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  • 201.
    Karabulut, Erdem
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Marais, Andrew
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Wet-resilient, low density aerogels from nanofibrillated cellulose: Their properties and use as templates for layer-by-layer modification2013In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 245, p. 73-PMSE-Article in journal (Other academic)
  • 202. Karaush, Nataliya N.
    et al.
    Bondarchuk, Sergey V.
    Baryshnikov, Gleb V.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. Bohdan Khmelnytsky National University, Ukraine.
    Minaeva, Valentina A.
    Sun, Wen-Hua
    Minaev, Boris F.
    Computational study of the structure, UV-vis absorption spectra and conductivity of biphenylene-based polymers and their boron nitride analogues2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, no 55, p. 49505-49516Article in journal (Refereed)
    Abstract [en]

    In the present study, we calculated the electronic and spectral properties of the one- and two-dimensional carbon and boron nitride materials composed of four-, six- and eight-membered rings (the (4, 6, 6, 8) topology) on the basis of density functional theory, including the band structure analysis for the infinite structures. We found that biphenylene-based two-dimensional (2D) sheets and zigzag-type biphenylene-based one-dimensional (1D) ribbons exhibit a semi-metal character. At the same time, the armchair 1D biphenylene-based ribbons possess a narrow-band-gap structure, while boron nitride 2D sheets, 1D zigzag- and armchair-type ribbons exhibit a wide-band-gap semiconducting nature. Simple single-point calculations with a periodic boundary condition generally underestimate the band-gap values in comparison with band structure calculations accounting for the supercell optimization. But in the general case, both approaches provide a correct explanation of the band-gap value. In this work, we also performed for the first time computational modelling of a novel porous biphenylene-based wide-band-gap carbon allotrope, which demonstrated the complexation ability relative to metal atoms forming the metal-carbon intercalates.

  • 203.
    Karlson, Agnes
    et al.
    Stockholm University, Department of Systems Ecology.
    Mozuraitis, Raimondas
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Deposit-feeders accumulate the cyanobacterial toxin nodularin2011In: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 12, p. 77-81Article in journal (Refereed)
    Abstract [en]

    Blooms of toxic cyanobacteria may potentially affect food web productivity and even be a human health hazard. In the Baltic Sea, regularly occurring summer blooms of nitrogen-fixing cyanobacteria are often dominated by Nodularia spumigena, which produces the potent hepatotoxin nodularin. Evidence of sedimentation of these blooms indicates that benthic fauna can be exposed to nodularin. In a one month experiment, we simulated the settling of a summer bloom dominated by N. spumigena in sediment microcosms with three species of sediment-dwelling, deposit-feeding macrofauna, the amphipods Monoporeia affinis and Pontoporeia femorata and the bivalve Macoma balthica, and analyzed nodularin in the animals by HPLC-ESI-MS (high-performance liquid chromatography-electrospray ionization-mass spectrometry). We found nodularin in quantities of 50-120ngg-1 DW. The results show that deposit-feeding macrofauna in the Baltic Sea may contribute to trophic transfer of nodularin.

  • 204.
    Karlsson, H. L.
    et al.
    Unit for Analytical Toxicology, Department of Biosciences at Novum, Karolinska Institutet.
    Cronholm, P.
    Unit for Analytical Toxicology, Department of Biosciences at Novum, Karolinska Institutet.
    Gustafsson, J.
    Unit for Analytical Toxicology, Department of Biosciences at Novum, Karolinska Institutet.
    Midander, Klara
    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.
    Möller, L.
    Unit for Analytical Toxicology, Department of Biosciences at Novum, Karolinska Institutet.
    Copper nanoparticles are highly cytotoxic and interact with hemoglobin2009In: 4th International Conference on Nanotechnology, Occupational and environmental health, Aug 26-29, 2009, 2009Conference paper (Refereed)
  • 205.
    Kharkov, Boris B.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Dvinskikh, Sergey V.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Chain dynamics of surfactants in mesoporous silica2013In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 15, no 42, p. 18620-18626Article in journal (Refereed)
    Abstract [en]

    Mesostructured porous materials possess unique surface, structural, and bulk properties that lead to important practical applications. By retaining structure-directing species in the product material, mesostructured organic-inorganic composites are obtained which are of broad interest for fundamental studies of confinement effects and surface interaction on structural and dynamic properties of organic molecules. In the present study, solid state dipolar C-13-H-1 NMR spectroscopy is applied to quantitatively characterize the conformational dynamics of organic surfactants in the mesostructured composite CTAB-MCM41. Such an approach does not require assumptions and adjustable parameters and reflects the changes in conformational dynamics without relying on specific motional models. The conformational dynamics of the surfactant confined in solid hexagonal arrays is compared to that in hexagonal aggregates formed in a concentrated aqueous solution. The study showed that in cylindrical pores of hexagonal mesoporous silica the order parameter gradually decreases towards the end of the chain. The degree of order and the order parameter profile is similar to that observed in hexagonal liquid crystalline phases. However, the mobility of segments close to the head group is more restricted compared to that in the mesophase, as the result of interaction with the solid silica interface.

  • 206.
    Khosravi, Sara
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science. AkzoNobel, Casco Adhesives, Sweden.
    Protein-Based Adhesives for Particleboards2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The main objective of this study was to elucidate the possibilities to use wheat gluten (WG) as a binder for particleboards, as well as soy protein isolate (SPI). The focus was on the effect of the adhesive formulation and the processing conditions, while the press parameters were kept constant. Some aspects of the dispersion and the preparation of the dispersions that were investigated are: the dispersing agent (sodium hydroxide 0.1 M or citric acid 0.05 M), the time (1, 3 or 5h) to prepare the dispersion, the temperature (room temperature, 50 or 80°C) during the preparation of the dispersions and the effect of storing (1, 2.5 or 4 days) the dispersions before application. Additionally, utilization of cross-linker polyamidoamine-epichlorohydrin (PAAE) and trimethylolpropane triacetoacetate (AATMP) were evaluated. Furthermore, the utilization of green particles versus dried particles was examined. The concentration (12, 16, 20 or 24%) of WG dispersion and the process for applying it to the particles were studied. Two application methods were evaluated, in application method 1 (appl. 1) all the dispersion was added to the particles in one step before the particles were dried. When application method 2 (appl. 2) was employed the dispersion was added in two steps, some of the dispersion was added before the drying and some after the drying. The considered board properties were internal bond (IB), thickness swelling (TS) and water absorption (ABS). The wetting, penetration and film formation of the WG dispersions on the wood was investigated employing different microscopy techniques. For the WG dispersions it looks as if a lower temperature is preferable for the preparation of the dispersion and that the time to prepare the dispersion is of no importance. Furthermore, storing the dispersions for more than one day before it was used as an adhesive for particleboards (PB) resulted in poorer boards. Using the right cross-linker, such as PAAE enhances the binding abilities of WG. According to this study it is beneficial to use dried particles instead of green particles. Additionally, the results show that the interaction between the concentration of WG dispersion and how it is applied is a significant factor, considering the IB value. However, in general the two step process (appl. 2) is preferable. The microscopy study reveals that this can be explained by the balance between wetting, penetration, and flow of the dispersion on the wood. The two step application results in less over-penetration when the viscosity of the dispersion is low.

  • 207.
    Khosravi, Sara
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Khabbaz, F.
    Nordqvist, Petra
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Johansson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Wheat-gluten-based adhesives for particle boards: Effect of crosslinking agents2014In: Macromolecular materials and engineering (Print), ISSN 1438-7492, E-ISSN 1439-2054, Vol. 299, no 1, p. 116-124Article in journal (Refereed)
    Abstract [en]

    WG proteins show potential as environmentally friendly replacements for amino/formaldehyde resins in particle boards. The performance of WG dispersions in combination with crosslinkers as adhesives for particle boards is studied. The WG dispersions are prepared with sodium hydroxide or citric acid as the dispersing agent. Polyamidoamine-epichlorohydrin (PAAE) and trimethylolpropane triacetoacetate (AATMP) are employed as crosslinkers. The performance of the WG dispersions and the crosslinkers are evaluated based on board properties, i.e., internal bond, thickness swelling, and water absorption. The results show an enhanced performance of WG using PAAE as crosslinker. The results reveal it is advantageous to disperse WG in sodium hydroxide compared to citric acid. The potential of crosslinked wheat-gluten-based adhesives for particle boards is demonstrated. The effect of parameters such as crosslinking type and pH is described. A formaldehyde-free particle board adhesive is thus obtained.

  • 208.
    Klett, Matilda
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Svens, Pontus
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry. Scania CV AB, Sweden.
    Tengstedt, Carl
    Seyeux, Antoine
    Swiatowska, Jolanta
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Wreland Lindström, Rakel
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Uneven Film Formation across Depth of Porous Graphite Electrodes in Cycled Commercial Li-Ion Batteries2015In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 119, no 1, p. 90-100Article in journal (Refereed)
    Abstract [en]

    A critical aging mechanism in lithium-ion batteries is the decomposition of the electrolyte at the negative electrode forming a solid electrolyte interphase (SEI) layer that increases impedance and consumes cyclable lithium. In contrast to the typical nanometer SEI layer generally discussed, this paper reports on the formation of a micrometer thick film on top of and within the upper part of a porous graphite electrode in a deep-cycled commercial cylindrical LiFePO4/graphite cell. Morphological, chemical, and electrochemical characterizations were performed by means of cross-sectional electron microscopy in combination with energy dispersive X-ray spectroscopy and focused ion-beam milling, time-of-flight secondary ion mass spectrometry, and electrochemical impedance spectroscopy (EIS) to evaluate the properties and impact of the uneven film. It is shown that the film is enriched in PO and carbonate species but is otherwise similar in composition to the thin SEI formed on a calendar-aged electrode and clogs the pores in the electrode closest to the separator. Performance evaluation by physics-based EIS modeling supports a local porosity decrease, impeding the effective electrolyte transport in the electrode. The local variation of electrode properties implies that current distribution in the porous electrode under these cycling conditions causes inefficient material utilization and sustained uneven electrode degradation.

  • 209.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    On the early development of organic dyes for dye-sensitized solar cells2013In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 49, no 59, p. 6580-6583Article in journal (Refereed)
    Abstract [en]

    This viewpoint describes the background of the development of organic dyes for dye-sensitized solar cells, the impact of the 2006 ChemComm paper by Sun, Hagfeldt and co-workers regarding the D5 D-pi-A-family of dyes, some recent developments and possible future challenges to meet.

  • 210.
    Kochumalayil, Joby J.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Berglund, Lars A.
    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.
    Moisture-stable clay-xyloglucan nanocomposites prepared from hydrocolloidal suspensions2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, p. 204-CELL-Article in journal (Other academic)
  • 211.
    Kochumalayil, Joby J.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Water-soluble hemicelluloses for high humidity applications - enzymatic modification of xyloglucan for mechanical and oxygen barrier properties2014In: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 16, no 4, p. 1904-1910Article in journal (Refereed)
    Abstract [en]

    Bio-based polymers are of increasing interest in packaging applications as alternatives to petroleum-based polymers. Xyloglucan (XG) derived from tamarind seed waste was recently explored as a high performance biopolymer for packaging applications. Xyloglucan films have high strength, stiffness and oxygen barrier performance, but suffer from limitations in properties under high humidity conditions. This aspect is addressed in the present work using XG modification by enzymatic removal of side chain galactose residues. The modified XG was characterized using carbohydrate analysis and MALDI-TOF MS analysis for sugar and oligosaccharide compositions respectively. The consequence of galactose removal for XG chain packing was theoretically predicted using a group contribution method and the estimation of Hansen's solubility parameters. The properties of films made from modified XG in terms of tensile, oxygen transmission rate, and thermo-mechanical behaviour were measured and related to the structure of modified XGs. Modified XG films preserved the Young's modulus at high humidity at a level of 4.3 GPa at 92% relative humidity. Moreover, the oxygen permeability of modified XG samples was very low and was about 1.5 cc mu m [m(2) day](-1) kPa(-1) at 80% relative humidity, more than 80% lower than that for native XG. The main reason is that modified XG absorbs less moisture, due to a decreased solubility. Decreased free volume may also contribute, as galactose residues are removed and XG branches become shorter.

  • 212.
    Koklukaya, Oruc N.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Fire resistant wood fibre-based materials2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, p. 278-CELL-Article in journal (Other academic)
  • 213.
    Kuang, Guanglin
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Liang, Lijun
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. Zhejiang University, China.
    Brown, Christian
    KTH, School of Biotechnology (BIO), Glycoscience.
    Wang, Qi
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience. Univ Adelaide, Australia.
    Tu, Yaoquan
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Insight into the adsorption profiles of the Saprolegnia monoica chitin synthase MIT domain on POPA and POPC membranes by molecular dynamics simulation studies2016In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 18, no 7, p. 5281-5290Article in journal (Refereed)
    Abstract [en]

    The critical role of chitin synthases in oomycete hyphal tip growth has been established. A microtubule interacting and trafficking (MIT) domain was discovered in the chitin synthases of the oomycete model organism, Saprolegnia monoica. MIT domains have been identified in diverse proteins and may play a role in intracellular trafficking. The structure of the Saprolegnia monoica chitin synthase 1 (SmChs1) MIT domain has been recently determined by our group. However, although our in vitro assay identified increased strength in interactions between the MIT domain and phosphatidic acid (PA) relative to other phospholipids including phosphatidylcholine (PC), the mechanism used by the MIT domain remains unknown. In this work, the adsorption behavior of the SmChs1 MIT domain on POPA and POPC membranes was systematically investigated by molecular dynamics simulations. Our results indicate that the MIT domain can adsorb onto the tested membranes in varying orientations. Interestingly, due to the specific interactions between MIT residues and lipid molecules, the binding affinity to the POPA membrane is much higher than that to the POPC membrane. A binding hotspot, which is critical for the adsorption of the MIT domain onto the POPA membrane, was also identified. The lower binding affinity to the POPC membrane can be attributed to the self-saturated membrane surface, which is unfavorable for hydrogen-bond and electrostatic interactions. The present study provides insight into the adsorption profile of SmChs1 and additionally has the potential to improve our understanding of other proteins containing MIT domains.

  • 214.
    Kubyshkina, Elena
    et al.
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Jonsson, B. Lars G.
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering. ABB Corporate Research, Sweden.
    Unge, Mikael
    KTH, School of Chemical Science and Engineering (CHE).
    ZnO-polyethylene interface: Band alignment2017In: Proceedings of the International Symposium on Electrical Insulating Materials, Institute of Electrical Engineers of Japan , 2017, Vol. 1, p. 363-365Conference paper (Refereed)
    Abstract [en]

    Zinc oxide-polyethylene nanocomposites have a potential to be used for high voltage insulation. Here, we investigate electronic properties of zinc oxide-polyethylene interface using density functional theory. Interface states up to 1 eV below conduction band edge are found in polyethylene. Our results suggest that the energy bands of ZnO and polyethylene align to comply with vacuum level equality. We use our findings to establish mechanisms of band alignment at the interfaces between polyethylene and crystal materials.

  • 215. Kuhs, Manuel
    et al.
    Zeglinski, Jacek
    Rasmuson, Åke C.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Influence of History of Solution in Crystal Nucleation of Fenoxycarb: Kinetics and Mechanisms2014In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 14, no 3, p. 905-915Article in journal (Refereed)
    Abstract [en]

    Nearly 1800 induction time experiments have been performed on crystal nucleation of fenoxycarb in isopropanol to investigate the influence of solution pretreatment. For each preheating temperature and preheating time, at least 80 experiments were performed to obtain statistically valid results. The relationship between the inverse of the induction time and the preheating time can be reasonably described as an exponential decay having time constants ranging up to days depending on the temperature. This dependence on the preheating temperature corresponds to an activation energy of more than 200 kJ/mol. Given sufficiently long preheating time and high temperature, the solution appears to reach a steady-state where the "memory" effect has disappeared. Density functional theory modeling suggests that the molecular packing in the crystal lattice is not the thermodynamically stable configuration at the level of simple dimers in solution, while modeling of the first solvation shell reveals that solute aggregation must exist in solution due to the low solvent-to-solute molecular ratio. It is thus hypothesized that the dissolution of crystalline material at first leaves molecular assemblies in solution that retain features of the crystalline structure which facilitates subsequent nucleation. However, the longer the solution is kept at a temperature above the saturation temperature and the higher the temperature, the more these assemblies disintegrate and transform into molecular structures less suited to form critical nuclei.

  • 216.
    Kumpulainen, Atte J
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry.
    Tyrode, Eric C.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry.
    Eriksson, Jan Christer
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry.
    Soluble monolayers of sugar-based surfactants at the air-solution interface2009In: Sugar-Based Surfactants / [ed] Cristobal Carnero Ruiz, CRC Press, 2009, Vol. 143, no Sugar-Based Surfactants, p. 153-206Chapter in book (Refereed)
    Abstract [en]

    A review. Surface activity, thermodn. relations for sol. monolayers, surface tension isotherms, adsorption, VSFS spectroscopy, Henry range, micelle formation, mixed solns., surface entropy, and some types of surfactants are discussed. [on SciFinder(R)]

  • 217. Kyllonen, Lasse
    et al.
    Parviainen, Arno
    Deb, Somdatta
    Lawoko, Martin
    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.
    Gorlov, Mikhail
    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.
    Kilpelainen, Ilkka
    King, Alistair W. T.
    Solubility of wood in non-derivatizing ionic liquids2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, p. 79-CELL-Article in journal (Other academic)
  • 218. Kyllönen, Lasse
    et al.
    Parviainen, Arno
    Deb, Somdatta
    Lawoko, Martin
    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.
    Gorlov, Mikhail
    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.
    Kilpeläinen, Ilkka
    King, Alistair W. T.
    On the solubility of wood in non-derivatising ionic liquids2013In: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 15, no 9, p. 2374-2378Article in journal (Refereed)
    Abstract [en]

    Norway spruce wood was mechanically pulverized to varying degrees. The solubility of the wood samples, in a range of common ionic and molecular solvents, was quantified using a novel P-31 NMR technique. The results show that intact wood is not soluble under mild treatment conditions, in cellulose-dissolving or swelling solvents.

  • 219.
    Källbom, Susanna
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Materials.
    Moghaddam, Maziar Sedighi
    Wålinder, Magnus E. P.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Materials.
    Liquid sorption, swelling and surface energy properties of unmodified and thermally modified Scots pine heartwood after extraction2018In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 72, no 3, p. 251-258Article in journal (Refereed)
    Abstract [en]

    The effect of extractives removal on liquid sorption, swelling and surface energy properties of unmodified wood (UW) and thermally modified Scots pine heartwood (hW) (TMW) was studied. The extraction was performed by a Soxtec procedure with a series of solvents and the results were observed by the multicycle Wilhelmy plate method, inverse gas chromatography (IGC) and Fourier transform infrared (FTIR) spectroscopy. A significantly lower rate of water uptake was found for the extracted UW, compared with the unextracted one. This is due to a contamination effect in the latter case from water-soluble extractives increasing the capillary flow into the wood voids, proven by the decreased water surface tension. The swelling in water increased after extraction 1.7 and 3 times in the cases of UW and TMW, respectively. The dispersive part of the surface energy was lower for the extracted TMW compared to the other sample groups, indicating an almost complete removal of the extractives. The FTIR spectra of the extracts showed the presence of phenolic compounds but also resin acids and aliphatic compounds.

  • 220.
    Larsson, Emma
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Cobo Sanchez, Carmen
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Karabulut, Erdem
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Carlmark, Anna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Modification of nanofibrillated cellulose (NFC) with thermo-responsive block copolymers2013In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 245Article in journal (Other academic)
  • 221.
    Larsson, Per A.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Ductile All-Cellulose Nanocomposite Films Fabricated from Core-Shell Structured Cellulose Nanofibrils2014In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 15, no 6, p. 2218-2223Article in journal (Refereed)
    Abstract [en]

    Cellulosic materials have many desirable properties such as high mechanical strength and low oxygen permeability and will be an important component in a sustainable biomaterial-based society, but unfortunately they often lack the ductility and formability offered by petroleum-based materials. This paper describes the fabrication and characterization of nanocomposite films made of core-shell modified cellulose nanofibrils (CNEs) surrounded by a shell of ductile dialcohol cellulose, created by heterogeneous periodate oxidation followed by borohydride reduction of the native cellulose in the external parts of the individual fibrils. The oxidation with periodate selectively produces dialdehyde cellulose, and the process does not increase the charge density of the material. Yet the modified cellulose fibers could easily be homogenized to CNFs. Prior to film fabrication, the CNF was shown by atomic force microscopy to be 0.5-2 mu m long and 4-10 nm wide. The films were fabricated by filtration, and besides uniaxial tensile testing at different relative humidities, they were characterized by scanning electron microscopy and oxygen permeability. The strength-at-break at 23 degrees C and 50% RH was 175 MPa, and the films could, before rupture, be strained, mainly by plastic deformation, to about 15% and 37% at 50% RH and 90% RH, respectively. This moisture plasticization was further utilized to form a demonstrator consisting of a double-curved structure with a nominal strain of 24% over the curvature. At a relative humidity of 80%, the films still acted as a good oxygen barrier, having an oxygen permeability of 5.5 mL-mu L/(m(2).24 h.kPa). These properties indicate that this new material has a potential for use as a barrier in complex-shaped structures and hence ultimately reduce the need for petroleum-based plastics.

  • 222.
    Laval, Clemence Elizabeth
    KTH, School of Chemical Science and Engineering (CHE).
    Development of Cosmetics2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Since 1990, the global cosmetic market is in constant growth with the constant discovery of new needs and the increasing expectations of customers. Cosmetics are used a lot in developed countries, but also more and more in developing countries.Thus, cosmetics companies have to be reactive and develop more and more products (which can be creams, lotions, serums, masks, milks etc…) to be competitive but they also have to follow the rules in terms of ingredients allowance and dosage.

    In broad strokes, for the R&D team, the development of a cosmetic product consists of sourcing the raw materials, working on the formulation, drawing up the production protocol, and carrying out different tests on the product. Every step is precisely planned in order to be on time for the launching date. All the orders, R&D, production, and marketing steps have to be taken into account for each project planning and delays have to be anticipated. However, sometimes, risks are taken in order to save time and money. Formulation is the key step of a product development. Indeed, in this step, the product becomes real. The texture is chosen, which means that the sense of touch that we want to create while taking the product out of its package and while applying on the skin is defined and then created. Furthermore, the rich or light effect of a cream (more “greasy” or more “water-like”), the penetration of the product into the skin, the slippery effect of its application, and the sense of touch on the skin after application are other parameters that are carefully studied in order to find the best texture for the product Then, industrial transposition is another key point in a product development since it allows the formulation to be scaled-up to an industrial production. Consequently, the R&D team has a very interesting work to do but also has to face problems which can happen at each step of the product development or even after its launching on the market. This can lead to a reformulation work. This situation also occurs when rules about cosmetics ingredients change or when a company wants to expand into a country with stricter regulations.

     I carried out my Master thesis for six months in cosmetic formulation in Biologique Recherche, a high-class cosmetics company located in Suresnes, a suburb of Paris. I took part in different reformulation works and in new products formulations, with a main project on developing a new whitening cream and a new whitening serum. I made bibliographic research, worked on finding appropriate and stable formulations, had to face some problems during this, and I worked on industrial transpositions.Finally, I could work with other departments in the company, such as the Quality and Marketing departments as well as the Production team and I could see the importance of good manufacturing practices, traceability, and safety of goods and people within a cosmetics production laboratory.

  • 223. Laxman, Karthik
    et al.
    Al Gharibi, Laila
    Dutta, Joydeep
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM. Sultan Qaboos University, Oman.
    Capacitive deionization with asymmetric electrodes: Electrode capacitance vs electrode surface area: Electrode capacitance vs electrode surface area2015In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 176, p. 420-425Article in journal (Refereed)
    Abstract [en]

    Asymmetry of electrodes on the equilibrium salt adsorption capacity in a capacitive configuration was studied. Experiments were carried out by using activated carbon cloth (ACC) with a specific surface area and specific capacitance of similar to 1000 m(2)/g and 44 F/g as the anode and ACC coated with zinc oxide nanorods (ZnO NR) with a specific surface area and specific capacitance of 637 m(2)/g and 57 F/g as the cathode. The electrodes were characterized electrically and their salt adsorption capacities measured for various anode-cathode configurations to conclude that for multimodal electrodes, specific capacitance and not specific surface area regulates the salt adsorption capacity. The adsorption trends were analyzed and equated to an electrical model to qualitatively predict the equilibrium salt adsorption capacity, where the smaller capacitance was observed to be the limiting factor. The results in this work are especially useful for practical CDI units, where anode-cathode capacitance should be matched to achieve maximum salt removal efficiency.

  • 224.
    Laxman, Karthik
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Al Rashdi, Manal
    Al Sabahi, Jamal
    Al Abri, Mohammed
    Dutta, Joydeep
    KTH, School of Engineering Sciences (SCI), Applied Physics, Functional Materials, FNM. Sultan Qaboos University, Oman.
    Supported versus colloidal zinc oxide for advanced oxidation processes2017In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 411, p. 285-290Article in journal (Refereed)
    Abstract [en]

    Photocatalysis is a green technology which typically utilizes either supported or colloidal catalysts for the mineralization of aqueous organic contaminants. Catalyst surface area and surface energy are the primary factors determining its efficiency, but correlation between the two is still unclear. This work explores their relation and hierarchy in a photocatalytic process involving both supported and colloidal catalysts. In order to do this the active surface areas of supported zinc oxide nanorods (ZnO NR's) and colloidal zinc oxide nanoparticles (having different surface energies) were equalized and their phenol oxidation mechanism and capacity was analyzed. It was observed that while surface energy had subtle effects on the oxidation rate of the catalysts, the degradation efficiency was primarily a function of the surface area; which makes it a better parameter for comparison when studying different catalyst forms of the same material. Thus we build a case for the use of supported catalysts, wherein their catalytic efficiency was tested to be unaltered over several days under both natural and artificial light, suggesting their viability for practical applications.

  • 225.
    Lazarevic-Pasti, Tamara
    et al.
    Univ Belgrade, Vinca Inst Nucl Sci, Dept Phys Chem, Mike Petrovica Alasa 12-14,POB 522, Belgrade 11001, Serbia..
    Anicijevic, Vladan
    Univ Belgrade, Fac Phys Chem, Studentski Trg 12-16, Belgrade 11158, Serbia..
    Baljozovic, Milos
    Paul Scherrer Inst, Lab Micro & Nanotechnol, Villigen, Switzerland..
    Anicijevic, Dragana Vasic
    Univ Belgrade, Vinca Inst Nucl Sci, Dept Phys Chem, Mike Petrovica Alasa 12-14,POB 522, Belgrade 11001, Serbia..
    Gutic, Sanjin
    Univ Sarajevo, Dept Chem, Fac Sci, Zmaja Bosne 33-35, Sarajevo, Bosnia & Herceg..
    Vasic, Vesna
    Univ Belgrade, Vinca Inst Nucl Sci, Dept Phys Chem, Mike Petrovica Alasa 12-14,POB 522, Belgrade 11001, Serbia..
    Skorodumova, Natalia V.
    KTH. Uppsala Univ, Dept Phys & Astron, Box 516, S-75120 Uppsala, Sweden.;KTH Royal Inst Technol, Sch Ind Engn & Management, Dept Mat Sci & Engn, Brinellvagen 23, S-10044 Stockholm, Sweden..
    Pasti, Igor A.
    KTH.
    The impact of the structure of graphene-based materials on the removal of organophosphorus pesticides from water2018In: ENVIRONMENTAL SCIENCE-NANO, ISSN 2051-8153, Vol. 5, no 6, p. 1482-1494Article in journal (Refereed)
    Abstract [en]

    The wide use of pesticides in modern agriculture and other areas results in an urgent need for their efficient removal from the environment. Adsorption of pesticides is one of the most commonly used strategies for this task. Here we analyze the adsorption of two organophosphorus pesticides, dimethoate (DMT) and chlorpyrifos (CPF), on graphene-based materials. The adsorption was found to be very sensitive to the structure of the adsorbents used. In particular, aliphatic DMT was found to prefer hydrophilic oxidized graphene surfaces. The CPF molecule, which contains an aromatic moiety, prefers adsorption on the surface of a graphene basal plane with high structural order and preserved electron system. The toxicity of pesticide solutions is reduced after adsorption, suggesting that there is no oxidation of DMT and CPF to more toxic oxo forms. We emphasize that the combination of structural properties of adsorbents and adsorbates defines the adsorption of organophosphorus pesticides on graphene-based materials, while the specific surface area of adsorbents is not the major factor.

  • 226.
    Le Normand, Myriam
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    New materials and chemicals from bark2012Conference paper (Other academic)
  • 227.
    Le Normand, Myriam
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Edlund, Ulrica
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Ek, Monica
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Extraction and valorization of spruce bark hemicelluloses and pectins2011In: The third Nordic Wood Biorefinery Conference: 22-24 March, 2011 Stockholm, Sweden, 2011, p. 274-275Conference paper (Other academic)
  • 228.
    Le Normand, Myriam
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Edlund, Ulrica
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Ek, Monica
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Spruce bark hemicelluloses and pectins: extraction and characterization2011In: 16th International Symposium on Wood, Fiber and Pulping Chemistry Proceedings Vol. I: Tianjin, China June 8-10, 2011, 2011, p. 103-106Conference paper (Other academic)
    Abstract [en]

    In industrial spruce bark, up to 20 % of the dry mass consists of non-cellulosic polysaccharides. These polysaccharides can easily be extracted with pressurized hot water and have a large potential as a starting polymeric biomass for functional materials development.

    In this study, spruce bark was collected directly after the debarking process. The different steps of extraction were performed in an Accelerated Solvent Extractor (ASE). Bark was first extracted with acetone at 100 °C to remove extractives. Spruce bark polysaccharides could then be extracted with pressurized water at 100-160 °C with the highest yield at 140 °C. They were mainly composed of glucose, arabinose and galacturonic acid units which revealed the presence of pectic substances, starch and arabinose-rich hemicelluloses, e.g. arabinans. Molecular weight estimations showed the presence of rather large polysaccharides with a Mw varying between 10 to 30 kDa, depending of the extraction conditions.

  • 229.
    Le Normand, Myriam
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Edlund, Ulrica
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Holmbom, Bjarne
    Åbo Akademi University, Finland.
    Ek, Monica
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Hot-water extraction and characterization of spruce bark non-cellulosic polysaccharides2012In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 27, no 1, p. 18-23Article in journal (Refereed)
    Abstract [en]

    Non-cellulosic polysaccharides (NCP) from bark offer large potential as a class of natural raw materials for functional materials development and production of biochemicals. We have elaborated a process for sequential extraction of NCP from industrial Norway spruce bark using an accelerated solvent extraction (ASE) with water at 100 to 160°C. Carbohydrates, Klason lignin and ash content as well as size-exclusion chromatography (SEC) analyses were performed for all hot-water extracts. NCP were mainly composed of glucose, arabinose and galacturonic acid units which revealed the presence of starch, arabinose-rich hemicelluloses and pectins. In total, the industrial bark of Norway spruce contained up to 20% of NCP which were extracted with pressurized hot water. NCP were mainly extractable at 140°C and started to undergo degradation at higher temperature.

  • 230.
    Le Normand, Myriam
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Krogell, Jens
    Laboratory of Wood and Paper Chemistry, Process Chemistry Centre, Åbo Akademi University, Turku/Åbo, Finland.
    Holmbom, Bjarne
    Laboratory of Wood and Paper Chemistry, Process Chemistry Centre, Åbo Akademi University, Turku/Åbo, Finland.
    Ek, Monica
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    HOT-WATER EXTRACTION AND CHARACTERIZATIONOF HEMICELLULOSES AND PECTINS FROM BARK OF NORWAY SPRUCE (PICEA ABIES)2010In: 11th European Workshop on Lignocellulosics and Pulp: August 16-19, 2010 Hamburg/Germany, 2010, p. 243-246Conference paper (Other academic)
    Abstract [en]

    Bark of Norway spruce (Picea abies) contains 20 to 30% of hemicelluloses and pectins which could be extractedwith pressurized hot water. Hemicelluloses and pectins from the fresh inner bark were extracted with anAccelerated Solvent Extractor (ASE) with water at 100 °C, 140 °C and 160 °C. A large amount of arabinose andgalacturonic acid units in the water extract obtained at 140 °C revealed the presence of arabinans and pectins. Atthis temperature, the extraction of hemicelluloses and pectins was the most effective and generated high-molarmassnon-cellulosic polysaccharides with an average molar mass Mw around 40 kDa. Aromatic substancespresent in the hot-water extract at 140 °C could partly be removed by sorption on DAX-8 polyacrylate resin.

  • 231. Lee, Koon-Yang
    et al.
    Aitomaki, Yvonne
    Berglund, Lars A.
    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.
    Oksman, Kristiina
    Bismarck, Alexander
    Utilising the full potential of bacterial cellulose in composite materials: Can it be done?2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, p. 309-CELL-Article in journal (Other academic)
  • 232.
    Leygraf, Christofer
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Atmospheric corrosion: (authorized translation into Chinese from the English version that appeared in John Wiley Sons in 2000)2005In: Chemical industry press, ChinaArticle in journal (Other academic)
  • 233.
    Leygraf, Christofer
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry.
    Bertling, Sofia
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry.
    Chen, Z.
    Johnson, Magnus
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface Chemistry.
    Atmospheric corrosion: New fundamental and environmental aspects2005In: Proc. 16th International Corrosion Congress, Beijing, Sept. 2005, 2005Conference paper (Other academic)
  • 234.
    Leygraf, Christopher
    et al.
    KTH.
    Chang, Tingru
    KTH.
    Odnevall Wallinder, Inger
    KTH.
    De La Fuente, D.
    Chico, B.
    Diaz, I.
    Morcillo, M.
    Analysis of historic copper patinas 1: Influence of substrate on patina uniformity2017In: EUROCORR 2017 - The Annual Congress of the European Federation of Corrosion, 20th International Corrosion Congress and Process Safety Congress 2017, Asociace koroznich inzenyru z.s.- AKI - Czech Association of Corrosion Engineers , 2017Conference paper (Refereed)
  • 235.
    Leygraf, Christopher
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Odnevall Wallinder, Inger
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Tidblad, J.
    Graedel, T.
    Atmospheric Corrosion: Second Edition2016Chapter in book (Other academic)
    Abstract [en]

    Presents a comprehensive look at atmospheric corrosion, combining expertise in corrosion science and atmospheric chemistry Is an invaluable resource for corrosion scientists, corrosion engineers, and anyone interested in the theory and application of Atmospheric Corrosion Updates and expands topics covered to include, international exposure programs and the environmental effects of atmospheric corrosion Covers basic principles and theory of atmospheric corrosion chemistry as well as corrosion mechanisms in controlled and uncontrolled environments Details degradation of materials in architectural and structural applications, electronic devices, and cultural artifacts Includes appendices with data on specific materials, experimental techniques, atmospheric species.

  • 236. Li, F.
    et al.
    Li, H.
    Zhu, Y.
    Du, J.
    Wang, Y.
    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 water oxidation by a nickel oxide film derived from a molecular precursor2017In: Cuihuà xuébào, ISSN 0253-9837, E-ISSN 1872-2067, Vol. 38, no 11, p. 1812-1817Article in journal (Refereed)
    Abstract [en]

    In this study, we fabricated a NiOx film by electrodeposition of an ethanediamine nickel complex precursor (pH = 11) on a fluorine-doped tin oxide substrate. The resulting film is robust and exhibits high catalytic activity for electrochemical water oxidation. Water oxidation is initiated with an overpotential of 375 mV (1 mA/cm2) and a steady current density of 8.5 mA/cm2 is maintained for at least 10 h at 1.3 V versus the normal hydrogen electrode. Kinetic analysis reveals that there is a 2e−/3H+ pre-equilibrium process before the chemical rate-determining step. The low-cost preparation, robustness, and longevity make this catalyst competitive for applications in solar energy conversion and storage.

  • 237.
    Li, Fusheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Design of Water Splitting Devices via Molecular Engineering2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Converting solar energyto fuels such as hydrogen by the reaction of water splitting is a promising solution for the future sustainable energy systems. The theme of this thesis is to design water splitting devices via molecular engineering; it concerns the studies of both electrochemical-driven and photo-electrochemical driven molecular functional devices for water splitting.

    The first chapter presents a general introduction about Solar Fuel Conversion. It concerns molecular water splitting catalysts, light harvesting materials and fabrication methods of water splitting devices.

    The second chapter describes an electrode by immobilizing a molecular water oxidation catalyston carbon nanotubes through the hydrophobic interaction. This fabrication method is corresponding to the question: “How to employ catalysts in functional devices without affecting their performances?”

    In the third chapter, molecular water oxidation catalysts were successfully immobilized on glassy carbon electrode surface via electrochemical polymerization method. The O-O bond formation pathways of catalysts on electrode surfaces were studied. This kinetic studyis corresponding to the question: “How to get kinetic information of RDS whena catalyst is immobilized on the electrode surface?”

    Chapter four explores molecular water oxidation catalysts immobilized on dye-sensitized TiO2 electrodeand Fe2O3 semiconductor electrode via different fabrication methods. The reasons of photocurrent decay are discussed and two potential solutions are provided. These studies are corresponding to the question: “How to improvethe stability of photo-electrodes?”

    Finally, in the last chapter, two novel Pt-free Z-schemed molecular photo-electrochemical cells with both photoactive cathode and photoactive anode for visible light driven water splitting driven were demonstrated. These studies are corresponding to the question: “How to utilizethe concept of Z-schemein photosynthesis to fabricate Pt-free molecular based PEC cells?

  • 238.
    Li, Fusheng
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Duan, Lele
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Fan, Ke
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Daniel, Quentin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Wang, Lei
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Chen, Hong
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. Dalian University of Technology, China.
    Control the O-O bond formation pathways by immobilizing molecular catalysts on glassy carbon via electrochemical polymerizationManuscript (preprint) (Other academic)
    Abstract [en]

    Molecular water oxidation catalysts Ru-bda (1) and Ru-pda (2) are electrochemically polymerized on glassy carbon (GC) electrodes. Reaction orders and kinetic isotope effects (KIE) of the corresponding electrodes are studied. Results indicate that poly-1@GC goes through a radical coupling pathway. By adding poly-styrene (PSt) as a “blocking unit” in the poly-1, the radical coupling process of Ru-bda is blocked, and poly-1+PSt@GC catalyzes water oxidation through the water nucleophilic attack pathway. In comparison, catalyst 2, which oxidizes water via water nucleophilic attack path in homogeneous systems, goes through a radical coupling pathway as well when 2 is polymerized on glassy carbon (poly-2@GC).

  • 239. Li, Hua
    et al.
    Li, Fei
    Zhang, Biaobiao
    Zhou, Xu
    Yu, Fengshou
    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.
    Visible Light-Driven Water Oxidation Promoted by Host-Guest Interaction between Photosensitizer and Catalyst with A High Quantum Efficiency2015In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 137, no 13, p. 4332-4335Article in journal (Refereed)
    Abstract [en]

    A highly active supramolecular system for visible light-driven water oxidation was developed with cyclodextrin-modified ruthenium complex as the photosensitizer, phenyl-modified ruthenium complexes as the catalysts, and sodium persulfate as the sacrificial electron acceptor. The catalysts were found to form 1:1 host-guest adducts with the photosensitizer. Stopped-flow measurement revealed the host-guest interaction is essential to facilitate the electron transfer from catalyst to sensitizer. As a result, a remarkable quantum efficiency of 84% was determined under visible light irradiation in neutral aqueous phosphate buffer. This value is nearly 1 order of magnitude higher than that of noninteraction system, indicating that the noncovalent incorporation of sensitizer and catalyst is an appealing approach for efficient conversion of solar energy into fuels.

  • 240. Li, S.
    et al.
    Xue, L.
    Fu, K.
    Xia, X.
    Zhao, Chengxin
    KTH, School of Information and Communication Technology (ICT).
    Zhang, X.
    High-performance Sn/carbon composite anodes derived from Sn(II) acetate/polyacrylonitrile precursors by electrospinning technology2013In: Current organic chemistry, ISSN 1385-2728, E-ISSN 1875-5348, Vol. 17, no 13, p. 1448-1454Article in journal (Refereed)
    Abstract [en]

    Sn/carbon composite nanofibers with various compositions were prepared from Sn(II) acetate/polyacrylonitrile (PAN) precursors by a combination of electrospinning and carbonization methods, and their potential use as anode materials for rechargeable lithiumion batteries was investigated. The composite electrode derived from 20 wt% Sn(II) acetate/PAN precursor showed excellent electrochemical properties, including a large reversible capacity of 699 mAh g-1 and a high capacity retention of 83% in 50 cycles. Sn/carbon composite nanofibers exhibited enhanced electrochemical performance ascribing to the combination of the properties of both Sn nanoparticles (large Li storage capability) and carbon matrices (long cycle life), and therefore could be potentially used in high-energy rechargeable lithium-ion batteries.

  • 241.
    Li, Sa
    KTH.
    Pressure induced phase transitions in Cm2013In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 245Article in journal (Other academic)
  • 242.
    Li, Xin
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Zhu, Liangliang
    Duan, Sai
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Zhao, Yanli
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Aggregation-induced chiral symmetry breaking of a naphthalimide-cyanostilbene dyad2014In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 16, no 43, p. 23854-23860Article in journal (Refereed)
    Abstract [en]

    Spontaneously emerged supramolecular chirality and chiral symmetry breaking from achiral/racemic constituents remain poorly understood. We here report that supramolecular chirality may emerge from the structural flexibility of achiral aryl nitrogen centres which provide instantaneous chirality. Employing a naphthalimide-cyanostilbene dyad as a model, we explored the underlying mechanism of aggregation-induced chiral symmetry breaking and found that the conformations of the N-naphthylpiperazine and the N, N-dimethylaniline units facilitate the formation of ordered supramolecular structures and offer opposite handedness. Furthermore, chiral symmetry breaking of the monomers was amplified by the formation of dimers. The microscopic and the macroscopic observations from the theoretical simulations and experimental measurements are thus rationalized by connecting the population of the dihedral angles of the aryl nitrogen centres, the morphology of the self-assemblies, and the observed circular dichroism spectra.

  • 243.
    Liang, Lijun
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. Zhejiang University, China.
    Zhang, Zhisen
    Shen, Jiawei
    Zhe, Kong
    Wang, Qi
    Wu, Tao
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Tu, Yaoquan
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Theoretical studies on the dynamics of DNA fragment translocation through multilayer graphene nanopores2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 92, p. 50494-50502Article in journal (Refereed)
    Abstract [en]

    Motivated by several potential advantages over common sequencing technologies, solid-state nanopores, in particular graphene nanopores, have recently been extensively explored as biosensor materials for DNA sequencing. Studies carried out on monolayer graphene nanopores aiming at single-base resolution have recently been extended to multilayer graphene (MLG) films, indicating that MLG nanopores are superior to their monolayer counterparts for DNA sequencing. However, the underlying dynamics and current change in the DNA translocation to thread MLG nanopores remain poorly understood. In this paper, we report a molecular dynamics study of DNA passing through graphene nanopores of different layers. We show that the DNA translocation time could be extended by increasing the graphene layers up to a moderate number (7) under a high electric field and that the current in DNA translocation undergoes a stepwise change upon DNA going through an MLG nanopore. A model is built to account for the relationship between the current change and the unoccupied volume of the MLG nanopore. We demonstrate that the dynamics of DNA translocation depends specifically on the interaction of nucleotides with the graphene sheet. Thus, our study indicates that the resolution of DNA detection could be improved by increasing the number of graphene layers in a certain range and by modifying the surface of the graphene nanopores.

  • 244. Liimatainen, Henrikki
    et al.
    Ezekiel, Ngesa
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Sliz, Rafal
    Ohenoja, Katja
    Sirviö, Juho Antti
    Berglund, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Hormi, Osmo
    Niinimäki, Jouko
    High-Strength Nanocellulose-Talc Hybrid Barrier Films2013In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 5, no 24, p. 13412-13418Article in journal (Refereed)
    Abstract [en]

    Hybrid organic inorganic films mimicking natural nacre-like composite structures were fabricated from cellulose nanofibers obtained from sequential periodate chlorite oxidation treatment and talc platelets, using a simple vacuum-filtration method. As a pretreatment, commercial talc aggregates were individualized into well-dispersed talc platelets using a wet stirred media mill with high-shear conditions to promote the homogeneity and mechanical characteristics of hybrids. The nanofiber talc hybrids, which had talc contents from 1 to 50 wt %, were all flexible in bending, and possessed tensile strength and Young's modulus values up to 211 +/- 3 MPa and 12 +/- 1 GPa, respectively, the values being remarkably higher than those reported previously for nanofibrillated cellulose talc films. Because of the lamellar and well-organized structure of hybrids in which the talc platelets were evenly embedded, they possessed a small pore size and good oxygen barrier properties, as indicated by the preliminary results. The talc platelets decreased the moisture adsorption of highly talc-loaded hybrids, although they still exhibited hydrophilic surface characteristics in terms of contact angles.

  • 245.
    Lima, Raquel Bohn
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Raza, Rizwan
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Qin, Haiying
    KTH, School of Industrial Engineering and Management (ITM), Energy 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.
    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.
    Zhu, Bin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Direct lignin fuel cell for power generation2013In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 3, no 15, p. 5083-5089Article in journal (Refereed)
    Abstract [en]

    Lignin, the second most abundant component after cellulose in biomass, has been examined in this study as a fuel for direct conversion into electricity using direct carbon fuel cells (DCFC). Two different types of industrial lignins were investigated: Lignosulfonate (LS) and Kraft lignin (KL), in their commercial forms, after their blending with commercial active carbon (AC) or after alteration of their structures by a pH adjustment to pH 10. It was found that the open circuit voltage (OCV) of the DCFC could reach around 0.7 V in most of the trials. Addition of active carbon increased the maximum current density from 43-57 to 83-101 mA cm(-2). The pH adjustment not only increased the maximum current density but also reduced the differences between the two types of lignins, resulting in an OCV of 0.68-0.69 V and a maximum current density of 74-79 mA cm(-2) from both lignins. Typical power density was 12 (for KL + AC) and 24 mW cm(-2) (for LS + AC). It is concluded that a direct lignin fuel cell is feasible and the lignin hydrophilicity is critical for the cell performance.

  • 246.
    Lindell, David
    Swerea KIMAB, Stockholm.
    Characterisation and pickling behaviour of oxides formed during production annealing of stainless steel2010Licentiate thesis, comprehensive summary (Other academic)
  • 247.
    Lingström, Rikard
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Johansson, Erik
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Polyelectrolyte Multilayers for Fibre Engineering2009In: The Nanoscience and Technology of Renewable Biomaterials, John Wiley & Sons, 2009, p. 123-148Chapter in book (Refereed)
  • 248.
    Liu, Jin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Svärd, Michael
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena. University of Limerick, Ireland.
    Rasmuson, Åke C.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena. University of Limerick, Ireland.
    Influence of Agitation on Primary Nucleation in Stirred Tank Crystallizers2015In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 15, no 9, p. 4177-4184Article in journal (Refereed)
    Abstract [en]

    The influence of agitation on nucleation of butyl paraben and m-hydroxybenzoic acid polymorphs has been investigated through 330 cooling crystallization experiments. The induction time has been measured at different supersaturations and temperatures in three parallel jacketed vessels equipped with different overhead stirring agitators. In each case, the nucleating polymorph of m-hydroxybenzoic acid has been identified by infrared spectroscopy. The influences of agitation rate, impeller type, impeller diameter, impeller to bottom clearance, and the use of baffles have been investigated. A general trend in all of the experiments is that the induction time decreases with increasing agitation rate. Across all experiments with different fluid mechanics for the butyl paraben system, the induction time is correlated to the average energy dissipation rate raised to the power -0.3. It is shown that this dependence is consistent with a turbulent flow enhanced cluster coalescence mechanism. In experiments with m-hydroxybenzoic acid, the metastable form II was always obtained at higher nucleation driving force while both polymorphs were obtained at lower driving force. In the latter case, form I was obtained in the majority of experiments at low agitation rate (100 rpm) while form II was obtained in all experiments at higher agitation rate (>= 300 rpm).

  • 249.
    Liu, Yi
    KTH, School of Chemical Science and Engineering (CHE).
    Metal release of stainless steel particles in artificial lung fluid: complexation and synergistic effects2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Numerous metal release data have been published by the Div. Surface and Corrosion Science and the AISI 316L stainless steel particles’ behavior in artificial lysosomal fluid (ALF). This study aims to evaluate the effect of chemical components in ALF on metal release from stainless steel particles with a bottom-up methodology. Two sizes of 316L stainless steel particles were used to assess the particle size influence on the metal release in detail.

    The results show that organic complexing agents e.g. lactate, tartrate and citrate are responsible for the high metal release rate in ALF. Correlations between the metal release rate and the number of carboxyl groups of the organic ligand were observed. Moreover, metal release data in this study indicates no synergistic effects in ALF solution, and continued research is on-going to study the synergistic effects further. No quantitative rules of iron, chromium and nickel release from the same stainless particles could be found which may indicate that these metals are released through different pathways e.g. diffusion or chemical dissolution. In different solutions with different chemical components, one or more metal release mechanisms dominate over others and make the metal release rate unpredictable.

  • 250.
    Long, Hui
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Cellulose reinforced hydrogel via click chemistry2012In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 243Article in journal (Other academic)
2345678 201 - 250 of 480
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