence. Upon addition of Ca2+ the intensity of the emitted light is increased and blue-shifted. The geometrical alteration of the polymer chains can further be utilized for recording of the binding of calcineurin to the calcium-activated POWT−calmodulin complex. This novel methodology, using a conformation-sensitive probe, allows fluorometric detection of conformational changes in biomolecules and protein−protein interactions without any covalent modifications of the biomolecules. The rapid and selective method is based on noncovalent interactions between a zwitterionic polythiophene derivative and the biomolecule of interest. This offers a novel way to create microarrays without using covalent attachment of the receptor or labeling of the analyte.

  • 23.
    Nilsson, Peter
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Olsson, Johan
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Konradsson, Peter
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Enantiomeric substituents determine the chirality of luminescent conjugated polythiophenes2004Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 37, nr 17, s. 6316-6321Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Chiral isomers of 3-substituted polythiophenes with amino acid functiontionalized side chains are compared. The polymers show pH-dependent absorption, emission, and circular dichroism spectra in buffered aqueous solution. At pH equal to pI of the amino acid, the backbones adopt nonplanar helical conformations, and the polymer chains are separated from each other. Increasing pH leads to more planar conformations of the backbones and an aggregation of the polymer chains occurs. A lower pH will also lead to more planar conformation of the backbones, but aggregation of the polymer chains appears to be absent. The nonplanar to planar transition of the polymer backbone and the separation/aggregation of different polymer chains is not affected by stereochemistry of the zwitterionic side chain. The two isomers have almost identical pH-dependent absorption and emission spectra. However, the chirality of the zwitterionic side chain is reflected in the conformation of the polymer backbone, giving rise to a right-handed and left-handed helical form of polythiophene chains since the induced circular dichroism patterns of the two polymers are mirror images.

  • 24.
    Nilsson, Peter
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Olsson, Johan
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Stabo-Eeg, Franz
    The Norwegian University of Scinece and Technology.
    Lindgren, Mikael
    The Norwegian University of Science and Technology.
    Konradsson, Peter
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Organisk Kemi.
    Inganäs, Olle
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik.
    Chiral Recognition of a Synthetic Peptide Using Enantiomeric Conjugated Polyelectrolytes and Optical Spectroscopy2005Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 38, s. 6813-6821Artikkel i tidsskrift (Fagfellevurdert)
  • 25.
    Patil, Nagaraj
    et al.
    University of Liege, Belgium.
    Cordella, Daniela
    University of Liege, Belgium.
    Aqil, Abdelhafid
    University of Liege, Belgium.
    Debuigne, Antoine
    University of Liege, Belgium.
    Molla, Shimelis
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten. University of Addis Ababa, Ethiopia.
    Jerome, Christine
    University of Liege, Belgium.
    Detrembleur, Christophe
    University of Liege, Belgium.
    Surface- and Redox-Active Multifunctional Polyphenol-Derived Poly(ionic liquid)s: Controlled Synthesis and Characterization2016Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 49, nr 20, s. 7676-7691Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Combining the redox activity and remarkable adhesion propensity of polyphenols (such as catechol or pyrogallol) with the numerous tunable properties of poly(ionic liquid)s (PILs) is an attractive route to design inventive multifunctional macromolecular platforms. In this contribution, we describe the first synthesis of a novel family of structurally well-defined PILs functionalized with catechol/pyrogallol/phenol pendants by organometallic-mediated radical polymerization (OMRP) using an alkyl cobalt(III) complex as initiator and mediating agent. The living character of the chains is also exploited to produce di- and triblock PILs, and the facile counteranion exchange reactions afforded a library of PILs-bearing free phenol/catechol/pyrogallol moieties. Electrochemical investigations of catechol/pyrogallol-derived PILs in aqueous medium demonstrated the characteristic catechol to o-quinone transformations, whereas, quasi reversible doping/undoping with supporting electrolyte cations (Li+/tetrabutylammonium(+)) has been observed in organic media, suggesting a bright future for this new family of redox-active PILs as cathode material for secondary energy storage devices. Also, pendant catechol/pyrogallol groups mediated sustained anchoring onto the gold surface conferred PILs properties to the interface. As a proof-of-concept, both the adsorption and inhibition of proteins on polymer modified surfaces have been demonstrated in real time using the quartz crystal microbalance with dissipation technique. The exquisite physicochemical tunability of these innovative surface- and redox-active PILs makes them excellent candidates for a broad range of potential applications, including "smart surfaces" and electrochemical energy storage devices.

  • 26.
    Piletsky, SA
    et al.
    Cranfield University, Institute BioScience and Technology, Bedford MK45 4DT, England; .
    Guerreiro, A
    Cranfield University, Institute BioScience and Technology, Bedford MK45 4DT, England; .
    Piletska, EV
    Cranfield University, Institute BioScience and Technology, Bedford MK45 4DT, England; .
    Chianella, I
    Cranfield University, Institute BioScience and Technology, Bedford MK45 4DT, England; .
    Karim, K
    Cranfield University, Institute BioScience and Technology, Bedford MK45 4DT, England; .
    Turner, APF
    Cranfield University, UK.
    Polymer cookery. 2. Influence of polymerization pressure and polymer swelling on the performance of molecularly imprinted polymers2004Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 37, nr 13, s. 5018-5022Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A set of polymers was imprinted with (+)-ephedrine at ambient and 10 bar pressure. The performance of the synthesized materials was studied by HPLC at six different temperatures: 0, 10, 20, 30, 40, and 50 degreesC. It was shown that the polymer morphology (surface area and porosity) and enantioselective properties are different for these two polymers-an unexpected result which was in contradiction with the theoretical forecasts. A possible mechanism which explains the observed phenomenon is discussed. The contributing factor which influenced the polymer performance was the polymer swelling. This shows that, in addition to temperature, other physical parameters such as pressure and polymer swelling should be analyzed and accounted for in the quality control of MIP synthesis and application.

  • 27.
    Piletsky, SA
    et al.
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Mijangos, I
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Guerreiro, A
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Piletska, EV
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Chianella, I
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Karim, K
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Polymer cookery: Influence of polymerization time and different initiation conditions on performance of molecularly imprinted polymers2005Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 38, nr 4, s. 1410-1414Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A set of polymers was imprinted with (-)-ephedrine using thermal and UV initiation. The performance of the synthesized materials was studied by HPLC. It was shown that the polymer morphology and enantioselective properties are dependent on the polymerization conditions and time of the reaction. The binding mechanism of synthesized polymers was studied using Vant Hoff analysis. The results of testing strongly indicate that the polymer receptor structure is shaped during the initial phase of polymer gelation. The present study shows the importance of controlling experimental conditions in the MIP synthesis and highlights potential problems expected during scaling up of MIP production.

  • 28.
    Piletsky, SA
    et al.
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; GlaxoSmithKline Research and Dev, Stevenage SG1 2NY, Herts, England; .
    Piletska, EV
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; GlaxoSmithKline Research and Dev, Stevenage SG1 2NY, Herts, England; .
    Karim, K
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; GlaxoSmithKline Research and Dev, Stevenage SG1 2NY, Herts, England; .
    Freebairn, KW
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; GlaxoSmithKline Research and Dev, Stevenage SG1 2NY, Herts, England; .
    Legge, CH
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; GlaxoSmithKline Research and Dev, Stevenage SG1 2NY, Herts, England; .
    Turner, APF
    Cranfield University, UK.
    Polymer cookery: Influence of polymerization conditions on the performance of molecularly imprinted polymers2002Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 35, nr 19, s. 7499-7504Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A set of polymers has been imprinted with (-)-ephedrine at six different temperatures, ranging from -30 to +80 degreesC. Polymer affinity and specificity were observed to be strongly dependent on the polymerization temperature. The experimental results suggest that the polymer is able to "memorize" the temperature used in the polymerization process in a manner similar to previously documented MIP "memory" effects for the template and polymerization solvent. In a study of the effect of temperature on retention and selectivity in HPLC (using the MIP as a column packing), a clear gradient change in the Vant Hoff plots was observed at 20-30 degreesC. This indicates a transition in binding mechanism from exothermic at higher temperatures to endothermic at lower temperatures. These results, supported by the evidence of template-induced MIP swelling, are interpreted in terms of desolvation and conformational changes in the polymers induced by the interaction with the template.

  • 29.
    Selegård, Robert
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Rouhbalchsh, Zeinab
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Shirani, Hamid
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska fakulteten.
    Johansson, Leif
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Norman, Patrick
    KTH Royal Institute Technology, Sweden.
    Linares, Mathieu
    KTH Royal Institute Technology, Sweden.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Nilsson, Peter
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska fakulteten.
    Distinct Electrostatic Interactions Govern the Chiro-Optical Properties and Architectural Arrangement of Peptide-Oligothiophene Hybrid Materials2017Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 50, nr 18, s. 7102-7110Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The development of chiral optoelectronic materials is of great interest due to their potential of being utilized in electronic devices, biosensors, and artificial enzymes. Herein, we report the chiral optical properties and architectural arrangement of optoelectronic materials generated from noncovalent self-assembly of a cationic synthetic peptide and five chemically defined anionic pentameric oligothiophenes. The peptide-oligothiophene hybrid materials exhibit a three-dimensional ordered helical structure and optical activity in the pi-pi* transition region that are observed due to a single chain induced chirality of the conjugated thiophene backbone upon interaction with the peptide. The latter property is highly dependent on electrostatic interactions between the peptide and the oligothiophene, verifying that a distinct spacing of the carboxyl groups along the thiophene backbone is a major chemical determinant for having a hybrid material with distinct optoelectronic properties. The necessity of the electrostatic interaction between specific carboxyl functionalities along the thiophene backbone and the lysine residues of the peptide, as well as the induced circular dichroism of the thiophene backbone, was also confirmed by theoretical calculations. We foresee that our findings will aid in designing optoelectronic materials with dynamic architectonical precisions as well as offer the possibility to create the next generation of materials for organic electronics and organic bioelectronics.

  • 30.
    Sergeyeva, TA
    et al.
    Natl Acad Science Ukraine, Institute Mol Biol and Genet, UA-03143 Kiev, Ukraine; Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Natl Acad Science Ukraine, Institute Macromol Chemistry, UA-02160 Kiev, Ukraine; .
    Piletsky, SA
    Natl Acad Science Ukraine, Institute Mol Biol and Genet, UA-03143 Kiev, Ukraine; Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Natl Acad Science Ukraine, Institute Macromol Chemistry, UA-02160 Kiev, Ukraine; .
    Piletska, EV
    Natl Acad Science Ukraine, Institute Mol Biol and Genet, UA-03143 Kiev, Ukraine; Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Natl Acad Science Ukraine, Institute Macromol Chemistry, UA-02160 Kiev, Ukraine; .
    Brovko, OO
    Natl Acad Science Ukraine, Institute Mol Biol and Genet, UA-03143 Kiev, Ukraine; Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Natl Acad Science Ukraine, Institute Macromol Chemistry, UA-02160 Kiev, Ukraine; .
    Karabanova, LV
    Natl Acad Science Ukraine, Institute Mol Biol and Genet, UA-03143 Kiev, Ukraine; Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Natl Acad Science Ukraine, Institute Macromol Chemistry, UA-02160 Kiev, Ukraine; .
    Sergeeva, LM
    Natl Acad Science Ukraine, Institute Mol Biol and Genet, UA-03143 Kiev, Ukraine; Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Natl Acad Science Ukraine, Institute Macromol Chemistry, UA-02160 Kiev, Ukraine; .
    Elskaya, AV
    Natl Acad Science Ukraine, Institute Mol Biol and Genet, UA-03143 Kiev, Ukraine; Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Natl Acad Science Ukraine, Institute Macromol Chemistry, UA-02160 Kiev, Ukraine; .
    Turner, APF
    Cranfield University, UK.
    In situ formation of porous molecularly imprinted polymer membranes2003Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 36, nr 19, s. 7352-7357Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Molecularly imprinted polymer membranes for a model compound, atrazine, were prepared in situ from a monomer mixture containing methacrylic acid, tri(ethylene glycol) dimethacrylate, and atrazine using U-V-initiated polymerization. To improve flexibility and mechanical stability of these membranes, oligourethane acrylate was added to the mixture of monomers. Polymeric additives were used to increase porosity of membranes and their permeability as well as to make them suited for filtration experiments. This process resulted in the formation of thin, flexible, and porous membranes containing atrazine-specific binding sites. The atrazine-imprinted membranes showed higher affinity to this herbicide than to structurally similar compounds (simazine, prometryn, and metribuzin). The binding capacity of MIP membranes was found to be significantly higher than that observed previously for MIP systems. The high affinity, specificity, and binding capacity of MIP membranes, together with their straightforward and easy preparation, provide a good basis for their application in separation and purification, e.g., in membrane chromatography.

  • 31.
    Tao, Qiang
    et al.
    Xiangtan University, Peoples R China; Chalmers, Sweden.
    Xia, Yuxin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Xu, Xiaofeng
    Chalmers, Sweden.
    Hedstrom, Svante
    Lund University, Sweden.
    Backe, Olof
    Chalmers, Sweden.
    James, David I.
    Chalmers, Sweden.
    Persson, Petter
    Lund University, Sweden.
    Olsson, Eva
    Chalmers, Sweden.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Hou, Lintao
    Jinan University, Peoples R China.
    Zhu, Weiguo
    Xiangtan University, Peoples R China.
    Wang, Ergang
    Chalmers, Sweden.
    D-A(1)-D-A(2) Copolymers with Extended Donor Segments for Efficient Polymer Solar Cells2015Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 48, nr 4, s. 1009-1016Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Typically a donor-acceptor (D-A) design strategy is used for engineering the bandgap of polymers for solar cells. However, in this work, a series of alternating D-A(1-)D-A(2) copolymers PnTQTI(F) were synthesized and characterized with oligothiophenes (nT, n = 1, 2, 3) as the donor and two electron-deficient moieties, quinoxaline and isoindigo, as the acceptors in the repeating unit. We have studied the influence of the donor segments with different numbers of thiophene units and the effect of the addition of fluorine to the quinoxaline unit of the D-A(1)-D-A(2) polymers. The photophysical, electrochemical, and photovoltaic properties of the polymers were examined via a range of techniques and related to theoretical simulations. On increasing the length of the donor thiophene units, broader absorption spectra were observed in addition to a sequential increase in HOMO levels, while the LUMO levels displayed very small variations. The addition of fluorine to the quinoxaline unit not only decreased the HOMO levels of the resulting polymers but also enhanced the absorption coefficients. A superior photovoltaic performance was observed for the P3TQTI-F-based device with a power conversion efficiency (PCE) of 7.0%, which is the highest efficiency for alternating D-A(1)-D-A(2) polymers reported to date. The structureproperty correlations of the PnTQTI(F) polymers demonstrate that varying of the length of the donor segments is a valuable method for designing high-performance D-A(1)-D-A(2) copolymers and highlight the promising nature of D-A(1)-D-A(2) copolymers for efficient bulk-heterojunction solar cells.

  • 32.
    Zotti, G.
    et al.
    Istituto CNR l'Energetica Interfasi, C.o Stati Uniti 4, 35127 Padova, Italy.
    Zecchin, S.
    Istituto CNR l'Energetica Interfasi, C.o Stati Uniti 4, 35127 Padova, Italy.
    Schiavon, G.
    Istituto CNR l'Energetica Interfasi, C.o Stati Uniti 4, 35127 Padova, Italy.
    Louwet, F.
    R and D Materials Research, Chemistry Department, Agfa Gevaert N.V., Septelaan 27, B-2640 Mortsel, Belgium.
    Groenendaal, L.
    R and D Materials Research, Chemistry Department, Agfa Gevaert N.V., Septelaan 27, B-2640 Mortsel, Belgium.
    Crispin, Xavier
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för teknik och naturvetenskap.
    Osikowicz, Wojciech
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi.
    Salaneck, William R
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi.
    Fahlman, Mats
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi.
    Electrochemical and XPS studies toward the role of monomeric and polymeric sulfonate counterions in the synthesis, composition, and properties of poly(3,4-ethylenedioxythiophene)2003Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 36, nr 9, s. 3337-3344Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Electrochemically prepared poly(3,4-ethylenedioxythiophene) (PEDT) poly(styrenesulfonate) (PSS), produced from acidic (PSSH) and basic (PSSNa) PSS, was characterized by cyclic voltammetry CV, UV-vis spectroscopy, in situ conductivity, and XPS spectroscopy and was compared with electrochemically prepared PEDT/tosylate and chemically prepared PEDT/PSS. CV analysis shows that the polymer synthesis is strongly affected by the nucleophilic character of the counteranion. Although CV and UV-vis spectroscopy show that the structure and degree of polymerization (oligomeric, ca. 10 EDT units) of the PEDT backbone is the same for all polymers, XPS is able to explain the different conductivity values for these materials (ranging from 1 S cm-1 for PEDT/PSSNa to 400-450 S cm-1 for PEDT/tosylate) based on doping level and composition. In particular, critical results are observed to be the ratios between sulfonate and thiophene units in the polymers: the higher the PEDT concentration, the higher the conductivity. XPS also explains by solvent-induced nanometer-scale segregation between PEDT/PSS and excess PSS particles the often reported conductivity enhancement of chemically prepared PEDT/PSS upon treatment with polar solvents.

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