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  • 701. Zhang, Biaobiao
    et al.
    Li, Fei
    Yu, Fengshou
    Wang, Xiaohong
    Zhou, Xu
    Li, Hua
    Jiang, Yi
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Electrochemical and Photoelectrochemical Water Oxidation by Supported Cobalt-Oxo Cubanes2014In: ACS Catalysis, ISSN 2155-5435, Vol. 4, no 3, 804-809 p.Article in journal (Refereed)
    Abstract [en]

    Cobalt-oxo cubane clusters were immobilized on a Nafion film-coated fluorine-doped tin oxide (FTO) electrode and an alpha-Fe2O3 photoanode as surface catalysts for water oxidation. The performance of electrochemical water splitting indicated that these earth-abundant metal complexes retain their homogeneous reactivity on the electrode. Furthermore, efficient visible light-driven water oxidation was realized by coupling a molecular electrocatalyst with an inorganic semiconductor as a noble metal-free photoanode, showing a stability significantly improved with respect to that of the homogeneous system.

  • 702.
    Zhang, Fan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Xie, Guoxin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science. Tsinghua University, China.
    Pan, Jinshan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Tunable Adsorption and Film Formation of Mussel Adhesive Protein by Potential Control2017In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 33, no 35, 8749-8756 p.Article in journal (Refereed)
    Abstract [en]

    Mussel adhesive proteins are of great interest in many applications because of their outstanding adhesive property and film forming ability. Understanding and controlling the film formation and its performance is crucial for the effective use of such proteins. In this study, we focus on the potential controlled film formation and compaction of one mussel adhesive protein, Mefp-1. The adsorption and film-forming behavior of Mefp-1 on a platinum (Pt) substrate under applied potentials were investigated by cyclic voltammetry, potential-controlled electro-chemical impedance spectroscopy (EIS), and quartz crystal microbalance with dissipation monitoring (QCM-D). Moreover, microfriction measurements were performed to evaluate the mechanical properties of the Mefp-1 films formed at selected potentials. The results led to the conclusion that Mefp-1 adsorbs on the Pt substrate through both electrostatic and nonelectrostatic interactions and shows an effective blocking effect for the electroactive sites on the substrate. The properties of the adsorbed Mefp-1 film vary with the applied potential, and the compactness of the adsorbed Mefp-1 film can be reversibly tuned by the applied potential.

  • 703.
    Zhang, Liming
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Chemical structure of condensed tannins from 8 different tree species studied by NMR techniques2011In: 16th International Symposium on Wood, Fiber and Pulping Chemistry: Proceedings, ISWFPC, Tianjin, China, 2011, 93-97 p.Conference paper (Refereed)
    Abstract [en]

    NMR techniques were applied to study and to compare the chemical structure of tannins from 8 different tree species, i.e., Norway spruce (Picea abies), Scots pine (Pinus sylvestris), larch (Larix gmelini), French maritime pine bark extractive, Quebracho (Schinopsis lorentzii), black wattle (Acacia mearnsii), Mangium (Acacia mangium) and Chinese Bayberry tree (Myrica rubra). The tannins from Norway spruce bark and Scots pine bark were extracted in our laboratory by using fresh bark harvested in Stockholmarea. The other tannins were obtained as commercial samples. It was found in this study that the complicated chemical structures of condensed tannins can be elucidated by applying 13C, DEPT90, and 2D HSQC NMR techniques. The tannins from pines and larch were found to be structurally similar to each other, containing mainly the procyanidins. In the case of Norway spruce tannin, stilbene polymer or stilbene- procyanidin co-polymer were found to comprise about half of the tannin content together with procyanidins. Quebracho tannin was found to contain predominantly the profisetinidins, in agreement with results of other earlier studies. Black wattle tannin was also found to contain profisetinidins as the major components, and proanthocyanidins and probably prorobinetinidins as the minor components. Tannin from Mangium was found to contain the prorobinetinidins as the major components. The Chinese Bayberry (Myrica rubra) tannin, however was found to contain mainly the prorobinetinidins and also small amount of the prodelphinidins.

  • 704. Zhang, Linlin
    et al.
    Gao, Yan
    Ding, Xin
    Yu, Ze
    Sun, Licheng
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. State Key Laboratory of Fine Chemicals, Institute of Artificial Photosynthesis, DUT-KTH Joint Education and Research Center on Molecular Devices, Dalian University of Technology (DUT), China.
    High-Performance Photoelectrochemical Cells Based on a Binuclear Ruthenium Catalyst for Visible-Light-Driven Water Oxidation2014In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 7, no 10, 2801-2804 p.Article in journal (Refereed)
    Abstract [en]

    Two photoanodes based on a binuclear (2) and a mononuclear ruthenium (3) water oxidation catalysts were assembled in combination with a molecular photosensitizer (1) by using a co-adsorption method. The anodes were used in dye-sensitized photoelectrochemical cells (DS-PECs) for visible-light-driven water splitting. A DS-PEC device using TiO2(1+2) as working electrode (WE) exhibits better performance than TiO2(1+3) as WE in light-driven water splitting. Detailed photoelectrochemical studies on these DS-PEC devices are discussed.

  • 705. Zhang, Peili
    et al.
    Wang, Mei
    Gloaguen, Frederic
    Chen, Lin
    Quentelb, Francois
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Electrocatalytic hydrogen evolution from neutral water by molecular cobalt tripyridine-diamine complexes2013In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 49, no 82, 9455-9457 p.Article in journal (Refereed)
    Abstract [en]

    A cobalt complex with a tripyridine-diamine pentadentate ligand was found to be a highly active catalyst for electrochemical H-2 production from neutral water, with an activity of 860 mol H-2 (mol cat)(-1) h(-1) (cm(2) Hg)(-1) over 60 h CPE experiment at-1.25 V in a pH 7 phosphate buffer solution, without considerable deactivation.

  • 706. Zhang, Qi-Wei
    et al.
    Li, Dengfeng
    Li, Xin
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    White, Paul B.
    Mecinovic, Jasmin
    Ma, Xiang
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Nolte, Roeland J. M.
    Tian, He
    Multicolor Photoluminescence Including White-Light Emission by a Single Host-Guest Complex2016In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 138, no 41, 13541-13550 p.Article in journal (Refereed)
    Abstract [en]

    Achieving multicolor photoluminescence, 'especially white-light emission, under mild conditions based on a single "fluorescent compound-is a great challenge. Herein, we report a novel colorful-emission host guest complex BPCY, which is composed of a two-arm fluorescent guest molecule (BPC) and gamma-cyclodextrin (gamma-CD) as the host-molecule. BPC bears a unique asymmetrical donor acceptor donor (D-1-A(+)similar to D-2)-type structure, where D-1, A(+), and D-2 stand for the binaphthol electron donor, pyridinium electron acceptor, and coumarin electron donor, respectively. The luminescence property of BPC shows dual-sensitivity, i.e., toward the excitation wavelength and the cyclodextrin host molecule. Under certain conditions, the complex shows three different emission wavelengths, allowing the realization of multicolor photoluminescence, including red (R), green (G), and blue (B) as well as various intermediate colors by orthogonally modulating these two stimuli. In this way, nearly pure white-light emission with CIE coordinates (0.33, 0.34) could be generated. A combination of structural, spectroscopic, and computational simulation studies revealed the occurrence of synergetic mechanistic processes for the stimuli-responsive multicolor luminescence of the BPCY complex, namely, host-enhanced intramolecular charge-transfer (ICT) and host-induced restriction of intramolecular rotation (RIR). This new supramolecular complex with superior multicolor emission abilities may find wide applications in the fields of information processing and display media. Furthermore, the molecular design rationale presented here may provide a new design strategy for the development of high performance optical materials using a single supramolecular platform.

  • 707.
    Zhang, Xian
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Leygraf, Christofer
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Odnevall Wallinder, Inger
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Selected area visualization by FIB-milling for corrosion-microstructure analysis with submicron resolution2013In: Materials letters (General ed.), ISSN 0167-577X, E-ISSN 1873-4979, Vol. 98, 230-233 p.Article in journal (Refereed)
    Abstract [en]

    We report the successful use of focussed ion beam (FIB) milling of trenches in a material of complex microstructure in order to visualize a selected area (32×32 μm) for further multi-analysis with submicron resolution. This capability is demonstrated for a Zn-5 wt% Al coating Galfan™ on steel. The very same eutectic surface area was analyzed by three complementary and independent techniques providing consistent information on the lateral distribution of morphology and elemental composition (scanning electron microscopy with x-ray microanalysis, SEM/EDS), topography and Volta potential (scanning Kelvin probe force microscopy, SKPFM) and oxide composition (confocal Raman microspectroscopy, CRM). The approach enables a straightforward way to explore the interplay between microstructure and local corrosion of metallic materials.

  • 708.
    Zhang, Xian
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Qiu, Ping
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Leygraf, Christofer
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Odnevall Wallinder, Inger
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Surface structure of 55% Al-Zn alloy coating and corrosion product distribution after exposure in chloride-containing electrolytes2011In: Proceedings The 10th International Conference on the Structure of Surfaces (ICSOS-10), 2011Conference paper (Refereed)
  • 709.
    Zhang, Xian
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Vu, Thanh-Nam
    Laboratoire de Physico-chimie des Surfaces, ENSCP-CNRS, Ecole Nationale Supérieure de Chimie de Paris, Paris, France.
    Volovitch, P.
    Laboratoire de Physico-chimie des Surfaces, ENSCP-CNRS, Ecole Nationale Supérieure de Chimie de Paris, Paris, France.
    Leygraf, Christofer
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Ogle, K.
    Laboratoire de Physico-chimie des Surfaces, ENSCP-CNRS, Ecole Nationale Supérieure de Chimie de Paris, Paris, France.
    Odnevall Wallinder, Inger
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    The initial release of zinc and aluminum from non-treated Galvalume and the formation of corrosion products in chloride containing media2011In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 258, no 10, 4351-4359 p.Article in journal (Refereed)
    Abstract [en]

    This study explores the initial release of zinc and aluminum from non-treated Galvalume and the parallel formation of corrosion products when exposed to synthetic seawater and rainwater of different chloride content. Comparisons were made with long-term field exposures at non-sheltered marine conditions. Observed release rates from short-term conditions agree qualitatively with the long-term findings with a selective release of zinc over aluminum. The release and corrosion processes were intertwined through the formation of corrosion products with properties that influence the long-term release process. Prior to exposure, Al2O3 dominated the entire surface, and was subject to local destruction upon interaction with chloride ions. As a consequence Al2O3 was gradually replaced and covered by zinc-rich corrosion products primarily in interdendritic areas during the first year of marine exposure. This was followed by the gradual formation and integration of aluminum-rich corrosion products, reflected by an increased zinc release rate during the first year, followed by a gradually decreased rate during subsequent years. The importance of Al2O3 was also evident in deaerated synthetic rainwater or seawater, where the formation of Al2O3 was presumably hindered. In synthetic rain water this resulted in a higher ratio between released aluminum and zinc compared with non-deaerated conditions.

  • 710.
    Zhang, Yujia
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Li, Jiebing
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. Chalmers, Sweden.
    Lindström, Mikael E.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. Chalmers, Sweden.
    Mischnick, Petra
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. Tech Univ Carolo Wilhelmina Braunschweig, Germany.
    Reactivity investigation of glucomannan from spruce2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, no 113-CELLArticle in journal (Other academic)
  • 711.
    Zhao, Yadong
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Li, Jiebing
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Comprehensive comparison between woody and tunicate celluloses2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, 95-CARB- p.Article in journal (Other academic)
  • 712.
    Zhao, Yadong
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Skaar, Katrine Sandnes
    Thompson, Eric
    Ray, Jessica Louise
    Li, Jiebing
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Troedsson, Christofer
    Qualitative and quantitative analysis of Ciona intestinalis gut content using polymerase chain reaction (PCR) technique2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, 283-BIOT- p.Article in journal (Other academic)
  • 713.
    Zhe, Li
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Relative influences of uncertainty in physical-chemical property data and variability in climate parameters in determining the fate of PCBs2011Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Persistent organic pollutants (POPs) present a class of substances which are of high concern due to their toxicity and ecotoxicity, long-range atmospheric transport and resistance to degradation. A combination of analytical measurement and modeling researchis a powerful means for understanding chemical fate and behavior. Among all availablemodeling approaches, multi-compartmental fugacity modeling is a common and relatively simpleway to simulate the concentrations and distributions of pollutants. This approach isalso applied hereto study a well-studiedgroup of POPs –polychlorinated biphenyls (PCBs).

    Climate changeis potentially one of the largest global environmental problems facing society today. Climate change resulting from anthropogenic activities may impact the transport, fate and exposure of POPs due to alterations in climatic and landscape properties (e.g. temperature, windspeed, precipitation etc.). Modeling studies have previously been carried out to investigate their influence on POPs fate under defined scenarios.However, in previous work the uncertainty of chemical properties has not been considered. We hypothesize that the uncertainties in physical-chemical parameters could actually cause a greater impact predicted concentrations than variability in climate parameters such as temperature, wind speed and precipitation.

    To test the hypothesis, a 4-compartment Level III fugacity model –ChemCAN spreadsheet model is used. A combination of8 climate variables, 3 physical-chemical properties and 4 degradation properties are chosen to investigate how the variability and uncertainty affect the environmental fate of 6 selected PCBs congeners. In total, 18 forecasts are createdin the investigation and outputs provided forconcentrations, distributions, total amounts, long-range transport potential indicators and persistence of the chemicals. We arbitrarily model the Japan region for which we had environmental parameterization in the ChemCAN model. Monte-Carlo simulations areundertakenusing the

    Crystal Ball®computer software to perform correlation and sensitivity analyses, in order to specifically examine andcompare the influence brought from variability and uncertainty.Datafor climate variablesarecollected and calculated from Intergovernmental Panel on Climate Change –Data Distribution Centre (IPCC-DDC), while thosefor chemical propertyuncertainty arecollected and calculated from literature sources/methods.

    The results are interpreted focusing on the two types of analyses –correlation and sensitivity. Within the correlation analysis between climate variables and PCB fate predictions, temperature is the most important factor affecting total amount, concentrations and distributions, especially in the atmosphere compartment. It alsoinfluencesthefugacity of the PCBs in each media, as well asthe reactive residence times. The uncertainty of temperature increases resulting fromclimate change has more influence thanvariability in mean temperature however. Precipitation hardly has any influence onPCB fate,althoughthe change in precipitationdue to climate changecould affect distributions in surface water and surface soil for light chlorinated PCBs congeners due to the extremely high coefficient of variation. Wind speedalso has little impact onpredictions other than for long-range transport potential descriptors, namely characteristic transport distance and transfer efficiency. Wind speed also affectsthe advective residence timein theair compartment forPCBs.Within the correlation analysis between properties and PCB fate predictions, all the chosen 3 physical-chemical properties, vapor pressure, water solubility and water-octanol partition coefficient, significantly affect the predictions. Vapor pressure has more influence onpredictions related to air and more significantly on lighter PCBs, while water solubility and the water-octanol partition coefficient mostly affect the heavier PCBs, especially

    MSc. Thesis in Environmental Chemistry

    II

    the predicted outcomes in water and sediment. Despite a fairly small uncertainty inphysical-chemical propertiescompared to many other chemicals, the influence on PCB fate is noticeable. Degradation properties, which have a rather high uncertainty, also significantly affect PCB environmental fate and degradation half-lives in air and soil have much more significant influence than those in water and sediment.

    In the sensitivity analysis, variability and uncertainty are assembled into a single simulation. When excluding degradation properties, it could be concluded that uncertainty inphysical-chemical properties is usually dominant forPCBs. One notable exception isthat precipitation change has a greaterinfluence on PCB-8, which is also the lightestincluded inthe study. If degradation propertiesare included, degradation half-lives in air and soil are always the dominantsource of uncertainty to predictions.

    The main conclusion of this thesis is that the uncertainty in chemical property datais generally more important than variability in climate parameters in controlling variance in predicted environmental concentrations.This supports the hypothesis of that was raised at the beginning of this study.

     

     

  • 714.
    Zhou, Juan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Butchosa, Nuria
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Jayawardena, H. Surangi N.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Yan, Mingdi
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Ramström, Olof
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Glycan-Functionalized Fluorescent Chitin Nanocrystals for Biorecognition Applications2014In: Bioconjugate chemistry, ISSN 1043-1802, E-ISSN 1520-4812, Vol. 25, no 4, 640-643 p.Article in journal (Refereed)
    Abstract [en]

    A new platform based on chitin nanocrystals has been developed for biorecognition applications. TEMPO-oxidized chitin nanocrystals (TCNs) were labeled with a fluorescent imidazoisoquinolinone dye, and simultaneously conjugated with carbohydrate ligands, resulting in dually functionalized TCNs. The biorecognition properties of the nanocrystals were probed with lectins and bacteria, resulting in selective interactions with their corresponding cognate carbohydrate-binding proteins, as visualized by optical, fluorescence, STEM, and TEM imaging. This represents a new approach to multifunctional nanomaterials based on naturally occurring polymers, holding high potential for biomedical applications.

  • 715.
    Zhou, Qi
    et al.
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Butchosa, Núria
    KTH, School of Biotechnology (BIO), Glycoscience.
    Nanocellulose-based Green Nanocomposite Materials2016In: Biodegradable Green Composites, John Wiley & Sons, 2016, 118-148 p.Chapter in book (Refereed)
  • 716. Zhou, Xu
    et al.
    Li, Fei
    Li, Hua
    Zhang, Biaobiao
    Yu, Fengshou
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Photocatalytic Water Oxidation by Molecular Assemblies Based on Cobalt Catalysts2014In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 7, no 9, 2453-2456 p.Article in journal (Refereed)
    Abstract [en]

    Chromophore-catalyst molecular assemblies towards visible light-driven water oxidation were synthesized by covalent integration of a light-harvesting complex [Ru(bpy)(3)](2+) (bpy= 2,2'-bipyridine) and a Co4O4 cubane water oxidation catalyst. The two components were assembled either in linear or macrocyclic configurations. In the presence of the sacrificial reagent, the Ru-Co metallocycle exhibits remarkable photocatalytic activity for oxygen evolution, which is one order of magnitude higher than that of a multicomponent system and exceeds that of a linear assembly by a factor of five, offering access to highly active photocatalyst through molecular design.

  • 717.
    Zhu, Binzhu
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Reaction Engineering.
    Mellander, B. -E
    Fluoride-based electrolytes and their applications for intermediate temperature ceramic fuel cells2005In: Fluorinated Materials for Energy Conversion, Elsevier, 2005, 419-437 p.Chapter in book (Other academic)
    Abstract [en]

    This chapter focuses on fluoride-based electrolytes and their applications for intermediate temperature ceramic fuel cells. Among all fuel cell (FC) technologies, the solid oxide fuel cell (SOFC) can utilize a number of different fuels. The conventional SOFCs use a ceramic electrolyte, e.g., yttria-stabilized zirconia (YSZ), and operate at high temperature, typically 1000°C. The high operating temperature puts very high demands on the materials and technology, which poses a major challenge for the further development of SOFCs into the market. For developing cost-effective SOFCs, much effort has been devoted to obtain a lower operating temperature. All these efforts have, however, limitations due to the deficiency of technology and the stability of the material. Ceramic fuel cells (CFCs) are sometimes used as a more general term for fuel cells based on ceramic materials, which have the desired properties. In the chapter, the focus is on possible proton and oxygen ion conduction in fluoride-based electrolytes that may be of interest for fundamental and applied research. Also, the focus is to develop new advanced CFCs for intermediate temperatures.

  • 718.
    Zhu, Hongli
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Li, Yuanyuan
    Pettersson, Bert
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Zhang, Liming
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Lindström, Mikael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Henriksson, Gunnar
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Technical soda lignin dissolved in urea as an environmental friendly binder in wood fiberboard2014In: Journal of Adhesion Science and Technology, ISSN 0169-4243, E-ISSN 1568-5616, Vol. 28, no 5, 490-498 p.Article in journal (Refereed)
    Abstract [en]

    The application of lignin as binder in wood composite panel is not only environmentally friendly but also commercially attractive. The dissolving of technical soda lignin is the most premier challenge in its application. In this study, the effect of different key factors on soda lignin solubility in urea was investigated. The maximum solubility of 60.16g/L was obtained under the temperature 70 degrees C, urea concentration 8M, lignin content 7%, and pH 8.8. Then, different kinds of wood fiber material were mixed with the dissolved lignin solution to make fiber board separately. The results showed that the lignin can enhance the tensile strength of particleboard and can be used as a binder in wood material, but the strength will be different with different materials. The optimal tensile strength obtained was 44.63MPa with the sample made from oriented cotton linter sheet.

  • 719.
    Zhu, Jiefang
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Photocatalysts for Hydrogen Production2015In: Advanced Materials For Clean Energy / [ed] Xu, Q; Kobayashi, T, CRC PRESS-TAYLOR & FRANCIS GROUP , 2015, 391-419 p.Chapter in book (Refereed)
  • 720.
    Álvarez Asencio, Rubén
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Bettini, Eleonora
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Pan, Jinshan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Thormann, Esben
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Rutland, Mark
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science. SP Technical Research Institute of Sweden, Sweden .
    Friction Coefficient Mapping (FCM) and Contact Adhesion Mapping (CAM): Surface Microstructure and Function2013In: 5th World Tribology Congress, WTC 2013, 2013, Vol. 4, 3120-3121 p.Conference paper (Refereed)
  • 721. Álvarez-Asencio, R.
    et al.
    Wallqvist, Viveca
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Kjellin, Mikael
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science.
    Rutland, Mark W.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. Department of Surface and Corrosion Science, School of Chemical Science and Engineering, KTH Royal Institute of Technology.
    Camacho, A.
    Nordgren, Niklas
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Luengo, G. S.
    Nanomechanical properties of human skin and introduction of a novel hair indenter2016In: Journal of The Mechanical Behavior of Biomedical Materials, ISSN 1751-6161, E-ISSN 1878-0180, Vol. 54, 185-193 p.Article in journal (Refereed)
    Abstract [en]

    The mechanical resistance of the stratum corneum, the outermost layer of skin, to deformation has been evaluated at different length scales using Atomic Force Microscopy. Nanomechanical surface mapping was first conducted using a sharp silicon tip and revealed that Young’s modulus of the stratum corneum varied over the surface with a mean value of about 0.4 GPa. Force indentation measurements showed permanent deformation of the skin surface only at high applied loads (above 4 μN). The latter effect was further demonstrated using nanomechanical imaging in which the obtained depth profiles clearly illustrate the effects of increased normal force on the elastic/plastic surface deformation. Force measurements utilizing the single hair fiber probe supported the nanoindentation results of the stratum corneum being highly elastic at the nanoscale, but revealed that the lateral scale of the deformation determines the effective elastic modulus.This result resolves the fact that the reported values in the literature vary greatly and will help to understand the biophysics of the interaction of razor cut hairs that curl back during growth and interact with the skin.

  • 722.
    Álvarez-Asencio, Rubén
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science. Institute for Advanced Studies, IMDEA Nanoscience, C/Faraday 9, Spain.
    Wallqvist, V.
    Kjellin, M.
    Rutland, Mark
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science. SP Technical Research Institute of Sweden, SP Chemistry, Materials and Surfaces, Sweden.
    Camacho, A.
    Nordgren, N.
    Luengo, G. S.
    Nanomechanical properties of human skin and introduction of a novel hair indenter2016In: Journal of The Mechanical Behavior of Biomedical Materials, ISSN 1751-6161, E-ISSN 1878-0180, Vol. 54, 185-193 p.Article in journal (Refereed)
    Abstract [en]

    The mechanical resistance of the stratum corneum, the outermost layer of skin, to deformation has been evaluated at different length scales using Atomic Force Microscopy. Nanomechanical surface mapping was first conducted using a sharp silicon tip and revealed that Young’s modulus of the stratum corneum varied over the surface with a mean value of about 0.4 GPa. Force indentation measurements showed permanent deformation of the skin surface only at high applied loads (above 4 μN). The latter effect was further demonstrated using nanomechanical imaging in which the obtained depth profiles clearly illustrate the effects of increased normal force on the elastic/plastic surface deformation. Force measurements utilizing the single hair fiber probe supported the nanoindentation results of the stratum corneum being highly elastic at the nanoscale, but revealed that the lateral scale of the deformation determines the effective elastic modulus.This result resolves the fact that the reported values in the literature vary greatly and will help to understand the biophysics of the interaction of razor cut hairs that curl back during growth and interact with the skin.

  • 723.
    Ågren, Hans
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry (closed 20110512).
    Tu, Yaoquan
    KTH, School of Biotechnology (BIO), Theoretical Chemistry (closed 20110512).
    Modeling of Non-linear Optic Properties of Guest-Host Systems2006In: Nonlinear Optics, Quantum Optics: concepts in modern optics, ISSN 1543-0537, Vol. 35, no 1-3, 39-55 p.Article in journal (Refereed)
    Abstract [en]

    In this paper we summarize our recent work in computer modeling of nonlinear optical (NLO) properties of guest-host systems. The modeling involves quantum chemistry calculations to predict the NLO properties of a single chromophore molecule and molecular dynamics simulations to estimate the macroscopic NLO properties of the corresponding guest-host systems and to find the microscopic origin behind the macroscopic properties. The systems studied cover solutions solvated with NLO chromophores and amorphous polymers doped with dipolar chromophore molecules. Some gained insight and conclusions obtained from the combined modeling approaches are presented.

  • 724. Öhman, Anders
    et al.
    Lycksell, P O
    Juréus, A
    Langel, U
    Bartfai, T
    Gräslund, A
    NMR study of the conformation and localization of porcine galanin in SDS micelles. Comparison with an inactive analog and a galanin receptor antagonist.1998In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 37, no 25Article in journal (Refereed)
    Abstract [en]

    Galanin is a 29/30-residue neuro-endocrine peptide which performs its many important physiological functions via a membrane-bound receptor. By using two-dimensional proton NMR spectroscopy, complete relaxation matrix analysis, and simulated annealing, the conformation of porcine galanin was determined in a membrane-mimicking solvent containing sodium dodecyl sulfate (SDS) micelles. The final family of calculated structures displays three well-defined beta- or gamma-turn regions, comprising residues 1-5, 7-10, and 24-27, but has otherwise a random conformation. The receptor-interacting N-terminal part, residues 1-5, was found to be best defined with a backbone RMSD value of 0.12 A. The mode of association between galanin and the SDS micelle was determined by observing the broadening effect on proton resonances, when spin-labeled 5- and 12-doxyl stearate molecules were added. It was concluded that galanin is located close to the surface of the micelle with two regions, residues 6-9 and 24-29, as well as two single residues, 18 and 21, reaching out into the aqueous solvent. Additional NMR studies were carried out on an inactive analogue, Ala2-galanin, and an antagonist M40. The results show that the proton resonances of galanin and M40 have identical chemical shifts in the N-terminal receptor-interacting region, indicating similar solution structures in this region. For Ala2-galanin, the same region displays a spectral heterogeneity with chemical shifts clearly different from the other two peptides, indicative of different secondary structures. These results may provide a structural background for the antagonist activity of M40 and the hormonal inactivity of Ala2-galanin, as compared to galanin.

  • 725.
    Öhman, Anders
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience.
    Rak, Alexey
    Dontsova, Maria
    Garber, Maria B
    Härd, Torleif
    NMR structure of the ribosomal protein L23 from Thermus thermophilus.2003In: Journal of Biomolecular NMR, ISSN 0925-2738, E-ISSN 1573-5001, Vol. 26, no 2Article in journal (Refereed)
    Abstract [en]

    The ribosomal protein L23 is a component of the large ribosomal subunit in which it is located close to the peptide exit tunnel. In this position L23 plays a central role both for protein secretion and folding. We have determined the solution structure of L23 from Thermus thermophilus. Uncomplexed L23 consists of a well-ordered part, with four anti-parallel beta-strands and three alpha-helices connected as beta-alpha-beta-alpha-beta-beta-alpha, and a large and flexible loop inserted between the third and fourth beta-strand. The observed topology is distantly related to previously known structures, primarily within the area of RNA biochemistry. A comparison with RNA-complexed crystal structures of L23 from T. thermophilus, Deinococcus radiodurans and Haloarcula marismourtui, shows that the conformation of the well-ordered part is very similar in the uncomplexed and complexed states. However, the flexible loop found in the uncomplexed solution structure forms a rigid extended structure in the complexed crystal structures as it interacts with rRNA and becomes part of the exit tunnel wall. Structural characteristics of importance for the interaction with rRNA and with the ribosomal protein L29, as well as the functional role of L23, are discussed.

  • 726.
    Öhman, Maria
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    An in situ spectro-electrochemical study of aluminium/polymer interfaces: development of ATR-FTIR and its integration with EIS for corrosion studies2006Licentiate thesis, comprehensive summary (Other scientific)
    Abstract [en]

    In order to extend the applications of aluminium, organic coatings may be applied on sheet materials, for instance for corrosion protection or aesthetic surface finish purposes in the automotive and construction industries, or on foil materials in the flexible packaging industry.

    The most common mechanisms for deterioration and structural failure of organically coated aluminium structures are triggered by exposures to the surrounding environment. Despite the great importance to elucidate the influence of exposure parameters on a buried aluminium/polymer interface, there is still a lack of knowledge regarding the mechanisms that destabilise the structure. It is generally believed that a detailed in situ analysis of the transport of corroding species to the buried interface, or of surface processes occurring therein, is most difficult to perform at relevant climatic and real-time conditions.

    In this work, Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) in the Kretschmann-ATR configuration was successfully applied to in situ studies of the transport of water and ionic species through polymer films to the aluminium/polymer interface upon exposure to ultra pure deionised water and to a 1 M sodium thiocyanate (NaSCN) model electrolyte. Other main processes distinguished were the formation of corrosion products on the aluminium surface and swelling of the surface-near polymer network. Hence, in situ ATR-FTIR was capable to separate deterioration-related processes from each other.

    To perform more unambiguous interpretations, a spectro-electrochemical method was also developed for in situ studies of the buried aluminium/polymer interface by integrating the ATR-FTIR technique with a complementary acting technique, Electrical Impedance Spectroscopy (EIS). While transport of water and electrolyte through the polymer film to the aluminium/polymer interface and subsequent oxidation/corrosion of aluminium could be followed by ATR-FTIR, the protective properties of the polymer as well as of processes at the aluminium surface were simultaneously studied by EIS. The integrated set-up provided complementary information of the aluminium/polymer sample investigated, with ATR-FTIR being sensitive to the surface-near region and EIS being sensitive to the whole system. While oxidation/corrosion and delamination are difficult to distinguish by EIS, oxide formation could be confirmed by ATR-FTIR. Additionally, while delamination and polymer swelling may be difficult to separate with ATR-FTIR, EIS distinguished swelling of the polymer network and also identified ultimate failure as a result of delamination.

    The capability of the integrated ATR-FTIR / EIS in situ technique was explored by studying aluminium/polymer systems of varying characteristics. Differences in water and electrolyte ingress could be monitored, as well as metal corrosion, polymer swelling and delamination.

  • 727.
    Öhman, Maria
    et al.
    Kimab.
    Persson, Dan
    Kimab.
    Leygraf, Christofer
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    In situ ATF-FTIR studies of the aluminium/polymer interface upon exposure to water and electrolyte2006In: Progress in organic coatings, ISSN 0300-9440, Vol. 57, no 1, 78-88 p.Article in journal (Refereed)
    Abstract [en]

    Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) with the Kretschmann configuration was applied for in situ studies of the transport of water and ionic species through a polymer film to an aluminium/polymer interface. The time dependent intensity changes of the infrared bands of water were used to follow the transport of water to the aluminium/polymer interfacial region and a NaSCN solution was employed as model electrolyte to follow the transport and accumulation of thiocyanate ions. Apart from water sorption and ion transport, the main processes identified were corrosion/oxidation of the aluminium surface and swelling of the polymer film. The method proved to be useful for detailed in situ studies of changes at a polymer coated metal surface, such as oxidation and surface film formation on the metal. It should also be possible to study the effects of defects and pores in the polymer film on the transport properties of water and ions to the metal/polymer interface, as well as adsorption and other chemical reactions and physical interactions in the metal/polymer interfacial region.

  • 728.
    Österlund, Lise-Lotte
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Redox models in chemistry:  A depiction of the conceptions held by secondary school students of redox reactions2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    According to previous research, students show difficulties in learning redox reactions. By the historical development different redox models exist to explain redox reactions, the oxygen model, the hydrogen model, the electron model and the oxidation number model. This thesis reports about three studies concerning conceptions held by secondary school students of redox reactions. A textbook analysis is also included in the thesis.

    The first study was an investigation of the students’ use of redox models in inorganic contexts, their use of the activity series of metals, and the students’ ability to transfer redox knowledge. Then the students’ work with an open-ended biochemical task, where the students had access of the textbook was studied. The students talk about redox reactions, the questions raised by the students, what resources used to answer the questions and what kind of talk developed were investigated. A textbook analysis based on chemistry books from Sweden and one book from England was performed. The redox models used as well as the dealing with redox related learning difficulties was studied. Finally, the students’ conceptions about redox in inorganic, organic and biochemistry after completed chemistry courses were studied.

    The results show that the students were able to use the electron model as a tool to explain inorganic redox reactions and the mutuality of oxidation and reduction was fundamental. The activity series of metals became a tool for the prediction of reducing agent in some reactions. Most of the students rejected that oxygen is a prerequisite for a redox reaction. In the biochemical task the resource most used to answer the raised questions were the students’ consultation of the textbook – together or individually. Most questions resulted in short answers and the majority of these questions were answered. Questions concerning redox were analysed by the students and integrated into a chemical context but they could neither identify the substances oxidised or reduced nor couple the concepts to transfer of hydrogen atoms. The majority of these redox questions became unanswered. The textbook helped the students to structure a poster as well as to answer basic chemistry questions. For questions about organic and biochemical redox, the book was of no help. The textbook analysis showed that all historical redox models are used. Different models are used in inorganic, organic and biochemistry. The mutuality of oxidation and reduction is treated differently in subject areas. The textbooks did not help the reader linking the different redox models that were used. Few redox-related learning difficulties are addressed in the books. After completed chemistry courses the students had major problems to justify a redox reaction explained by transfer of hydrogen atoms both in the organic and biochemistry examples.

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