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  • 51.
    Bhagavathiachari, Muthuraaman
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Elumalai, Viswanathan
    Vlachopoulos, Nick
    Safdari, Majid
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Gao, Jiajia
    KTH, School of Chemical Science and Engineering (CHE), Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Gardner, James M.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    A quasi-liquid polymer-based cobalt redox mediator electrolyte for dye-sensitized solar cells2013In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 15, no 40, p. 17419-17425Article in journal (Refereed)
    Abstract [en]

    Recently, cobalt redox electrolyte mediators have emerged as a promising alternative to the commonly used iodide/triiodide redox shuttle in dye-sensitized solar cells (DSCs). Here, we report the successful use of a new quasi-liquid, polymer-based electrolyte containing the Co3+/Co2+ redox mediator in 3-methoxy propionitrile solvent in order to overcome the limitations of high cell resistance, low diffusion coefficient and rapid recombination losses. The performance of the solar cells containing the polymer based electrolytes increased by a factor of 1.2 with respect to an analogous electrolyte without the polymer. The performances of the fabricated DSCs have been investigated in detail by photovoltaic, transient electron measurements, EIS, Raman and UV-vis spectroscopy. This approach offers an effective way to make high-performance and long-lasting DSCs.

  • 52.
    Biler, Michal
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Biedermann, David
    Valentova, Katerina
    Kren, Vladimir
    Kubala, Martin
    Quercetin and its analogues: optical and acido-basic properties2017In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 19, no 39, p. 26870-26879Article in journal (Refereed)
    Abstract [en]

    This study is focused on eight structurally analogous natural flavonoids that exhibit a wide range of biological activities, which are of interest in pharmacy, cosmetics and the food industry. Using both experimental and theoretical approaches, we relate their fundamental physico-chemical properties to the structural motifs, with particular focus on UV/Vis absorption properties and pH dependence. We highlight the role of the C2-C3 double bond, whose presence or absence is responsible for the switch between absorption bands in the UVB and UVA regions, which is rationalized by strong modification of the involved molecular orbitals. After deprotonation in an alkaline environment, a typical switch in intensity at the maximum absorption wavelength (lambda(max)) is observed enabling the calculation of pK(a) values for compounds with a C2-C3 single bond, whereas a bathochromic shift of lambda(max) vs. pH is observed for the C2-C3 double bond containing compounds. These behaviors are also rationalized and understood by MO analysis. Interestingly, high pH (above 11 for ampelopsin and above 9 for myricetin) induces the formation of a long-wavelength peak arising from double and/or triple deprotonation. Substitution at position C3 by the OH group has almost no effect on lambda(max) for taxifolin and eriodictyol, whereas the effect is larger for quercetin and luteolin. An additional sugar moiety at C3 has a stabilizing effect and induces only minor changes in spectral behavior.

  • 53.
    Björkbacka, Åsa
    KTH, School of Chemical Science and Engineering (CHE).
    Radiation induced corrosion of copper2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Swedish concept for storage of highly radioactive spent nuclear fuel is called the KBS-3 program. The proposed procedure is that the waste will be stored in a deep repository, 500 meters down in the Swedish bedrock, for 100 000 years. The fuel will be sealed inside cast iron cylinders surrounded by copper. The iron-copper canisters will then be placed one by one in holes and embedded in bentonite clay. The environment in the deep repository will be that of an underground rock cave, there will be groundwater and low amounts of oxygen present.

    Substances which are likely to react with the copper canister and cause corrosion are oxygen, sulphides and reactive water radiolysis products. Gamma radiation from the spent nuclear fuel will penetrate through the canister and further into the bentonite clay. When the gamma radiation comes in contact with the water in the bentonite clay, water radiolysis will occur. Corrosive radiolysis products are for example hydroxyl radicals, solvated electrons and hydrogen peroxide.

    The main purpose of this work was to study the effect of gamma radiation on copper pieces, in an aqueous environment, both under oxic and anoxic conditions. The surfaces of the copper pieces were characterized using scanning electron microscopy (SEM) and infrared absorption spectroscopy (IRAS). The dissolution of copper was measured using inductively coupled plasma spectroscopy (ICP).

    A second study was also performed where the reactions of three different oxidants; hydrogen peroxide, permanganate and iridium hexachloride, were studied in the presence of copper in an inert environment. All of the reactions were studied spectrophotometrically and the dissolution of copper was measured using inductively coupled plasma spectroscopy (ICP).

    The SEM measurements showed corrosion products on the irradiated copper pieces both under oxic and anoxic conditions. Under anoxic conditions the corrosion products had a center of a small cavity which was surrounded by a larger, flat, circular area. From that area, wider cavities were spreading out in apparently random directions. SEM-EDS measurements detected oxygen on the surface of the corrosion products. ICP measurements of the water phase showed that the water from irradiated samples contained higher levels of copper than unirradiated samples. ICP measurements from the reactions of copper in the presence of oxidants showed that copper was only dissolved in the presence of iridium hexachloride.

    These results show that gamma radiation causes corrosion of copper in an aqueous environment, both under oxic and anoxic conditions. It can also be concluded that hydrogen peroxide is not the radiolysis product that causes the dissolution of copper when copper is irradiated in an aqueous and inert environment.

  • 54. Blachnio, Magdalena
    et al.
    Budnyak, Tetyana M.
    KTH.
    Derylo-Marczewska, Anna
    Marczewski, Adam W.
    Tertykh, Valentin A.
    Chitosan-Silica Hybrid Composites for Removal of Sulfonated Azo Dyes from Aqueous Solutions2018In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 34, no 6, p. 2258-2273Article in journal (Refereed)
    Abstract [en]

    In this study,. the influence of the chitosan immobilization method on the properties of final hybrid materials was performed. Chitosan was immobilized on the surface of mesoporous (ChS2) and fumed silica (ChS3) by physical adsorption and the sol gel method (ChS1). It was found that physical immobilization of chitosan allows to obtain hybrid composites (ChS) with a homogeneous distribution of polymer on the surface, relatively wide pores, and specific surface area of about 170 m(2)/g, PHpzc = 5.7 for ChS3 and 356 m(2)/g and pH(pzc) = 6.0 for ChS2. The microporous chitosan silica material with a specific surface area of 600 m(2)/g and a more negatively charged surface (pH(pzc) = 4.2) was obtained by the sol gel reaction. The mechanisms of azo dye adsorption were studied, and the correlation with the composite structure was distinguished. The generalized Langmuir equation and its special cases, that is, Langmuir-Freundlich and Langmuir equations, were applied for the analysis of adsorption isotherm data. The adsorption study showed that physically adsorbed chitosan (ChS1 and ChS2) on a silica surface has a higher sorption capacity, for example, 0.48 mmol/g for the acid red 88 (AR88) dye (ChS2) and 0.23 mmol/g for the acid orange 8 (AO8) dye (ChS1), compared to the composite obtained by the sol-gel method [ChS1, 0.05 mmol/g for the A08 dye]. For a deeper understanding of the behavior of immobilized chitosan in the adsorption processes, various kinetic equations were applied: first-order, second-order, mixed 1,2-order (MOE), multiexponential, and fractal-like MOE as well as intraparticle and pore diffusion model equations. In the case of AO8 dye, the adsorption rates were differentiated for three composites: for ChS3, 50% of the dye was removed from the solution after merely 5 min and almost 90% after 80 min. The slowest adsorption process controlled by the diffusion rate of dye molecules into the internal space of the pore structure was found for ChS1 (225 min halftime). In the case of ChS2, the rates for various dyes change in the following order: acid orange (AO7) > orange G (OG) > acid red 1 (AR1) > AR88 > AO8 (halftimes: 10.5 < 15.7 < 23.7 < 34.9 < 42.9 min).

  • 55.
    Bohn Lima, Raquel
    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.
    Khan, Mohammed A.
    Core-shell ceria-carbonates nanocomposite electrolyte for Lignin based fuel cell2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, p. 66-ENFL-Article in journal (Other academic)
  • 56. Bosmans, Toon J.
    et al.
    Stepan, Agnes M.
    Toriz, Guillermo
    Renneckar, Scott
    Karabulut, Erdem
    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.
    Wågberg, Lars
    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.
    Gatenholm, Paul
    Nanoparticles based on linear xylans and their assembly onto cellulose surfaces2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, p. 207-CELL-Article in journal (Other academic)
  • 57.
    Boström, Fanny
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    Lundström, Johanna
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    Biokols struktur och dess förmåga att adsorbera näringsämnen2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of this project is to create a deeper understanding of biochar’s ability to adsorbnutrients. In the long run the aim is to find a way to use the most suitable structures of biocharfor a maximum adsorption of different kinds of nutrients. The objective of this project is tofind, through case studies and practical experiments, an effective method to examine andanalyze the structure of biochars and their ability to adsorb nitrates and phosphates.

    The conclusion of the project was that analysis of the biochar’s ability to adsorb is a complexmatter. The BET-analysis is a good method to find the structure of the biochar. However, iodinenumber analysis could be a better alternative to directly find a value on the biochar’s ability toadsorb. The ICP-analysis of the solutions only works for phosphor, therefore spectroscopywould be a better alternative since it also can detect nitrogen and the different compounds.

  • 58.
    Boujemaoui, Assya
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Sanchez, Carmen Cobo
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Engström, Joakim
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Bruce, Carl
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Fogelström, Linda
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Carlmark, Anna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. RISE Innventia AB, Stockholm, Sweden.
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Polycaprolactone Nanocomposites Reinforced with Cellulose Nanocrystals Surface-Modified via Covalent Grafting or Physisorption: A Comparative Study2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 40, p. 35305-35318Article in journal (Refereed)
    Abstract [en]

    In the present work, cellulose nanocrystals (CNCs) have been surface-modified either via covalent grafting or through physisorption of poly(n-butyl methacrylate) (PBMA) and employed as reinforcement in PCL. Covalent grafting was achieved by surface-initiated atom transfer radical polymerization (SI-ATRP). Two approaches were utilized for the physisorption: using either micelles of poly(dimethyl aminoethyl methacrylate)-block-poly(n-butyl methacrylate) (PDMAEMA-b-PBMA) or latex nanoparticles of poly(dimethyl aminoethyl methacrylate-co-methacrylic acid)-block-poly(n-butyl methacrylate) (P(DMAEMA-co-MAA)-b-PBMA). Block copolymers (PDMAEMA-b-PBMA)s were obtained by ATRP and subsequently micellized. Latex nanoparticles were produced via reversible addition-fragmentation chain-transfer (RAFT) mediated surfactant-free emulsion polymerization, employing polymer-induced self-assembly (PISA) for the particle formation. For a reliable comparison, the amounts of micelles/latex particles adsorbed and the amount of polymer grafted onto the CNCs were kept similar. Two different chain lengths of PBMA were targeted, below and above the critical molecular weight for chain entanglement of PBMA (M-n,M-c similar to 56 000 g mo1(-1)). Poly(epsilon-caprolactone) (PCL) nanocomposites reinforced with unmodified and modified CNCs in different weight percentages (0.5, 1, and 3 wt %) were prepared via melt extrusion. The resulting composites were evaluated by UV-vis, scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and tensile testing. All materials resulted in higher transparency, greater thermal stability, and stronger mechanical properties than unfilled PCL and nanocomposites containing unmodified CNCs. The degradation temperature of PCL reinforced with grafted CNCs was higher than that of micelle-modified CNCs, and the latter was higher than that of latex-adsorbed CNCs with a long PBMA chain length. The results clearly indicate that covalent grafting is superior to physisorption with regard to thermal and mechanical properties of the final nanocomposite. This unique study is of great value for the future design of CNC-based nanocomposites with tailored properties.

  • 59.
    Bruce, Carl
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation.
    Javakhishvili, Irakli
    Fogelström, Linda
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation.
    Carlmark, Anna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation.
    Hvilsted, Søren
    Malmström, Eva
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation.
    Well-defined ABA- and BAB-type block copolymers of PDMAEMA and PCL2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 49, p. 25809-25818Article in journal (Refereed)
    Abstract [en]

    Triblock copolymers of ABA- and BAB-type consisting of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA, A) and poly(epsilon-caprolactone) (PCL, B) have successfully been prepared. PDMAEMA-b-PCL-b-PDMAEMA (ABA) and PCL-b-PDMAEMA-b-PCL (BAB) were synthesised by a combination of ring-opening polymerisation of epsilon-CL, atom transfer radical polymerisation of DMAEMA and end-group conversion, performed through either acylation or azide-alkyne "click" chemistry. All samples were analysed by size exclusion chromatography where it was found that the evaluation of PDMAEMA-containing polymers was difficult due to the thermoresponsivity of PDMAEMA, affecting the solubility of the polymer in the temperature range at which the SEC was operated. From differential scanning calorimetry measurements it was shown that the crystallinity could be altered by changing the order of the blocks; with PDMAEMA as the outer block (ABA), the inherent crystallinity of PCL was destroyed while with PCL as the outer block (BAB), the degree of crystallinity was in the same proximity as for a PCL homopolymer.

  • 60.
    Brömstrup, Torben
    et al.
    KTH, School of Engineering Sciences (SCI), Theoretical Physics, Theoretical & Computational Biophysics.
    Murail, Samuel
    KTH, School of Engineering Sciences (SCI), Theoretical Physics, Theoretical & Computational Biophysics. Inst Pasteur, Grp Recepteurs Canaux, France.
    Lindahl, Erik
    KTH, School of Engineering Sciences (SCI), Theoretical Physics, Theoretical & Computational Biophysics.
    Single-site mutation changes the location of the most favored Desflurane binding site in the GLIC ligand-gated ion channel2012In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 243Article in journal (Other academic)
  • 61.
    Budnyak, Tetyana M.
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. Natl Acad Sci Ukraine, Chuiko Inst Surface Chem, 17 Gen Naumov Str, UA-03164 Kiev, Ukraine..
    Aminzadeh, Selda
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Pylypchuk, Ievgen V.
    Swedish Univ Agr Sci SLU, Dept Mol Sci, Allmas Alle 5, SE-75007 Uppsala, Sweden..
    Sternik, Dariusz
    Marie Curie Sklodowska Univ, 2 M Curie Sklodowska Sq, PL-20031 Lublin, Poland..
    Tertykh, Valentin A.
    Natl Acad Sci Ukraine, Chuiko Inst Surface Chem, 17 Gen Naumov Str, UA-03164 Kiev, Ukraine..
    Lindström, Mikael E.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Sevastyanova, Olena
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Methylene Blue dye sorption by hybrid materials from technical lignins2018In: Journal of Environmental Chemical Engineering, ISSN 2160-6544, E-ISSN 2213-3437, Vol. 6, no 4, p. 4997-5007Article in journal (Refereed)
    Abstract [en]

    New hybrid sorbents were synthesized from technical lignins and silica and were applied for the removal of Methylene Blue dye (MB) from aqueous solution. Kraft softwood lignins from LignoBoost (LBL) and CleanFlowBlack (CFBL) processes were used to understand the influence of molecular weight and functionality of initial lignins on the properties of the final hybrids. The synthesized materials were applied as adsorbents for the removal of MB from aqueous solutions. The effects of parameters such as contact time, initial concentration of dye and initial pH on the adsorption capacity were evaluated. The hybrids exhibited higher adsorption capacity than the initial macromolecules of lignin with respect to MB. The hybrid based on CFBL exhibited an adsorption capacity of 60 mg/g; this value was 30% higher than the capacity of the hybrid based on LBL, which was 41.6 mg/g. Lignin hybrid materials extract 80-99% of the dye in a pH range from 3 to 10. The equilibrium and kinetic characteristics of MB uptake by the hybrids followed the Langmuir isotherm model and pseudosecond-order model, rather than the Freundlich and Temkin models, the pseudo-first-order or the intraparticle diffusion model. The attachment of the dye to the hybrid surface was confirmed via FE-SEM and FTIR spectroscopy. The mechanism for MB adsorption was proposed. Due to the high values of regeneration efficiency of the surface of both lignin-silica hybrid materials in 0.1 M HCl (up to 75%) and ethanol (99%), they could be applied as effective sorbents in industrial wastewater treatment processes.

  • 62.
    Burks, Terrance
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Avila, Marta
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Akhtar, F.
    Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden.
    Götelid, Mats
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
    Lansåker, P. C.
    Department of Engineering Sciences, The Ångström Laboratory, Uppsala University, Uppsala, Sweden.
    Toprak, Muhammet S.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Uheida, Abdusalam
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Studies on the adsorption of chromium(VI) onto 3-Mercaptopropionic acid coated superparamagnetic iron oxide nanoparticles2014In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 425, p. 36-43Article in journal (Refereed)
    Abstract [en]

    Chromium (Cr) in the form of Cr(VI) is deemed toxic in water due to its mutagenic and carcinogenic properties. For the successful removal of Cr(VI), we demonstrate a novel adsorbent consisting of superparamagnetic iron oxide nanoparticles (SPION) functionalized with 3-Mercaptopropionic acid (3-MPA). Fourier transform infrared spectroscopy (FT-IR) confirmed the functionalization of nanoparticles and presence of sulfonate groups. Batch adsorption experiments showed that the functionalized adsorbent recovered 45 mg of Cr(VI)/g of 3-MPA coated SPION at initial concentration of 50 mg/L aqueous solution at pH 1 with less than 1% of Fe dissolution from SPION. The results from X-ray photoelectron spectroscopy confirmed that Cr(VI) chemisorbed onto the adsorbent. Hence, the XPS spectra did not indicate any reduction of Cr(VI) to Cr(III) upon adsorption. The adsorption data were better fitted for the Freundlich model. Moreover, the Cr(VI) adsorption kinetics on functionalized SPION followed a pseudo-second order rate, revealing chemisorption as the dominant mechanism. The high Cr(VI) removal, rapid adsorption kinetics and stability of adsorbent indicate that 3-MPA coated SPION could be an efficient adsorbent for the removal of Cr(VI).

  • 63. Butchosa, Nria
    et al.
    Brown, Christian
    KTH, School of Biotechnology (BIO), Glycoscience.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    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.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Antimicrobial activity of biocomposites based on bacterial cellulose and chitin nanoparticles2012In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 243Article in journal (Other academic)
  • 64.
    Butchosa, Nuria
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Brown, Christian
    KTH, School of Biotechnology (BIO), Glycoscience.
    Larsson, Per Tomas
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    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.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Nanocomposites of bacterial cellulose nanofibers and chitin nanocrystals: fabrication, characterization and bactericidal activity2013In: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 15, no 12, p. 3404-3413Article in journal (Refereed)
    Abstract [en]

    An environmentally friendly approach was implemented for the production of nanocomposites with bactericidal activity, using bacterial cellulose (BC) nanofibers and chitin nanocrystals (ChNCs). The antibacterial activity of ChNCs prepared by acid hydrolysis, TEMPO-mediated oxidation or partial deacetylation of a-chitin powder was assessed and the structure of the ChNC nanoparticles was characterized by X-ray diffraction, atomic force microscopy, and solid-state C-13-NMR. The partially deacetylated ChNCs (D-ChNC) showed the strongest antibacterial activity, with 99 +/- 1% inhibition of bacterial growth compared to control samples. Nanocomposites were prepared from BC nanofibers and D-ChNC by (i) in situ biosynthesis with the addition of D-ChNC nanoparticles in the culture medium of Acetobacter aceti, and (ii) post-modification by mixing D-ChNC with disintegrated BC in an aqueous suspension. The structure and mechanical properties of the BC/D-ChNC nanocomposites were characterized by Fourier transform infrared spectroscopy, elemental analysis, field-emission scanning electron microscopy, and an Instron universal testing machine. The bactericidal activity of the nanocomposites increased with the D-ChNC content, with a reduction in bacterial growth by 3.0 log units when the D-ChNC content was 50%. D-ChNC nanoparticles have great potential as substitutes for unfriendly antimicrobial compounds such as heavy metal nanoparticles and synthetic polymers to introduce antibacterial properties to cellulosic materials.

  • 65.
    Butchosa, Nuria
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Leijon, Felicia
    KTH, School of Biotechnology (BIO), Glycoscience.
    Bulone, Vincent
    KTH, School of Biotechnology (BIO), Glycoscience.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Enhancing toughness of cellulose nanofibrils through the expression of cellulose-binding modules in plantManuscript (preprint) (Other academic)
  • 66.
    Butchosa, Nuria
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Water redispersible nanofibrillated cellulose adsorbed with carboxymethyl cellulose2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, p. 130-CELL-Article in journal (Other academic)
  • 67.
    Cao, Xinrui
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Fu, Qiang
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Luo, Yi
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Catalytic activity of Pd-doped Cu nanoparticles for hydrogenation as a single-atom-alloy catalyst2014In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 16, no 18, p. 8367-8375Article in journal (Refereed)
    Abstract [en]

    The single atom alloy of extended surfaces is known to provide remarkably enhanced catalytic performance toward heterogeneous hydrogenation. Here we demonstrate from first principles calculations that this approach can be extended to nanostructures, such as bimetallic nanoparticles. The catalytic properties of the single-Pd-doped Cu-55 nanoparticles have been systemically examined for H-2 dissociation as well as H atom adsorption and diffusion, following the concept of single atom alloy. It is found that doping a single Pd atom at the edge site of the Cu-55 shell can considerably reduce the activation energy of H-2 dissociation, while the single Pd atom doped at the top site or in the inner layers is much less effective. The H atom adsorption on Cu-55 is slightly stronger than that on the Cu(111) surface; however, a larger nanoparticle that contains 147 atoms could effectively recover the weak binding of the H atoms. We have also investigated the H atom diffusion on the 55-atom nanoparticle and found that spillover of the produced H atoms could be a feasible process due to the low diffusion barriers. Our results have demonstrated that facile H-2 dissociation and weak H atom adsorption could be combined at the nanoscale. Moreover, the effects of doping one more Pd atom on the H-2 dissociation and H atom adsorption have also been investigated. We have found that both the doping Pd atoms in the most stable configuration could independently exhibit their catalytic activity, behaving as two single-atom-alloy catalysts.

  • 68.
    Cappellini, Francesca
    et al.
    Karolinska Inst, Inst Environm Med, Stockholm, Sweden..
    Hedberg, Yolanda
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. Karolinska Inst, Inst Environm Med, Stockholm, Sweden.
    McCarrick, Sarah
    Karolinska Inst, Inst Environm Med, Stockholm, Sweden..
    Hedberg, Jonas
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Derr, Remco
    Toxys, Leiden, Netherlands..
    Hendriks, Giel
    Toxys, Leiden, Netherlands..
    Odnevall Wallinder, Inger
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Karlsson, Hanna L.
    Karolinska Inst, Inst Environm Med, Stockholm, Sweden..
    Mechanistic insight into reactivity and (geno)toxicity of well-characterized nanoparticles of cobalt metal and oxides2018In: Nanotoxicology, ISSN 1743-5390, E-ISSN 1743-5404, Vol. 12, no 6, p. 602-620Article in journal (Refereed)
    Abstract [en]

    An increasing use of cobalt (Co)-based nanoparticles (NPs) in different applications and exposures at occupational settings triggers the need for toxicity assessment. Improved understanding regarding the physiochemical characteristics of Co metal NPs and different oxides in combination with assessment of toxicity and mechanisms may facilitate decisions for grouping during risk assessment. The aim of this study was to gain mechanistic insights in the correlation between NP reactivity and toxicity of three different Co-based NPs (Co, CoO, and Co3O4) by using various tools for characterization, traditional toxicity assays, as well as six reporter cell lines (ToxTracker) for rapid detection of signaling pathways of relevance for carcinogenicity. The results showed cellular uptake of all NPs in lung cells and induction of DNA strand breaks and oxidative damage (comet assay) by Co and CoO NPs. In-depth studies on the ROS generation showed high reactivity of Co, lower for CoO, and no reactivity of Co3O4 NPs. The reactivity depended on the corrosion and transformation/dissolution properties of the particles and the media highlighting the role of the surface oxide and metal speciation as also confirmed by in silico modeling. By using ToxTracker, Co NPs were shown to be highly cytotoxic and induced reporters related to oxidative stress (Nrf2 signaling) and DNA strand breaks. Similar effects were observed for CoO NPs but at higher concentrations, whereas the Co3O4 NPs were inactive at all concentrations tested. In conclusion, our study suggests that Co and CoO NPs, but not Co3O4, may be grouped together for risk assessment.

  • 69.
    Carlsson, Linn K.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Boujemaoui, Assya
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Sehaqui, Houssine
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Lachini, Mohammad
    Malmström Jonsson, Eva E.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Carlmark, Anna E.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Synthesis and characterization of biocomposites from cellulose nano- and filter papers prepared by ring-opening polymerization of epsilon-caprolactone with titanium based catalyst2012In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 243Article in journal (Other academic)
  • 70.
    Carrick, Christopher
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Larsson, Per A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Brismar, Hjalmar
    KTH, School of Engineering Sciences (SCI), Applied Physics, Cell Physics. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Aidun, Cyrus
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Native and functionalized micrometre-sized cellulose capsules prepared by microfluidic flow focusing2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 37, p. 19061-19067Article in journal (Refereed)
    Abstract [en]

    Cellulose capsules with average outer and inner radii of approximately 44 mu m and 29 mm respectively were prepared from cellulose dissolved in a mixture of lithium chloride and dimethylacetamide using a microfluidic flow focusing device (MFFD). The MFFD had three inlets where octane oil in a cellulose solution in silicone oil was used to produce a double emulsion containing a cellulose capsule. This technique enables the formation of capsules with a narrow size distribution which can be beneficial for drug delivery or controlled release capsules. In this respect, cellulose is a highly interesting material since it is known to cause no autoimmune reactions when used in contact with human tissue. Furthermore, by controlling the chemical properties of the cellulose, it is possible to trigger a swelling of the capsules and consequentially the release of an encapsulated substance, e. g. a model drug, when the capsule becomes exposed to an external stimulus. To demonstrate this, capsules were functionalized by carboxymethylation to be pH- responsive and to expand approximately 10% when subjected to a change in pH from 3 to 10. The diffusion constant of a model drug, a 4 kDa fluorescently labelled dextran, through the native capsule wall was estimated to be 6.5 X 10(-14) m(2) s(-1) by fitting fluorescence intensity data to Fick's second law.

  • 71.
    Carrick, Christopher
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Lindström, Stefan B.
    Larsson, Per Tomas
    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 Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Lightweight, Highly Compressible, Noncrystalline Cellulose Capsules2014In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 30, no 26, p. 7635-7644Article in journal (Refereed)
    Abstract [en]

    We demonstrate how to prepare extraordinarily deformable, gas-filled, spherical capsules from nonmodified cellulose. These capsules have a low nominal density, ranging from 7.6 to 14.2 kg/m(3), and can be deformed elastically to 70% deformation at 50% relative humidity. No compressive strain-at-break could be detected for these dry cellulose capsules, since they did not rupture even when compressed into a disk with pockets of highly compressed air. A quantitative constitutive model for the large deformation compression of these capsules is derived, including their high-frequency mechanical response and their low-frequency force relaxation, where the latter is governed by the gas barrier properties of the dry capsule. Mechanical testing corroborated these models with good accuracy. Force relaxation measurements at a constant compression rendered an estimate for the gas permeability of air through the capsule wall, calculated to 0.4 mL mu m/m(2) days kPa at 50% relative humidity. These properties taken together open up a large application area for the capsules, and they could most likely be used for applications in compressible, lightweight materials and also constitute excellent model materials for adsorption and adhesion studies.

  • 72.
    Carrick, Christopher
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Ruda, Marcus
    Pettersson, Bert
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Larsson, Per Tomas
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology. 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 Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Hollow cellulose capsules from CO2 saturated cellulose solutions - Their preparation and characterization2013In: RSC Advances, ISSN 2046-2069, Vol. 3, no 7, p. 2462-2469Article in journal (Refereed)
    Abstract [en]

    A new material consisting of mm-sized hollow cellulose spheres, for biomedical applications or for the preparation of low weight porous materials has been prepared by a unique solution precipitation (SP) method. The technique is based on three separate steps. In the first step, high molecular mass, non-modified cellulose is dissolved in a suitable solvent. This cellulose solution is then saturated with a suitable gas (CO2 or N2 in the present work) and finally this gas-saturated solution is drop-wise added to a water reservoir. In this step, the cellulose is precipitated and a gas bubble is nucleated in the center of the cellulose sphere. When stored in water, the hollow center is filled with water, indicating that the capsule wall is porous in nature. This was also supported by BET-area measurements as well as by high resolution SEM-images of broken capsule walls. The internal void volume of a capsule was about 5 μl and the wall volume was about 8 μl. It was also established that the properties of the cellulose capsules, i.e. wall and void volume, the specific surface area, the average pore size of the capsule wall, the wall density, and the compressive load capacity could be tuned by the choice of cellulose concentration in the solution before precipitation. The capsule wall volume and void volume were also affected by the choice of gas, the gas pressure and the gas dissolution time during the gas saturation step. The response of the cellulose wall of the prepared capsules to changes in pH and ion concentration in the surrounding solution was also investigated. The swelling-shrinking behavior was further investigated by introducing more charges to the capsule wall, via carboxymethylation of the cellulose. This was achieved by using carboxymethylated cellulose which increased the swelling-shrinking effect. The results show a typical polyelectrolyte gel behavior of the capsule wall and the wet modulus of the cellulose wall was determined to be between 0.09-0.2 MPa depending on the charge of the cellulose in the capsule wall. Furthermore, the freeze dried cellulose spheres had a modulus of 1.9-7.4 MPa, depending on the cellulose concentration during the preparation of the spheres. These cellulose capsules are suitable both for the preparation of porous materials, where these larger spheres are joined together in 3D-shaped materials, and for controlled release where the interior of the capsules is filled with active substances and these substances are released by controlling the pores in the capsule walls.

  • 73.
    Carrick, Christopher
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.
    Aidun, Cyrus
    Preparation of cellulose capsule: New renewable material based on regenerated cellulose from the LiCl/DMAc solvent system2012In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 243Article in journal (Other academic)
  • 74.
    Carrick, Christopher
    et al.
    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.
    Larsson, Per A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation.
    Immunoselective cellulose nanospheres by antibody conjugation2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, p. 727-COLL-Article in journal (Other academic)
  • 75.
    Chatterjee, S
    et al.
    Swiss Federal Institute for Materials Science and Technology, Empa.
    Wang, J.W.
    National Cheng Kung University, Taiwan.
    Kuo, W.S.
    Feng Chia University, Taiwan.
    Tai, N.H.
    National Tsing Hua University, Hsinchu, Taiwan.
    Salzmann, C.
    University College London, London, UK.
    Li, W.L.
    Hollertz, Rebecca
    Swiss Fed Labs Mat Sci & Technol Empa, Lab Funct Polymers, Switzerland.
    Nüesch, F.
    Chu, B.T.T.
    Mechanical reinforcement and thermal conductivity in expanded graphene nanoplatelets reinforced epoxy composites2012In: Chemical Physics Letters, ISSN 0009-2614, E-ISSN 1873-4448, Vol. 531, p. 6-10Article in journal (Refereed)
    Abstract [en]

    Influence of reinforcements on mechanical and thermal properties of graphene nanoplatelets/epoxy composites is investigated. Amine functionalized expanded graphene nanoplatelets (EGNPs) were dispersed within epoxy resins using high-pressure processor followed by three roll milling. Functionality on the EGNPs was confirmed with FTIR and micro-Raman spectroscopy. Bending and nano-mechanical testing was performed on the composites. Incorporation of EGNPs improved the flexural modulus and hardness of the composite and increased fracture toughness by up to 60%. Marked improvement was observed in thermal conductivity of the composites reaching 36% at 2 wt.% loading. Functionalized EGNPs exhibited significant improvements indicating favorable interaction at EGNPs/polymer interface.

  • 76. Chen, Bin
    et al.
    Li, Xin
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Wu, Wenjun
    Zha, Quanzheng
    Xie, Yongshu
    A novel trigeminal zinc porphyrin and corresponding porphyrin monomers for dye-sensitized solar cells2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 21, p. 10439-10449Article in journal (Refereed)
    Abstract [en]

    A novel trigeminal zinc porphyrin sensitizer (T) and two zinc porphyrin monomers (M1 and M2) were successfully designed and synthesized. The spectral, electrochemical, and photovoltaic properties of the porphyrin dyes were investigated. Compared with M1, the molecule of M2 has an additional aliphatic n-hexyloxyl chain at the meso-position of the porphyrin framework, and such a structure is favorable for the formation of a compact hydrophobic layer at the TiO2 surface and the retardation of the diffusion of I-3(-) ions into the nanoporous TiO2 electrode, resulting in more effective suppression of the charge recombination process and a higher V-oc. Meanwhile, M2 has larger IPCE values than those of M1, leading to the higher J(sc) value. Thus, the DSSC devices based on M2 demonstrated a relatively high power conversion efficiency of 5.77%, with the J(sc), V-oc and ff values of 13.93 mA cm(-2), 732 mV, and 0.566, respectively. Even though dye T has the highest molar absorption coefficients and multiple binding moieties, the corresponding power conversion efficiency is 2.30%, which is lower than those for M1 and M2. These observations may be ascribed to the low efficiency of the electron injection process caused by the isolation of the LUMOs from the anchoring carboxyl groups in addition to the lowest adsorption amount.

  • 77. Chen, Cheng
    et al.
    Yang, Xichuan
    Cheng, Ming
    Zhang, Fuguo
    Zhao, Jianghua
    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.
    Highly efficient organic dyes containing a benzopyran ring as a pi-bridge for DSSCs2013In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 3, no 31, p. 12688-12693Article in journal (Refereed)
    Abstract [en]

    A series of novel organic dyes containing a benzopyran ring as a p-bridge have been designed and applied in dye-sensitized solar cells (DSSCs). This series of dyes show the excellent DSSCs' performance, due to their efficient light-to-photocurrent conversion in the region from 380 nm to 600 nm, with the highest IPCE values exceeding 90%. Through modification of the donor units, an efficiency as high as 7.5% has been achieved under standard light illumination (AM 1.5G, 100 mW cm(-2)) by the dye CC103.

  • 78. Chen, Guanying
    et al.
    Ohulchanskyy, Tymish Y.
    Kachynski, Aliaksandr
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Prasad, Paras N.
    Intense Visible and Near-Infrared Upconversion Photoluminescence in Colloidal LiYF4:Er3+ Nanocrystals under Excitation at 1490 nm2011In: ACS NANO, ISSN 1936-0851, Vol. 5, no 6, p. 4981-4986Article in journal (Refereed)
    Abstract [en]

    We report intense upconversion photoluminescence (PL) In colloidal LiYF4:Er(3+)nanocrystals under excitation with telecom-wavelength at 1490 nm. The intensities of two- and three-photon anti-Stokes upconversion PL bands are higher than or comparable to that of the Stokes emission under excitation with low power density in the range 5-120 W/cm(2). The quantum yield of the uptonversion PL was measured to be as high as similar to 1.2 +/- 0.1%, which is almost 4 times higher than the highest upconversion PL quantum yield reported to date for lanthanide-doped nanocrystals In 100 nm sized hexagonal NaYF4:Yb(3+)20%, Er(3+)2% using excitation at similar to 980 nm. A power dependence study revealed that the intensities of all PL bands have linear dependence on the excitation power density, which was explained by saturation effects in the intermediate energy states.

  • 79. Chen, H.
    et al.
    Gao, Y.
    Ye, L.
    Yao, Y.
    Chen, X.
    Wei, Y.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    A Cu2Se-Cu2O film electrodeposited on titanium foil as a highly active and stable electrocatalyst for the oxygen evolution reaction2018In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 54, no 39, p. 4979-4982Article in journal (Refereed)
    Abstract [en]

    Many nonprecious metal-selenide-based materials have been reported as electrocatalysts with high activity for the oxygen evolution reaction (OER). Herein, a hybrid catalyst film composed of Cu2Se and Cu2O nanoparticles directly grown on Ti foil (Cu2Se-Cu2O/TF) was prepared through a simple and fast cathodic electrodeposition method. Surprisingly, this electrode required a relatively low overpotential of 465 mV to achieve a catalytic current density of 10 mA cm-2 for the OER in 0.2 M carbonate buffer (pH = 11.0). Furthermore, a long-term constant current electrolysis test confirmed the high durability of the Cu2Se-Cu2O/TF anode at a current density of 10 mA cm-2 over 20 h. The XRD, TEM and XPS analysis of the sample after the OER indicated that a CuO protective layer formed on the surface of the Cu2Se-Cu2O catalyst, which effectively suppressed further oxidation of the Cu2Se-Cu2O catalyst during the OER and resulted in sustained catalytic oxidation of water.

  • 80.
    Cheng, Jie
    et al.
    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.
    Lu, X.
    Micro-galvanic corrosion of cu-ru couple in potassium periodate (KIO4) solution2015In: European Corrosion Congress, EUROCORR 2015, Austrian Society for Metallurgy and Materials (ASMET) , 2015, Vol. 3, p. 1829-1829Conference paper (Refereed)
  • 81. Cheng, Ming
    et al.
    Yang, Xichuan
    Chen, Cheng
    Zhao, Jianghua
    Tan, Qin
    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.
    Effect of the acceptor on the performance of dye-sensitized solar cells2013In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 15, no 40, p. 17452-17459Article in journal (Refereed)
    Abstract [en]

    Three new phenothiazine dyes were designed and synthesized, utilizing different acceptor groups. Upon application to TiO2-based solar cells, the effects of different acceptors on the photophysical and electrochemical properties of the dyes and the solar cell performance are detailed. The introduction of a pyridinium unit or 5-carboxy-1-hexyl-2,3,3-trimethyl-indolium unit into the molecular frame as the acceptor instead of cyano acrylic acid can effectively cause a red shift in the absorption spectra. Applied to DSSCs, the devices sensitized by CM502 with the pyridinium unit as the acceptor show the highest efficiency of 7.3%. The devices fabricated with dye CM501 with cyano acrylic acid as the acceptor exhibited the highest V-oc while for the devices sensitized by the dye CM503 with 5-carboxy-1-hexyl2,3,3- trimethyl-3H-indolium unit as the acceptor, the Voc value was the lowest, at 494 mV. The addition of TBP in the electrolyte can improve the performance of DSSCs fabricated using CM501 and CM502, with the Voc value greatly improved but the J(sc) value slightly decreased. However, with the addition of TBP in the electrolyte, the efficiency of the cells sensitized by CM503 dropped significantly (from 4.9% to 1.0% when 0.1 M TBP was added).

  • 82. Chico, B.
    et al.
    Fuente, D. D. L.
    Jiménez, J. A.
    Chang, Tingru
    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.
    Leygraf, Christopher
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Morcillo, M.
    Analysis of historic copper patinas 2: Characterization of 400 year old patina from Royal Summer Palace in Prague2017In: 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)
    Abstract [en]

    This paper presents an in-depth characterisation study of the patina formed on a copper tile taken from the roof of Queen Anne's Summer Palace in Prague after close to 400 years of exposure to the action of the atmosphere. A wide variety of techniques have been performed, including metallographic and chemical analysis (electrogravimetry, AAS, XRF) of the copper matrix, and spectroscopic and microscopic investigations (GIXRD, TEM/EDS and SEM/EDS) to determine the composition and structure of the patina. The major conclusions of the study are: (a) the base copper contains abundant inclusions mainly of rosiaite (PbSb2O6); (b) the patina is formed by an inner sublayer of cuprite (Cu2O) and an outer sublayer of brochantite [Cu4SO4(OH)6] and antlerite [Cu3SO4(OH)4] and traces of azurite [Cu3(CO3)2(OH)2]; and (c) the brochantite/antlerite crystals are randomly doped with Fe and C.

  • 83.
    Chinnasamy, Thiruppathiraja
    et al.
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Segerink, Loes I.
    Nystrand, Mats
    Gantelius, Jesper
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Andersson Svahn, Helene
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Point-of-Care Vertical Flow Allergen Microarray Assay: Proof of Concept2014In: Clinical Chemistry, ISSN 0009-9147, E-ISSN 1530-8561, Vol. 60, no 9, p. 1209-1216Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Sophisticated equipment, lengthy protocols, and skilled operators are required to perform protein microarray-based affinity assays. Consequently, novel tools are needed to bring biomarkers and biomarker panels into clinical use in different settings. Here, we describe a novel paper-based vertical flow microarray (VFM) system with a multiplexing capacity of at least 1480 microspot binding sites, colorimetric readout, high sensitivity, and assay time of < 10 min before imaging and data analysis. METHOD: Affinity binders were deposited on nitrocellulose membranes by conventional microarray printing. Buffers and reagents were applied vertically by use of a flow controlled syringe pump. As a clinical model system, we analyzed 31 precharacterized human serum samples using the array system with 10 allergen components to detect specific IgE reactivities. We detected bound analytes using gold nanoparticle conjugates with assay time of <= 10 min. Microarray images were captured by a consumer-grade flatbed scanner. RESULTS: A sensitivity of 1 ng/mL was demonstrated with the VFM assay with colorimetric readout. The reproducibility (CV) of the system was < 14%. The observed concordance with a clinical assay, Immuno-CAP, was R-2 = 0.89 (n = 31). CONCLUSIONS: In this proof-of-concept study, we demonstrated that the VFM assay, which combines features from protein microarrays and paper-based colorimetric systems, could offer an interesting alternative for future highly multiplexed affinity point-of-care testing.

  • 84. Choong, Ferdinand X.
    et al.
    Back, Marcus
    Steiner, Svava E.
    Melican, Keira
    Nilsson, K. Peter R.
    Edlund, Ulrica
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Richter-Dahlfors, Agneta
    Nondestructive, real-time determination and visualization of cellulose, hemicellulose and lignin by luminescent oligothiophenes2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, article id 35578Article in journal (Refereed)
    Abstract [en]

    Enabling technologies for efficient use of the bio-based feedstock are crucial to the replacement of oil-based products. We investigated the feasibility of luminescent conjugated oligothiophenes (LCOs) for non-destructive, rapid detection and quality assessment of lignocellulosic components in complex biomass matrices. A cationic pentameric oligothiophene denoted p-HTEA (pentamer hydrogen thiophene ethyl amine) showed unique binding affinities to cellulose, lignin, hemicelluloses, and cellulose nanofibrils in crystal, liquid and paper form. We exploited this finding using spectrofluorometric methods and fluorescence confocal laser scanning microscopy, for sensitive, simultaneous determination of the structural and compositional complexities of native lignocellulosic biomass. With exceptional photostability, p-HTEA is also demonstrated as a dynamic sensor for real-time monitoring of enzymatic cellulose degradation in cellulolysis. These results demonstrate the use of p-HTEA as a non-destructive tool for the determination of cellulose, hemicellulose and lignin in complex biomass matrices, thereby aiding in the optimization of biomass-converting technologies.

  • 85.
    Chubarova, Elena V.
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics, Biomedical and X-ray Physics. Jacobs Univ, Sch Sci & Engn, Germany.
    Dickman, M. H.
    Keita, B.
    Nadjo, L.
    Miserque, F.
    Mifsud, M.
    Arends, I. W. C. E.
    Kortz, U.
    Self-assembly of a heteropolyoxopalladate nanocube: [PdII 13AsV 8O34(OH)6] 8-2008In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 47, no 49, p. 9542-9546Article in journal (Refereed)
    Abstract [en]

    (Chemical Equation Presented) Not like the others: A molecular palladium oxide cluster was formed by self-assembly of palladium(II) and arsenic(V) using mild reaction conditions. The resulting heteropolypalladate [Pd II 13AsV 8O34(OH) 6]8- has a distorted cubic shape and edge lengths of about 1 nm. The thirteen PdII ions retain four-coordinate square-planar geometry, in marked contrast to all other known discrete polyoxometalates.

  • 86.
    Claesson, Per
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Dédinaité, Andra
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Meszaros, R.
    Varga, Imre
    Association between Polyelectrolytes and Oppositely Charged Surfactants in Bulk and at Solid/Liquid Interfaces2007In: Colloid Stability and Application in Pharmacy: Volume 3, Weinheim: Wiley-VCH Verlagsgesellschaft, 2007, p. 337-395Chapter in book (Other academic)
    Abstract [en]

    Mixtures of polyelectrolytes and oppositely charged surfactants find applications in many processes and products that are used in our daily life. Such systems also show many interesting features from a scientific point of view. Due to the combined technological relevance and scientific challenge, considerable research efforts have been made in this area in recent years. This has resulted in new theoretical approaches, the development of simulation methods and new experimental techniques and, of course, a large body of new findings. Together, these efforts have increased the understanding significantly, especially during the last 5 years. This chapter reviews some aspects of this topic, focusing on bulk association and association at solid/liquid interfaces. The review is focused on developments during the 21st century, even though in some cases a historical perspective is also offered.

  • 87.
    Claesson, Per
    et al.
    KTH, Superseded Departments, Chemistry.
    Poptochev, Evgeni
    KTH, Superseded Departments, Chemistry.
    Blomberg, Eva
    KTH, Superseded Departments, Chemistry.
    Surface Forces and Emulsion Stability2004In: Food Emulsions / [ed] Sjöblom, J., Friberg, S. and Larsson, K., New York: Marcel Dekker, 2004, 4, p. 257-297Chapter in book (Other academic)
  • 88.
    Claesson, Per
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Stubenrausch, C
    Krustev, R
    Johansson, I
    Thin Film and Foam Properties of Sugar-Based Surfactants2009In: Sugar-Based Surfactants: Fundamentals and Applications / [ed] Ruiz, Cristóbal Carnero, Boca Raton: Taylor & Francis Group, 2009, p. 105-152Chapter in book (Other academic)
  • 89.
    Claesson, Per
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    van der Wal, Andreas
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Fogden, Andrew
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    New Techniques for Optimization of Particulate Cleaning2007In: Handbook for Cleaning/Decontamination of Surfaces Vol 2 / [ed] I. Johansson, and P. Somasundaran, Amsterdam: Elsevier, 2007, p. 885-927Chapter in book (Other academic)
  • 90.
    Corkery, Robert W.
    Procter and Gamble, Ross, Ohio, USA.
    A variation on Luzzati's soap phases: Room temperature thermotropic liquid crystals2004In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 6, no 7, p. 1534-1546Article in journal (Refereed)
    Abstract [en]

    Remarkable room-temp. liq. crystallinity is obsd. for a wide range of metal soaps. Incorporation of satd., mid-chain mono-Me branched C17 fatty acid (mid-chain branched fatty acid) into metal soaps lowers the liq. cryst. transition to below room temp. Soaps of Na, Mg, Al, Ca, Cu, Zn, Sr, Ag, Cd, La, Ce, Tb and Lu were synthesized and characterized via XRD, FTIR, DSC, optical microscopy, d. detns. and other phys. methods. The main room temp. mesophase identified in the soaps here is a liq. cryst. hexagonal columnar phase, 1st described by Luzzati et al. A comparative anal. of the branched soaps with their satd., linear analogs is given. Implications for room temp. columnar soap structure is discussed in terms of the various phys. parameters found for these soaps.

  • 91.
    Corkery, Robert W.
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    Aspects of the differential geometry and topology of bicontinuous liquid-crystalline phases2005In: Surfactant Sci. Ser., ISSN 0081-9603, Vol. 127, no Bicontinuous Liquid Crystals, p. 99-127Article in journal (Refereed)
    Abstract [en]

    A review. This chapter provides a semiformal, though largely qual., look at the mathematics of triply periodic minimal surfaces (TPMS) in relation to bicontinuous and polycontinuous liq. crystals. It is motivated largely by research of Stephen Hyde and others at the Applied Mathematics Department, Australian National University, Canberra, Australia and by the discovery of these TPMS liq. crystal partitions by Kare Larsson and the late Krister Fontell at Lund University. The article is meant to complement the existing, more rigorous papers and provide an introduction to the more fundamental topics of differential geometry and topol. of TPMS. Bicontinuous liq. crystals contain 2 mutually interpenetrating labyrinths sepd. by a hyperbolic partition that is often best described as a triply periodic minimal surface (TPMS). Properties of these surfaces can be broken down into local and global types. Local properties pertain to small, isolated surface patches and include intrinsic measures such as the metric, surface areas, and angles and the Gaussian curvature. The global properties require a look at the surface as a whole, embedded in 3D space. The global measures include parameters such as the Cartesian coordinates, topol., curvature distributions, and overall symmetries. These local and global properties are connected through the Gauss-Bonnet theorem that relates the topol. to the Gaussian curvature. For the simplest TPMS, such as the P, D, and G surfaces, the local Gaussian curvature detd. from small patches of the surface can give information regarding the stability of bicontinuous liq. crystals. For some simpler TPMS, the small surface patches are polygonal (e.g., triangles), according to the various symmetries of the surface. These small 2D surface patches can be built up into the entire 3D surface using various 3D construction algorithms based on symmetries, the same way 3D crystals can be built up from unique atoms. Alternatively these patches can be usefully represented in 2 dimensions by various mappings to the sphere, hyperbolic plane, and complex plane; then built up in those spaces using analogous symmetry operations; and then embedded in 3D space by folding and "gluing" the edges of the 2D representations. The 2D forms of these surfaces offer simple ways of constructing known and novel surfaces, algorithmically, and also explicitly through the Weierstrass parametrization, which gives the exact and explicit (x,y,z) coordinates of the actual minimal surface (not approximates) via the complex plane representation. Armed with this explicit information, modeling the stabilities, phase changes, and other phys. processes involving these minimal surfaces is rigorously quantifiable from a geometric perspective. A novel, topol.-preserving phase transformation between the P, D, and G cubic phases arises directly from the anal. of rhombohedral and tetrahedral distortions of the P, D, and G surfaces using this method. Networks decorating TPMS are of interest for generating and analyzing crystal networks. The simplest networks overlay the polygonally decorated surfaces built up of the fundamental patches. Families of networks can be generated for individual TPMS using supergroup-subgroup symmetry relationships between the decorating tesselation and the underlying symmetry elements of the TPMS itself. Of direct relevance to liq. cryst. mesophases is the set of polycontinuous networks that can be generated on various TPMS. These are generated by commensurately decorating 2D surface representations of TPMS with tree networks. With some well-chosen constraints, folding and gluing operations can result in surfaces decorated by entangled thickets of unconnected networks. In turn, these embedded networks can be used to form tri-, quadra-, octa- and other polycontinuous morphologies, with their resp. mutually interpenetrating labyrinths sepd. by a single triply periodic minimal surface.

  • 92.
    Corkery, Robert W.
    Applied Mathematics Research School of Physical Sciences and Engineering Australian National University, Canberra, Australia.
    Metal organic framework (MOF) liquid crystals: 1D, 2D and 3D ionic coordination polymer structures in the thermotropic mesophases of metal soaps, including alkaline earth, transition metal and lanthanide soaps2008In: Current Opinion in Colloid & Interface Science, ISSN 1359-0294, E-ISSN 1879-0399, Vol. 13, no 4, p. 288-302Article in journal (Refereed)
    Abstract [en]

    aken together, the body of existing literature on metal soap crystal structures and mesophases supports the view that much is to be gained by treating the soaps as metal organic frameworks (MOF's) when relating their structure and liquid crystallinity. We argue that metal soaps mesophases often consist of disordered metal organic (carboxylate) frameworks (MOF's). Metal atoms are linked by bridging carboxylates, and the metal-oxygen networks form semi-flexible rods, chains and sheets of M-O polyhedra within their co-bonded, mesotructured, self-assemblies of lipidic chains. The packing of the molten hydrocarbon chains allows otherwise unconnected MOF networks to coexist as spatially isolated units in the same unit cell. For instance the lamellar phases are true 2D MOF's or layers of 1-D MOF's. The phase transitions can then be regarded as coupled disordering/re-ordering transitions involving rotational and conformational disordering of the hydrocarbon chains balanced with disordering of MOF symmetries, MOF topological transformations, depolymerizations and dimensionality reductions ultimately leading to anisotropic melts. By way of demonstration, thermotropic phase transitions of homologous series of lanthanide soaps are systematically studied using a variety of experimental methods, and the data are used in a topological model for testing the consistency with the MOF concept of metal soap crystal structures and thermotropic: mesophases. Finally, an interpenetrating bicontinuous MOF comprised of SrO6 polyhedral rods is presented as an atomically resolved model for the network topology of the cubic mesophase of strontium soaps. Metal soaps are therefore shown to afford a bridge between liquid crystals and metal organic framework (MOF) materials. 

  • 93.
    Corkery, Robert W.
    et al.
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    Blute, Irena A.
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    Friberg, Stig E.
    School of Chemistry and Chemical Engineering, Yangzhou University.
    Guo, Rong
    School of Chemistry and Chemical Engineering, Yangzhou University.
    Emulsion Inversion in the PIT Range: Quantitative Phase Variations in a Two-Phase Emulsion2010In: Journal of Chemical and Engineering Data, ISSN 0021-9568, E-ISSN 1520-5134, Vol. 55, no 10, p. 4471-4475Article in journal (Refereed)
    Abstract [en]

    The phase-inversion temperature (PIT) phenomenon is for the first time given l quantitative treatment for systems having a sufficiently small surfactant content to be limited to two phases at the PIT. The results show that the early opinion of a phase transfer of the surfactant as the major event in the transversal of the temperature range is not entirely correct; the major phenomenon is instead an expulsion of water from the low-temperature aqueous micellar solution. In addition, the results unexpectedly give an indication of the existence of three phases at temperatures beneath the PIT, in spite of the the fact that system consists of only two phases at the actual PIT.

  • 94.
    Corkery, Robert W.
    et al.
    Frito Lay North America INC.
    Feiler, Adam
    Grover, Julie Anne
    Dimelow, Chris
    George, Eapen
    Anti-caking agent for flavored products2010Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    The present invention generally relates to the use of porous particles to control the release of a liquid, such as the release of a flavor in a food product. Liquid components, such as flavorants, are loaded into porous particles to form a composition. The pore diameter, pore tortuosity and loading parameters determine the characteristics of the composition and the release profile of the liquid.

  • 95.
    Corkery, Robert W.
    et al.
    Naturalnano INC.
    Fleischer, Cathy
    Naturalnano INC.
    Polymeric coatings including nanoparticle filler2007Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    Disclosed is a polymeric composite coating including a nanoparticle filler, where the filler may be suitable to alter one or more characteristics of the coating. More particularly, one embodiment of the present invention provides a halloysite nanoparticle filler which has the general configuration of a cylinder or a rolled scroll-like shape, and a polymer protective coating contg. the halloysite nanoparticle or equiv. nanotubular filler. [on SciFinder(R)]

  • 96.
    Corkery, Robert W.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science. KTH, School of Chemical Science and Engineering (CHE), Chemistry, Physical Chemistry (closed 20110630).
    Fleischer, Cathy
    Daly, Robert C.
    Polymeric composition, adhesive including nanoparticle filler and composite production.2006Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    Nanoparticle fillers, including a novel halloysite nanoparticle filler, are generally cylindrical or tubular nanoparticles (e.g. rolled scroll-like shape). The filler is effectively employed in a polymer nanoparticle adhesive composite, contg. the halloysite nanoparticle or other equiv. naturally occurring nanotubular filler, in which the advantages of the nanoparticle filler are provided (e.g., reinforcement, flame retardant, etc.) while maintaining or improving mech. performance of the adhesive composite (e.g., adhesive strength and tack). [on SciFinder(R)]

  • 97.
    Corkery, Robert W
    et al.
    Physical Chemistry 1, Center for Chemistry and Chemical Engineering, Lund University.
    Fogden, Andrew
    Physical Chemistry 1, Center for Chemistry and Chemical Engineering, Lund University.
    On the formation and structure of nanometric polyhedral foams: toward the dry limit2008In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 24, no 18, p. 10443-10452Article in journal (Refereed)
    Abstract [en]

    High surface area, high porosity, nanometric polygonal silica foams with hierarchically connected and uniformly sized pore systems are reported here. We observe a remarkable increase in foam cell sizes from mesoscopic to macroscopic dimensions upon swelling the self-assembled template with oil. The resultant structures resemble classical macroscopic soap foams and display, among other features, Plateau borders and volume fractions approaching the dry limit of 100%. In well-developed foams of this kind, dimensionally isometric polyhedral cells are connected by relatively short, flat cylindrical mesopores through polyhedral faces and micropores through the walls. For one sample, with approximately 75 nm diameter primary foam cells, we infer three separate sets of cell-connecting mesopores puncturing tetragonal, pentagonal, and hexagonal faces of the component polyhedra. A multiple step model of foam formation is discussed where an organic silica precursor progressively hydrolyzes and condenses as a growing flexible shell from the core-corona interface of oil-swollen triblock copolymer micelles or microemulsion droplets, inducing a clouding phenomena in the otherwise stabilizing poly(ethylene oxide) chains, leading to aggregation, deformation, and jamming to high volume fractions.

  • 98.
    Corkery, Robert W.
    et al.
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    Rousseau, Derick
    chool of Nutrition, Ryerson University, Toronto, Ontario, Canada.
    Smith, Paul
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    Pink, David A.
    Department of Physics, St. Francis Xavier University, Antigonish, Nova Scotia, Canada.
    Hanna, Charles B.
    Canada, and Department of Physics, Boise State University, Boise, Idaho, USA.
    A case for discotic liquid crystals in molten triglycerides2007In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 23, no 13, p. 7241-7246Article in journal (Refereed)
    Abstract [en]

    To date, essentially only two structural models have been proposed and debated in detail for explaining the liquid state order of triglycerides, and both invoke a form of thermotropic liquid crystalline order in triglyceride melts. These are the paralamellar model of Larsson et al. (J. Am. Oil Chem. Soc. 1992, 69, 835) and the nematic model of Cebula et al. (J. Am. Oil Chem Soc. 1992, 69, 130). An alternative discotic model is proposed here that adequately accounts for the broad small-angle X-ray diffraction peak often observed in the liquid state of fats and oils. In this alternative model, triglyceride molecules exist in the liquid state with fully splayed chains, approximating "Y"-shapes (Y-conformers). These are loosely bound within discs that stack into flexible, relatively short cylindrical rods of colloidal dimension, which in turn assemble into rod-packings with short-range order akin to disordered versions of thermotropic discotic liquid crystalline phases in other lipidic systems.

  • 99. Cronholm, Pontus
    et al.
    Karlsson, Hanna L.
    Hedberg, Jonas
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Lowe, Troy A.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Winnberg, Lina
    Elihn, Karine
    Odnevall Wallinder, Inger
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Möller, Lennart
    Intracellular Uptake and Toxicity of Ag and CuO Nanoparticles: A Comparison Between Nanoparticles and their Corresponding Metal Ions2013In: Small, ISSN 1613-6810, E-ISSN 1613-6829, Vol. 9, no 7, p. 970-982Article in journal (Refereed)
    Abstract [en]

    An increased understanding of nanoparticle toxicity and its impact on human health is essential to enable a safe use of nanoparticles in our society. The aim of this study is to investigate the role of a Trojan horse type mechanism for the toxicity of Ag-nano and CuO-nano particles and their corresponding metal ionic species (using CuCl2 and AgNO3), i.e., the importance of the solid particle to mediate cellular uptake and subsequent release of toxic species inside the cell. The human lung cell lines A549 and BEAS-2B are used and cell death/membrane integrity and DNA damage are investigated by means of trypan blue staining and the comet assay, respectively. Chemical analysis of the cellular dose of copper and silver is performed using atomic absorption spectroscopy. Furthermore, transmission electron microscopy, laser scanning confocal microscopy, and confocal Raman microscopy are employed to study cellular uptake and particle-cell interactions. The results confirm a high uptake of CuO-nano and Ag-nano compared to no, or low, uptake of the soluble salts. CuO-nano induces both cell death and DNA damage whereas CuCl2 induces no toxicity. The opposite is observed for silver, where Ag-nano does not cause any toxicity, whereas AgNO3 induces a high level of cell death. In conclusion: CuO-nano toxicity is predominantly mediated by intracellular uptake and subsequent release of copper ions, whereas no toxicity is observed for Ag-nano due to low release of silver ions within short time periods.

  • 100. Céolin, D.
    et al.
    Rueff, J. -P
    Zimin, Andrei
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. Siberian Federal University, Russian Federation.
    Morin, P.
    Kimberg, Victor
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. Siberian Federal University, Russian Federation.
    Polyutov, S.
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. Siberian Federal University, Russian Federation.
    Gelmukhanov, Faris
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology. Siberian Federal University, Russian Federation.
    Far-Zone Resonant Energy Transfer in X-ray Photoemission as a Structure Determination Tool2017In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 8, no 12, p. 2730-2734Article in journal (Refereed)
    Abstract [en]

    Near-zone Förster resonant energy transfer is the main effect responsible for excitation energy flow in the optical region and is frequently used to obtain structural information. In the hard X-ray region, the Förster law is inadequate because the wavelength is generally shorter than the distance between donors and acceptors; hence, far-zone resonant energy transfer (FZRET) becomes dominant. We demonstrate the characteristics of X-ray FZRET and its fundamental differences with the ordinary near-zone resonant energy-transfer process in the optical region by recording and analyzing two qualitatively different systems: high-density CuO polycrystalline powder and SF6 diluted gas. We suggest a method to estimate geometrical structure using X-ray FZRET employing as a ruler the distance-dependent shift of the acceptor core ionization potential induced by the Coulomb field of the core-ionized donor.

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