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  • 1.
    Benselfelt, Tobias
    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.
    Design of Cellulose-based Materials by Supramolecular Assemblies2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    På grund av klimatförändringar och ständigt ökande plastföroreningar finns det en växande efterfrågan på biobaserade material med egenskaper som liknar dem hos vanliga plaster och som samtidigt är biologiskt nedbrytbara. I detta avseende är cellulosa är en stark kandidat som redan framställs i stor industriell skala, men egenskaperna skiljer sig markant från plasternas med avseende på formbarhet och vattentålighet.

    Denna avhandling undersöker hur supramolekylära interaktioner kan användas för att skräddarsy egenskaperna hos cellulosa-baserade material genom att modifiera cellulosaytor eller styra hur cellulosa nanofibriller (CNFs) sätts samman. Huvuddelen av arbetet berör grundläggande studier kring interaktioner i vatten, men några materialkoncept och potentiella tillämpningar diskuteras.

    Den första delen avhandlar hur spontan adsorption av xyloglukan eller polyelektrolyter kan användas för att modifiera cellulosa. Resultaten indikerar att xyloglukan adsorberar till cellulosa på grund av den ökade entropin hos vatten som frigörs från ytorna, vilket liknar den ökade entropin hos frigjorda motjoner som driver polyelektrolytadsorption. Adsorptionen av polyeletrolyter beror på cellulosans laddning upp till en viss gräns, varefter laddningstätheten endast påverkar adsorptionen i första lagret i en multilager formering.

    Adsorption av latexnanopartiklar med en korona av polyeletrolyter, ger hydrofoba cellulosaytor med stark och töjbar, våt vidhäftning, om kärnans glasövergång sker vid lägre temperatur än omgivningens.

    Syftet med den andra delen av avhandlingen är att förklara interaktioner mellan olika typer av cellulosa nanofibriller i närvaro av olika joner. Detta görs med en modell bestående av jon-jonkorrelation och specifika joneffekter, som kan användas för rationell design av vattentåliga och transparenta filmer av nanocellulosa. Tillsatsen av små mängder alginat skapar också interpenetrerande dubbla nätverk, och dessa nätverk leder till en synergi som förbättrar både styvheten och töjbarheten hos filmerna i vatten.

    En nätverksmodell utvecklades för att förstå dessa material. Modellen klarar av att förklara hur egenskaperna hos fibrillnätverk beror av parametrar som fibrillernas geometri, nätverkets soliditet och friktionen som induceras av specifika joner. Med hjälp av nätverksmodellen och modellen för joninducerade interaktioner kan vi skapa filmer med våtstyrka som överträffar den hos många plaster, eller med en töjbarhet som är lämplig för hygroplastisk formpressning till vattentåliga och biologiskt nedbrytbara förpackningar. Filmernas transparens och vatteninnehåll, samt biokompatibiliteten hos cellulosa, gör dem lämpliga som biomaterial eller för bioelektronikapplikationer.

    Publikationen är tillgänglig i fulltext från 2019-12-31 23:59
  • 2.
    Benselfelt, Tobias
    et al.
    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.
    Nordenström, Malin
    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.
    Hamedi, Mahiar
    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.
    Wågberg, Lars
    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.
    Ion-induced assemblies of highly anisotropic nanoparticles are governed by ion-ion correlation and specific ion effects2019Ingår i: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 11, nr 8, s. 3514-3520Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ion-induced assemblies of highly anisotropic nanoparticles can be explained by a model consisting of ion-ion correlation and specific ion effects: dispersion interactions, metal-ligand complexes, and local acidic environments. Films of cellulose nanofibrils and montmorillonite clay were treated with different ions, and their subsequent equilibrium swelling in water was related to important parameters of the model in order to investigate the relative importance of the mechanisms. Ion-ion correlation was shown to be the fundamental attraction, supplemented by dispersion interaction for polarizable ions such as Ca2+ and Ba2+, or metal-ligand complexes for ions such as Cu2+, Al3+ and Fe3+. Ions that form strong complexes induce local acidic environments that also contribute to the assembly. These findings are summarized in a comprehensive semi-quantitative model and are important for the design of nanomaterials and for understanding biological systems where specific ions are involved.

  • 3.
    Benselfelt, Tobias
    et al.
    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.
    Nordenström, Malin
    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.
    Lindström, Stefan
    Linköping University.
    Wågberg, Lars
    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.
    Explaining the exceptional wet integrity of transparent cellulose nanofibril films in the presence of multivalent ions - Suitable substrates for biointerfacesManuskript (preprint) (Övrigt vetenskapligt)
  • 4.
    Benselfelt, Tobias
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Unidirectional Swelling of Dynamic Cellulose Nanofibril Networks: A Platform for Tunable Hydrogels and Aerogels with 3D Shapeability2019Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, nr 6, s. 2406-2412Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A process has been developed to create self-supporting hydrogels with low solids content (down to 0.5 wt %) and anisotropic aerogels with a low density (down to 5 kg/m(3)) from cellulose nanofibrils (CNFs). The CNF networks were formed by vacuum filtration of dilute dispersions (0.2 wt %) of 90% CNFs and 10% alginate. We call this process "the dynamic CNF network approach" since the solids content of these hydrogels can be tuned in the range of 0.5-3 wt % by reswelling the filter cakes in a medium with a controlled osmotic pressure. These hydrogels are significantly stronger than the 1-2 wt % CNF gels typically used to prepare hydrogels and aerogels because the dynamic CNF networks are formed below their arrested state threshold (ca. 0.5 wt %) and are thus homogeneous. The vacuum filtration leads to a directional reswelling vertical to the plane of the filter cake, and this is crucial in order to turn a two-dimensional (2D) shape, cut from the filter cake, into a 3D hydrogel without distorting the 2D shape. The anisotropic swelling was used to create intricate 3D-shaped hydrogels and solved some of the issues involved in the degassing and molding of high-viscosity CNF gels. Multivalent ions were used to lock the CNF and alginate networks at the desired solids content and 3D shape, and resulted in an increase by an order of magnitude in storage modulus. Moreover, the self-supporting nature of the hydrogels allowed us to freeze-cast them into anisotropic aerogels with the same 3D shape without using any container. The 5 kg/m(3) aerogel had a specific modulus of 43 kN m/kg and an anisotropy index of 12, which are impressive properties in relation to earlier experiences. The process can be used for applications where a precise control of density and shape is critical.

  • 5.
    Berglund, Jennie
    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, Fiberteknologi.
    Mikkelsen, Deirdre
    Univ Queensland, Queensland Alliance Agr & Food Innovat, Ctr Nutr & Food Sci, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Flanagan, Bernadine
    Univ Queensland, Queensland Alliance Agr & Food Innovat, Ctr Nutr & Food Sci, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Dhital, Sushil
    Univ Queensland, Queensland Alliance Agr & Food Innovat, Ctr Nutr & Food Sci, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Yakubov, Gleb
    Univ Queensland, Sch Chem Engn, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Gidley, Michael
    Univ Queensland, Queensland Alliance Agr & Food Innovat, Ctr Nutr & Food Sci, ARC Ctr Excellence Plant Cell Walls, Brisbane, Qld, Australia..
    Vilaplana, Francisco
    KTH, Tidigare Institutioner (före 2005), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Hydrogels of bacterial cellulose and wood hemicelluloses as a model of plant secondary cell walls2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 6. Carosio, F.
    et al.
    Ghanadpour, Maryam
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Alongi, J
    Wågberg, L
    Layer-by-layer assembled chitosan/phosphporylated nanocellulose as a bio-based and flame protecting nano-exoskeleton on PU foams2018Ingår i: Artikel i tidskrift (Övrig (populärvetenskap, debatt, mm))
  • 7.
    Chen, Chao
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Pettersson, Torbjörn
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Illergård, Josefin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Ek, Monica
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi. KTH, Tidigare Institutioner (före 2005), Fiber- och polymerteknologi.
    Influence of Cellulose Charge on Bacteria Adhesion and Viability to PVAm/CNF/PVAm-Modified Cellulose Model Surfaces2019Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A contact-active antibacterial approach based on the physical adsorption of a cationic polyelectrolyte onto the surface of a cellulose material is today regarded as an environment-friendly way of creating antibacterial surfaces and materials. In this approach, the electrostatic charge of the treated surfaces is considered to be an important factor for the level of bacteria adsorption and deactivation/killing of the bacteria. In order to clarify the influence of surface charge density of the cellulose on bacteria adsorption as well as on their viability, bacteria were adsorbed onto cellulose model surfaces, which were modified by physically adsorbed cationic polyelectrolytes to create surfaces with different positive charge densities. The surface charge was altered by the layer-by-layer (LbL) assembly of cationic polyvinylamine (PVAm)/anionic cellulose nanofibril/PVAm onto the initially differently charged cellulose model surfaces. After exposing the LbL-treated surfaces to Escherichia coli in aqueous media, a positive correlation was found between the adsorption of bacteria as well as the ratio of nonviable/viable bacteria and the surface charge of the LbL-modified cellulose. By careful colloidal probe atomic force microscopy measurements, it was estimated, due to the difference in surface charges, that interaction forces at least 50 nN between the treated surfaces and a bacterium could be achieved for the surfaces with the highest surface charge, and it is suggested that these considerable interaction forces are sufficient to disrupt the bacterial cell wall and hence kill the bacteria.

  • 8.
    Colson, Jerome
    et al.
    Univ Nat Resources & Life Sci Vienna, Dept Mat Sci & Proc Engn, Inst Wood Technol & Renewable Mat, Konrad Lorenz Str 24, A-3430 Tulin, Austria..
    Pettersson, Torbjörn
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Asaadi, Shirin
    Aalto Univ, Sch Chem Engn, Dept Bioprod & Biosyst, Vuorimiehentie 1, Espoo 02150, Finland..
    Sixta, Herbert
    Aalto Univ, Sch Chem Engn, Dept Bioprod & Biosyst, Vuorimiehentie 1, Espoo 02150, Finland..
    Nypelo, Tiina
    Chalmers Univ Technol, Dept Chem & Chem Technol, Kemigarden 4, S-41296 Gothenburg, Sweden..
    Mautner, Andreas
    Univ Vienna, Fac Chem, Inst Mat Chem & Res, Wahringer Str 42, A-1090 Vienna, Austria..
    Konnerth, Johannes
    Univ Nat Resources & Life Sci Vienna, Dept Mat Sci & Proc Engn, Inst Wood Technol & Renewable Mat, Konrad Lorenz Str 24, A-3430 Tulin, Austria..
    Adhesion properties of regenerated lignocellulosic fibres towards poly (lactic acid) microspheres assessed by colloidal probe technique2018Ingår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 532, s. 819-829Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the field of polymer reinforcement, it is important to understand the interactions involved between the polymer matrix and the reinforcing component. This paper is a contribution to the fundamental understanding of the adhesion mechanisms involved in natural fibre reinforced composites. We report on the use of the colloidal probe technique for the assessment of the adhesion behaviour between poly(lactic acid) microspheres and embedded cross-sections of regenerated lignocellulosic fibres. These fibres consisted of tailored mixtures of cellulose, lignin and xylan, the amount of which was determined beforehand. The influence of the chemical composition of the fibres on the adhesion behaviour was studied in ambient air and in dry atmosphere. In ambient air, capillary forces resulted in larger adhesion between the sphere and the fibres. Changing the ambient medium to a dry nitrogen atmosphere allowed reducing the capillary forces, leading to a drop in the adhesion forces. Differences between fibres of distinct chemical compositions could be measured only on freshly cut surfaces. Moreover, the surface energy of the fibres was assessed by inverse gas chromatography. Compared to fibres containing solely cellulose, the presence of lignin and/or hemicellulose led to higher adhesion and lower surface energy, suggesting that these chemicals could serve as natural coupling agents between hydrophobic and hydrophilic components.

  • 9.
    Edlund, Ulrica
    et al.
    KTH, Tidigare Institutioner (före 2005), Polymerteknologi. KTH, Tidigare Institutioner (före 2005), Fiber- och polymerteknologi.
    Navarro, Julien R. G.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Alander, Eva
    RISE Bioecon, Stockholm, Sweden..
    Engineering the surface chemistry of nanocelluloses for material applications2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 10.
    Engström, Joakim
    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, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Hatton, Fiona
    Loughborough Univ, Dept Mat, Loughborough, Leics, England..
    Benselfelt, Tobias
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Freire, Carmen
    Univ Aveiro, Aveiro Inst Mat, Aveiro, Portugal..
    Vilela, Carla
    Univ Aveiro, Aveiro Inst Mat, Aveiro, Portugal..
    Boujemaoui, Assya
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi. KTH Royal Inst Technol, Fibre & Polymer Technol, Stockholm, Sweden..
    Sanchez, Carmen
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Lo Re, Giada
    Chalmers Univ Technol, Gothenburg, Sweden..
    Wågberg, Lars
    KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellens Centrum BiMaC Innovation. KTH, Tidigare Institutioner (före 2005), Pappers- och massateknik. KTH, Tidigare Institutioner (före 2005), Fiber- och polymerteknologi. KTH, Skolan för teknikvetenskap (SCI), Mekanik. KTH, Skolan för teknikvetenskap (SCI), Centra, Linné Flow Center, FLOW. KTH Royal Inst Technol, Fibre & Polymer Technol, Stockholm, Sweden.;KTH Royal Inst Technol, Wallenberg Wood Sci Ctr, Stockholm, Sweden..
    D'Agosto, Franck
    UCBL, CPE Lyon, C2P2, CNRS,CPE, Bat 308F, Villeurbanne, France..
    Lansalot, Muriel
    UCBL, CPE Lyon, C2P2, CNRS,CPE, Bat 308F, Villeurbanne, France..
    Carlmark, Anna
    RISE, Stockholm, Sweden..
    Malmström, Eva
    KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellens Centrum BiMaC Innovation. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Tailored PISA-latexes for modification of nanocellulosics: Investigating compatibilizing and plasticizing effects2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 11.
    Erlandsson, Johan
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Francon, Hugo
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Marais, Andrew
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Granberg, Hjalmar
    RISE Bioecon, Papermaking & Packaging, Box 5604, SE-11486 Stockholm, Sweden..
    Wågberg, Lars
    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.
    Cross-Linked and Shapeable Porous 3D Substrates from Freeze-Linked Cellulose Nanofibrils2019Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, nr 2, s. 728-737Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Chemically cross-linked highly porous nano cellulose aerogels with complex shapes have been prepared using a freeze-linking procedure that avoids common post activation of cross-linking reactions and freeze-drying. The aerogel shapes ranged from simple geometrical three-dimensional bodies to swirls and solenoids. This was achieved by molding or extruding a periodate oxidized cellulose nanofibril (CNF) dispersion prior to chemical cross-linking in a regular freezer or by reshaping an already prepared aerogel by plasticizing the structure in water followed by reshaping and locking the aerogel into its new shape. The new shapes were most likely retained by new cross-links formed between CNFs brought into contact by the deformation during reshaping. This self-healing ability to form new bonds after plasticization and redrying also contributed to the mechanical resilience of the aerogels, allowing them to be cyclically deformed in the dry state, reswollen with water, and redried with good retention of mechanical integrity. Furthermore, by exploiting the shapeability and available inner structure of the aerogels, a solenoid-shaped aerogel with all surfaces coated with a thin film of conducting polypyrrole was able to produce a magnetic field inside the solenoid, demonstrating electromagnetic properties. Furthermore, by biomimicking the porous interior and stiff exterior of the beak of a toucan bird, a functionalized aerogel was created by applying a 300 mu m thick stiff wax coating on its molded external surfaces. This composite material displayed a 10-times higher elastic modulus compared to that of the plain aerogel without drastically increasing the density. These examples show that it is possible to combine advanced shaping with functionalization of both the inner structure and the surface of the aerogels, radically extending the possible use of CNF aerogels.

  • 12.
    Erlandsson, Johan
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Pettersson, Torbjörn
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Ingverud, Tobias
    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.
    Granberg, H.
    Larsson, Per A.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellens Centrum BiMaC Innovation.
    Malkoch, Michael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    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 behind freezing-induced chemical crosslinking in ice-templated cellulose nanofibril aerogels2018Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 6, nr 40, s. 19371-19380Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The underlying mechanism related to freezing-induced crosslinking of aldehyde-containing cellulose nanofibrils (CNFs) has been investigated, and the critical parameters behind this process have been identified. The aldehydes introduced by periodate oxidation allows for formation of hemiacetal bonds between the CNFs provided the fibrils are in sufficiently close contact before the water is removed. This is achieved during the freezing process where the cellulose components are initially separated, and the growth of ice crystals forces the CNFs to come into contact in the thin lamellae between the ice crystals. The crosslinked 3-D structure of the CNFs can subsequently be dried under ambient conditions after solvent exchange and still maintain a remarkably low density of 35 kg m-3, i.e. a porosity greater than 98%. A lower critical amount of aldehydes, 0.6 mmol g-1, was found necessary in order to generate a crosslinked 3-D CNF structure of sufficient strength not to collapse during the ambient drying. The chemical stability of the 3-D structure can be further enhanced by converting the hemiacetals to acetals by treatment with an alcohol under acidic conditions.

  • 13.
    Farahani, Saina Kishani
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Vilaplana, Francisco
    KTH, Tidigare Institutioner (före 2005), Fiber- och polymerteknologi.
    Ruda, Marcus
    Hansson, Per
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    The influence of solubility on the adsorption of different Xyloglucan fractions at Cellulose Water InterfacesManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Xylogucan (XG) fractions with different molar masses were prepared while preserving the natural structure of the XG. The solubility of the fractions was investigated using light- scattering, chromatography and microscopy techniques. The conformational changes of the XG molecules and their association and phase separation were investigated together with concentration and molar mass changes. The knowledge gained was then applied to investigate the interaction of different XG fractions at cellulose model surfaces using a quartz crystal microbalance with dissipation. The results indicate that there is a cluster formation and phase separation of the XG molecules at the cellulose/water interface induced by the increase in XG concentration close to the surface. Concomitantly, the adsorption regimes are altered for the XG fractions depending on the solubility properties, indicating that the insolubility, association and phase separation of XGs in aqueous media affect their interaction with cellulose. The study is of vital importance for improving the functionality of sustainable materials made from xyloglucan/cellulose natural composites.

  • 14.
    Fogelström, Linda
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellens Centrum BiMaC Innovation. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Norström, Emelie
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Khabbaz, Farideh
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Brucher, Jorg
    Holmen, Holmen Dev, Örnskoldsvik, Sweden..
    Malmström, Eva
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH Royal Inst Technol, Wallenberg Wood Sci Ctr, Stockholm, Sweden.;KTH Royal Inst Technol, Dept Fibre & Polymer Technol, Stockholm, Sweden..
    A fully green wood adhesive based on hemicelluloses derived from pulp processes2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 15.
    Ghanadpour, Maryam
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Phosphorylated Cellulose Nanofibrils: A Nano-Tool for Preparing Cellulose-Based Flame-Retardant Materials2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The growing awareness of the need for a circular society and a circular chemistry has spurred the interest in using wood-based cellulose as a raw material for the preparation of new macroscopic devices and construction materials. The interest has been particularly focused on cellulose nanofibrils (CNF), which has led to the development of new material concepts through a nanoscale bottom-up engineering using renewable CNF. In order to be industrially applicable, the CNF must however possess a set of properties among which good flame-retardation is crucial. This thesis presents a) a way to chemically modify delignified wood fibers by phosphorylation to produce phosphorylated CNF, b) the fabrication and characterization of flame-retardant thin films, coatings and nanocomposite foams from the phosphorylated fibrils and c) the flame-retardant mechanisms of the phosphorylated CNF-based substances.

    Chemically delignified fibers have been phosphorylated by (NH4)2HPO4 in the presence of urea, and the resulting material has been used to prepare phosphorylated CNF (P-CNF). The flame-retardant properties of the phosphorylated fibrils were significantly improved by the phosphorus functionalization of the cellulose chain, converting the fibrils to an inherently flame-retardant material. The P-CNF was applied to make thin films/coatings using the Layer-by-Layer (LbL) technique. All-cellulose free-standing films were prepared through LbL self-assembly of the P-CNF and fibrils prepared from aminated cellulose-rich fibers (cationic CNF). The LbL-assembled film showed a high thermal stability, excellent flame resistance and superior mechanical performance. P-CNF/chitosan (CH) assemblies were also prepared as a fire protection for polyurethane (PU) foams. The five bilayer CH/P-CNF coating yielded a nano-exoskeleton on the surface of PU foam, shown to be capable of increasing the modulus of the foam by a factor of three and entirely preventing its melt dripping during the flammability testing.

    P-CNF/montmorillonite (MMT), sepiolite (Sep) clay or sodium hexametaphosphate (SHMP) films were also fabricated by vacuum filtration/solvent casting of the composite suspensions, and the structural and compositional features of these different films were used to study the mechanisms behind their flame-retardant properties. Only the P-CNF/MMT films were able to completely prevent ignition during cone calorimetry, when used as coatings for highly flammable polyethylene (PE) films and this was mainly ascribed to the excellent barrier properties of these films. The results also showed that the excellent strength and stiffness of the P-CNF/MMT samples, compared to those of the P-CNF/Sep and P-CNF/SHMP films, were essential for maintaining the barrier effect during combustion. Finally, nanostructured foams were prepared by freeze-casting of the P-CNF/Sep suspensions. The foams showed extensive flame-resistance, maintaining a temperature drop of more than 600 °C across the thickness during the flame penetration test. This performance was related mainly to the charring capability of the phosphorylated fibrils combined with the significant thermal insulation of Sep clay.

  • 16.
    Ghanadpour, Maryam
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Carosio, F
    Ruda, M.C.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Flame-retardant nanocomposite thin films based on phosphorylated cellulose nanofibrils: A study of flame-retardant mechanisms2018Ingår i: Artikel i tidskrift (Övrig (populärvetenskap, debatt, mm))
  • 17.
    Ghanadpour, Maryam
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Wicklein, Bernd
    Carosio, Federico
    Wågberg, Lars
    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.
    All-natural and highly flame-resistant freeze-cast foams based on phosphorylated cellulose nanofibrils2018Ingår i: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 10, nr 8, s. 4085-4095Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pure cellulosic foams suffer from low thermal stability and high flammability, limiting their fields of application. Here, light-weight and flame-resistant nanostructured foams are produced by combining cellulose nanofibrils prepared from phosphorylated pulp fibers (P-CNF) with microfibrous sepiolite clay using the freeze-casting technique. The resultant nanocomposite foams show excellent flame-retardant properties such as self-extinguishing behavior and extremely low heat release rates in addition to high flame penetration resistance attributed mainly to the intrinsic charring ability of the phosphorylated fibrils and the capability of sepiolite to form heat-protective intumescent-like barrier on the surface of the material. Investigation of the chemical structure of the charred residue by FTIR and solid state NMR spectroscopy reveals the extensive graphitization of the carbohydrate as a result of dephosphorylation of the modified cellulose and further dehydration due to acidic catalytic effects. Originating from the nanoscale dimensions of sepiolite particles, their high specific surface area and stiffness as well as its close interaction with the phosphorylated fibrils, the incorporation of clay nanorods also significantly improves the mechanical strength and stiffness of the nanocomposite foams. The novel foams prepared in this study are expected to have great potential for application in sustainable building construction.

  • 18.
    Granskog, Viktor
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Garcia-Gallego, Sandra
    KTH.
    von Kieseritzky, Johanna
    Karolinska Inst, Stockholm, Sweden..
    Pettersson, Jennifer
    RISE Res Inst Sweden, Boras, Sweden..
    Stenlund, Patrik
    RISE Res Inst Sweden, Boras, Sweden..
    Zhang, Yuning
    KTH.
    Petronis, Sarunas
    RISE Res Inst Sweden, Boras, Sweden..
    Lyven, Benny
    RISE Res Inst Sweden, Boras, Sweden..
    Arner, Marianne
    Karolinska Inst, Stockholm, Sweden..
    Hakansson, Joakim
    RISE Res Inst Sweden, Boras, Sweden..
    Malkoch, Michael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    High-performance and biocompatible thiol-ene based adhesive for bone fracture fixation2018Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 256Artikel i tidskrift (Övrigt vetenskapligt)
  • 19.
    Hajian, Alireza
    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.
    Wang, Zhen
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    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.
    Hamedi, Mahiar M.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Cellulose Nanopaper with Monolithically Integrated Conductive Micropatterns2019Ingår i: Advanced Electronic Materials, ISSN 2199-160X, Vol. 5, nr 3, artikel-id 1800924Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This work presents a route to fabricate micropatterned conductive structures where the conductors are monolithically integrated with nanocellulose-based paper. To fabricate conductive features, microstructures are patterned on filter papers using wax-printing, followed by vacuum filtration of carbon nanotubes (CNTs) or silver nanowires (AgNWs) dispersed in aqueous cellulose nanofibrils (CNFs). These patterns are then laminated onto a pure CNF substrate (both in gel-state) and dried to form cellulose nanopapers with integrated conductive micropatterns. Resolutions of the conductive features are shown down to 400 µm wide, 250 nm thick, and with conductivity values of 115 ± 5 S cm −1 for the CNF–CNT and 3770 ± 230 S cm −1 for the CNF–AgNW micropatterns. The nanopaper and the conductive patterns both constitute random fibrous networks, and they display similar ductility and swelling behavior in water. Thus, the integrated conductive micropatterns can withstand folding, as well as wetting cycles. This stability of the micropatterns makes them useful in various devices based on nanocellulose substrates. As an example, an electroanalytical nanopaper device that operates in wet conditions is demonstrated.

  • 20.
    Hellwig, Johannes
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    López Durán, Vernica
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Pettersson, Torbjörn
    KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellens Centrum BiMaC Innovation. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Measuring elasticity of wet cellulose fibres with AFM using indentation and a linearized Hertz model2018Ingår i: Analytical Methods, ISSN 1759-9660, E-ISSN 1759-9679, Vol. 10, nr 31Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The mechanical properties of different pulp fibres in liquid were measured using an atomic force microscope. Specifically a custom-made sample holder was used to indent the fibre surface, without causing any motion, and the Young's modulus was calculated from the indentation using a linearized Hertz model.

  • 21.
    Ingverud, Tobias
    et al.
    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.
    Erlandsson, Johan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Malkoch, Michael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    The combination of a dendritic polyampholyte and cellulose nanofibrils – a new type of functional materialManuskript (preprint) (Övrigt vetenskapligt)
  • 22.
    Kaldéus, Tahani
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Nordenström, Malin
    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, Fiberteknologi.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Malmström, Eva
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Redispersibility properties of dried cellulose nanofibrils - influence on structure and mechanical propertiesManuskript (preprint) (Övrigt vetenskapligt)
  • 23.
    Kaldéus, Tahani
    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, Ytbehandlingsteknik.
    Nordenström, Malin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Erlandsson, Johan
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Malmström, Eva
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Redispersibility properties of dried cellulose nanofibrils - influence on structure and mechanical properties2019Ingår i: Artikel i tidskrift (Övrigt vetenskapligt)
  • 24.
    Kaldéus, Tahani
    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, Ytbehandlingsteknik.
    Träger, Andrea
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Berglund, Lars
    KTH, Skolan för teknikvetenskap (SCI), Farkost och flyg.
    Malmström, Eva
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lo Re, Giada
    Chalmers University of Technology.
    Molecular engineering of cellulose-PCL bio-nanocomposite interface by reactive amphiphilic copolymer nanoparticles2019Ingår i: Artikel i tidskrift (Refereegranskat)
  • 25.
    Koklukaya, Oruc
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Flame-Retardant Cellulose Fibre/Fibril Based Materials via Layer-by-Layer Technique2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    According to an analysis conducted by the Swedish Chemicals Inspectorate in 2006, the approximate numbers of fire injuries per year in Sweden are 100 deaths, 700 major and 700 minor injuries.1 Observations also show that there has been an increase in the number of house fires during recent years. One possible explanation can be the increased use of plastics in the building industry and in furniture. The advantages of easy processing, light weight and low cost make plastic materials most prevalent in the market.  However, plastics behave significantly differently from natural materials in the case of fire. Polymeric materials, including rigid polyurethane foams (PU) which are widely used in the building industry due to their insulating properties, are highly flammable and they release heat at a very high rate. In addition, polymeric materials release more harmful smoke, toxic gases and combustion products than natural materials. A house fire typically starts with the ignition of a combustible material. Flames then spread to nearby materials and shortly thereafter the heat radiation generated reaches a point where the contents of the room suddenly and simultaneously ignite. This stage is called a flash over. After this stage, the fire is fully developed and it continues until everything is consumed. The higher rate of heat and smoke production from plastic materials reduces the time to flash over and hence the time to escape from a fire. The traditional flame-retardant treatments are based mainly on halogenated compounds which are classified as gas phase flame-retardants. The halogenated flame-retardants are under severe investigation due to their adverse effect on health and on the environment since they release toxic gases during combustion and they may leach out and accumulate in the food chain.2-3 The restrictions due to growing environmental concerns have been a driving force to develop alternative flame-retardants by using natural and renewable resources. In recent years, the layer-by-layer (LbL) technique has been used as a simple and versatile surface engineering technique to construct functional nanocoatings through the sequential adsorption of polyelectrolytes and charged nanoparticles in an effort to impart flame-retardant characteristics by inhibiting the combustion cycle.4-5 This thesis presents the physical modification of cellulose fibre/fibril based materials as a means of improving flame-retardant properties.

    In the first part of work described in this thesis, the adsorption of polyelectrolyte multilayers onto pulp fibres was investigated as a way to impart flame-retardant characteristics to paper-based materials. It was found that intumescent nanocoatings consisting of nitrogen and phosphorus containing polyelectrolytes such as chitosan (CH) and poly(vinylphosphonic acid) (PVPA) were able to significantly improve the thermal stability and flame-retardant properties of sheets made of LbL-treated fibres, and were able to self-extinguish the flame in the horizontal flame test (HFT). High magnification images revealed that this improvement in flame-retardancy was due to the formation of a coherent char layer on the fibres (Paper I).6 In addition to imparting flame-retardancy by the LbL-coating of polyethylenimine (PEI) and sodium hexametaphosphate (SHMP), it was also possible to improve the mechanical properties of the paper material with this treatment (Paper III).7

    In the second part of the work, wet-stable porous cellulose fibril-based aerogels were developed by freeze-drying and used as a template for the build-up of intumescent nano-brick wall assemblies. The formation of multilayers of CH, PVPA and montmorillonite clay (MMT) was investigated as a function of solution concentration, and it was found that five quadlayers (QL) of CH/PVPA/CH/MMT treated aerogels using 5 g/L solutions of the respective components were able to self-extinguish the flame in HFT and that they showed no ignition under the heat flux of 35 kW/m2 used in cone calorimetry (Paper II).8 In a different application, a novel low density, porous, wet-stable cellulose fibre network was developed using chemically modified cellulose fibres by solvent exchange from water to acetone followed by drying at room temperature. The fibre networks (FN) were modified using the LbL technique to construct a flame-retardant nanocoating consisting of CH, SHMP, and inorganic particles (i.e., MMT, sepiolite (SEP), and colloidal silica (SNP)). The influence of the shape of the nanoparticles on flame-retardancy was investigated and it was found that plate-like and rod-like clays with a high aspect ratio showed self-extinguishing behaviour in HFT. A 5 QL of CH/SHMP/CH/SEP reduced the peak heat release rate and total smoke release by 47% and 43%, respectively, with an addition of only ~8 wt% to FN (Paper IV).

    Finally, non-crystalline cellulose gel beads were used as a substrate for the LbL assembly of CH and SHMP in model studies aimed at identifying the molecular mechanisms responsible for the fire-retardant properties of the LbL structures. The beads were formed by precipitating the dissolved cellulose-rich fibres according to an earlier described procedure,9 and it was shown that these smooth cellulose beads can be utilized as a model substrate to study the influence of LbL chemistry and nanostructure on flame-retardancy. These new types of model systems thus constitute a new important tool for clarifying the mechanism behind flame-retardant nanocoating systems (Paper V).  

    Publikationen är tillgänglig i fulltext från 2020-12-31 10:00
  • 26.
    Koklukaya, Oruc
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Carosio, Federico
    López Durán, Vernica
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Development of hybrid coatings to reduce flammability of low density cellulose fiber networks via layer-by-layer assemblyManuskript (preprint) (Övrigt vetenskapligt)
  • 27.
    Koklukaya, Oruc
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Carosio, Federico
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Tailoring flame-retardancy and strength of papers via layer-by-layer treatment of cellulose fibers2018Ingår i: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 25, nr 4, s. 2691-2709Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The layer-by-layer (LbL) technology was used to adsorb polyelectrolyte multilayers consisting of cationic polyethylenimine (PEI) and anionic sodium hexametaphosphate (SHMP) onto cellulose fibers in order to enhance the flame-retardancy and tensile strength of paper sheets made from these fibers. The fundamental effect of PEI molecular mass on the build-up of the multilayer film was investigated using model cellulose surfaces and a quartz crystal microbalance technique. The adsorption of a low (LMw) and a high molecular weight (HMw) PEI onto cellulose fibers and carboxymethylated (CM) cellulose fibers was investigated using polyelectrolyte titration. The fibers were consecutively treated with PEI and SHMP to deposit 3.5 bilayers (BL) on the fiber surfaces, and the treated fibers were then used to prepare sheets. In addition, a wet-strength paper sheet was prepared and treated with the same LbL coatings. Thermal gravimetric analysis of LbL-treated fibers showed that the onset temperature for cellulose degradation was lowered and that the amount of residue at 800 °C increased. A horizontal flame test and a vertical flame test were used to evaluate the combustion behavior of the paper sheets. Papers prepared from both cellulose fibers and CM-cellulose fibers treated with HMw-PEI/SHMP LbL-combination self-extinguished in a horizontal configuration despite the rather low amounts of adsorbed polymer which form very thin films (wet thickness of ca. 17 nm). The tensile properties of handsheets showed that 3.5 BL of HMw-PEI and SHMP increased the stress at break by 100% compared to sheets prepared from untreated cellulose fibers.

  • 28.
    Koklukaya, Oruc
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Karlsson, Rose-Marie Pernilla
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Carosio, Federico
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    A study of layer-by-layer nanocoatings on model cellulose gel beads to clarify their flame-retardant characteristicsManuskript (preprint) (Övrigt vetenskapligt)
  • 29.
    Larsson, Per
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Chemical modification of cellulose fibres and nanofibrils for an expanded material property space and novel applications2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 30.
    Larsson, Per Tomas
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi. Innventia AB, Stockholm, Sweden..
    Karlsson, Pernilla
    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.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Swelling behavior of cellulose rich materials in water2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 31.
    Li, Hailong
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Pettersson, Torbjörn
    KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellens Centrum BiMaC Innovation. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wågberg, Lars
    KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellens Centrum BiMaC Innovation. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi. KTH Royal Inst Technol, Fibre Technol, Stockholm, Sweden..
    Internal structural evolution of regenerated cellulose beads during drying2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 32.
    López Durán, Veronica
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellens Centrum BiMaC Innovation.
    Erlandsson, Johan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellens Centrum BiMaC Innovation.
    Larsson, Per A.
    KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellens Centrum BiMaC Innovation. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Novel, Cellulose-Based, Lightweight, Wet-Resilient Materials with Tunable Porosity, Density, and Strength2018Ingår i: ACS SUSTAINABLE CHEMISTRY & ENGINEERING, ISSN 2168-0485, Vol. 6, nr 8, s. 9951-9957Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Highly porous materials with low density were developed from chemically modified cellulose fibers using solvent-exchange and air drying. Periodate oxidation was initially performed to introduce aldehydes into the cellulose chain, which were then further oxidized to carboxyl groups by chlorite oxidation. Low-density materials were finally achieved by a second periodate oxidation under which the fibers self-assembled into porous fibrous networks. Following a solvent exchange to acetone, these networks could be air-dried without shrinkage. The properties of the materials were tuned by mechanical mixing with a high intensity mixer for different times prior to the second periodate oxidation, which resulted in porosities between 94.4% and 96.3% (i.e., densities between 54 and 82 kg/m(3)). The compressive strength of the materials was between 400 and 1600 kPa in the dry state and between 20 and 50 kPa in the wet state. It was also observed that in the wet state the fiber networks could be compressed up to 80% while still being able to recover their shape. These networks are highly interesting for use in different types of absorption products, and since they also have a high wet integrity, they can be modified with physical methods for different high-value-added end-use applications.

  • 33.
    López Durán, Veronica
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Hellwig, Johannes
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Larsson, Per A.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Effect of Chemical Functionality on the Mechanical and Barrier Performance of Nanocellulose Films2018Ingår i: ACS APPLIED NANO MATERIALS, ISSN 2574-0970, Vol. 1, nr 4, s. 1959-1967Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the present work, we have partially modified fibrils chemically to eate a shell of derivatized cellulose that surrounds the crystalline re of native cellulose. Through the different modifications, we aimed creating a toolbox to enable the properties of CNF materials and terials containing CNFs to be tuned to meet specific material demands. total, nine different chemical modifications using different ueous-based procedures were used as chemical pretreatments before CNF oduction through homogenization. Eight of these modifications included riodate oxidation with an average of 27% of the anhydroglucose units the cellulose chain being cleaved into dialdehydes. The presence of dehydes then facilitated a conversion to other functional groups.

  • 34.
    López Durán, Verónica
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Chemical Modification of Cellulose Fibres and Fibrils for Design of New Materials2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Due to the growing interest in biobased materials in today’s society, where the need for a cyclic economy is obvious, there has been a huge increase in the  interest for using cellulose due to its excellent mechanical and chemical properties. However, the properties of cellulose have to be modified and improved in order to satisfy advanced material applications where the cellulose properties can be tuned to fit the properties of other components in composite mixtures. This thesis explores the heterogeneous chemical modification of cellulose for improved material properties of cellulose-based materials and the use of cellulose fibres and fibrils in novel applications.

    In the first part of the work described in this thesis, a fundamental study was performed to clarify how the chemical composition and the fibre/fibril structure of the cellulose following chemical modification affect the material properties. The second part of the work was aimed at exploring the potential for using the chemically modified fibres/fibrils in novel material applications. 

    Lignocellulosic fibres with different chemical compositions were modified by periodate oxidation and borohydride reduction, and it was found that the most important factor was the amount of holocellulose present in the fibres, since lignin-rich fibres were less reactive and less responsive to the treatments. Despite the lower reactivity of lignin-rich fibres, it was however possible to improve their mechanical properties and to achieve a significant increase in the compressive strength of papers prepared from modified unbleached kraft fibres.

    The chemical modifications were then expanded to nine different molecular structures and two different degrees of modification. Fibres modified at low degrees of modification were used to prepare handsheets, followed by mechanical and physical characterization. Highly modified fibres were also used to prepare cellulose nanofibrils (CNFs). It was found that the properties of handsheets and films prepared from modified fibres/fibrils are highly dependent on the chemical structure of the modified cellulose and, as an example, the ductility was greatly improved by converting secondary alcohols to primary alcohols. A detailed analysis of the modified fibres and fibrils also showed that, due to the heterogeneous chemical reaction used, the modified fibrils had a core-shell structure with a shell of modified cellulose with a lower crystalline order surrounding a core of crystalline cellulose. The results also showed that the chemical structure of the modified shell dramatically affects the interaction with moisture. Materials from fibrils containing covalent crosslinks have shown to be less sensitive to moisture at the cost of being more brittle. 

    In a different application, modified CNFs were used as paper strength additives. Three differently modified CNFs were used: carboxymethylated CNFs, periodate-oxidised carboxymethylated CNFs and dopamine-grafted carboxymethylated CNFs. The properties of these CNFs were compared with that of a microfibrillated cellulose from unbleached kraft fibres. In general, a great improvement in the dry mechanical properties of handsheets was observed with the addition of the periodate-oxidised oxidised and dopamine-grafted modified fibrils, whereas only the periodate-oxidised carboxymethylated CNFs improved the wet strength.

    Finally, it was found that the chemically modified fibres could be used to prepare a novel low-density material with good mechanical strength, both wet and dry, and excellent shape recovery capacity in the wet state after mechanical compression. The fibre networks were produced by solvent exchange from water to acetone followed by air drying at room temperature. The properties of the fibre networks could also fairly easily be tuned in terms of porosity, density and strength.

  • 35.
    Mystek, Katarzyna
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Larsson, Per
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Svagan, Anna Justina
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wågberg, Lars
    KTH, Skolan för teknikvetenskap (SCI), Centra, VinnExcellens Centrum BiMaC Innovation. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi. KTH Royal Inst Technol, Fibre & Polymer Technol, Stockholm, Sweden..
    Wet-expandable cellulose-based capsules2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 36. Müller, C.
    et al.
    Ouyang, Liangqi
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Lund, A.
    Moth-Poulsen, K.
    Hamedi, Mahiar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    From Single Molecules to Thin Film Electronics, Nanofibers, e-Textiles and Power Cables: Bridging Length Scales with Organic Semiconductors2019Ingår i: Advanced Materials, artikel-id 1807286Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Organic semiconductors are the centerpiece of several vibrant research fields from single-molecule to organic electronics, and they are finding increasing use in bioelectronics and even classical polymer technology. The versatile chemistry and broad range of electronic functionalities of conjugated materials enable the bridging of length scales 15 orders of magnitude apart, ranging from a single nanometer (10 −9 m) to the size of continents (10 6 m). This work provides a taste of the diverse applications that can be realized with organic semiconductors. The reader will embark on a journey from single molecular junctions to thin film organic electronics, supramolecular assemblies, biomaterials such as amyloid fibrils and nanofibrillated cellulose, conducting fibers and yarns for e-textiles, and finally to power cables that shuffle power across thousands of kilometers.

  • 37.
    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)
  • 38.
    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)
  • 39.
    Tian, Weiqian
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    VahidMohammadi, Armin
    Auburn Univ, Dept Mech & Mat Engn, Auburn, AL 36849 USA..
    Reid, Michael S.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wang, Zhen
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Ouyang, Liangqi
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Erlandsson, Johan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Pettersson, Torbjörn
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Wågberg, Lars
    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.
    Beidaghi, Majid
    Auburn Univ, Dept Mech & Mat Engn, Auburn, AL 36849 USA..
    Hamedi, Mahiar
    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.
    Multifunctional Nanocomposites with High Strength and Capacitance Using 2D MXene and 1D Nanocellulose2019Ingår i: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, artikel-id 1902977Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The family of two-dimensional (2D) metal carbides and nitrides, known as MXenes, are among the most promising electrode materials for supercapacitors thanks to their high metal-like electrical conductivity and surface-functional-group-enabled pseudocapacitance. A major drawback of these materials is, however, the low mechanical strength, which prevents their applications in lightweight, flexible electronics. A strategy of assembling freestanding and mechanically robust MXene (Ti3C2Tx) nanocomposites with one-dimensional (1D) cellulose nanofibrils (CNFs) from their stable colloidal dispersions is reported. The high aspect ratio of CNF (width of approximate to 3.5 nm and length reaching tens of micrometers) and their special interactions with MXene enable nanocomposites with high mechanical strength without sacrificing electrochemical performance. CNF loading up to 20%, for example, shows a remarkably high mechanical strength of 341 MPa (an order of magnitude higher than pristine MXene films of 29 MPa) while still maintaining a high capacitance of 298 F g(-1) and a high conductivity of 295 S cm(-1). It is also demonstrated that MXene/CNF hybrid dispersions can be used as inks to print flexible micro-supercapacitors with precise dimensions. This work paves the way for fabrication of robust multifunctional MXene nanocomposites for printed and lightweight structural devices.

  • 40.
    Tian, Weiqian
    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.
    VahidMohammadi, Armin
    Auburn Univ, Dept Mech & Mat Engn, Auburn, AL 36849 USA..
    Reid, Michael S.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Wang, Zhen
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi. KTH Royal Inst Technol, Dept Fibre & Polymer Technol, Tekn Ringen 56, S-10044 Stockholm, Sweden..
    Ouyang, Liangqi
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Erlandsson, Johan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Pettersson, Torbjörn
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Wågberg, Lars
    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.
    Beidaghi, Majid
    Auburn Univ, Dept Mech & Mat Engn, Auburn, AL 36849 USA..
    Hamedi, Mahiar
    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.
    Multifunctional Nanocomposites with High Strength and Capacitance Using 2D MXene and 1D Nanocellulose2019Ingår i: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, artikel-id 1902977Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The family of two-dimensional (2D) metal carbides and nitrides, known as MXenes, are among the most promising electrode materials for supercapacitors thanks to their high metal-like electrical conductivity and surface-functional-group-enabled pseudocapacitance. A major drawback of these materials is, however, the low mechanical strength, which prevents their applications in lightweight, flexible electronics. A strategy of assembling freestanding and mechanically robust MXene (Ti3C2Tx) nanocomposites with one-dimensional (1D) cellulose nanofibrils (CNFs) from their stable colloidal dispersions is reported. The high aspect ratio of CNF (width of approximate to 3.5 nm and length reaching tens of micrometers) and their special interactions with MXene enable nanocomposites with high mechanical strength without sacrificing electrochemical performance. CNF loading up to 20%, for example, shows a remarkably high mechanical strength of 341 MPa (an order of magnitude higher than pristine MXene films of 29 MPa) while still maintaining a high capacitance of 298 F g(-1) and a high conductivity of 295 S cm(-1). It is also demonstrated that MXene/CNF hybrid dispersions can be used as inks to print flexible micro-supercapacitors with precise dimensions. This work paves the way for fabrication of robust multifunctional MXene nanocomposites for printed and lightweight structural devices.

  • 41.
    Tian, Weiqian
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    VahidMohammadi, Armin
    Auburn Univ, Dept Mech & Mat Engn, Auburn, AL 36849 USA..
    Wang, Zhen
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Ouyang, Liangqi
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Beidaghi, Majid
    Auburn Univ, Dept Mech & Mat Engn, Auburn, AL 36849 USA..
    Hamedi, Mahiar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Layer-by-layer assembly of pillared MXene multilayers for high volumetric energy storage and beyond2019Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Artikel i tidskrift (Övrigt vetenskapligt)
  • 42.
    Wang, Zhen
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Malti, Abdellah
    KTH.
    Ouyang, Liangqi
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Tu, D.
    Tian, Weiqian
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    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.
    Hamedi, Mahiar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Copper-Plated Paper for High-Performance Lithium-Ion Batteries2018Ingår i: Small, ISSN 1613-6810, E-ISSN 1613-6829, Vol. 14, nr 48, artikel-id 1803313Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Paper is emerging as a promising flexible, high surface-area substrate for various new applications such as printed electronics, energy storage, and paper-based diagnostics. Many applications, however, require paper that reaches metallic conductivity levels, ideally at low cost. Here, an aqueous electroless copper-plating method is presented, which forms a conducting thin film of fused copper nanoparticles on the surface of the cellulose fibers. This paper can be used as a current collector for anodes of lithium-ion batteries. Owing to the porous structure and the large surface area of cellulose fibers, the copper-plated paper-based half-cell of the lithium-ion battery exhibits excellent rate performance and cycling stability, and even outperforms commercially available planar copper foil-based anode at ultra-high charge/discharge rates of 100 C and 200 C. This mechanically robust metallic-paper composite has promising applications as the current collector for light-weight, flexible, and foldable paper-based 3D Li-ion battery anodes.

  • 43.
    Wang, Zhen
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Ouyang, Liangqi
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Tian, Weiqian
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Erlandsson, Johan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Marais, Andrew
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Tybrandt, Klas
    Linkoping Univ, Dept Sci & Technol, Lab Organ Elect, S-60174 Norrkoping, Sweden.;Linkoping Univ, Dept Sci & Technol, Lab Organ Elect, Wallenberg Wood Sci Ctr, S-60174 Norrkoping, Sweden..
    Wågberg, Lars
    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.
    Hamedi, Mahiar
    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.
    Layer-by-Layer Assembly of High-Performance Electroactive Composites Using a Multiple Charged Small Molecule2019Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 35, nr 32, s. 10367-10373Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Layer-by-layer (LbL) assembly is a versatile tool for fabricating multilayers with tailorable nanostructures. LbL, however, generally relies on polyelectrolytes, which are mostly insulating and induce large interlayer distances. We demonstrate a method in which we replace polyelectrolytes with the smallest unit capable of LbL self-assembly: a molecule with multiple positive charges, tris(3-aminopropyl)amine (TAPA), to fabricate LbL films with negatively charged single-walled carbon nanotubes (CNTs). TAPA introduces less defects during the LbL build-up and results in more efficient assembly of films with denser micromorphology. Twenty bilayers of TAPA/CNT showed a low sheet resistance of 11 k Omega, a high transparency of 91% at 500 nm, and a high electronic conductivity of 1100 S/m on planar substrates. We also fabricated LbL films on porous foams with a conductivity of 69 mS/m and used them as electrodes for supercapacitors with a high specific capacitance of 43 F/g at a discharging current density of 1 A/g.

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