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  • 251.
    Mueller, Katharina
    et al.
    Helmholtz Zentrum Dresden Rossendorf, Inst Resource Ecol, Bautzner Landstr 400, D-01328 Dresden, Germany..
    Szabo, Zoltan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Zhang, Xiaobin
    Univ Manitoba, Dept Chem, 144 Dysart Rd, Winnipeg, MB R3T 2N2, Canada..
    Interdisciplinary Round-Robin Test on Molecular Spectroscopy of the U(VI) Acetate System2019Inngår i: ACS Omega, ISSN 2470-1343, Vol. 4, nr 5, s. 8167-8177Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A comprehensive molecular analysis of a simple aqueous complexing system. U(VI) acetate. selected to be independently investigated by various spectroscopic (vibrational, luminescence, X-ray absorption, and nuclear magnetic resonance spectroscopy) and quantum chemical methods was achieved by an international round-robin test (RRT). Twenty laboratories from six different countries with a focus on actinide or geochemical research participated and contributed to this scientific endeavor. The outcomes of this RRT were considered on two levels of complexity: first, within each technical discipline, conformities as well as discrepancies of the results and their sources were evaluated. The raw data from the different experimental approaches were found to be generally consistent. In particular, for complex setups such as accelerator-based X-ray absorption spectroscopy, the agreement between the raw data was high. By contrast, luminescence spectroscopic data turned out to be strongly related to the chosen acquisition parameters. Second, the potentials and limitations of coupling various spectroscopic and theoretical approaches for the comprehensive study of actinide molecular complexes were assessed. Previous spectroscopic data from the literature were revised and the benchmark data on the U(VI) acetate system provided an unambiguous molecular interpretation based on the correlation of spectroscopic and theoretical results. The multimethodologic approach and the conclusions drawn address not only important aspects of actinide spectroscopy but particularly general aspects of modern molecular analytical chemistry.

  • 252.
    Mushi, Ngesa Ezekiel
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. Department of Mechanical and Industrial Engineering, College of Engineering and Technology, University of Dar Es Salaam, Dar es Salaam, Tanzania.
    Nishino, Takashi
    Kobe Univ, Dept Chem Sci & Engn, Kobe, Hyogo 6578501, Japan..
    Berglund, Lars A.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Zhou, Qi
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Strong and Tough Chitin Film from alpha-Chitin Nanofibers Prepared by High Pressure Homogenization and Chitosan Addition2019Inngår i: ACS Sustainable Chemistry and Engineering, ISSN 2168-0485, Vol. 7, nr 1, s. 1692-1697Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Chitin nanofibers are an interesting biological nanomaterial for advanced applications, for example, in medicine, electronics, packaging and water purification. The challenge is to separate chitin nanofibers from protein in the exoskeleton structure of arthropods and avoid nanofibril aggregation to realize the mechanical potential of chitin. In this work, we developed a new method for the preparation of chitin nanofibers from lobster shell exoskeleton using 10 wt % chitosan as a sacrificial polymer. The addition of chitosan in the raw chitin colloidal suspension during high pressure homogenization process at pH 3 significantly reduced the agglomeration of chitin nanofibers as revealed by dynamic light scattering and transmission electron microscopy. Chitin film prepared from the chitin nanofiber suspension by vacuum filtration exhibited a true nanofibrils network structure without fibril aggregations as characterized by scanning electron microscopy. The presence of chitosan not only improves the colloidal stability of chitin nanofibers suspension but also facilitates the formation of chitin nanofiber network structure in the film as indicated by wide-angle X-ray diffraction analysis. The chitin nanofiber film with 4 +/- 1 wt % residual chitosan showed high tensile strength (187.2 +/- 5.6 MPa) and high work of fracture (12.1 +/- 0.4 MJ/m(3)), much higher than those chitin and chitosan films reported previously in the literature.

  • 253. Nadiv, R.
    et al.
    Fernandes, Ricardo M. F.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Ochbaum, G.
    Dai, Jing
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Buzaglo, M.
    Varenik, M.
    Biton, R.
    Furo, Istvan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Regev, O.
    Polymer nanocomposites: Insights on rheology, percolation and molecular mobility2018Inngår i: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 153, s. 52-60Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The integration of carbon nanotubes (CNTs) into a polymer matrix strongly affects the rheological behavior that in turn may hamper the overall performance of the resulting composite. Research in this topic has focused on bulk rheological properties, while here we employ NMR diffusion experiments to explore the mobility (diffusivity) of epoxy molecules when loaded with CNTs. Rheology and light microscopy indicate percolation of CNT aggregates. Those aggregates cage a substantial amount of epoxy molecules while small angle X-ray scattering indicates some rearrangement of epoxy molecules in the vicinity of the nanotubes. NMR diffusion experiments distinguish between the slow diffusion of the caged molecules and that of the free ones, and relate the fraction of the former to the macroscopic system viscosity. The demonstrated surface-induced slowing-down of diffusion is attributed to strong intermolecular π-π interactions among the epoxy molecules, and between them and the CNT surface. These findings demonstrate the utility of NMR diffusion experiments as an additional method applied to nanocomposites. 

  • 254.
    Natarajan Arul, Murugan
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Teoretisk kemi och biologi.
    Nordberg, Agneta
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Centra, Albanova VinnExcellence Center for Protein Technology, ProNova. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi.
    Different Positron Emission Tomography Tau Tracers Bind to Multiple Binding Sites on the Tau Fibril: Insight from Computational Modeling2018Inngår i: ACS Chemical Neuroscience, ISSN 1948-7193, E-ISSN 1948-7193, Vol. 9, nr 7, s. 1757-1767Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Using the recently reported cryo-EM structure for the tau fibril [Fitzpatrick et al. (2017) Nature 547, 185-190], which is a potential target concerning Alzheimer's disease, we present the first molecular modeling studies on its interaction with various positron emission tomography (PET) tracers. Experimentally, based on the binding assay studies, at least three different high affinity binding sites have been reported for tracers in the tau fibril. Herein, through integrated modeling using molecular docking, molecular dynamics, and binding free energy calculations, we provide insight into the binding patterns of various tracers to the tau fibril. We suggest that there are four different high affinity binding sites available for many of the studied tracers showing varying binding affinity to different binding sites. Thus, PBB3 binds most strongly to site 4, and interestingly, this site is not a preferable site for any other tracers. For THIC5351, our data show that it strongly binds to sites 3 and 1, the former one being more preferable. We also find that MK6240 and T807 bind to site 1 specifically. The modeling data also give some insight into whether a tracer bound to a specific site can be replaced by others or not. For example, the displacement of T807 by PBB3 as reported experimentally can also be explained and attributed to the larger binding affinity of the latter compound in all binding sites. The binding free energy results explain very well the small binding affinity of THK523 compared to all the aryl quinoline moieties containing THK tracers. The ability of certain tau tracers, like FDDNP and THK523, to bind to amyloid fibrils has also been investigated. Furthermore, such off-target interaction of tau tracers with amyloid beta fibrils has been validated using a quantum mechanical fragmentation approach.

  • 255.
    Ni, Shengjun
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Carbocation Catalysis for Organic Synthesis2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The most common view of carbocations in organic chemistry is that they are short-lived intermediates in several fundamental reactions, e.g. the classic SN1-reaction. However, carbocations that can delocalize their positive charge can be stable enough to be isolated and used as Lewis acid catalysts, phase transfer catalysts or oxidants in various reactions. The theme of this thesis concerns applying trityl cations as Lewis acid catalysts in different organic reactions. The first chapter presents a general introduction of the field of Lewis acids, the characteristics and applications of carbocations in different organic reactions, and the aims of this thesis. The second chapter describes the carbocation-catalyzed asymmetric Diels–Alder reactions assisted by chiral counteranions. The third chapter shows that carbocations can be utilized as catalysts in oxa-Diels–Alder reactions with unactivated aldehydes and dienes as substrates. The fourth chapter investigates the application of carbocation catalysis in bromination reactions for selective functionalization at the benzylic position and on the aromatic ring, respectively. The fifth chapter highlights that carbocation-catalyzed aldehyde–olefin metathesis reactions can be achieved in high yields by suppressing the decomposition of both starting materials and products.

  • 256.
    Ni, Shengjun
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Abd El Aleem Ali Ali El Remaily, Mahmoud
    Franzén, Johan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Carbocation Catalyzed Bromination of Alkyl Arenes, a Chemoselective sp3 vs. sp2 C−H Functionalization2018Inngår i: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 360, nr 21, s. 4197-4204Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The versatility of the trityl cation (TrBF4) as a highly efficient Lewis acid organocatalyst isdemonstrated in a light induced benzylic brominaion of alkyl-arenes under mild conditions. The reaction wasconducted at ambient temperature under common hood light (55 W fluorescent light) with catalyst loadingsdown to 2.0 mol% using N-bromosuccinimide (NBS) as the brominating agent. The protocol is applicable toan extensive number of substrates to give benzyl bromides in good to excellent yields. In contrast to mostpreviously reported strategies, this protocol does not require any radical initiator or extensive heating. Forelectron-rich alkyl-arenes, the trityl ion catalyzed bromination could be easily switched between benzylic sp3CH functionalization and arene sp2 CH functionalization by simply alternating the solvent. Thischemoselective switch allows for high substrate control and easy preparation of benzyl bromides andbromoarenes, respectively. The chemoselective switch was also applied in a one-pot reaction of 1-methylnaphthalene for direct introduction of both sp3 CBr and sp2 CBr functionality.

  • 257.
    Ni, Shengjun
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Franzén, Johan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Carbocation catalysed ring closing aldehyde-olefin metathesis2018Inngår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 54, nr 92, s. 12982-12985Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A highly efficient aldehyde-olefin metathesis catalysed by the carbocation, 4-phenylphenyl-diphenylmethylium ion, has been developed. This protocol is characterized by high yields, low catalyst loading (down to 2 mol%), good functional group compatibility and mild reaction conditions.

  • 258.
    Ni, Shengjun
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Franzén, Johan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Carbocation Catalyzed Ring Closing Aldehyde-Olefin MetathesisManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    A highly efficient aldehyde-olefin metathesis catalyzed by the carbocation, 4-phenylphenyl-diphenylmethylium ion has been developed. This protocol is characterized by high yields, low catalyst loading (down to 2 mol%), good functional group compatibility and mild reaction conditions.

  • 259. Ni, Wenjun
    et al.
    Gurzadyan, Gagik G.
    Zhao, Jianzhang
    Che, Yuanyuan
    Li, Xiaoxin
    Sun, Licheng
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Singlet Fission from Upper Excited Electronic States of Cofacial Perylene Dimer2019Inngår i: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 10, nr 10, s. 2428-2433Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Singlet fission directly from the upper excited vibrational and electronic states of cofacial perylene dimers, bypassing the relaxed state S-1, was detected within 50 fs. This process competes well with vibrational cooling in S-1 (4.7-7.0 ps) and S-2 -> S-1 internal conversion (380 fs). The singlet fission has the energy threshold E = 3.06 eV. Other competitive relaxation processes are excimer and dimer cation formation on an ultrafast time scale. Excitation to higher energy levels (4.96 eV) leads to a higher efficiency of singlet fission.

  • 260. Niga, P.
    et al.
    Hansson-Mille, P. M.
    Swerin, Agne
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap. RISE – Research Institute of Sweden.
    Claesson, Per M.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap. RISE – Research Institute of Sweden.
    Schoelkopf, J.
    Gane, P. A. C.
    Bergendal, Erik
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Tummino, A.
    Campbell, R. A.
    Johnson, C. Magnus
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Interactions between model cell membranes and the neuroactive drug propofol2018Inngår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 526, s. 230-243Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Vibrational sum frequency spectroscopy (VSFS) complemented by surface pressure isotherm and neutron reflectometry (NR) experiments were employed to investigate the interactions between propofol, a small amphiphilic molecule that currently is the most common general anaesthetic drug, and phospholipid monolayers. A series of biologically relevant saturated phospholipids of varying chain length from C18 to C14 were spread on either pure water or propofol (2,6-bis(1-methylethyl)phenol) solution in a Langmuir trough, and the change in the molecular structure of the film, induced by the interaction with propofol, was studied with respect to the surface pressure. The results from the surface pressure isotherm experiments revealed that propofol, as long as it remains at the interface, enhances the fluidity of the phospholipid monolayer. The VSF spectra demonstrate that for each phospholipid the amount of propofol in the monolayer region decreases with increasing surface pressure. Such squeeze out is in contrast to the enhanced interactions that can be exhibited by more complex amphiphilic molecules such as peptides. At surface pressures of 22–25 mN m−1, which are relevant for biological cell membranes, most of the propofol has been expelled from the monolayer, especially in the case of the C16 and C18 phospholipids that adopt a liquid condensed phase packing of its alkyl tails. At lower surface pressures of 5 mN m−1, the effect of propofol on the structure of the alkyl tails is enhanced when the phospholipids are present in a liquid expanded phase. Specifically, for the C16 phospholipid, NR data reveal that propofol is located exclusively in the head group region, which is rationalized in the context of previous studies. The results imply a non-homogeneous distribution of propofol in the plane of real cell membranes, which is an inference that requires urgent testing and may help to explain why such low concentration of the drug are required to induce general anaesthesia.

  • 261.
    Niga, Petru
    et al.
    RISE Res Inst Sweden Chem Mat & Surfaces, Box 5607, SE-11486 Stockholm, Sweden..
    Hansson-Mille, Petra M.
    RISE Res Inst Sweden Chem Mat & Surfaces, Box 5607, SE-11486 Stockholm, Sweden..
    Swerin, Agne
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Claesson, Per M.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Schoelkopf, Joachim
    Omya Int AG, Baslerstr 42, CH-4665 Oftringen, Switzerland..
    Gane, Patrick A. C.
    Omya Int AG, Baslerstr 42, CH-4665 Oftringen, Switzerland.;Aalto Univ, Sch Chem Technol, Dept Bioprod & Biosyst, FI-00076 Helsinki, Finland..
    Dai, Jing
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Furo, Istvan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Campbell, Richard A.
    Inst Laue Langevin, 71 Ave Martyrs,CS20156, F-38042 Grenoble 9, France.;Univ Manchester, Div Pharm & Optometry, Manchester M13 9PT, Lancs, England..
    Johnson, C. Magnus
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Propofol adsorption at the air/water interface: a combined vibrational sum frequency spectroscopy, nuclear magnetic resonance and neutron reflectometry study2019Inngår i: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 15, nr 1, s. 38-46Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Propofol is an amphiphilic small molecule that strongly influences the function of cell membranes, yet data regarding interfacial properties of propofol remain scarce. Here we consider propofol adsorption at the air/water interface as elucidated by means of vibrational sum frequency spectroscopy (VSFS), neutron reflectometry (NR), and surface tensiometry. VSFS data show that propofol adsorbed at the air/ water interface interacts with water strongly in terms of hydrogen bonding and weakly in the proximity of the hydrocarbon parts of the molecule. In the concentration range studied there is almost no change in the orientation adopted at the interface. Data from NR show that propofol forms a dense monolayer with a thickness of 8.4 angstrom and a limiting area per molecule of 40 angstrom(2), close to the value extracted from surface tensiometry. The possibility that islands or multilayers of propofol form at the air/water interface is therefore excluded as long as the solubility limit is not exceeded. Additionally, measurements of the 1H NMR chemical shifts demonstrate that propofol does not form dimers or multimers in bulk water up to the solubility limit.

  • 262.
    Nordgren, Niklas
    et al.
    SP Tech Res Inst Sweden, Stockholm, Sweden..
    Alvarez-Asencio, Ruben
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap. IMDEA Nanosci, Inst Adv Studies, Madrid, Spain..
    Wallqvist, Viveca
    SP Tech Res Inst Sweden, Stockholm, Sweden..
    Kjellin, Mikael
    SP Tech Res Inst Sweden, Stockholm, Sweden..
    Rutland, Mark W.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap. SP Tech Res Inst Sweden, Stockholm, Sweden..
    Camacho, Alejandra
    LOreal Res & Innovat, Chicago, IL USA..
    Luengo, Gustavo
    LOreal Res & Innovat, Aulnay Sous Bois, France..
    Nanomechanical properties of the stratum corneum and its interaction with a single hair fiber2016Inngår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 251Artikkel i tidsskrift (Annet vitenskapelig)
  • 263.
    Nordgren, Niklas
    et al.
    KTH, Skolan för kemivetenskap (CHE).
    Eklöf, Jens
    KTH, Skolan för bioteknologi (BIO).
    Zhou, Qi
    KTH, Tidigare Institutioner (före 2005), Bioteknologi. AlbaNova Univ Ctr, Royal Inst Technol, Sch Biotechnol, S-10691 Stockholm, Sweden..
    Brumer, Harry
    KTH, Skolan för bioteknologi (BIO).
    Rutland, Mark W.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    CELL 260-Top-down grafting of xyloglucan to gold monitored by QCM-D and AFM: Enzymatic activity and interactions with cellulose2008Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 235Artikkel i tidsskrift (Annet vitenskapelig)
  • 264.
    Nordgren, Niklas
    et al.
    KTH, Skolan för kemivetenskap (CHE).
    Rutland, Mark W.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    COLL 468-Nanotribological properties of responsive films: Effect of pH and temperature2008Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 235Artikkel i tidsskrift (Annet vitenskapelig)
  • 265.
    Nordgren, Niklas
    et al.
    SP Tech Res Inst Sweden, SP Chem Mat & Surfaces, Stockholm, Sweden..
    Skedung, Lisa
    SP Tech Res Inst Sweden, SP Chem Mat & Surfaces, Stockholm, Sweden..
    Baghdadli, Nawel
    LOreal Res & Innovat, Aulnay Sous Bois, France..
    Rutland, Mark W.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap. SP Tech Res Inst Sweden, SP Chem Mat & Surfaces, Stockholm, Sweden.;KTH Royal Inst Technol, Dept Chem, Stockholm, Sweden..
    Luengo, Gustavo
    LOreal Res & Innovat, Aulnay Sous Bois, France..
    Tactile and hair-hair friction behavior of hair fibers2017Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 253Artikkel i tidsskrift (Annet vitenskapelig)
  • 266.
    Nordgren, Niklas
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi.
    Stiernstedt, Johanna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi.
    Brumer, Harry
    KTH.
    Wågberg, Lars
    KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellens Centrum BiMaC Innovation. KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW.
    Gray, Derek G.
    Rutland, Mark W.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    CELL 109-Interactions of cellulose surfaces: Friction, adhesion and polysaccharide adsorption2007Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 233, s. 838-838Artikkel i tidsskrift (Annet vitenskapelig)
  • 267.
    Norrfors, K. Karin
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Björkbacka, Åsa
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Kessler, Amanda
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Wold, Susanna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Jonsson, Mats
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    γ-radiation induced corrosion of copper in bentonite-water systems under anaerobic conditions2018Inngår i: Radiation Physics and Chemistry, ISSN 0969-806X, E-ISSN 1879-0895, Vol. 144, s. 8-12Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this work we have experimentally studied the impact of bentonite clay on the process of radiation-induced copper corrosion in anoxic water. The motivation for this is to further develop our understanding of radiation-driven processes occurring in deep geological repositories for spent nuclear fuel where copper canisters containing the spent nuclear fuel will be embedded in compacted bentonite. Experiments on radiation-induced corrosion in the presence and absence of bentonite were performed along with experiments elucidating the impact irradiation on the Cu2+ adsorption capacity of bentonite. The experiments presented in this work show that the presence of bentonite clay has no or very little effect on the magnitude of radiation-induced corrosion of copper in anoxic aqueous systems. The absence of a protective effect similar to that observed for radiation-induced dissolution of UO2 is attributed to differences in the corrosion mechanism. This provides further support for the previously proposed mechanism where the hydroxyl radical is the key radiolytic oxidant responsible for the corrosion of copper. The radiation effect on the bentonite sorption capacity of Cu2+ (reduced capacity) is in line with what has previously been reported for other cations. The reduced cation sorption capacity is partly attributed to a loss of Al-OH sites upon irradiation.

  • 268.
    Nystrom, Lina
    et al.
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Nordstrom, Randi
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Frenning, Goran
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Saunders, Brian
    Univ Manchester, Manchester, Lancs, England..
    Alvarez-Asencio, Ruben
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Rutland, Mark W.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Malmsten, Martin
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Peptide loaded microgels as antimicrobial surface coatings2017Inngår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 253Artikkel i tidsskrift (Annet vitenskapelig)
  • 269.
    Nyström, Lina
    et al.
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Nordström, Randi
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Bramhill, Jane
    Univ Manchester, Manchester, Lancs, England..
    Saunders, Brian
    Univ Manchester, Manchester, Lancs, England..
    Alvarez-Asencio, Ruben
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap. IMDEA Nanosci, Inst Adv Studies, Madrid, Spain..
    Rutland, Mark W.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap. SP Tech Res Inst Sweden, SP Chem Mat & Surfaces, Stockholm, Sweden.
    Malmsten, Martin
    Uppsala Univ, Dept Pharm, Uppsala, Sweden.;Univ Copenhagen, Dept Pharm, Copenhagen, Denmark..
    Peptide-loaded microgels as carriers of antimicrobial peptides2018Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Artikkel i tidsskrift (Annet vitenskapelig)
  • 270.
    Nyström, Lina
    et al.
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Nordström, Randi
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Strömstedt, Adam
    Uppsala Univ, Dept Med Chem, Uppsala, Sweden..
    Saunders, Brian
    Univ Manchester, Manchester, Lancs, England..
    Alvarez-Asencio, Ruben
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Rutland, Mark W.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Malmsten, Martin
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Peptide-loaded microgels as antimicrobial surface coatings2018Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Artikkel i tidsskrift (Annet vitenskapelig)
  • 271.
    Okur, Halil I.
    et al.
    Ecole Polytech Fed Lausanne, Inst Bioengn IBI, Sch Engn STI, Lab Fundamental BioPhoton LBP, CH-1015 Lausanne, Switzerland.;Ecole Polytech Fed Lausanne, Inst Mat Sci IMX, Sch Engn STI, CH-1015 Lausanne, Switzerland.;Ecole Polytech Fed Lausanne, Lausanne Ctr Ultrafast Sci LACUS, CH-1015 Lausanne, Switzerland..
    Drexler, Chad I.
    Penn State Univ, Dept Chem, University Pk, PA 16802 USA..
    Tyrode, Eric
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi. Ecole Polytech Fed Lausanne, Inst Bioengn IBI, Sch Engn STI, Lab Fundamental BioPhoton LBP, CH-1015 Lausanne, Switzerland.;Ecole Polytech Fed Lausanne, Inst Mat Sci IMX, Sch Engn STI, CH-1015 Lausanne, Switzerland.;Ecole Polytech Fed Lausanne, Lausanne Ctr Ultrafast Sci LACUS, CH-1015 Lausanne, Switzerland..
    Cremer, Paul S.
    Penn State Univ, Dept Chem, University Pk, PA 16802 USA.;Penn State Univ, Biochem & Mol Biol, University Pk, PA 16802 USA..
    Roke, Sylvie
    Ecole Polytech Fed Lausanne, Inst Bioengn IBI, Sch Engn STI, Lab Fundamental BioPhoton LBP, CH-1015 Lausanne, Switzerland.;Ecole Polytech Fed Lausanne, Inst Mat Sci IMX, Sch Engn STI, CH-1015 Lausanne, Switzerland.;Ecole Polytech Fed Lausanne, Lausanne Ctr Ultrafast Sci LACUS, CH-1015 Lausanne, Switzerland..
    The Jones-Ray Effect Is Not Caused by Surface-Active Impurities2018Inngår i: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 9, nr 23, s. 6739-6743Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Pure aqueous electrolyte solutions display a minimum in surface tension at concentrations of 2 +/- 1 mM. This effect has been a source of controversy since it was first reported by Jones and Ray in the 1930s. The Jones Ray effect has frequently been dismissed as an artifact linked to the presence of surface-active impurities. Herein we systematically consider the effect of surface-active impurities by purposely adding nanomolar concentrations of surfactants to dilute electrolyte solutions. Trace amounts of surfactant are indeed found to decrease the surface tension and influence the surface chemistry. However, surfactants can be removed by repeated aspiration and stirring cycles, which eventually deplete the surfactant from solution, creating a pristine surface. Upon following this cleaning procedure, a reduction in the surface tension by millimolar concentrations of salt is still observed. Consequently, we demonstrate that the Jones Ray effect is not caused by surface-active impurities.

  • 272. Ou, J.
    et al.
    Xiang, J.
    Liu, J.
    Sun, Licheng
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi. State Key Laboratory of Fine Chemicals, Institute of Artificial Photosynthesis, Dalian University of Technology, Dalian, 116024, China.
    Surface-Supported Metal-Organic Framework Thin-Film-Derived Transparent CoS 1.097 @N-Doped Carbon Film as an Efficient Counter Electrode for Bifacial Dye-Sensitized Solar Cells2019Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, nr 16, s. 14862-14870Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An effective design for counter electrode (CE) catalytic materials with superior catalytic activity, excellent stability, low cost, and a facile fabrication process is urgently needed for industrialization of dye-sensitized solar cells (DSSCs). Herein, we report a facile in situ method to fabricate transparent CoS 1.097 anchored on an N-doped carbon film electrode through sulfurization of a cobalt-metalloporphyrin metal-organic framework thin film on fluorine-doped tin oxide glass. The transparent film as counter electrode in bifacial DSSCs exhibited higher power conversion efficiency (9.11% and 6.64%), respectively, from front and rear irradiation than that of Pt (8.04% and 5.87%). The uniformly dispersed CoS 1.097 nanoparticles on an N-doped carbon film provide a large catalytic active area and facilitate the electron transfer, which leads to the excellent catalytic ability of the CoS 1.097 @N-doped carbon film. In addition, the in situ preparation of the uniform film with a nanosheet structure offers high electrical conductivity and unobstructed access for the diffusion of triiodide to available electroactive sites, resulting in excellent device performance with superior long-term stability over 1000 h under natural conditions.

  • 273.
    Parrilla, Marc
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Cuartero, Maria
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Crespo, Gaston A.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Wearable potentiometric ion sensors2019Inngår i: TrAC. Trends in analytical chemistry, ISSN 0165-9936, E-ISSN 1879-3142, Vol. 110, s. 303-320Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Wearable potentiometric ion sensors (WPISs) have become an exciting analytical platform that combines chemical, material and electronic efforts to supply physiological information during certain human activities. The real possibility of wearing an analytical device with diverse configurations-sweatband, patches, garments-without disturbing the welfare of the carrier has enabled potentiometric ion sensors both as health quality and sport performance controllers. Recent studies show a large involvement of WPISs in the following of critical biomarkers (timely or continuously), such as sodium, potassium, calcium, magnesium, ammonium and chloride, which are present at relatively high concentrations in sweat (similar to mM levels). Certainly, the non-invasive nature of WPISs and other significant features, e.g., simplicity and cost-effectiveness, have broadened new horizons in relation to applied analytical chemistry. This has been pointed out in the literature over the last decade with the predominance of two analytical outcomes: (i) the improvement of sport performance as a result of continuous detection of ions in sweat (health status of the individual) while decreasing physiological complications (injuries, muscle cramps, fatigue and dehydration) during practice; and (ii) advancements in clinical diagnostics and preventive medicine as a consequence of the monitoring of the health status of patients suffering from any kind of disorder. Beyond the undeniable importance of the integration of WPISs to satisfy current societal needs, the following crucial questions about misleading and missing analytical features need to be answered: To what extent is WPIS technology a reliable analytical tool for the quantification of ions? Is cross-validation the current bottleneck toward further progress? Which are the fundamental steps involving the ion-selective electrode side that would benefit WPIS outcomes? Why is sweat the main (and almost the only) biological fluid to be monitored by WPISs? What is the best sampling strategy to be incorporated into WPIS devices for on-body monitoring of sweat? Which precision limits should be considered to assure a reliable decision-making process? Accordingly, this review focuses on the progression of WPISs from an analytical perspective-merely our vision of the field-within the period between 2010 and 2018. An updated search using specific keywords (wearable, ion, potentiometry, sensor) provided 43 contributions, which are herein highlighted, with a sustainable acceleration over the last three years. Thus, this review describes the current state of WPIS technology, the construction of wearable all-solid-state potentiometric sensors, critical requirements of potentiometric sensors to be fulfilled in a wearable configuration and key features regarding the ideal implementation of WPISs as reliable messengers of physiological information in real scenarios.

  • 274.
    Parrilla, Marc
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Cuartero, Maria
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Sanchez, Sara Padrell
    Karolinska Inst, Dept Clin Sci Intervent & Technol, K 57, SE-14186 Stockholm, Sweden.;Karolinska Univ Sjukhuset, Div Obstet & Gynecol, S-14186 Stockholm, Sweden..
    Rajabi, Mina
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Mikro- och nanosystemteknik.
    Roxhed, Niclas
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Mikro- och nanosystemteknik.
    Niklaus, Frank
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Mikro- och nanosystemteknik.
    Crespo, Gaston A.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Wearable All-Solid-State Potentiometric Microneedle Patch for Intradermal Potassium Detection2019Inngår i: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 91, nr 2, s. 1578-1586Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new analytical all-solid-state platform for intradermal potentiometric detection of potassium in interstitial fluid is presented here. Solid microneedles are modified with different coatings and polymeric membranes to prepare both the potassium-selective electrode and reference electrode needed for the potentiometric readout. These microneedle-based electrodes are fixed in an epidermal patch suitable for insertion into the skin. The analytical performances observed for the potentiometric cell (Nernstian slope, limit of detection of 10(-4.9) potassium activity, linear range of 10(-4.2) to 10(-1.1), drift of 0.35 +/- 0.28 mV h(-1)), together with a fast response time, adequate selectivity, and excellent reproducibility and repeatability, are appropriate for potassium analysis in interstitial fluid within both clinical and harmful levels. The potentiometric response is maintained after several insertions into animal skin, confirming the resiliency of the microneedle-based sensor. Ex vivo tests based on the intradermal detection of potassium in chicken and porcine skin demonstrate that the microneedle patch is suitable for monitoring potassium changes inside the skin. In addition, the dimensions of the microneedles modified with the corresponding layers necessary to enhance robustness and provide sensing capabilities (1000 mu m length, 45 degrees tip angle, 15 mu m thickness in the tip, and 435 mu m in the base) agree with the required ranges for a painless insertion into the skin. In vitro cytotoxicity experiments showed that the patch can be used for at least 24 h without any side effect for the skin cells. Overall, the developed concept constitutes important progress in the intradermal analysis of ions related to an electrolyte imbalance in humans, which is relevant for the control of certain types of diseases.

  • 275.
    Parrilla, Marc
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Ortiz-Gomez, Inmaculada
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi. Univ Granada, Fac Sci, Dept Analyt Chem, Campus Fuentenueva, E-18071 Granada, Spain..
    Canovas, Rocio
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi.
    Salinas-Castillo, Alfonso
    Univ Granada, Fac Sci, Dept Analyt Chem, Campus Fuentenueva, E-18071 Granada, Spain..
    Cuartero, Maria
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Crespo, Gaston A.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Wearable Potentiometric Ion Patch for On-Body Electrolyte Monitoring in Sweat: Toward a Validation Strategy to Ensure Physiological Relevance2019Inngår i: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 91, nr 13, s. 8644-8651Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Herein, the reproducibility and a double validation of on-body measurements provided by new wearable potentiometric ion sensors (WPISs) is presented. Sweat collected during sport practice was first analyzed using the developed device, the pH-meter, and ion chromatography (IC) prior to onbody measurements (off-site validation). Subsequently, the accuracy of onbody measurements accomplished by the WPISs was evaluated by comparison with pH-meter readings and IC after collecting sweat (every 10-12.5 min) during sport practice. The developed device contains sensors for pH, Cl-, K+, and Na+ that are embedded in a flexible sampling cell for sweat analysis. The electrode array was fabricated employing MWCNTs (as an ion-to-electron transducer) and stretchable materials that have been exhaustively characterized in terms of analytical performance, presenting Nernstian slopes within the expected physiological range of each ion analyte (Cl-, 10-100 mM; 10-10 mM; and Na+, 10- 100 mM and pH, 4.5-7.5), drift suitable for midterm exercise practice (0.3 +/- 0.2 mV h(-1)), fast response time, adequate selectivity for sweat measurements, and excellent reversibility. Besides that, the designed sampling cell avoids any sweat contamination and evaporation issues while supplying a passive sweat flow encompassing specifically the individual's perspiration. The interpretation of ion concentration profiles may permit the identification of personal dynamic patterns in sweat composition while practicing sport.

  • 276.
    Paulraj, Thomas
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Crespo, Gaston
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi.
    Svagan, Anna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Cage-like cellulose nanofiber-based microcapsules for electrochemical and biosensor applications2018Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 256Artikkel i tidsskrift (Annet vitenskapelig)
  • 277.
    Paulraj, Thomas
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wennmalm, Stefan
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Experimentell biomolekylär fysik. KTH, Centra, Science for Life Laboratory, SciLifeLab. ..
    Riazanova, Anastasia, V
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wu, Qiong
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Crespo, Gaston A.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Svagan, Anna J.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Porous Cellulose Nanofiber-Based Microcapsules for Biomolecular Sensing2018Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, nr 48, s. 41146-41154Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Cellulose nanofibers (CNFs) have recently attracted a lot of attention in sensing because of their multifunctional character and properties such as renewability, nontoxicity, biodegradability, printability, and optical transparency in addition to unique physicochemical, barrier, and mechanical properties. However, the focus has exclusively been devoted toward developing two-dimensional sensing platforms in the form of nanopaper or nanocellulose-based hydrogels. To improve the flexibility and sensing performance in situ, for example, to detect biomarkers in vivo for early disease diagnostics, more advanced CNF-based structures are needed. Here, we developed porous and hollow, yet robust, CNF-based microcapsules using only the primary plant cell wall components, CNF, pectin, and xyloglucan, to assemble the capsule wall. The fluorescein isothiocyanate-labeled dextrans with M-w of 70 and 2000 kDa could enter the hollow capsules at a rate of 0.13 +/- 0.04 and 0.014 +/- 0.009 s(-1), respectively. This property is very attractive because it minimizes the influence of mass transport through the capsule wall on the response time. As a proof of concept, glucose oxidase (GOx) enzyme was loaded (and cross-linked) in the microcapsule interior with an encapsulation efficiency of 68 +/- 2%. The GOx-loaded microcapsules were immobilized on a variety of surfaces (here, inside a flow channel, on a carbon-coated sensor or a graphite rod) and glucose concentrations up to 10 mM could successfully be measured. The present concept offers new opportunities in the development of simple, more efficient, and disposable nanocellulose-based analytical devices for several sensing applications including environmental monitoring, healthcare, and diagnostics.

  • 278. Peng, T.
    et al.
    Yan, Q.
    Li, Gen
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Zhang, X.
    The Influence of Cu/Fe Ratio on the Tribological Behavior of Brake Friction Materials2018Inngår i: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 66, nr 1, artikkel-id 18Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Copper and iron are the major ingredients in friction materials, among which Fe often been served as friction reinforcement in the past. But in our recent study, the coefficients of friction (COF) decreased with increasing iron content in composites. In order to study the influence of Cu/Fe ratio on the tribological behavior of the composite under simulative braking conditions, a subscale testing apparatus with the pad-on-disk configuration under various initial braking speeds (IBS) was applied. The changes in mean COFs, wear rates, morphologies and chemical constitutions of friction surface for different composites were investigated. Results showed that the composite containing more Fe content always showed lower mean COF and wear rate, which different from the previous studies. This is because, under severe braking conditions, the tribological behavior of composite mainly depends on the evolution of tribo-oxide film on the surface, not just on the substrate themselves. Higher Fe content accelerated the formation of tribo-oxide film and in turn inhibited the destruction of tribo-oxide film on the surface, which leading to lower mean COF and wear rate, as well as a higher critical IBS for the transition of mean COF and wear rate. This work also provides a way to characterize the fracture strength of tribo-film by carried out a peeling test.

  • 279.
    Petronico, Aaron
    et al.
    Univ Illinois, Dept Chem, Urbana, IL 61801 USA..
    Moneypenny, Timothy P., II
    Univ Illinois, Dept Chem, Urbana, IL 61801 USA.;Univ Illinois, Beckman Inst Adv Sci & Technol, Urbana, IL 61801 USA..
    Nicolau, Bruno G.
    Univ Illinois, Dept Chem, Urbana, IL 61801 USA..
    Moore, Jeffrey S.
    Univ Illinois, Dept Chem, Urbana, IL 61801 USA.;Univ Illinois, Beckman Inst Adv Sci & Technol, Urbana, IL 61801 USA..
    Nuzzo, Ralph G.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap. Univ Illinois, Dept Chem, Urbana, IL 61801 USA.
    Gewirth, Andrew A.
    Univ Illinois, Dept Chem, Urbana, IL 61801 USA..
    Solid-Liquid Lithium Electrolyte Nanocomposites Derived from Porous Molecular Cages2018Inngår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 140, nr 24, s. 7504-7509Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We demonstrate that solid-liquid nanocomposites derived from porous organic cages are effective lithium ion electrolytes at room temperature. A solid-liquid electrolyte nanocomposite (SLEN) fabricated from a LiTFSI/DME electrolyte system and a porous organic cage exhibits ionic conductivity on the order of 1 x 10(-3) S cm(-1). With an experimentally measured activation barrier of 0.16 eV, this composite is characterized as a superionic conductor. Furthermore, the SLEN displays excellent oxidative stability up to 4.7 V vs Li/Li+. This simple three-component system enables the rational design of electrolytes from tunable discrete molecular architectures.

  • 280.
    Petrou, Georgia
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Investigating mucin interactions with diverse surfaces for biomedical applications2019Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Mucous membranes are covered with mucus, a viscoelastic hydrogel that plays an essential role in their protection from shear and pathogens. The viscoelasticity of mucus is owing to mucins, a group of densely glycosylated proteins. Mucins can interact with a wide range of surfaces; thus, there is big interest in exploring and manipulating such interactions for biomedical applications. This thesis presents investigations of mucin interactions with hydrophobic surfaces in order to identify the key features of mucin lubricity, as well as describes the development of materials that are optimized to interact with mucins.

     

    In Paper I we investigated the domains which make mucins outstanding boundary lubricants. The results showed that the hydrophobic terminal domains of mucins play a crucial role in the adsorption and lubrication on hydrophobic surfaces. Specifically, protease digestion of porcine gastric mucins and salivary mucins resulted in the cleavage of these domains and the loss of lubricity and surface adsorption. However, a “rescue” strategy was successfully carried out by grafting hydrophobic phenyl groups to the digested mucins and enhancing their lubricity. This strategy also enhanced the lubricity of polymers which are otherwise bad lubricants.

     

    In Paper II we developed mucoadhesive materials based on genetically engineered partial spider silk proteins. The partial spider silk protein 4RepCT was successfully functionalized with six lysines (pLys-4RepCT), or the Human Galectin-3 Carbohydrate Recognition Domain (hGal3-4RepCT). These strategies were aiming to either non-specific electrostatic interactions between the positive lysines and the negative mucins, or specific binding between the hGal3 and the mucin glycans. Coatings, fibers, meshes and foams were prepared from the new silk proteins, and the adsorption of porcine gastric mucins and bovine submaxillary mucins was measured, demonstrating enhanced adsorption.

     

    The work presented demonstrates how mucin-material interactions can provide us with valuable information for the development of new biomaterials. Specifically, mucin-based and mucin-inspired lubricants could provide desired lubrication to a wide range of surfaces, while our new silk based materials could be valuable tools for the development of mucosal dressings.

  • 281.
    Petrou, Georgia
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Crouzier, Thomas
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Mucins as multifunctional building blocks of biomaterials2018Inngår i: Biomaterials Science, ISSN 2047-4830, E-ISSN 2047-4849, Vol. 6, nr 9, s. 2282-2297Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Mucins are large glycoproteins that are ubiquitous in the animal kingdom. Mucins coat the surfaces of many cell types and can be secreted to form mucus gels that assume important physiological roles in many animals. Our growing understanding of the structure and function of mucin molecules and their functionalities has sparked interest in investigating the use of mucins as building blocks for innovative functional biomaterials. These pioneering studies have explored how new biomaterials can benefit from the barrier properties, hydration and lubrication properties, unique chemical diversity, and bioactivities of mucins. Owing to their multifunctionality, mucins have been used in a wide variety of applications, including as antifouling coatings, as selective filters, and artificial tears and saliva, as basis for cosmetics, as drug delivery materials, and as natural detergents. In this review, we summarize the current knowledge regarding key mucin properties and survey how they have been put to use. We offer a vision for how mucins could be used in the near future and what challenges await the field before biomaterials made of mucins and mucin-mimics can be translated into commercial products.

  • 282.
    Petrou, Georgia
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Jansson, Ronnie
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Protein Engineering.
    Hogqvist, Mark
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH).
    Erlandsson, Johan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Hedhammar, My
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Proteinteknologi.
    Crouzier, Thomas
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Genetically Engineered Mucoadhesive Spider Silk2018Inngår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 19, nr 8, s. 3268-3279Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mucoadhesion is defined as the adhesion of a material to the mucus gel covering the mucous membranes. The mechanisms controlling mucoadhesion include nonspecific electrostatic interactions and specific interactions between the materials and the mucins, the heavily glycosylated proteins that form the mucus gel. Mucoadhesive materials can be used to develop mucosal wound dressings and noninvasive transmucosal drug delivery systems. Spider silk, which is strong, biocompatible, biodegradable, nontoxic, and lightweight would serve as an excellent base for the development of such materials. Here, we investigated two variants of the partial spider silk protein 4RepCT genetically engineered in order to functionalize them with mucoadhesive properties. The pLys-4RepCT variant was functionalized with six cationically charged lysines, aiming to provide nonspecific adhesion from electrostatic interactions with the anionically charged mucins, while the hGal3-4RepCT variant was genetically fused with the Human Galectin-3 Carbohydrate Recognition Domain which specifically binds the mucin glycans Gal beta 1-3GlcNAc and Gal beta 1-4GlcNAc. First, we demonstrated that coatings, fibers, meshes, and foams can be readily made from both silk variants. Measured by the adsorption of both bovine submaxillary mucin and pig gastric mucin, the newly produced silk materials showed enhanced mucin binding properties compared with materials of wild-type (4RepCT) silk. Moreover, we showed that pLys-4RepCT silk coatings bind mucins through electrostatic interactions, while hGal3-4RepCT silk coatings bind mucins through specific glycan-protein interactions. We envision that the two new mucoadhesive silk variants pLys-4RepCT and hGal3-4RepCT, alone or combined with other biofunctional silk proteins, constitute useful new building blocks for a range of silk protein-based materials for mucosal treatments.

  • 283.
    Petrou, Georgia
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Jansson, Ronnie
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Proteinteknologi.
    Högqvist, Mark
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Proteinteknologi.
    Hedhammar, My
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Proteinteknologi.
    Crouzier, Thomas
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Engineering mucoadhesive silk2018Inngår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Artikkel i tidsskrift (Annet vitenskapelig)
  • 284. Pham, Trang A.T.
    et al.
    Schwerdt, Julian G.
    Shirley, Neil J.
    Xing, Xiaohui
    Hsieh, Yves S. Y.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Srivastava, Vaibhav
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Bulone, Vincent
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Little, Alan
    Analysis of cell wall synthesis and metabolism during early germination of Blumeria graminis f. sp. hordei conidial cells induced in vitro2019Inngår i: The Cell Surface, ISSN 2468-2330, Vol. 5, s. 100030-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    As an obligate biotroph, Blumeria graminis f. sp. hordei (Bgh) cannot be grown in an axenic culture, and instead must be cultivated on its host species, Hordeum vulgare (barley). In this study an in vitro system utilizing n-hexacosanal, a constituent of the barley cuticle and known inducer of Bgh germination, was used to cultivate Bgh and differentiate conidia up to the appressorial germ tube stage for analysis. Transcriptomic and proteomic profiling of the appressorial germ tube stage revealed that there was a significant shift towards energy and protein production during the pre-penetrative phase of development, with an up-regulation of enzymes associated with cellular respiration and protein synthesis, modification and transport. Glycosidic linkage analysis of the cell wall polysaccharides demonstrated that during appressorial development an increase in 1,3- and 1,4-linked glucosyl residues and xylosyl residues was detected along with a significant decrease in galactosyl residues. The use of this in vitro cultivation method demonstrates that it is possible to analyse the pre-penetrative processes of Bgh development in the absence of a plant host.

  • 285.
    Phuyal, Dibya
    et al.
    Uppsala Univ, Dept Phys & Astron, Solid State Phys, Angstrom Lab, Box 516, SE-75121 Uppsala, Sweden..
    Safdari, Majid
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Pazoki, Meysam
    Uppsala Univ, Dept Engn Sci, Solid State Phys, Angstrom Lab, SE-75121 Uppsala, Sweden..
    Liu, Peng
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad materialfysik. KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Philippe, Bertrand
    Uppsala Univ, Dept Phys & Astron, Solid State Phys, Angstrom Lab, Box 516, SE-75121 Uppsala, Sweden..
    Kyashnina, Kristina O.
    ESRF, Rossendorf Beamline, CS40220, F-38043 Grenoble 9, France.;HZDR, Inst Resource Ecol, POB 510119, D-01314 Dresden, Germany..
    Karis, Olof
    Uppsala Univ, Dept Phys & Astron, Solid State Phys, Angstrom Lab, Box 516, SE-75121 Uppsala, Sweden..
    Butorin, Sergei M.
    Uppsala Univ, Dept Phys & Astron, Solid State Phys, Angstrom Lab, Box 516, SE-75121 Uppsala, Sweden..
    Rensmo, Hakan
    Uppsala Univ, Dept Phys & Astron, Solid State Phys, Angstrom Lab, Box 516, SE-75121 Uppsala, Sweden..
    Edvinsson, Tomas
    Uppsala Univ, Dept Engn Sci, Solid State Phys, Angstrom Lab, SE-75121 Uppsala, Sweden..
    Kloo, Lars
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Gardner, James M.
    KTH, Skolan för kemivetenskap (CHE), Centra, Molekylär elektronik, CMD.
    Electronic Structure of Two-Dimensional Lead(II) Iodide Perovskites: An Experimental and Theoretical Study2018Inngår i: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 30, nr 15, s. 4959-4967Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Layered two-dimensional (2D) hybrid organic-inorganic perovskites (HOP) are promising materials for light-harvesting applications because of their chemical stability, wide flexibility in composition and dimensionality, and increases in photovoltaic power conversion efficiencies. Three 2D lead iodide perovskites were studied through various X-ray spectroscopic techniques to derive detailed electronic structures and band energetics profiles at a titania interface. Core-level and valence band photoelectron spectra of HOP were analyzed to resolve the electronic structure changes due to the reduced dimensionality of inorganic layers. The results show orbital narrowing when comparing the HOP, the layered precursor PbI2, and the conventional 3D (CH3NH3)PbI3 such that different localizations of band edge states and narrow band states are unambiguously due to the decrease in dimensionality of the layered HOPs. Support from density functional theory calculations provide further details on the interaction and band gap variations of the electronic structure. We observed an interlayer distance dependent dispersion in the near band edge electronic states. The results show how tuning the interlayer distance between the inorganic layers affects the electronic properties and provides important design principles for control of the interlayer charge transport properties, such as the change in effective charge masses as a function of the organic cation length. The results of these findings can be used to tune layered materials for optimal functionality and new applications.

  • 286.
    Piela, Katarzyna
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi.
    Tyrode, Eric C.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Furo, Istvan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Tillämpad fysikalisk kemi.
    Cryoporometry in Femtoliter Volumes by Confocal Raman Spectroscopy2019Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 35, nr 26, s. 8823-8828Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The properties of porous material are largely dependent on the size, shape, and connectivity of the pores. Here, we present a method based on confocal Raman spectroscopy to quantify porosity using a cryoporometric approach. We show that the phase transition of water imbibed in porous silica can be accurately determined using two different, but complementary methodologies. The first one relies on integrating the temperature-dependent spectral intensities across the whole OH (H2O) or OD (D2O) stretching region. The second, more quantitative approach, deconvolutes the spectral contributions within the pores in terms of liquid and solid fractions. The results show the expected reciprocal dependence of the average phase transition point with pore size, as well as the typical hysteresis between the freezing and melting transitions. One of the key advantages of the confocal Raman approach is its high spatial resolution, with sampling volumes starting from just a few femtoliters, opening the possibility of mapping the structure in heterogeneous porous materials.

  • 287.
    Pilkington, Georgia A.
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Harris, Kathryn
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Bergendal, Erik
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Reddy, Akepati Bhaskar
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).
    Pålsson, G. K.
    Vorobiev, A.
    Antzutkin, O. N.
    Glavatskih, Sergei
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.). Ghent University, Belgium.
    Rutland, Mark W.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap. RISE Research Institutes of Sweden.
    Electro-responsivity of ionic liquid boundary layers in a polar solvent revealed by neutron reflectance2018Inngår i: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 148, nr 19, artikkel-id 193806Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Using neutron reflectivity, the electro-responsive structuring of the non-halogenated ionic liquid (IL) trihexyl(tetradecyl)phosphonium-bis(mandelato)borate, [P6,6,6,14][BMB], has been studied at a gold electrode surface in a polar solvent. For a 20% w/w IL mixture, contrast matched to the gold surface, distinct Kiessig fringes were observed for all potentials studied, indicative of a boundary layer of different composition to that of the bulk IL-solvent mixture. With applied potential, the amplitudes of the fringes from the gold-boundary layer interface varied systematically. These changes are attributable to the differing ratios of cations and anions in the boundary layer, leading to a greater or diminished contrast with the gold electrode, depending on the individual ion scattering length densities. Such electro-responsive changes were also evident in the reflectivities measured for the pure IL and a less concentrated (5% w/w) IL-solvent mixture at the same applied potentials, but gave rise to less pronounced changes. These measurements, therefore, demonstrate the enhanced sensitivity achieved by contrast matching the bulk solution and that the structure of the IL boundary layers formed in mixtures is strongly influenced by the bulk concentration. Together these results represent an important step in characterising IL boundary layers in IL-solvent mixtures and provide clear evidence of electro-responsive structuring of IL ions in their solutions with applied potential.

  • 288. Poptoshev, E.
    et al.
    Rutland, Mark W.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Claesson, P. M.
    Surface forces in aqueous polyvinylamine solutions. I. Glass surfaces1999Inngår i: Langmuir, Vol. 15, nr 22, s. 7789-7794Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A noninterferometric surface force apparatus has been used to measure interactions between glass spheres in dilute aqueous polyvinylamine solutions at two different salt concentrations. Close to the substrate charge neutralization point, an attractive interaction is present mainly because of bridging of the extending polymer tails. Additional adsorption leads to an overcompensation of the glass negative surface charge, and the interaction at this point is dominated by a long-range double-layer repulsion. The results from fitting the Derjaguin-Landau-Verwey-Overbeek theory to the measured force curves demonstrate that the degree of overcompensation increases with polyelectrolyte concentration and increasing ionic strength of the solution (addition of indifferent electrolyte). An increase in ionic strength results in the screening of the electrostatic forces which leads to: (i) a reduced free energy cost of creating a charged interface, (ii) a decreased repulsion between protonated amine groups along the polymer backbone and a corresponding increased chain flexibility, (iii) a reduced electrostatic attraction between the polyelectrolyte and the surface. The first effect is apparently is the most important in the present case.

  • 289.
    Pourmand, Payam
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Kemi.
    Hedenqvist, Mikael S.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Furo, Istvan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Kemi.
    Gedde, Ulf W
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Deterioration of highly filled EPDM rubber by thermal ageing in air: Kinetics and non-destructive monitoring2017Inngår i: Polymer testing, ISSN 0142-9418, E-ISSN 1873-2348, Vol. 64, s. 267-276Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The effects of air ageing at different temperatures between 110 and 170 degrees C on cable transit seals based on highly filled EPDM rubber used in nuclear power plants were studied. The changes of the macroscopic mechanical properties (Young's modulus, indentation modulus and strain-at-break) were in accordance with the Arrhenius equation with an activation energy of 110 kJ mol(-1). Profiling to assess the structure and property gradients within aged blocks was performed via IR spectroscopy, micro-indentation, gravimetric analysis of n-heptane-extracted samples and non-invasive portable NMR spectroscopy. A previously developed methodology was used to separate the deterioration into three different processes: polymer oxidation that was diffusion-limited at all temperatures, migration of low-molar-mass species to the surrounding media and anaerobic changes to the polymer network. The methodology allowed the assessment of the kinetics (rate as a function of time and temperature) of the different processes. It was noticed that polymer oxidation yielded more crosslinking at higher temperatures than at lower temperatures. The data obtained by both the portable NMR (a non-invasive method) and the indentation modulus profiling showed correlations with strain-at-break data, indicating their usefulness as condition monitoring methods.

  • 290.
    Pradhan, Sulena
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Hedberg, Jonas
    KTH, Skolan för teknikvetenskap (SCI), Fysik.
    Rosenqvist, Jorgen
    Jonsson, Caroline M.
    Wold, Susanna
    Blomberg, Eva
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Odnevall Wallinder, Inger
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Influence of humic acid and dihydroxy benzoic acid on the agglomeration, adsorption, sedimentation and dissolution of copper, manganese, aluminum and silica nanoparticles - A tentative exposure scenario2018Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, nr 2, artikkel-id e0192553Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This work focuses on kinetic aspects of stability, mobility, and dissolution of bare Cu, Al and Mn, and SiO2 NPs in synthetic freshwater (FW) with and without the presence of natural organic matter (NOM). This includes elucidation of particle and surface interactions, metal dissolution kinetics, and speciation predictions of released metals in solution. Dihydroxy benzoic acid (DHBA) and humic acid adsorbed rapidly on all metal NPs (< 1 min) via multiple surface coordinations, followed in general by rapid agglomeration and concomitant sedimentation for a large fraction of the particles. In contrast, NOM did not induce agglomeration of the SiO2 NPs during the test duration (21 days). DHBA in concentrations of 0.1 and 1 mM was unable to stabilize the metal NPs for time periods longer than 6 h, whereas humic acid, at certain concentrations (20 mg/L) was more efficient (> 24 h). The presence of NOM increased the amount of released metals into solution, in particular for Al and Cu, whereas the effect for Mn was minor. At least 10% of the particle mass was dissolved within 24 h and remained in solution for the metal NPs in the presence of NOM. Speciation modeling revealed that released Al and Cu predominantly formed complexes with NOM, whereas less complexation was seen for Mn. The results imply that potentially dispersed NPs of Cu, Al and Mn readily dissolve or sediment close to the source in freshwater of low salinity, whereas SiO2 NPs are more stable and therefore more mobile in solution.

  • 291. Qu, Jishuang
    et al.
    Jiang, Xiaoqing
    Yu, Ze
    Lai, Jianbo
    Zhao, Yawei
    Hu, Maowei
    Yang, Xichuan
    Sun, Licheng
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Improved performance and air stability of perovskite solar cells based on low-cost organic hole-transporting material X60 by incorporating its dicationic salt2018Inngår i: Science in China Series B: Chemistry, ISSN 1674-7291, E-ISSN 1869-1870, Vol. 61, nr 2, s. 172-179Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The development of an efficient, stable, and low-cost hole-transporting material (HTM) is of great significance for perovskite solar cells (PSCs) from future commercialization point of view. Herein, we specifically synthesize a dicationic salt of X60 termed X60(TFSI)(2), and adopt it as an effective and stable "doping" agent to replace the previously used lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) for the low-cost organic HTM X60 in PSCs. The incorporation of this dicationic salt significantly increases the hole conductivity of X60 by two orders of magnitude from 10(-6) to 10(-4) S cm(-1). The dramatic enhancement of the conductivity leads to an impressive power conversion efficiency (PCE) of 19.0% measured at 1 sun illumination (100 mW cm(-2), AM 1.5 G), which is comparable to that of the device doped with LiTFSI (19.3%) under an identical condition. More strikingly, by replacing LiTFSI, the PSC devices incorporating X60(TFSI)(2) also show an excellent long-term durability under ambient atmosphere for 30 days, mainly due to the hydrophobic nature of the X60(TFSI)(2) doped HTM layer, which can effectively prevent the moisture destroying the perovskite layer. The present work paves the way for the development of highly efficient, stable, and low-cost HTM for potential commercialization of PSCs.

  • 292.
    Quero, Amparo Jimenez
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Rudjito, Reskandi C.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Martinez-Abad, Antonio
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Ruthes, Andrea C.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Extraction of distinct populations of bioactive arabinoxylans from wheat bran using sequential chemo-enzymatic processes2018Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Artikkel i tidsskrift (Annet vitenskapelig)
  • 293.
    Radiom, Milad
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Ionic liquid–solid interface and applications in lubrication and energy storage2019Inngår i: Current Opinion in Colloid & Interface Science, ISSN 1359-0294, E-ISSN 1879-0399, Vol. 39, s. 148-161Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Room-temperature ionic liquids (ILs) exhibit many attractive properties in proximity to solid surfaces. Primarily, they form well-defined interfacial layers that are tunable — electrically and thermally — as well as being stable — mechanically, electrically, and thermally — over a wide range. Recent investigations have aimed at understanding the molecular structuring of ILs at their interface with solids and in confinement, while in tandem, ILs are used as next-generation lubricants and energy storage materials. The result is a large volume of work that has appeared over the last decade. In this review, the recent literature is presented and future research directions are discussed.

  • 294.
    Radiom, Milad
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Pedraz, Patricia
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Pilkington, Georgia
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    Rohlmann, Patrick
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.).
    Glavatskih, Sergei
    KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.), Maskinkonstruktion (Avd.). Department of Electrical Energy, Metals, Mechanical Constructions and Systems, Ghent University, B-9052 Ghent, Belgium.
    Rutland, Mark W.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap. Surfaces, Processes and Formulation, RISE Research Institutes of Sweden, SE-100 44 Stockholm, Sweden.
    Anomalous Interfacial Structuring of a Non-Halogenated Ionic Liquid: Effect of Substrate and Temperature2018Inngår i: Colloids and Interfaces, ISSN 2504-5377, Vol. 2, nr 4, artikkel-id 60Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We investigate the interfacial properties of the non-halogenated ionic liquid (IL), trihexyl(tetradecyl)phosphonium bis(mandelato)borate, [P6,6,6,14][BMB], in proximity to solid surfaces, by means of surface force measurement. The system consists of sharp atomic force microscopy (AFM) tips interacting with solid surfaces of mica, silica, and gold. We find that the force response has a monotonic form, from which a characteristic steric decay length can be extracted. The decay length is comparable with the size of the ions, suggesting that a layer is formed on the surface, but that it is diffuse. The long alkyl chains of the cation, the large size of the anion, as well as crowding of the cations at the surface of negatively charged mica, are all factors which are likely to oppose the interfacial stratification which has, hitherto, been considered a characteristic of ionic liquids. The variation in the decay length also reveals differences in the layer composition at different surfaces, which can be related to their surface charge. This, in turn, allows the conclusion that silica has a low surface charge in this aprotic ionic liquid. Furthermore, the effect of temperature has been investigated. Elevating the temperature to 40 &deg;C causes negligible changes in the interaction. At 80 &deg;C and 120 &deg;C, we observe a layering artefact which precludes further analysis, and we present the underlying instrumental origin of this rather universal artefact.

  • 295.
    Ramos, Marina
    et al.
    Univ Alicante, Dept Analyt Chem Nutr & Food Sci, ES-03690 Alicante, Spain..
    Burgos, Nuria
    Univ Alicante, Dept Analyt Chem Nutr & Food Sci, ES-03690 Alicante, Spain..
    Barnard, Almero
    Neem Biotech Ltd Units G&H, Abertillery NP13 1SX, Wales..
    Evans, Gareth
    Neem Biotech Ltd Units G&H, Abertillery NP13 1SX, Wales..
    Preece, James
    Neem Biotech Ltd Units G&H, Abertillery NP13 1SX, Wales..
    Graz, Michael
    Neem Biotech Ltd Units G&H, Abertillery NP13 1SX, Wales..
    Ruthes, Andrea C.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Jimenez-Quero, Amparo
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Martinez-Abad, Antonio
    Univ Alicante, Dept Analyt Chem Nutr & Food Sci, ES-03690 Alicante, Spain.;Neem Biotech Ltd Units G&H, Abertillery NP13 1SX, Wales..
    Vilaplana, Francisco
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Ngoc, Long Pham
    Brouwer, Abraham
    BioDetect Syst Bv, Sci Pk 406, NL-1098 XH Amsterdam, Netherlands..
    van der Burg, Bart
    BioDetect Syst Bv, Sci Pk 406, NL-1098 XH Amsterdam, Netherlands..
    del Carmen Garrigos, Maria
    Univ Alicante, Dept Analyt Chem Nutr & Food Sci, ES-03690 Alicante, Spain..
    Jimenez, Alfonso
    Univ Alicante, Dept Analyt Chem Nutr & Food Sci, ES-03690 Alicante, Spain..
    Agaricus bisporus and its by-products as a source of valuable extracts and bioactive compounds2019Inngår i: Food Chemistry, ISSN 0308-8146, E-ISSN 1873-7072, Vol. 292, s. 176-187Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Edible mushrooms constitute an appreciated nutritional source for humans due to their low caloric intake and their high content in carbohydrates, proteins, dietary fibre, phenolic compounds, polyunsaturated fatty acids, vitamins and minerals. It has been also demonstrated that mushrooms have health-promoting benefits. Cultivation of mushrooms, especially of the most common species Agaricus bisporus, represents an increasingly important food industry in Europe, but with a direct consequence in the increasing amount of by-products from their industrial production. This review focuses on collecting and critically investigating the current data on the bioactive properties of Agaricus bisporus as well as the recent research for the extraction of valuable functional molecules from this species and its by-products obtained after industrial processing. The state of the art regarding the antimicrobial, antioxidant, anti-allergenic and dietary compounds will be discussed for novel applications such as nutraceuticals, additives for food or cleaning products.

  • 296.
    REN, Yansong
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Dynamic Chemistry for Asymmetric Synthesis, Molecular Motion and Constitutional Exchange2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Living matter is built on complex dynamic systems consisting of numerus biotransformations. By exploiting the adaptive and evolutive behaviors ofmolecular matter, dynamic chemistry has developed as an important tool tounderstand the organization of nonliving matter into complex living systems.This thesis concerns three aspects of dynamic chemistry with a general focus onthe influence of different stimuli on the structures and functions of dynamicsystems.The first section focuses on dynamic kinetic resolution, where enzymes areutilized for asymmetric synthesis of an enantiopure (2R,5R)-1,3-oxathiolane. Byemploying surfactant-treated subtilisin Carlsberg and Candida antarcticalipase B, the absolute configuration of the resulting 1,3-oxathiolane ring couldbe efficiently controlled.The second section addresses the motional dynamics of configurational enamineswitch systems controlled by multiple stimuli. Complete forward and backwardrotation around the enamine C=C bond could be precisely regulated uponaddition of acid/base or metal ions. The enamine switches exhibited specificsensing ability for CuII ions in solution. Moreover, the enamines exhibitedswitchable aggregation-induced emission in the solid state, which could beapplied in the development of sensors as well as fluorescent organogel.Lastly, the enamine switches could readily undergo constitutional exchange withprimary amines under catalytic acidic conditions, resulting in dynamic enaminesystems. However, under basic conditions or in the presence of excessive acid,this process exhibited extremely slow kinetics, leading to an efficient regulationof the exchange process by controlling the switch status with regulation of pHin the system.

  • 297.
    REN, Yansong
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Hu, Lei
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Ramström, Olof
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Multienzymatic Cascade Synthesis of an Enantiopure (2R,5R)-1,3-Oxathiolane Anti-HIV Agent PrecursorManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    An enantiopure (2R,5R)-1,3-oxathiolane derivative was obtained using amultienzymatic cascade protocol. By employing a combination of surfactant-treatedsubtilisin Carlsberg and Candida antarctica lipase B, the absolute configuration of theresulting 1,3-oxathiolane ring was efficiently controlled, resulting in an excellentenantiomeric excess (> 99%). This enantiopure 1,3-oxathiolane derivative is a keyprecursor to anti-HIV agents, such as lamivudine, through subsequent N-glycosylation.

  • 298.
    Ren, Yansong
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Hu, Lei
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Ramström, Olof
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Multienzymatic cascade synthesis of an enantiopure (2R,5R)-1,3-oxathiolane anti-HIV agent precursor2019Inngår i: Molecular Catalysis, ISSN 2468-8231, Vol. 468, s. 52-56Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An enantiopure (2R,5R)-1,3-oxathiolane was obtained using a multienzymatic cascade protocol. By employing a combination of surfactant-treated subtilisin Carlsberg and Candida antarctica lipase B, the absolute configuration of the resulting 1,3-oxathiolane ring was efficiently controlled, resulting in an excellent enantiomeric excess (>99%). This enantiopure 1,3-oxathiolane derivative is a key precursor to anti-HIV agents, such as lamivudine, through subsequent N-glycosylation.

  • 299.
    REN, Yansong
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi. KTH, Dept Chem Organ Chem, Stockholm, Sweden..
    Hu, Lei
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi. KTH, Dept Chem Organ Chem, Stockholm, Sweden..
    Ramström, Olof
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi. KTH, Dept Chem Organ Chem, Stockholm, Sweden..
    Multienzymatic, one-pot cascade synthesis of enantiopure lamivudine precursor (2R, 5R)-1,3-oxathiolane2016Inngår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 252Artikkel i tidsskrift (Annet vitenskapelig)
  • 300.
    REN, Yansong
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Kravchenko, Oleksandr
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Ramström, Olof
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi.
    Configurational and Constitutional Dynamics in Enamine Molecular SwitchesManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Dual configurational and constitutional dynamics in systems based on enamine molecularswitches has been systematically studied. pH-responsive moieties, such as 2-pyridyl and 2-quinolinyl units, were required on the “stator” part, also providing enamine stability throughintramolecular hydrogen-bonding (IMHB) effects. Upon protonation or deprotonation, forward andbackward switching could be rapidly achieved. Extension of the stator π-system in the 2-quinolinylderivative provided a higher E-isomeric equilibrium ratio under neutral conditions, pointing to ameans to achieve quantitative forward/backward isomerization processes. The ‘rotor’ part of theenamine switches exhibited constitutional exchange ability with primary amines. Interestingly,considerably higher exchange rates were observed with amines containing ester groups, indicatingpotential stabilization of the transition state trough IMHB. Acids, particularly BiIII, were found toefficiently catalyze the constitutional dynamic processes. In contrast, the enamine and the formeddynamic enamine system showed excellent stability under basic conditions. This coupledconfigurational and constitutional dynamics expand the scope of dynamic C-C and C-N bonds, andpotentiates further studies and applications in the fields of molecular machinery and systemschemistry.

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