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  • 351.
    Nameer, Samer
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. Royal Institute of Technology.
    Exploring fatty acid derivatives from renewable resources as raw materials for coating applications2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    I arbetet som presenteras i denna avhandling undersöktes epoxifettsyraderivat vid bildandet av härdplaster för ytmodifieringsapplikationer. Förnybara råvarorna björkbark och epoxiderad linolja andändes för att erhålla epoxifettsyraderivaten. Björkbarken användes för att isolera 9,10-epoxi-18-hydroxidekansyra (EFA) och epoxoderad linolja användes för att extrahera metylstearat och 3 olika epoximetylestrar: epoximetyl oleat/linoleat/linolenat (EMO/EMLO/EMLEN). Epoxifettsyraderivaten användes i olika hartsformuleringar tillammans med andra reaktanter eller vid syntes av multifunktionella oligomerhartser med hjälp av enzymatisk katalys. Med hjälp av olika polymerisationstekniker så härdades alla hartser till härdplaster med en mängd olika egenskaper.Multifunktionella oligomerhartser syntetiserades med hjälp av enzymet Candida Antarctica lipas-b (CALB). Syntesen visade sig vara effektiv och oligomererna erhölls från en sats. Dessutom var selektiviteten hos CALB användbar för att bevara en mängd olika funktionella grupper (epoxider, alkener och tioler) i de slutliga oligomererna. Tiol-ene kemi eller katjonisk polymerisation användes sedan för att härda oligomererna, vilket resulterade i funktionella härdplaster. Vidare visades att ytegenskaperna kunde ändras genom möjlighet till funktionalisering av härdplasterna.Mjuka material återfås då man härdar rena fettsyrametylestrar. Ett sätt att öka de termiska och mekaniska egenskaperna undersöktes. De tre olika epoxifunktionella metylestrarna tillsammans med furan-2,5-dicarboxylsyraderivat blandades i hartser och härdades. Genom att variera de stökiometriska förhållanderna av reaktanterna så erhölls glastemperaturer (Tg) under 0°C och över 100 °C.Undersökningen av termisk härdning av EFA som ett komponentssystem studerades genom modelstudier. Studierna visade att en självkatalyserad process sker då EFA värms upp. Detta leder således till att EFA kan termiskt härda utan behov av en tillsatt katalysator. Dessutom uppvisade härdplasten limegenskaper.Rå blandning innehållande metylstearate, EMO, EMLO och EMLEN som erhölls från epoxiderad linolja undersöktes som en reaktiv utspädare i spolbeläggningar. Blandningen jämfördes även med kommersiellt tillgängliga utspädare så som fettsyrametylestrar (FAME) erhållna från rapsolja. De erhållna resultaten påvisade att fler feta metylestrar kunde integreras i slutliga beläggningen när fettsyraderivat från epoxideradlinolja användes.Realtids Fourier-transform infrarödspektroskopi (RT-FTIR) användes under det mesta av arbetet som presenteras i denna avhandling. RT-FTIR visade sig vara ett kraftfullt vektyg för att övervaka de olika reaktionerna samt jämföra relativa reaktionshastigheter.

    Publikationen är tillgänglig i fulltext från 2020-05-01 10:00
  • 352.
    Nameer, Samer
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Deltin, Tomas
    PTE Coatings AB, Gamleby, SE-594 31, Sweden.
    Sundell, P. -E
    SSAB EMEA, Borlänge, SE-781 84, Sweden.
    Johansson, Mats
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Bio-based multifunctional fatty acid methyl esters as reactive diluents in coil coatings2019Ingår i: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 136, artikel-id 105277Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The increased environmental awareness has driven academia and industry to utilize environmentally benign sources. An industrially available process that is effective in the coatings industry is the coil-coating process where sheet steel can be pre-coated. During this process volatile organic compounds (VOCs) are generated and incinerated for energy recovery. One way to minimize VOCs is to use a reactive diluent i.e. a molecule that acts both as a solvent as well as chemically react into the final coating upon curing. Fatty acid methyl esters obtained from renewable resources such as vegetable oils are suitable candidates as reactive diluents. In this paper epoxidized fatty acid methyl esters (e-FAMEs) obtained from epoxidized linseed oil where compared with fatty acid methyl esters (FAMEs) obtained from rapeseed oil as reactive diluents in coil-coating formulations. Coil-coating formulations were followed by real-time Fourier transform infrared spectroscopy (RT-FTIR) in order to evaluate the e-FAMEs or the FAMEs reactivity in the coating system. In addition, coil-coating formulation containing e-FAME or FAME where cured in a pilot scale simulated coil-coating process. Moreover, thermal properties of the final coatings were evaluated by differential scanning calorimetry (DSC).

  • 353.
    Nameer, Samer
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. Royal Institute of Technology.
    Deltin, Tomas
    PTE Coatings AB, SE-594 31, Gamleby, Sweden.
    Sundell, Per-Erik
    SSAB EMEA, SE-781 84, Borlänge, Sweden.
    Johansson, Mats
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Bio-based multifunctional fatty acid methyl esters as reactive diluents in coil coatingsManuskript (preprint) (Övrigt vetenskapligt)
  • 354.
    Nameer, Samer
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Larsen, Daniel B.
    Tech Univ Denmark, Dept Chem & Biochem Engn, DPC, Soltofts Plads Bldg 227, DK-2800 Lyngby, Denmark.;Tech Univ Denmark, Dept Chem, Bygning 207, DK-2800 Lyngby, Denmark..
    Duus, Jens O.
    Tech Univ Denmark, Dept Chem, Bygning 207, DK-2800 Lyngby, Denmark..
    Daugaard, Anders E.
    Tech Univ Denmark, Dept Chem & Biochem Engn, DPC, Soltofts Plads Bldg 227, DK-2800 Lyngby, Denmark..
    Johansson, Mats
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Biobased Cationically Polymerizable Epoxy Thermosets from Furan and Fatty Acid Derivatives2018Ingår i: ACS Sustainable Chemistry and Engineering, ISSN 2168-0485, Vol. 6, nr 7, s. 9442-9450Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the pursuit of environmentally friendly building blocks in polymer chemistry the utilization of biobased monomers is highly desired. In the present study, the biobased monomer 2,5-furandicarboxylic acid (FDCA) has been extended into epoxy thermosets. The study presents the synthesis of diallyl furan-2,5-dicarboxylate (DAFDC) followed by an epoxidation of the allyls to form diglycidyl furan-2,5-dicarboxylate (DGFDC). DGFDC was then copolymerized in both stoichiometric and off-stoichiometric ratios with epoxidized fatty methyl esters to form a range of thermosets. The cross-linking reaction was either thermally or UV-induced cationic polymerization utilizing onium salt initiators where the reactivity was studied by DSC and real-time fourier transform infrared analysis. Furthermore, the structure-property relationships of the final thermosets were determined by dynamic mechanical thermal analysis revealing a possibility to tune the properties over a wide range. In addition thermosets were made from diglycidyl Bisphenol-A (DGEBA) with epoxidized fatty methyl esters made for comparative purposes.

  • 355.
    Nameer, Samer
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Larsen, Daniel
    Tech Univ Denmark, Dept Chem, Copenhagen, Denmark.;Tech Univ Denmark, Dept Biochem Engn, Copenhagen, Denmark..
    Johansson, Mats
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Bio-based epoxy thermosets from fatty acid derivatives2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 356.
    Nilsson, Fritjof
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Moyassari, Ali
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Bautista, Angela
    E2F, Plaza Benjamin Palencia 2-3,Entreplata 5, Albacete 02006, Spain..
    Castro, Abraham
    E2F, Plaza Benjamin Palencia 2-3,Entreplata 5, Albacete 02006, Spain..
    Arbeloa, Ignacio
    Amayuelas SL, C Orense 27,Esc B 5 Drch, Madrid 28020, Spain..
    Jarn, Mikael
    RISE Res Inst Sweden, Div Biosci & Mat, Box 5607, SE-11486 Stockholm, Sweden..
    Lundgren, Urban
    RISE Res Inst Sweden, Div Safety & Transport, Elect, Brinellgatan 4,Box 857, SE-50115 Boras, Sweden..
    Welinder, Jan
    RISE Res Inst Sweden, Div Safety & Transport, Elect, Brinellgatan 4,Box 857, SE-50115 Boras, Sweden..
    Johansson, Kenth
    RISE Res Inst Sweden, Div Biosci & Mat, Box 5607, SE-11486 Stockholm, Sweden..
    Modelling anti-icing of railway overhead catenary wires by resistive heating2019Ingår i: International Journal of Heat and Mass Transfer, ISSN 0017-9310, E-ISSN 1879-2189, Vol. 143, artikel-id 118505Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aggregation of ice on electrical cables and apparatus can cause severe equipment malfunction and is thus considered as a serious problem, especially in arctic climate zones. In particular, cable damage caused by ice accumulation on railway catenary wires is in wintertime a common origin for delayed trains in the northern parts of Europe. This study examines how resistive heating can be used for preventing formation of ice on metallic, non-insulated electrical cables. The heat equation and the Navier Stokes equations were solved simultaneously with FEM in 3D in order to predict the cable temperature as function of external temperature, applied voltage, wind speed, wind direction, and heating time. An analytical expression for the heat transfer coefficient was derived from the FEM simulations and it was concluded that the influence of wind direction can typically be neglected. Experimental validation measurements were performed on Kanthal cables in a climate chamber, giving temperature increase results in good agreement with the simulation predictions. The resistive heating efficiency, i.e. the ratio between applied electrical energy and resulting thermal energy, was found to be approximately 68% in this particular study.

  • 357.
    Niskanen, Ilpo
    et al.
    Univ Oulu, Fac Technol Struct & Construct Technol, POB 7300, FI-90014 Oulu, Finland. iskanen, Ilpo; Zakrisson, Daniel; Reza, Salim; Fedorov, Igor; Thungstrom, Goran.
    Forsberg, Viviane
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. Mid Sweden Univ, Dept Nat Sci, Holmgatan 10, SE-85170 Sundsvall, Sweden.
    Zakrisson, Daniel
    Reza, Salim
    Hummmelgård, Magnus
    Andres, Britta
    Federov, Igor
    Suopajärvi, Terhi
    Liimatainen, Henrikki
    Thungström, Göran
    Determination of nanoparticle size using Rayleigh approximation and Mie theory2019Ingår i: Chemical Engineering Science, ISSN 0009-2509, E-ISSN 1873-4405, Vol. 201, s. 222-229Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Accurate determination of the size of nanoparticles has an important role in many different scientific and industrial purposes, such as in material, medical and environment sciences, colloidal chemistry and astrophysics. We describe an effective optical method to determine the size of nanoparticles by analysis of transmission and scattering of visible spectral range data from a designed UV-Vis multi-spectrophotometer. The size of the nanoparticles was calculated from the extinction cross section of the particles using Rayleigh approximation and Mie theory. We validated the method using polystyrene nanospheres, cellulose nanofibrils, and cellulose nanocrystals. A good agreement was achieved through graphical analysis between measured extinction cross section values and theoretical Rayleigh approximation and Mie theory predictions for the sizes of polystyrene nanospheres at wavelength range 450-750 nm. Provided that Rayleigh approximation's forward scattering (FS)/back scattering (BS) ratio was smaller than 1.3 and Mie theory's FS/BS ratio was smaller than 1.8. A good fit for the hydrodynamic diameter of nanocellulose was achieved using the Mie theory and Rayleigh approximation. However, due to the high aspect ratio of nanocellulose, the obtained results do not directly reflect the actual cross-sectional diameters of the nanocellulose. Overall, the method is a fast, relatively easy, and simple technique to determine the size of a particle by a spectrophotometer. Consequently, the method can be utilized for example in production and quality control purposes as well as for research and development applications.

  • 358.
    Nordenström, Malin
    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.
    Nystrom, Gustav
    Empa, Lab Appl Wood Mat, Dubendorf, Switzerland..
    Fall, Andreas
    Res Inst Sweden, RISE, Bioecon, Stockholm, Sweden..
    Wågberg, Lars
    KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellens Centrum BiMaC Innovation. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Colloidal gels and glasses from nanocelluloses2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 359.
    Nordenström, Malin
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Riazanova, Anastasia
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Järn, Mikael
    RISE Res Inst Sweden, Div Biosci & Mat, SE-11428 Stockholm, Sweden..
    Paulraj, Thomas
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Turner, Charlotta
    Lund Univ, Dept Chem, SE-22100 Lund, Sweden..
    Ström, Valter
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Olsson, Richard
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Svagan, Anna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Superamphiphobic coatings based on liquid-core microcapsules with engineered capsule walls and functionality2018Ingår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, artikel-id 3647Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Microcapsules with specific functional properties, related to the capsule wall and core, are highly desired in a number of applications. In this study, hybrid cellulose microcapsules (1.2 +/- 0.4 mu m in diameter) were prepared by nanoengineering the outer walls of precursor capsules. Depending on the preparation route, capsules with different surface roughness (raspberry or broccoli-like), and thereby different wetting properties, could be obtained. The tunable surface roughness was achieved as a result of the chemical and structural properties of the outer wall of a precursor capsule, which combined with a new processing route allowed in-situ formation of silica nanoparticles (30-40 nm or 70 nm in diameter). By coating glass slides with "broccoli-like" microcapsules (30-40 nm silica nanoparticles), static contact angles above 150 degrees and roll-off angles below 6 degrees were obtained for both water and low surface-tension oil (hexadecane), rendering the substrate superamphiphobic. As a comparison, coatings from raspberry-like capsules were only strongly oleophobic and hydrophobic. The liquid-core of the capsules opens great opportunities to incorporate different functionalities and here hydrophobic superparamagnetic nanoparticles (SPIONs) were encapsulated. As a result, magnetic broccoli-like microcapsules formed an excellent superamphiphobic coating-layer on a curved geometry by simply applying an external magnetic field.

  • 360.
    Nordstrom, Randi
    et al.
    Uppsala Univ, Dept Pharm, SE-75123 Uppsala, Sweden..
    Andrén, Oliver C. J.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Singh, Shalini
    Uppsala Univ, Dept Pharm, SE-75123 Uppsala, Sweden..
    Malkoch, Michael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Davoudi, Mina
    Lund Univ, Dept Clin Sci, Div Dermatol & Venereol, SE-22184 Lund, Sweden..
    Schmidtchen, Artur
    Lund Univ, Dept Clin Sci, Div Dermatol & Venereol, SE-22184 Lund, Sweden.;Univ Copenhagen, Bispebjerg Hosp, Wound Healing Ctr, Dept Biomed Sci, DK-2200 Copenhagen, Denmark..
    Malmsten, Martin
    Uppsala Univ, Dept Pharm, SE-75123 Uppsala, Sweden.;Univ Copenhagen, Dept Pharm, DK-2100 Copenhagen, Denmark..
    Degradable dendritic nanogels as carriers for antimicrobial peptides2019Ingår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 554, s. 592-602Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the present study, we investigate degradable anionic dendritic nanogels (DNG) as carriers for antimicrobial peptides (AMPS). In such systems, the dendritic part contains carboxylic acid-based anionic binding sites for cationic AMPs, whereas linear poly(ethylene glycol) (PEG) chains form a shell for promotion of biological stealth. In order to clarify factors influencing membrane interactions of such systems, we here address effects of nanogel charge, cross-linking, and degradation on peptide loading/release, as well as consequences of these factors for lipid membrane interactions and antimicrobial effects. The DNGs were found to bind the AMPs LL-37 (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES) and DPK-060 (GKHKNKGKKNGKHNGWKWWW). For the smaller DPK-060 peptide, loading was found to increase with increasing nanogel charge density. For the larger LL-37, on the other hand, peptide loading was largely insensitive to nanogel charge density. In line with this, results on the secondary structure, as well as on the absence of stabilization from proteolytic degradation by the nanogels, show that the larger LL-37 is unable to enter into the interior of the nanogels. While 40-60% nanogel degradation occurred over 10 days, promoted at high ionic strength and lower cross-linking density/higher anionic charge content, peptide release at physiological ionic strength was substantially faster, and membrane destabilization not relying on nanogel degradation. Ellipsometry and liposome leakage experiments showed both free peptide and peptide/DNG complexes to cause membrane destabilization, indicated also by antimicrobial activities being comparable for nanogel-bound and free peptide. Finally, the DNGs were demonstrated to display low toxicity towards erythrocytes even at peptide concentrations of 100 mu M.

  • 361.
    Nordström, Randi
    et al.
    Ms, Dept Pharm, Uppsala, Sweden..
    Nyström, Lina
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Andrén, Oliver C. J.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Malkoch, Michael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Umerska, Anita
    MINT Univ Angers, Angers, France..
    Davoudi, Mina
    Lund Univ, Dept Clin Sci, Lund, Sweden..
    Schmidtchen, Artur
    Lund Univ, Dept Clin Sci, Lund, Sweden..
    Malmsten, Martin
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Poly(acrylic acid) microgels as carriers for antimicrobial peptides2018Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Artikel i tidskrift (Övrigt vetenskapligt)
  • 362.
    Norström, Emelie
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Hemicelluloses and other Polysaccharides for Wood Adhesive Applications2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The growing environmental awareness has led to an increased interest in bio-based polymers as replacement for fossil-based materials. The purpose of the work described in this thesis was to investigate the possibility of using hemicelluloses and other polysaccharides as replacement for fossil-based polymers in wood adhesives. Together with cellulose and lignin, hemicellulose is the main constituent of wood. In the pulp industry, significant amounts of hemicelluloses are obtained as by-products and combusted for energy recovery, but there is a growing interest in the biorefinery concept where all side-streams are utilized. If valuable applications, such as adhesives, of hemicelluloses and other by-products are found, large amounts can be obtained from the pulp industry. Water dispersions of hemicelluloses and other polysaccharides have been prepared and evaluated as adhesives for bonding different wood substrates together. The dry bond strength, water resistance, and heat resistance were investigated by exposing the bonded wood specimens to different conditioning methods and thereafter measuring the tensile shear strengths. As a replacement, the bio-based wood adhesive must possess similar or even better properties than the fossil-based adhesives. A commercial poly(vinyl acetate) (PVAc) wood adhesive used for indoor applications has been used as a reference benchmark. Wood hemicelluloses themselves do not have sufficient bonding performance probably because their low molecular weight does not provide adequate strength and makes the adhesive too brittle. The addition of dispersing agents and crosslinkers to the hemicellulose dispersions can significantly improve the bonding performance, and hemicellulose in combination with poly(vinyl amine) showed promising results superior those of PVAc. A fully bio-based adhesive comprising of hemicellulose and chitosan, another bio-based polysaccharide, obtain surprisingly good bonding performance especially with regard to water resistance. Gums, polysaccharides with similar structures to those of hemicelluloses but with higher molecular weights, have also been studied and locust bean gum dispersions without any modification showed a very good bonding performance with high dry bond strength and water resistance on a par with those of PVAc and a heat resistance superior to that of PVAc. Chitosan has very good adhesive properties especially with regard to water resistance, but the high viscosity of the chitosan dispersion makes it difficult to apply. Chitosan-grafted-PVAc dispersions were therefore prepared and an adhesive very similar in appearance to PVAc was obtained with a good bonding performance as well as good applicability.

  • 363.
    Odelius, Karin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Design of renewable polymeric materials through ring-opening reactions2018Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 256Artikel i tidskrift (Övrigt vetenskapligt)
  • 364.
    Odelius, Karin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Ring-opening reactions to functional polyamides and polyurethanes2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 365.
    Ogonowski, Martin
    et al.
    Stockholm Univ, Dept Environm Sci & Analyt Chem, Svante Arrhenius Vag 8, S-11418 Stockholm, Sweden..
    Edlund, Ulrica
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Gorokhova, Elena
    Stockholm Univ, Dept Environm Sci & Analyt Chem, Svante Arrhenius Vag 8, S-11418 Stockholm, Sweden..
    Linde, Margareta
    Stockholm Univ, Dept Environm Sci & Analyt Chem, Svante Arrhenius Vag 8, S-11418 Stockholm, Sweden..
    Ek, Karin
    Stockholm Univ, Dept Environm Sci & Analyt Chem, Svante Arrhenius Vag 8, S-11418 Stockholm, Sweden..
    Liewenborg, Birgitta
    Stockholm Univ, Dept Environm Sci & Analyt Chem, Svante Arrhenius Vag 8, S-11418 Stockholm, Sweden..
    Konnecke, Oda
    Stockholm Univ, Dept Environm Sci & Analyt Chem, Svante Arrhenius Vag 8, S-11418 Stockholm, Sweden..
    Navarro, Julien R. G.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Breitholtz, Magnus
    Stockholm Univ, Dept Environm Sci & Analyt Chem, Svante Arrhenius Vag 8, S-11418 Stockholm, Sweden..
    Multi-level toxicity assessment of engineered cellulose nanofibrils in Daphnia magna2018Ingår i: Nanotoxicology, ISSN 1743-5390, E-ISSN 1743-5404, Vol. 12, nr 6, s. 509-521Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cellulose nanofibril (CNF)-based materials are increasingly used in industrial and commercial applications. However, the impacts of CNF on aquatic life are poorly understood, and there are concerns regarding their potential toxicity. Using a combination of standard ecotoxicological tests and feeding experiments, we assessed the effects of CNF exposure (0.206-20.6 mg/L) on the feeding (food uptake and gut residence time) and life-history traits (growth and reproduction) in the cladoceran Daphnia magna. No mortality was observed in a 48 h acute exposure at 2060 mg/L. Moreover, a 21-day exposure at low food and moderate CNF levels induced a stimulatory effect on growth, likely driven by increased filtration efficiency, and, possibly, partial assimilation of the CNF by the animals. However, at low food levels and the highest CNF concentrations, growth and reproduction were negatively affected. These responses were linked to caloric restriction caused by dilution of the food source, but not an obstruction of the alimentary canal. Finally, no apparent translocation of CNF past the alimentary canal was detected. We conclude that CNF displays a low toxic potential to filter-feeding organisms and the expected environmental risks are low.

  • 366. Ohm, Wiebke
    et al.
    Rothkirch, Andre
    Pandit, Pallavi
    Koerstgens, Volker
    Mueller-Buschbaum, Peter
    Rojas, Ramiro
    Yu, Shun
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Brett, Calvin J.
    Soderberg, Daniel L.
    Roth, Stephan V.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Biokompositer.
    Morphological properties of airbrush spray-deposited enzymatic cellulose thin films2018Ingår i: JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, ISSN 1945-9645, Vol. 15, nr 4, s. 759-769Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigate the layer formation of enzymatic cellulose by airbrush spray coating on silicon oxide surfaces. The layer structure and morphology of enzymatic cellulose films in the thickness range between 86 nm and 2.1 A mu m is determined as a function of the spray coating procedures. For each spray coating step, layer buildup, surface topography, crystallinity as well as the nanoscale structure are probed with atomic force microscopy and surface-sensitive X-ray scattering methods. Without intermittent drying, the film thickness saturates; with intermittent drying, a linear increase in layer thickness with the number of spray pulses is observed. A closed cellulose layer was always observed. The crystallinity remains unchanged; the nanoscale structures show three distinct sizes. Our results indicate that the smallest building blocks increasingly contribute to the morphology inside the cellulose network for thicker films, showing the importance of tailoring the cellulose nanofibrils. For a layer-by-layer coating, intermittent drying is mandatory.

  • 367.
    Ohm, Wiebke
    et al.
    DESY, Hamburg, Germany..
    Rothkirch, Andre
    DESY, Hamburg, Germany..
    Pandit, Pallavi
    DESY, Hamburg, Germany..
    Koerstgens, Volker
    Tech Univ Munich, Garching, Germany..
    Mueller-Buschbaum, Peter
    Tech Univ Munich, Garching, Germany..
    Rojas, Ramiro
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Yu, Shun
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Brett, Calvin
    KTH, Skolan för teknikvetenskap (SCI), Mekanik, Strömningsfysik.
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för teknikvetenskap (SCI), Mekanik, Strömningsfysik.
    Roth, Stephan V.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Biokompositer. DESY, Hamburg, Germany..
    Morphological and crystalline properties of airbrush spray-deposited enzymatic cellulose thin films2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 368.
    Ojansivu, Miina
    et al.
    Tampere Univ, Fac Med & Hlth Technol, Adult Stem Cell Res Grp, Tampere, Finland.;Tampere Univ Hosp, Res Dev & Innovat Ctr, Tampere, Finland.;Univ Bergen, Fac Med, Dept Clin Dent, Tissue Engn Grp, Bergen, Norway..
    Rashad, Ahmad
    Univ Bergen, Fac Med, Dept Clin Dent, Tissue Engn Grp, Bergen, Norway..
    Ahlinder, Astrid
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Massera, Jonathan
    Tampere Univ, Fac Med & Hlth Technol, Lab Biomat & Tissue Engn, Tampere, Finland..
    Mishra, Ayush
    Tampere Univ, Fac Med & Hlth Technol, Lab Biomat & Tissue Engn, Tampere, Finland..
    Syverud, Kristin
    RISE PFI, Trondheim, Norway.;Norwegian Univ Sci & Technol, Dept Chem Engn, Trondheim, Norway..
    Finne Wistrand, Anna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Miettinen, Susanna
    Tampere Univ, Fac Med & Hlth Technol, Adult Stem Cell Res Grp, Tampere, Finland.;Tampere Univ Hosp, Res Dev & Innovat Ctr, Tampere, Finland..
    Mustafa, Kamal
    Univ Bergen, Fac Med, Dept Clin Dent, Tissue Engn Grp, Bergen, Norway..
    Wood-based nanocellulose and bioactive glass modified gelatin-alginate bioinks for 3D bioprinting of bone cells2019Ingår i: Biofabrication, ISSN 1758-5082, E-ISSN 1758-5090, Vol. 11, nr 3, artikel-id 035010Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A challenge in the extrusion-based bioprinting is to find a bioink with optimal biological and physicochemical properties. The aim of this study was to evaluate the influence of wood-based cellulose nanofibrils (CNF) and bioactive glass (BaG) on the rheological properties of gelatin-alginate bioinks and the initial responses ofbone cells embedded in these inks. CNF modulated the flow behavior of the hydrogels, thus improving their printability. Chemical characterization by SEM-EDX and ion release analysis confirmed the reactivity of the BaG in the hydrogels. The cytocompatibility of the hydrogels was shown to be good, as evidenced by the viability of human osteoblast-like cells (Saos-2) in cast hydrogels. For bioprinting, 4-layer structures were printed from cell-containing gels and crosslinked with CaCl2. Viability, proliferation and alkaline phosphatase activity (ALP) were monitored over 14 d. In the BaG-free gels, Saos-2 cells remained viable, but in the presence of BaG the viability and proliferation decreased in correlation with the increased viscosity. Still, there was a constant increase in the ALP activity in all the hydrogels. Further bioprinting experiments were conducted using human bone marrow-derived mesenchymal stem cells (hBMSCs), a clinically relevant cell type. Interestingly, hBMSCs tolerated the printing process better than Saos-2 cells and the ALP indicated BaG-stimulated early osteogenic commitment. The addition of CNF and BaG to gelatin-alginate bioinks holds great potential for bone tissue engineering applications.

  • 369.
    Oliveira de Castro, Danielle
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Karim, Zoheb
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Medina, Lilian
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Biokompositer.
    Svedberg, A.
    Wågberg, Lars
    Söderberg, Daniel
    KTH, Skolan för teknikvetenskap (SCI), Mekanik.
    Berglund, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Scale up of nanocellulose/hybrid inorganic films using a pilot web former2017Ingår i: International Conference on Nanotechnology for Renewable Materials 2017, TAPPI Press , 2017, s. 408-418Konferensbidrag (Refereegranskat)
  • 370.
    Olsen, Peter
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Jawerth, Marcus
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lawoko, Martin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Johansson, Mats
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Berglund, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Biokompositer. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Transforming technical lignins to structurally defined star-copolymers under ambient conditions2019Ingår i: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 21, nr 9, s. 2478-2486Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Transforming biomass derived components to materials with controlled and predictable properties is a major challenge. Current work describes the controlled synthesis of starcopolymers with functional and degradable arms from the Lignoboost (R) process. Macromolecular control is achieved by combining lignin fractionation and characterization with ring-opening copolymerization (ROCP). The cyclic monomers used are epsilon-caprolactone (epsilon CL) and a functional carbonate monomer, 2-allyloxymethyl-2-ethyltrimethylene carbonate (AOMEC). The synthesis is performed at ambient temperature, under bulk conditions, in an open flask, and the graft composition and allyl functionality distribution are controlled by the copolymerization kinetics. Emphasis is placed on understanding the initiation efficiency, structural changes to the lignin backbone and the final macromolecular architecture. The present approach provides a green, scalable and cost effective protocol to create well-defined functional macromolecules from technical lignins.

  • 371.
    Ottenhall, Anna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Antimicrobial materials from cellulose using environmentally friendly techniques2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Satsningen på ett mer biobaserat samhälle, där vi ersätter icke-förnybara material med förnyelsebara alternativ, är en pusselbit för en mer hållbar framtid samtidigt som den medför nya utmaningar. En viktig uppgift är att minska och kontrollera mikrobiell tillväxt, både för att skydda material från biologisk nedbrytning men också för att förhindra spridning av infektioner och toxiner.

    Cellulosabaserade material har behandlats med miljövänliga alternativ till traditionella biocider för att förhindra mikrobiell tillväxt och för ta bort bakterier från vatten. Två typer av antimikrobiella system har använts varefter den antimikrobiella effekten mot både mögel och bakterier utvärderats, med hjälp av både modellorganismer och mikrobiella odlingar från naturen.

    Den första typen av antimikrobiell metod som använts baseras på en kontakt-aktivt teknik. Cellulosafibrer har modifierats genom lager-på-lager polyelektrolytadsorption för att skapa en positiv ytladdning som kan attrahera och binda bakterier till fiberytan. Studien visar att modifierade pappersfilter, med porer som är mycket större än bakterier, kan filtrera bort mer än 99,9 % av E. coli från kontaminerat vatten. De polyelektrolyt-modifierade cellulosamaterialen påvisade goda antibakteriella egenskaper men förhindrade inte tillväxt av mögel.

    Den andra metoden som undersökts var att tillsätta biobaserade ämnen med antimikrobiella egenskaper till cellulosabaserade fiberskum. Kitosan och extraktivämnen från björkbark valdes ut som miljövänliga alternativ till vanliga biocider. Två typer av cellulosabaserade fiberskum har tagits fram och utvärderats för deras antimikrobiella egenskaper.

    Avhandlingen visar hur viktigt det är att veta hur materialet är tänkt att användas och vilken typ av mikroorganism som skall undvikas när man väljer antimikrobiell behandling av biobaserade material. God förståelse för både materialvetenskap och mikrobiologi är nödvändig när nya biobaserade material med antimikrobiella egenskaper skall designas.

  • 372.
    Ottenhall, Anna
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Henschen, Jonatan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Illergård, Josefin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Ek, Monica
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Cellulose-based water purification using paper filters modified with polyelectrolyte multilayers to remove bacteria from water through electrostatic interactions2018Ingår i: Environmental Science: Water Research & Technology, ISSN 2053-1400Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Filtration is a common way to obtain pure drinking water by removing particles and microorganisms based on size exclusion. Cellulose-based filters are affordable and biobased option for the removal of particles but bacteria are usually too small to be removed by size exclusion alone. In this article, the surfaces of cellulose fibres in two types of commercial paper filters have been given a positive net charge to trap bacteria through electrostatic interactions without releasing any biocides. The fibres were modified with the cationic polyelectrolyte polyvinylamine polymer in single layers (1 L) or in multilayers together with the anionic polyelectrolyte polyacrylic acid (3 L or 5 L) using a water-based process at room temperature. Filtration tests show that all filters, using both types of filter papers and a number of layers, can physically remove more than 99.9% of E. coli from water and that the 3 L modified filters can remove more than 97% of cultivatable bacteria from natural water samples. The bacterial reduction increased with increasing number of filter sheets used for the filtration and the majority of the bacteria were trapped in the top sheets of the filter. The results show the potential for creating water purification filters from bio-based everyday consumable products with a simple modification process. The filters could be used in the future for point-of-use water purification that may be able to save lives without releasing bactericides.

  • 373.
    Ottenhall, Anna
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Illergård, Josefin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Ek, Monica
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Water Purification Using Functionalized Cellulosic Fibers with Nonleaching Bacteria Adsorbing Properties2017Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 51, s. 7616-7623Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Portable purification systems are easy ways to obtain clean drinking water when there is no large-scale water treatment available. In this study, the potential to purify water using bacteria adsorbing cellulosic fibers, functionalized with polyelectrolytes according to the layer-by-layer method, is investigated. The adsorbed polyelectrolytes create a positive charge on the fiber surface that physically attracts and bonds with bacteria. Three types of cellulosic materials have been modified and tested for the bacterial removal capacity in water. The time, material-water ratio and bacterial concentration dependence, as well as the bacterial removal capacity in water from natural sources, have been evaluated. Freely dispersed bacteria adsorbing cellulosic fibers can remove greater than 99.9% of Escherichia coli from nonturbid water, with the most notable reduction occurring within the first hour. A filtering approach using modified cellulosic fibers is desirable for purification of natural water. An initial filtration test showed that polyelectrolyte multilayer modified cellulosic fibers can remove greater than 99% of bacteria from natural water. The bacteria adsorbing cellulosic fibers do not leach any biocides, and it is an environmentally sustainable and cheap option for disposable water purification devices.

  • 374.
    Ottenhall, Anna
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Seppänen, Tiinamari
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Ek, Monica
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Water-stable cellulose fiber foam with antimicrobial properties for bio based low-density materials2018Ingår i: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 25, nr 4, s. 2599-2613Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    New bio-based packaging materials are highly interesting for replacing conventional fossil based products for a more sustainable society. Water-stable cellulose fiber foams have been produced in a simple one-batch foam-forming process with drying under ambient conditions. The cellulose fiber foams have a low density (33–66 kg/m3) and can inhibit microbial growth; two highly valuable features for insulating packaging materials, especially in combination with stability in water. Cationic chitosan and/or polyvinylamine have been added during the foam-forming process to give the foams water-stability and antimicrobial properties. The structural and mechanical properties of the cellulose fiber foams have been studied and the antimicrobial properties have been evaluated with respect to both Escherichia coli, a common model bacteria and Aspergillus brasiliensis, a sporulating mold. The cellulose foams containing chitosan had both good water-stability and good antibacterial and antifungal properties, while the foams containing PVAm did disintegrate in water and did not inhibit fungal growth when nutrients were added to the foam, showing that it is possible to produce a bio-based foam material with the desired characters. This can be an interesting low-density packaging material for protection from both mechanical and microbial damage without using any toxic compounds.

  • 375.
    Ouyang, Liangqi
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi. Linkoping Univ, IFM, Linkoping, Sweden..
    Elfwing, Anders
    Linkoping Univ, IFM, Linkoping, Sweden..
    Ponseca, Carlito
    Linkoping Univ, IFM, Linkoping, Sweden..
    Cai, Wanzhu
    Linkoping Univ, IFM, Linkoping, Sweden..
    Inganas, Olle
    Linkoping Univ, IFM, Linkoping, Sweden..
    Decorating biomolecules and bio-structures with metallic conducting polymers2018Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 256Artikel i tidskrift (Övrigt vetenskapligt)
  • 376.
    Ozeren, Husamettin Deniz
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Nilsson, Fritjof
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Olsson, Richard
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Hedenqvist, Mikael S.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Prediction of plasticization mechanisms for biobased plastics through a combined experimental and molecular dynamics simulations approach2018Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 256Artikel i tidskrift (Övrigt vetenskapligt)
  • 377.
    Pandit, Pallavi
    et al.
    DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Schwartzkopf, Matthias
    DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Rothkirch, Andre
    DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Roth, Stephan V.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Bernstorff, Sigrid
    Elettra Sincrotrone Trieste, SS 14,Km 163-5, I-34149 Trieste, Italy..
    Gupta, Ajay
    Amity Univ, Ctr Spintron Mat, Noida 201313, UP, India..
    Structure-Function Correlations in Sputter Deposited Gold/Fluorocarbon Multilayers for Tuning Optical Response2019Ingår i: NANOMATERIALS, ISSN 2079-4991, Vol. 9, nr 9, artikel-id 1249Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new strategy to nanoengineer gold/fluorocarbon multilayer (ML) nanostructures is reported. We have investigated the morphological changes occurring at the metal-polymer interface in ML structures with varying volume fraction of gold (Au) and the kinetic growth aspect of the microscale properties of nano-sized Au in plasma polymer fluorocarbon (PPFC). Investigations were carried out at various temperatures and annealing times by means of grazing incidence small-angle and wide-angle X-ray scattering (GISAXS and GIWAXS). We have fabricated a series of MLs with varying volume fraction (0.12, 0.27, 0.38) of Au and bilayer periodicity in ML structure. They show an interesting granular structure consisting of nearly spherical nanoparticles within the polymer layer. The nanoparticle (NP) morphology changes due to the collective effects of NPs diffusion within ensembles in the in-plane vicinity and interlayer with increasing temperature. The in-plane NPs size distinctly increases with increasing temperature. The NPs become more spherical, thus reducing the surface energy. Linear growth of NPs with temperature and time shows diffusion-controlled growth of NPs in the ML structure. The structural stability of the multilayer is controlled by the volume ratio of the metal in polymer. At room temperature, UV-Vis shows a blue shift of the plasmon peak from 560 nm in ML Au/PTFE_1 to 437 nm in Au/PTFE_3. We have identified the fabrication and postdeposition annealing conditions to limit the local surface plasmon resonance (LSPR) shift from Delta lambda(LSPR) = 180 nm (Au/PTFE_1) to Delta lambda(LSPR) = 67 nm (Au/PTFE_3 ML)) and their optical response over a wide visible wavelength range. A variation in the dielectric constant of the polymer in presence of varying Au inclusion is found to be a possible factor affecting the LSPR frequency. Our findings may provide insights in nanoengineering of ML structure that can be useful to systematically control the growth of NPs in polymer matrix.

  • 378.
    Panzer, Matthew B.
    et al.
    Univ Virginia, Ctr Appl Biomech, Charlottesville, VA USA..
    Giudice, J. Sebastian
    Univ Virginia, Ctr Appl Biomech, Charlottesville, VA USA..
    Caudillo, Adrian
    Univ Virginia, Ctr Appl Biomech, Charlottesville, VA USA..
    Mukherjee, Sayak
    Univ Virginia, Ctr Appl Biomech, Charlottesville, VA USA..
    Kong, Kevin
    Univ Virginia, Ctr Appl Biomech, Charlottesville, VA USA..
    Cronin, Duane S.
    Univ Waterloo, Waterloo, ON, Canada..
    Barker, Jeffrey
    Univ Waterloo, Waterloo, ON, Canada..
    Gierczycka, Donata
    Univ Waterloo, Waterloo, ON, Canada..
    Bustamante, Michael
    Univ Waterloo, Waterloo, ON, Canada..
    Bruneau, David
    Univ Waterloo, Waterloo, ON, Canada..
    Corrales, Miguel
    Univ Waterloo, Waterloo, ON, Canada..
    Halldin, Peter
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Medicinteknik och hälsosystem, Neuronik.
    Fahlstedt, Madelen
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Medicinteknik och hälsosystem, Neuronik.
    Arnesen, Marcus
    Jungstedt, Erik
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Biokompositer. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Gayzik, F. Scott
    Wake Forest Univ, Bowman Gray Sch Med, Winston Salem, NC USA..
    Stitzel, Joel D.
    Wake Forest Univ, Bowman Gray Sch Med, Winston Salem, NC USA..
    Decker, William
    Wake Forest Univ, Bowman Gray Sch Med, Winston Salem, NC USA..
    Baker, Alex M.
    Wake Forest Univ, Bowman Gray Sch Med, Winston Salem, NC USA..
    Ye, Xin
    Wake Forest Univ, Bowman Gray Sch Med, Winston Salem, NC USA..
    Brown, Philip
    Wake Forest Univ, Bowman Gray Sch Med, Winston Salem, NC USA..
    NUMERICAL CROWDSOURCING OF NFL FOOTBALL HELMETS2018Ingår i: Journal of Neurotrauma, ISSN 0897-7151, E-ISSN 1557-9042, Vol. 35, nr 16, s. A148-A148Artikel i tidskrift (Övrigt vetenskapligt)
  • 379.
    Pappalardo, Daniela
    et al.
    Univ Sannio, Dept Sci & Technol, Via Mulini, I-82100 Benevento, Italy..
    Mathisen, Torbjorn
    Novus Sci AB, Virdings Alle 2, S-75450 Uppsala, Sweden..
    Finne Wistrand, Anna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Biocompatibility of Resorbable Polymers: A Historical Perspective and Framework for the Future2019Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, nr 4, s. 1465-1477Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The history of resorbable polymers containing glycolide, lactide, e-caprolactone and trimethylene carbonate, with a special emphasis being placed on the time frame of the 1960s-1990s is described. Reviewing the history is valuable when looking into the future perspectives regarding how and where these monomers should be used. This story includes scientific evaluations indicating that these polymers are safe to use in medical devices, while the design of the medical device is not considered in this report. In particular, we present the data regarding the tissue response to implanted polymers, as well as the toxicity and pharmacokinetics of their degradation products. In the translation of these polymers from "the bench to the bedside," various challenges have been faced by surgeons, medical doctors, biologists, material engineers and polymer chemists. This Perspective highlights the visionary role played by the pioneers, addressing the problems that occurred on a case by case basis in translational medicine.

  • 380.
    Paulraj, Thomas
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymera material.
    Plant cell-inspiredmicrocontainers: Fabrication, Characterization and Applications2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Biomimetiska material har inspirerat mänskligheten sedan längeför applikationer inom olika områden. Framställningen av lipidbaserade vesiklarhar särskilt bidragit till vår förståelse av olika funktioner i djurceller samt tjänatsom t.ex. läkemedelsleveranssystem och bioreaktorer. Tvärtom är beredningen avsyntetiska växtceller begränsad, vilket främst beror på utmaningarna med attbygga och kombinera den komplexa primära cellvägg en med ett lipid-baseratplasmamembran.Denna avhandling fokuserar på ”bottom-up” tillverkning avbiomimetiska mikrobehållare som kan fungera som enkla modellsystem förväxtceller. I den första delen undersöks växelverkningarna mellanväxtcellväggspolysackariderna, cellulosa-nanofibrer (CNF), pektin och xyloglucan.Kunskapen används i nästa steg vid tillverkning av mikrokapslar. Resultaten visaratt, om man vill införliva alla tre polysackarider, måste de adsorberas i en specifikordning. Dessutom beror den strukturella stabiliteten och permeabiliteten hoskapselväggen på kapselväggkompositionen. Permeabiliteten beror också påsammansättningen hos den omgivande vätskan.Den andra delen behandlar tillverkning av mer avanceradebiomimetiska mikrokapslar, som innehåller ett lipidskikt underpolysackaridkapselväggen. Dessa kapslar är permeabla för vissa storlekar avmolekyler men inte andra. Lipidernas fasbeteende utnyttjas för att växa tubulärastrukturer (långa trådformade strukturer) genom kapselväggen, samt för att skapaen inre kapselmiljö som består av många små vesiklar. Växtceller i naturenanvänder rörformade strukturer (så kallade plasmodesmata) för att transporteramolekyler mellan närliggande celler.I den tredje delen diskuteras applikationsorienterade aspekter.Mikrokapslarna, som tillverkat med LbL-tekniken (från den första delen), kanladdas med ett glukosoxidas-enzym, varigenom de går att använda somglukossensor. Permeabilitetsegenskaperna hos kapselväggen tillåter bara att småmolekyler att passerar snabbt. Slutligen visar cellkultursexperiment att kapslarnaär biokompatibla, vilket banar väg för nya biomedicinska applikationer.

    Publikationen är tillgänglig i fulltext från 2020-10-01 11:00
  • 381.
    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 applications2018Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 256Artikel i tidskrift (Övrigt vetenskapligt)
  • 382.
    Paulraj, Thomas
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Riazanova, A. V.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Svagan, A. J.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Bioinspired capsules based on nanocellulose, xyloglucan and pectin - The influence of capsule wall composition on permeability properties2018Ingår i: Acta Biomaterialia, ISSN 1742-7061, E-ISSN 1878-7568, Vol. 69, s. 196-205Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Materials based on renewable biopolymers, selective permeability and stimuli-responsive release/loading properties play an important role in biomedical applications. Here, in order to mimic the plant primary cell-wall, microcapsules have been fabricated using cell wall polysaccharides, namely pectin, xyloglucan and cellulose nanofibers. For the first time, a large amount of xyloglucan was successfully included in such capsules. These capsules demonstrated stimuli-responsive (ON/OFF) permeability and biocompatibility. The live cell staining revealed that the microcapsules' surface enhanced cell growth and also the non-toxic nature of the microcapsules. In water, the microcapsules were completely and partially permeable to fluorescent dextrans with an average molecular weight of 70 kDa (hydrodynamic diameter of ca. 12 nm) and 2000 kDa (ca. 54 nm), respectively. On the other hand, the permeability dropped quickly when the capsules were exposed to 250 mM NaCl solution, trapping a fraction of the 70 kDa dextrans in the capsule interior. The decrease in permeability was a direct consequence of the capsule-wall composition, i.e. the presence of xyloglucan and a low amount of charged molecules such as pectin. The low permeability of capsules in saline conditions (and in a model biological medium), combined with a capsule wall that is made from dietary fibers only, potentially enables their use in biological applications, such as colon targeted delivery in the gastro-intestinal tract. 

  • 383.
    Paulraj, Thomas
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymera material.
    Riazanova, Anastasia
    Yao, Kun
    KTH, Skolan för bioteknologi (BIO).
    Andersson, Richard L.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Müllertz, Anette
    Svagan, Anna Justina
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Bioinspired Layer-by-Layer Microcapsules Based on Cellulose Nanofibers with Switchable Permeability2017Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 18, nr 4, s. 1401-1410Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Green, all-polysaccharide based microcapsules with mechanically robust capsule walls and fast, stimulitriggered, and switchable permeability behavior show great promise in applications based on selective and timed permeability. Taking a cue from nature, the build-up and composition of plant primary cell walls inspired the capsule wall assembly, because the primary cell walls in plants exhibit high mechanical properties despite being in a highly hydrated state, primarily owing to cellulose microfibrils. The microcapsules (16 ± 4 μm in diameter) were fabricated using the layer-by-layer technique on sacrificial CaCO3 templates, using plant polysaccharides (pectin, cellulose nanofibers, and xyloglucan) only. In water, the capsule wall was permeable to labeled dextrans with a hydrodynamic diameter of ∼6.6 nm. Upon exposure to NaCl, the porosity of the capsule wall quickly changed allowing larger molecules (∼12 nm) to permeate. However, the porosity could be restored to its original state by removal of NaCl, by which permeants became trapped inside the capsule’s core. The high integrity of cell wall was due to the CNF and the ON/OFF alteration of the permeability properties, and subsequent loading/unloading of molecules, could be repeated several times with the same capsule demonstrating a robust microcontainer with controllable permeability properties.

  • 384.
    Paulraj, Thomas
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Svagan, Anna Justina
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Bioinspired capsules based on nanocellulose, xyloglucan and pectin for biomedical applications2018Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Artikel i tidskrift (Övrigt vetenskapligt)
  • 385.
    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 Sensing2018Ingår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, nr 48, s. 41146-41154Artikel i tidskrift (Refereegranskat)
    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.

  • 386.
    Paulraj, Thomas
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymera material.
    Wennmalm, Stefan
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Wieland, D.C. Florian
    Dédinaité, Andra
    KTH, Tidigare Institutioner (före 2005), Kemi.
    Pomorski, T. Günther
    Cárdenas, M.
    Svagan, Anna Justina
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Assembly of Primary Cell-Wall inspired Microcontainers, Plantosomes, as a step towards a Synthetic Plant-CellManuskript (preprint) (Övrigt vetenskapligt)
  • 387. Pavlidis, I. V.
    et al.
    Hendrikse, Natalie
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Syrén, Per-Olof
    KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Chapter 5: Computational Techniques for Efficient Biocatalysis2018Ingår i: RSC Catalysis Series, nr 32, s. 119-152Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Addressing some of the most challenging problems that we face today, including depletion of natural resources, sustainable energy production and the generation of green polymeric materials by the biocatalytic upcycling of renewable synthons, requires an expansion of the current available biochemical reaction space. Creating biocatalysts harboring novel chemistries - whether inside or outside the cell - is dependent on the discovery of novel enzymes and metabolic pathways, together with the de novo design of enzymes and directed evolution. Herein we review the high potential of using bioinformatics and in silico computer modelling tools to guide protein engineering and to enhance our fundamental understanding of biocatalysis. Following an overview of technical considerations and the current state-of-the art in sequence- and structure-based protein engineering methodologies, we highlight recent successful examples of their implementation in biocatalysis and synthetic biology. Moreover, we discuss how selected computational tools in concert with experimental biocatalysis could decipher how the sequence, structure and dynamics of proteins dictate their function. Using the methodologies discussed in this chapter, an accelerated biocatalytic manufacturing of chemicals, pharmaceuticals, biofuels and monomeric building blocks is envisioned.

  • 388.
    Pendergraph, Samuel A.
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Klein, Gregor
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Johansson, Mats
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Carlmark, Anna
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Surface-initiated ring opening polymerization of carbonates and siloxanes from cellulose surfaces2015Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 249Artikel i tidskrift (Övrigt vetenskapligt)
  • 389.
    Percec, Simona
    et al.
    Temple Univ, Philadelphia, PA 19122 USA..
    Albertsson, Ann-Christine
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Rational Design of Multifunctional Renewable-Resourced Materials2019Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, nr 2, s. 569-572Artikel i tidskrift (Refereegranskat)
  • 390.
    Peterson, Anna
    et al.
    Chalmers Univ Technol, Dept Chem & Chem Engn, S-41296 Gothenburg, Sweden..
    Ostergren, Ida
    Chalmers Univ Technol, Dept Chem & Chem Engn, S-41296 Gothenburg, Sweden..
    Lotsari, Antiope
    Chalmers Univ Technol, Dept Chem & Chem Engn, S-41296 Gothenburg, Sweden..
    Venkatesh, Abhijit
    Chalmers Univ Technol, Dept Ind & Mat Sci, S-41296 Gothenburg, Sweden..
    Thunberg, Johannes
    Chalmers Univ Technol, Dept Ind & Mat Sci, S-41296 Gothenburg, Sweden..
    Strom, Anna
    Chalmers Univ Technol, Dept Chem & Chem Engn, S-41296 Gothenburg, Sweden..
    Rojas, Ramiro
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Andersson, Martin
    Chalmers Univ Technol, Dept Chem & Chem Engn, S-41296 Gothenburg, Sweden..
    Berglund, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Boldizar, Antal
    Chalmers Univ Technol, Dept Ind & Mat Sci, S-41296 Gothenburg, Sweden.;Chalmers Univ Technol, Wallenberg Wood Sci Ctr, S-41296 Gothenburg, Sweden..
    Mueller, Christian
    Chalmers Univ Technol, Dept Chem & Chem Engn, S-41296 Gothenburg, Sweden.;Chalmers Univ Technol, Wallenberg Wood Sci Ctr, S-41296 Gothenburg, Sweden..
    Dynamic Nanocellulose Networks for Thermoset-like yet Recyclable Plastics with a High Melt Stiffness and Creep Resistance2019Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, nr 10, s. 3924-3932Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Many polymers, including polyethylene, feature a relatively low melting point and hence must be cross-linked to make them viable for applications that demand a high stiffness and creep resistance at elevated temperatures. The resulting thermoset plastics cannot be recycled, and therefore alternative materials with a reconfigurable internal network structure are in high demand. Here, we establish that such a thermoset-like yet recyclable material can be realized through the addition of a nanocellulose reinforcing agent. A network consisting of cellulose nanocrystals, nano- or microfibrils imparts many of the characteristics that are usually achieved through chemical cross-linking. For instance, the addition of only 7.5 wt % of either nanocellulose material significantly enhances the melt stiffness of an otherwise molten ethylene-acrylate copolymer by at least 1 order of magnitude. At the same time, the nanocellulose network reduces the melt creep elongation to less than 10%, whereas the neat molten matrix would rupture. At high shear rates, however, the molten composites do not display a significantly higher viscosity than the copolymer matrix, and therefore retain the processability of a thermoplastic material. Repeated re-extrusion at 140 degrees C does not compromise the thermomechanical properties, which indicates a high degree of recyclability. The versatility of dynamic nanocellulose networks is illustrated by 3D printing of a cellulose composite, where the high melt stiffness improves the printability of the resin.

  • 391.
    Petre, Daniela-Geta
    et al.
    Radboud Univ Nijmegen, Med Ctr, Dept Regenerat Biomat, Philips Leydenlaan 25, NL-6525 EX Nijmegen, Netherlands..
    Kucko, Nathan W.
    Radboud Univ Nijmegen, Med Ctr, Dept Regenerat Biomat, Philips Leydenlaan 25, NL-6525 EX Nijmegen, Netherlands.;CAM Bioceram BV, Zernikedreef 6, NL-2333 CL Leiden, Netherlands..
    Abbadessa, Anna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. Univ Utrecht, Fac Sci, UIPS, Dept Pharmaceut, NL-3508 TB Utrecht, Netherlands..
    Vermonden, Tina
    Univ Utrecht, Fac Sci, UIPS, Dept Pharmaceut, NL-3508 TB Utrecht, Netherlands..
    Polini, Alessandro
    Radboud Univ Nijmegen, Med Ctr, Dept Regenerat Biomat, Philips Leydenlaan 25, NL-6525 EX Nijmegen, Netherlands..
    Leeuwenburgh, Sander C. G.
    Radboud Univ Nijmegen, Med Ctr, Dept Regenerat Biomat, Philips Leydenlaan 25, NL-6525 EX Nijmegen, Netherlands..
    Surface functionalization of polylactic acid fibers with alendronate groups does not improve the mechanical properties of fiber-reinforced calcium phosphate cements2019Ingår i: Journal of The Mechanical Behavior of Biomedical Materials, ISSN 1751-6161, E-ISSN 1878-0180, Vol. 90, s. 472-483Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Calcium phosphate cements (CPCs) are frequently used as synthetic bone substitute, but their intrinsic low fracture toughness impedes their application in highly loaded skeletal sites. However, fibers can be used to reduce the brittleness of these CPCs provided that the affinity between the fibers and cement matrix facilitates the transfer of loads from the matrix to the fibers. The aim of the present work was to improve the interface between hydrophobic polylactic acid (PLA) microfibers and hydrophilic CPC. To this end, calcium-binding alendronate groups were conjugated onto the surface of PLA microfibers via different strategies to immobilize a tunable amount of alendronate onto the fiber surface. CPCs reinforced with PLA fibers revealed toughness values which were up to 50-fold higher than unreinforced CPCs. Nevertheless, surface functionalization of PLA microfibers with alendronate groups did not improve the mechanical properties of fiber-reinforced CPCs.

  • 392.
    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 Silk2018Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 19, nr 8, s. 3268-3279Artikel i tidskrift (Refereegranskat)
    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.

  • 393.
    Pettersson, Torbjörn
    KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellens Centrum BiMaC Innovation. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH Royal Inst Technol, Stockholm, Sweden..
    Molecular understanding of cellulose interactions2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 394.
    Pettersson, Torbjörn
    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.
    Erlandsson, Johan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Larsson, Per
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    On the mechanism of freeze-induced crosslinking of aerogels made from periodate-oxidised cellulose nanofibrils2018Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Artikel i tidskrift (Övrigt vetenskapligt)
  • 395.
    Pettersson, Torbjörn
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Pendergraph, Samuel A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Utsel, Simon
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Marais, Andrew
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Gustafsson, Emil
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Wågberg, Lars
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Robust and tailored wet adhesion in biopolymer thin film with wet adhesion and toughness superior to wet adhesion in bone2015Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 249Artikel i tidskrift (Övrigt vetenskapligt)
  • 396. Pi, J. -K
    et al.
    Yang, J.
    Zhong, Q.
    Wu, M. -B
    Yang, H. -C
    Schwartzkopf, M.
    Roth, Stephan V.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Müller-Buschbaum, P.
    Xu, Z. -K
    Dual-Layer Nanofilms via Mussel-Inspiration and Silication for Non-Iridescent Structural Color Spectrum in Flexible Displays2019Ingår i: ACS Applied Nano Materials, ISSN 2574-0970, Vol. 2, nr 7, s. 4556-4566Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Noniridescent structural colors are superior in photostability and energy efficiency as compared to pigments and bioluminescence counterparts. However, it is challenging to facilely and massively fabricate nanofilms with noniridescent structural colors spanning the full spectrum of visible light. Here, a one-pot synthesis strategy is demonstrated to prepare free-standing dual-layer nanofilms with different refractive indices in each layer via a combination of mussel-inspiration and silication at the air/water interface. XPS, 2D GISAXS, and ellipsometry were used to verify the dual-layer but interface-free structure with different refractive indices. Moreover, the full spectrum of noniridescent structural colors has been achieved by precisely tailoring the film thickness of each layer through regulating the kinetics of the two reactions. This strategy offers flexibility for further on-demand patterning because of the self-sealing property of the dual-layer nanofilms, which has great application potentials in flexible displays and sensors.

  • 397. Piri, Imelda Saran
    et al.
    Das, Oisik
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Hedenqvist, Mikael S.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Vaisanen, Taneli
    Ikram, Shafaq
    Bhattacharyya, Debes
    Imparting resiliency in biocomposite production systems: A system dynamics approach2018Ingår i: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 179, s. 450-459Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A biocomposite production system (BPS) contains a wide range of elements that are vulnerable to internal as well as external factors that may stimulate a system to be disrupted. Hence, there is a need to manifest resiliency in order to withstand the inevitable change without affecting its robustness and stability. The three aspects of a resilient BPS are interconnectivity, adaptability and transformability. The interconnectivity concept deals with the reliability and effectiveness of the supply chain network and production systems' resourcefulness. The adaptability aspect reinforces the agility and adjusting capacity of a system towards versatility and flexibility across the range of elements involved in the production system. Transformability deals with the capacity of a system to alter into a new system based on research, innovation and creativity. Therefore, the core aspects of resiliency in a BPS would result in increased stability and effectiveness. System dynamics models have been developed depicting the cause and effect of each of the three aspects. Finally, a model has been presented which could enable researchers and organizations to take guided decision towards a more robust and resilient BPS.

  • 398. Podkościelna, B.
    et al.
    Gordobil, O.
    Riazanova, Anastasiia
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Dobele, G.
    Labidi, J.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Gun'ko, V. M.
    Sevastyanova, Olena
    Novel Porous Materials Obtained from Technical Lignins and Their Methacrylate Derivatives Copolymerized with Styrene and Divinylbenzene2017Ingår i: ChemistrySelect, ISSN 2365-6549, Vol. 2, nr 7, s. 2257-2264Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The increasing availability of various types of technical lignins as result of the emergence of new biorefinery technologies has boosted the interest in the commercialization of lignin-based materials. Here we suggest a novel method for the preparation of uniform porous microspheres through emulsion-suspension polymerization of various technical lignins and related methacrylates with styrene (St) and divinylbenzene (DVB). Obtained microspheres have diameters in the range of 5–50 μm, with a more uniform shape for copolymers that contains lignin derivatives. Nitrogen sorption with DFT theory indicates that the microspheres are mesoporous materials with specific surface areas in the range of 230–270 m2g−1 but with significant differences in pore volume, especially in the mesopores size range (0–0.65 cm3g−1). Theoretical modeling of lignin alone and in St-DVB composites shows changes in polarity of the structures, which have become mosaics with hydrophilic and hydrophobic functionalities. This structure affects the properties of the interfacial water and, therefore, can affect the adsorption of both polar and nonpolar adsorbates in solid-phase extraction.

  • 399.
    Popov, Sergei
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Marinins, Aleksandrs
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Material- och nanofysik.
    Sychugov, Ilya
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik.
    Yan, Max
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Vasileva, Elena
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Fotonik.
    Li, Yuanyuan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Berglund, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Biokompositer.
    Udalcovs, Aleksejs
    RISE Acreo AB, Stockholm, Sweden..
    Ozolins, Oskars
    RISE Acreo AB, Stockholm, Sweden..
    Polymer photonics and nano-materials for optical communication2018Ingår i: 2018 17TH WORKSHOP ON INFORMATION OPTICS (WIO), Institute of Electrical and Electronics Engineers (IEEE), 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    Polymer materials offer process compatibility, design flexibility, and low cost technology as a multi-functional platform for optical communication and photonics applications. Design and thermal reflowing technology of low loss polymer waveguides, as well as demonstration of transparent wood laser are presented in this paper.

  • 400.
    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 monitoring2017Ingår i: Polymer testing, ISSN 0142-9418, E-ISSN 1873-2348, Vol. 64, s. 267-276Artikel i tidskrift (Refereegranskat)
    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.

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