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  • 51.
    Mushi, Ngesa Ezekiel
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Membrane and hydrogel properties from chitin fibril structures: Structure and properties at neutral pH2014Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, s. 21-CELL-Artikel i tidskrift (Övrigt vetenskapligt)
  • 52.
    Nordgren, Niklas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Eklöf, Jens
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Brumer, Harry
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Rutland, Mark W.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    CELL 260-Top-down grafting of xyloglucan to gold monitored by QCM-D and AFM: Enzymatic activity and interactions with cellulose2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    This study focuses on the manufacture and characterisation of model surfaces consisting of end grafted xyloglucan (XG), a naturally occurring polysaccharide, onto a gold substrate. The now well-established XET-technology was utilised for enzymatic incorporation of a thiol moiety at one end of the xyloglucan backbone. This functionalised macromolecule was subsequently top-down grafted to gold, forming a thiol-bonded xyloglucan brush-like layer. The grafting was monitored in-situ with QCM-D and a significant difference in the adsorbed/grafted amount between unmodified xyloglucan and the thiol-functionalised polymer was observed. The grafted surface was demonstrated to be accessible to enzyme digestion using the plant endo-xyloglucanase TmNXG1. The nanotribological properties towards cellulose of the untreated crystal, brush modified surface and enzyme exposed surfaces were compared with a view to understanding the role of xyloglucan in friction reduction. Friction coefficients obtained by the AFM colloidal probe technique using a cellulose functionalised probe on the xyloglucan brush showed an increase of a factor of two after the enzyme digestion and this result is interpreted in terms of surface roughness. Finally, the brush is shown to exhibit binding to cellulose despite its highly oriented nature.

  • 53.
    Nordgren, Niklas
    et al.
    KTH, Skolan för kemivetenskap (CHE).
    Eklöf, Jens
    KTH, Skolan för bioteknologi (BIO).
    Zhou, Qi
    KTH, Tidigare Institutioner (före 2005), Bioteknologi. AlbaNova Univ Ctr, Royal Inst Technol, Sch Biotechnol, S-10691 Stockholm, Sweden..
    Brumer, Harry
    KTH, Skolan för bioteknologi (BIO).
    Rutland, Mark W.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Yt- och korrosionsvetenskap.
    CELL 260-Top-down grafting of xyloglucan to gold monitored by QCM-D and AFM: Enzymatic activity and interactions with cellulose2008Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 235Artikel i tidskrift (Övrigt vetenskapligt)
  • 54.
    Nordgren, Niklas
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Eklöf, Jens
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Brumer III, Harry
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Rutland, Mark
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Top-Down Grafting of Xyloglucan to Gold Monitored by QCM-D and AFM: Enzymatic Activity and Interactions with Cellulose2008Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 9, nr 3, s. 942-948Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study focuses on the manufacture and characterisation of model surfaces consisting of end grafted xyloglucan (XG), a naturally occurring polysaccharide, onto a gold substrate.  The now well-established XET-technology was utilised for enzymatic incorporation of a thiol moiety at one end of the xyloglucan backbone.  This functionalised macromolecule was subsequently top-down grafted to gold, forming a thiol-bonded xyloglucan brush-like layer. The grafting was monitored in-situ with QCM-D and a significant difference in the adsorbed/grafted amount between unmodified xyloglucan and the thiol-functionalised polymer was observed.  The grafted surface was demonstrated to be accessible to enzyme digestion using the plant endo-xyloglucanase TmNXG1.  The nanotribological properties towards cellulose of the untreated crystal, brush modified surface and enzyme exposed surfaces were compared with a view to understanding the role of xyloglucan in friction reduction.  Friction coefficients obtained by the AFM colloidal probe technique using a cellulose functionalised probe on the xyloglucan brush showed an increase of a factor of two after the enzyme digestion and this result is interpreted in terms of surface roughness.  Finally, the brush is shown to exhibit binding to cellulose despite its highly oriented nature.

  • 55.
    Pei, Aihua
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Surface-modification of nanocelluloses and their applications in poly(lactic acid)/nanocellulose biocomposites2014Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, s. 163-CELL-Artikel i tidskrift (Övrigt vetenskapligt)
  • 56.
    Pei, Aihua
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Butchosa, Nuria
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Surface quaternized cellulose nanofibrils for high-performance anionic dyes removal in water2012Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 243Artikel i tidskrift (Övrigt vetenskapligt)
  • 57.
    Pei, Aihua
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Butchosa, Nuria
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Surface quaternized cellulose nanofibrils with high water absorbency and adsorption capacity for anionic dyes2013Ingår i: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 9, nr 6, s. 2047-2055Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Surface quaternized cellulose nanofibrils were mechanically disintegrated from wood pulp that was pretreated through a reaction with glycidyltrimethylammonium chloride. The resulting quaternized cellulose nanofibrils (Q-NFC) with trimethylammonium chloride contents of 0.59-2.31 mmol g(-1) were characterized by conductometric titration, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM), and atomic force microscopy (AFM). When the trimethylammonium chloride content on cellulose reached approximately 0.79 mmol g(-1) corresponding to a degree of substitution of 0.13 per bulk anhydroglucose unit, highly viscous and transparent aqueous dispersions of cellulose nanofibrils were obtained by mechanical homogenization of the chemically pretreated cellulose/water slurries. AFM observation showed that the dispersions consisted of individualized cellulose I nanofibrils 1.6-2.1 nm in width and 1.3-2.0 mu m in length. Cellulose nanopapers prepared from the Q-NFC aqueous dispersions exhibited high tensile strength (ca. 200 MPa) and Young's modulus (ca. 10 GPa) despite high porosity (37-48%). The nanopapers also demonstrated ultrahigh water absorbency (750 g g(-1)) with high surface cationic charge density. Stable hydrogels were obtained after swelling the nanopaper in water. The Q-NFC nanofibrils also possessed high anionic dye adsorption capability. The adsorption capacity increased with increasing trimethylammonium chloride content on cellulose.

  • 58.
    Pei, Aihua
    et al.
    KTH, Skolan för bioteknologi (BIO).
    Malho, Jani-Markus
    Ruokolainen, Janne
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Strong Nanocomposite Reinforcement Effects in Polyurethane Elastomer with Low Volume Fraction of Cellulose Nanocrystals2011Ingår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 44, nr 11, s. 4422-4427Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Polyurethane/cellulose nanocrystal nanocomposites with ultrahigh tensile strength and stain-to-failure with strongly improved modulus were prepared by adding cellulose nanocrystals (CNCs) during the preparation of prepolymer. The nanostructure of this polyurethane consisted of individualized nanocellulose crystals covalently bonded and specifically associated with the hard polyurethane (PU) microdomains as characterized by Fourier transform infrared spectroscopy and transmission electron microscopy. The storage modulus and thermal stability of the nanocomposites were significantly improved as measured by dynamic mechanical analysis. This was due to a combination of CNCs reinforcement in the soft matrix and increased effective cross-link density of the elastomer network due to CNC-PU molecular interaction. Tensile test revealed that the nanocomposites have both higher tensile strength and strain-to-failure. In particular, with only 1 wt % of cellulose nanocrystals incorporated, an 8-fold increase in tensile strength and 1.3-fold increase in strain-to-failure were achieved, respectively. Such high strength indicates that CNCs orient strongly at high strains and may also induce synergistic PU orientation effects contributing to the dramatic strength enhancement. The present elastomer nanocomposite outperforms conventional rubbery materials and polyurethane nanocomposites reinforced with microcrystalline cellulose, carbon nanotubes, or nanoclays.

  • 59.
    Pei, Aihua
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Functionalized cellulose nanocrystals as biobased nucleation agents in poly(L-lactide) (PLLA): Crystallization and mechanical property effects2010Ingår i: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 70, nr 5, s. 815-821Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The important industrial problem of slow crystallization of poly(l-lactide) (PLLA) is addressed by the use of cellulose nanocrystals as biobased nucleation reagents. Cellulose nanocrystals (CNC) were prepared by acid hydrolysis of cotton and additionally functionalized by partial silylation through reactions with n-dodecyldimethylchlorosilane in toluene. Such silylated cellulose nanocrystals (SCNC) were dispersible in tetrahydrofuran and chloroform, and formed stable suspensions. Nanocomposite films of PLLA and CNC or SCNC were prepared by solution casting. The effects of surface silylation of cellulose nanocrystals on morphology, non-isothermal and isothermal crystallization behavior, and mechanical properties of these truly nanostructured composites were investigated. The unmodified CNC formed aggregates in the composites, whereas the SCNC were well-dispersed and individualized in PLLA. As a result, the tensile modulus and tensile strength of the PLLA/SCNC nanocomposite films were more than 20% higher than for pure PLLA with only 1. wt.% SCNC, due to crystallinity effects and fine dispersion.

  • 60. Peltzer, Mercedes
    et al.
    Pei, Aihua
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Berglund, Lars
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Jiménez, Alfonso
    Surface modification of cellulose nanocrystals by grafting with poly(lactic acid)2014Ingår i: Polymer international, ISSN 0959-8103, E-ISSN 1097-0126, Vol. 63, nr 6, s. 1056-1062Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The use of biopolymers obtained from renewable resources is currently growing and they have found unique applications as matrices and/or nanofillers in 'green' nanocomposites. Grafting of polymer chains to the surface of cellulose nanofillers was also studied to promote the dispersion of cellulose nanocrystals in hydrophobic polymer matrices. The aim of this study was to modify the surface of cellulose nanocrystals by grafting from L-lactide by ring-opening polymerization in order to improve the compatibility of nanocrystals and hydrophobic polymer matrices. The effectiveness of the grafting was evidenced by the long-term stability of a suspension of poly(lactic acid)-grafted cellulose nanocrystals in chloroform, by the presence of the carbonyl peak in modified samples determined by Fourier transform infrared spectroscopy and by the modification in C1s contributions observed by X-ray photoelectron spectroscopy. No modification in nanocrystal shape was observed in birefringence studies and transmission electron microscopy.

  • 61.
    Prakobna, Kasinee
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Biokompositer. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Terenzi, Camilla
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Furo, Istvan
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Centra, Centrum för Industriell NMR-teknik.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Biokompositer. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Core-shell cellulose nanofibers for biocomposites: Nanostructural effects in hydrated state2015Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 125, s. 92-102Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Core-shell wood cellulose nanofibers (CNF) coated by an XG hemicellulose polymer are prepared and used to make biocomposites. CNF/XG biocomposites have interest as packaging materials and as hydrated CNF/XG plant cell wall analogues. Structure and properties are compared between Core-shell CNF/XG and more inhomogeneous CNF/XG. Experiments include XG sorption, dynamic light scattering of CNF nanoparticle suspensions, FE-SEM of nanostructure, moisture sorption, tensile testing in moist conditions and dynamic mechanical analysis. (2)H NMR relaxometry is performed on materials containing sorbed (2)H2O2 in order to assess water molecular dynamics in different materials. The results clarify the roles of CNF, XG and the CNF/XG interface in the biocomposites, both in terms of moisture sorption mechanisms and mechanical properties in moist state. The concept of core-shell nanofiber network biocomposites, prepared by filtering of colloids, provides improved control of polymer matrix distribution and interface structure. Also, present mechanical properties are much superior to comparable plant fiber biocomposites.

  • 62. Rueda, L.
    et al.
    Fernandez d'Arlas, B.
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Corcuera, M. A.
    Mondragon, I.
    Eceiza, A.
    Isocyanate-rich cellulose nanocrystals and their selective insertion in elastomeric polyurethane2011Ingår i: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 71, nr 16, s. 1953-1960Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cellulose nanocrystals (CNC) were successfully obtained and modified with 1,6-hexamethylene diisocyanate (HE)!) by means of in situ polymerization varying the CNC/HDI molar ratio to evaluate the number of anchored chains to the CNC. The modification was examined by elemental analysis, nuclear magnetic resonance ((13)C NMR) and attenuated total reflection Fourier transform infrared spectroscopy (IR-ATR). Nanocomposites containing 1.5 wt% CNC, modified and unmodified, were prepared by solvent casting. Thermal and mechanical properties of the resulting films were evaluated from the viewpoint of polyurethane microphase separated structure, soft and hard domains. CNC were effectively dispersed in the polyurethane matrix and depending on surface chemistry, the nanoreinforcement interacts selectively with matrix nanodomains. This interpretation is supported by differences in thermal and mechanical properties of the nanocomposites and also confirmed by AFM images. Isocyanate rich cellulose nanocrystals interacted with matrix hard phase, promoting physical association with hard segments, enhancing stiffness and dimensional stability versus temperature of the nanocomposite.

  • 63. Rueda, L.
    et al.
    Saralegi, A.
    Fernandez-d'Arlas, B.
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Alonso-Varona, A.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Mondragon, I.
    Corcuera, M. A.
    Eceiza, A.
    In situ polymerization and characterization of elastomeric polyurethane-cellulose nanocrystal nanocomposites. Cell response evaluation2013Ingår i: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 20, nr 4, s. 1819-1828Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Polyurethane/Cellulose nanocrystal (CNC) nanocomposites have been prepared by means of in situ polymerization using CNCs as precursors of polyurethane chains. Thermal, mechanical and morphological characterization has been analyzed to study the effect of CNC on the micro/nanostructure, which consisted of individualized nanocellulose crystallites covalently bonded to hard and soft segments of polyurethane. The incorporation of low CNC content led to a tough material whereas higher amount of CNC provoked an increase in soft and hard segments crystallization phenomenon. Moreover, from the viewpoint of polyurethane and polyurethane nanocomposites applications focused on biomedical devices, biocompatibility studies can be considered necessary to evaluate the influence of CNC on the biological behaviour. SEM micrographs obtained from cells seeded on top of the materials showed that L-929 fibroblasts massively colonized the materials surface giving rise to good substrates for cell adhesion and proliferation and useful as potential materials for biomedical applications.

  • 64. Rueda, L.
    et al.
    Saralegui, A.
    Fernandez d'Arlas, B.
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Corcuera, M. A.
    Mondragon, I.
    Eceiza, A.
    Cellulose nanocrystals/polyurethane nanocomposites. Study from the viewpoint of microphase separated structure2013Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 92, nr 1, s. 751-757Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cellulose nanocrystals (CNC) successfully obtained from microcrystalline cellulose (MCC) were dispersed in a thermoplastic polyurethane as matrix. Nanocomposites containing 1.5.5. 10 and 30 wt% CNC were prepared by solvent casting procedure and properties of the resulting films were evaluated from the viewpoint of polyurethane microphase separated structure, soft and hard domains. CNC were effectively dispersed in the segmented thermoplastic elastomeric polyurethane (STPUE) matrix due to the favorable matrix-nanocrystals interactions through hydrogen bonding. Cellulose nanocrystals interacted with both soft and hard segments, enhancing stiffness and stability versus temperature of the nanocomposites. Thermal and mechanical properties of STPUE/CNC nanocomposites have been associated to the generated morphologies investigated by AFM images.

  • 65.
    Rzeszutek, Elzbieta
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Diaz-Moreno, Sara M.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Ampomah, Osei Y.
    Inman, Annie
    Srivastava, Vaibhav
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Zhou, Qi
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Bulone, Vincent
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Glykovetenskap.
    Novel insights into chitin biosynthesis through heterologous expression and biochemical characterization of chitin synthase 5 from the pathogenic oomycete Saprolegnia parasitica Manuskript (preprint) (Övrigt vetenskapligt)
  • 66.
    Salajkova, Michaela
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. Brno University of Technology, Czech Republic .
    Sehaqui, Houssine
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Nanostructured composite materials from microfibrillated cellulose and carbon nanotubes2009Ingår i: ICCM-17 17th International Conference on Composite Materials, 2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    Thin composite films were prepared from the mixture of the aqueous suspension of microfibrillated cellulose (MFC) and multi-walled carbon nanotubes (MWCNTs). The morphology, electrical conductivity, and mechanical properties of the composites were characterized. Good electrical properties were obtained when the MWCNTs content was higher than 2 wt%.

  • 67.
    Salajkova, Michaela
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Valentini, Luca
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer. KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Berglund, Lars
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Tough nanopaper structures based on cellulose nanofibers and carbon nanotubes2013Ingår i: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 87, s. 103-110Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Carbon nanotube (CNT) nanocomposites based on CNT in a polymer matrix typically have low strain to failure in tensile loading. Furthermore, mixing of more than a few percent of CNT with either molten thermoplastics or monomers in bulk often results in agglomeration of CNT. Here, multiwalled CNT (MWCNT) are mixed with nanofibrillated cellulose (NFC) in aqueous suspension and filtered into tough nanopaper structures with up to 17 wt% of MWCNT commingled with NFC nanofibrils. Carbon nanotubes were surface treated with a surfactant, and homogenous suspensions of carbon nanotubes in water miscible with the NFC suspension was obtained. NFC/CNT nanopaper structures were characterized for porosity using mercury displacement, and studied by FE-SEM and AFM. Mechanical properties were tested in uniaxial tension and electrical conductivity was measured. The processing route is environmentally friendly and leads to well-mixed structures. Thin coatings as well as thicker films can be prepared, which show a combination of high electrical conductivity, flexibility in bending and high tensile strength.

  • 68.
    Salajková, Michaela
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Berglund, Lars
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Hydrophobic cellulose nanocrystals modified with quaternary ammonium salts2012Ingår i: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, nr 37, s. 19798-19805Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An environmentally friendly procedure in aqueous solution for the surface modification of cellulose nanocrystals (CNCs) using quaternary ammonium salts via adsorption is developed as inspired by organomodified layered silicates. CNCs with a high carboxylate content of 1.5 mmol g(-1) were prepared by a new route, direct hydrochloric acid hydrolysis of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized nanofibrillated cellulose from a softwood pulp, and characterized by atomic force microscopy (AFM) and X-ray diffraction (XRD). Four quaternary ammonium cation surfactants bearing long alkyl, phenyl, glycidyl, and diallyl groups were successfully used to modify CNCs carrying carboxylic acid groups as characterized by Fourier transform infrared spectroscopy (FTIR). The modified CNCs can be redispersed and individualized in an organic solvent such as toluene as observed by scanning transmission electron microscopy (STEM). One may envision removing excess surfactant to obtain CNC with a monolayer of surfactant. The toluene suspension of the modified CNCs showed strong birefringence under crossed polars but no further chiral- nematic ordering was observed. The model surface prepared by the CNCs modified with quaternary ammonium salts bearing C18 alkyl chains showed a significant increase in water contact angle (71 degrees) compared to that of unmodified CNCs (12 degrees). This new series of modified CNCs can be dried from solvent and have the potential to form well-dispersed nanocomposites with non-polar polymers.

  • 69.
    Sehaqui, Houssine
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Allais, Mael
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för bioteknologi (BIO), Centra, Albanova VinnExcellence Center for Protein Technology, ProNova.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Wood cellulose biocomposites with fibrous structures at micro- and nanoscale2011Ingår i: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 71, nr 3, s. 382-387Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    High-strength composites from wood fiber and nanofibrillated cellulose (NFC) were prepared in a semiautomatic sheet former. The composites were characterized by tensile tests, dynamic mechanical thermal analysis, field-emission scanning electron microscopy, and porosity measurements. The tensile strength increased from 98 MPa to 160 MPa and the work to fracture was more than doubled with the addition of 10% NFC to wood fibers. A hierarchical structure was obtained in the composites in the form of a micro-scale wood fiber network and an additional NFC nanofiber network linking wood fibers and also occupying some of the micro-scale porosity. Deformation mechanisms are discussed as well as possible applications of this biocomposites concept. (C) 2010 Published by Elsevier Ltd.

  • 70.
    Sehaqui, Houssine
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Liu, Andong
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Fast Preparation Procedure for Large, Flat Cellulose and Cellulose/Inorganic Nanopaper Structures2010Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 11, nr 9, s. 2195-2198Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nanostructured materials are difficult to prepare rapidly and as large structures. The present study is thus significant because a rapid preparation procedure for large, flat, smooth, and optically transparent cellulose nanopaper structures is developed using a semiautomatic sheet former. Cellulose/inorganic hybrid nanopaper is also produced. The preparation procedure is compared with other approaches, and the nanopaper structures are tested in uniaxial tensile tests. Optical transparency and high tensile strength are demonstrated in 200 mm diameter nanopaper sheets, indicating well-dispersed nanofibrils. The preparation time is 1 h for a typical nanopaper thickness of 60 pm. In addition, the application of the nanopaper-making strategy to cellulose/inorganic hybrids demonstrates the potential for "green" processing of new types of nanostructured functional materials.

  • 71.
    Sehaqui, Houssine
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Salajkova, Michaela
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. Brno University of Technology, Czech Republic .
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Biomimetic aerogels from microfibrillated cellulose and xyloglucan2009Ingår i: ICCM-17 17th International Conference on Composite Materials, 2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    Cellulose aerogels with density of 7-100 kg/m3 were prepared by freeze drying from microfibrillated cellulose water suspensions, and biomimetic aerogels were prepared with the addition of xyloglucan. Their microstructures and physical properties were characterized by scanning electron microscopy, nitrogen adsorption measurements, and tensile tests.

  • 72.
    Sehaqui, Houssine
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Salajkova, Michaela
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer. KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Mechanical performance tailoring of tough ultra-high porosity foams prepared from cellulose I nanofiber suspensions2010Ingår i: Soft Matter, ISSN 1744-683X, Vol. 6, nr 8, s. 1824-1832Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Low-density structures of mechanical function in plants, arthropods and other organisms, are often based on high- strength cellulose or chitin nanofibers and show an interesting combination of flexibility and toughness. Here, a series of plant-inspired tough and mechanically very robust cellular biopolymer foams with porosities as high as 99.5% (porosity range 93.1-99.5%) were therefore prepared by solvent-free freeze-drying from cellulose I wood nanofiber water suspensions. A wide range of mechanical properties was obtained by controlling density and nanofiber interaction in the foams, and density property relationships were modeled and compared with those for inorganic aerogels. Inspired by cellulose-xyloglucan (XG) interaction in plant cell walls, XG was added during preparation of the toughest foams. For the cellulose-XG nanocomposite foams in particular, the mechanical properties at comparable densities were superior to those reported in the literature for clay aerogel/cellulose whisker nanocomposites, epoxy/clay aerogels, polymer/clay/nanotube aerogels, and polymer/silica aerogels. The foam structure was characterized by high-resolution field-emission scanning electron microscopy and the specific surface area was measured by nitrogen physisorption. Dynamic mechanical thermal analysis and uniaxial compression tests were performed. The foam was thermally stable up to 275 degrees C where cellulose started to degrade.

  • 73.
    Sehaqui, Houssine
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    High-porosity aerogels of high specific surface area prepared from nanofibrillated cellulose (NFC)2011Ingår i: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 71, nr 13, s. 1593-1599Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Low-density aerogels based on nanofibrillated cellulose (NFC) from wood pulp were prepared from NFC aqueous dispersions using solvent exchange from water to tert-butanol followed by tert-butanol freeze-drying. In the present study, the dispersion of NFC nanofibers in the hydrocolloid was very well preserved in the aerogels. The "effective" diameter of the NFC nanofibers in the aerogels is around 10-18 nm corresponding to specific surface areas as high as 153-284 m(2) g(-1). Aerogels based on different NFC nanofibers were studied by FE-SEM, BET analysis (nitrogen gas adsorption), and mechanical properties were measured in compression for different densities of aerogels. The properties are compared with polymer foams and inorganic aerogels. Compared with cellular NFC foams, the present nanofibrous aerogels have lower modulus and show lower stress in compression for a given strain. Tert-butanol freeze-drying can therefore be used to create "soft" aerogels.

  • 74.
    Sehaqui, Houssine
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Nanofibrillated cellulose for enhancement of strength in high-density paper structures2013Ingår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 28, nr 2, s. 182-189Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In order to enhance dry and wet strength properties of paper, handsheets were made of wood pulp fibers and nanofibrillated cellulose (NFC). 10% NFC was mixed with wood pulp fibers (90%) subjected to different number of beating revolutions. Effects from xyloglucan (XG) hemicellulose addition were also studied. High density paper handsheets from these mixtures were prepared using a laboratory handsheet former. Strength properties were measured and densities of the materials estimated. Scanning electron microscopy was used to observe paper sheet surfaces. NFC significantly enhances strength for the paper handsheets both at 50% relative humidity and in the wet state so that NFC addition may be an alternative to mechanical beating. The main reason for property improvements is increased density of the final material. Tensile energy absorption improved strongly through favorable fiber-fiber interaction. NFC or NFC/XG addition combined with some mechanical beating may decrease energy needs compared with beating only.

  • 75.
    Sehaqui, Houssine
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Nanostructured biocomposites of high toughness-a wood cellulose nanofiber network in ductile hydroxyethylcellulose matrix2011Ingår i: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 7, nr 16, s. 7342-7350Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nanopaper from wood-based nanofibrillated cellulose (NFC) offers vastly improved strength and strain-to-failure compared with plant fiber-based paper and plant fiber biocomposites. In the present study, unique nanostructural toughening effects are reported in cellulose nanofiber/hydroxyethylcellulose (HEC) biocomposites. HEC is an amorphous cellulose derivative of high molar mass and toughness. A previously developed preparation route inspired by paper-making is used. It is "green", scalable, and allows high reinforcement content. In the present concept, nanostructural control of polymer matrix distribution is exercised as the polymer associates with the reinforcement. This results in nanocomposites of a soft HEC matrix surrounding nanofibrillated cellulose forming a laminated structure at the submicron scale, as observed by FE-SEM. We study the effect of NFC volume fraction on tensile properties, thermomechanical stability, creep properties and moisture sorption of the nanocomposites. The results show strong property improvements with NFC content due to the load-carrying ability of the NFC network. At an NFC volume fraction of 45%, the toughness was more than doubled compared with cellulose nanopaper. The present nanocomposite is located in previously unoccupied space in a strength versus strain-to-failure property chart, outside the regions occupied by microscale composites and engineering polymers. The results emphasize the potential for extended composites mechanical property range offered by nanostructured biocomposites based on high volume fraction nanofiber networks.

  • 76.
    Sehaqui, Houssine
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Ikkala, Olli
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Strong and Tough Cellulose Nanopaper with High Specific Surface Area and Porosity2011Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 12, nr 10, s. 3638-3644Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In order to better understand nanostructured fiber networks, effects from high specific surface area of nanofibers are important to explore. For cellulose networks, this has so far only been achieved in nonfibrous regenerated cellulose aerogels. Here, nanofibrillated cellulose (NFC) is used to prepare high surface area nanopaper structures, and the mechanical properties are measured in tensile tests. The water in NFC hydrogels is exchanged to liquid CO(2), supercritical CO(2), and tert-butanol, followed by evaporation, supercritical drying, and sublimation, respectively. The porosity range is 40-86%. The nanofiber network structure in nanopaper is characterized by FE-SEM and nitrogen adsorption, and specific surface area is determined. High-porosity TEMPO-oxidized NFC nanopaper (56% porosity) prepared by critical point drying has a specific surface area as high as 48(2) m(2) g(-1). The mechanical properties of this nanopaper structure are better than for many thermoplastics, but at a significantly lower density of only 640 kg m(-3). The modulus is 1.4 GPa, tensile strength 84 MPa, and strain-to-failure 17%. Compared with water-dried nanopaper, the material is softer with substantially different deformation behavior.

  • 77.
    Stiernstedt, Johanna
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Brumer III, Harry
    KTH, Skolan för bioteknologi (BIO).
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO).
    Teeri, Tuula
    KTH, Skolan för bioteknologi (BIO).
    Rutland, Mark
    KTH, Skolan för kemivetenskap (CHE), Kemi, Ytkemi.
    Friction between cellulose surfaces and the effect of and xyloglucan adsorption2006Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 7, nr 7, s. 2147-2153Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The forces and friction between cellulose spheres have been measured in the absence and presence of xyloglucan using an atomic force microscope. The forces between cellulose are monotonically repulsive with negligible adhesion after contact is achieved. The friction coefficient is observed to be unusually high in comparison with other nanotribological systems. We have confirmed that xyloglucan adsorbs strongly to cellulose, which results in a much stronger adhesion, which is dependent on the time the surfaces are in contact. Xyloglucan also increases the repulsion on approach of the cellulose surfaces, and the friction is markedly reduced. The apparently incompatible observations of decreased friction in combination with increased adhesion fulfills many of the necessary criteria for a papermaking additive.

  • 78. Svagan, A. J.
    et al.
    Kusic, A.
    De Gobba, C.
    Larsen, F. H.
    Sassene, P.
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Van De Weert, M.
    Mullertz, A.
    Jørgensen, B.
    Ulvskov, P.
    Rhamnogalacturonan-I based microcapsules for targeted drug release2016Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, nr 12, artikel-id e0168050Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Drug targeting to the colon via the oral administration route for local treatment of e.g. inflammatory bowel disease and colonic cancer has several advantages such as needle-free administration and low infection risk. A new source for delivery is plant-polysaccharide based delivery platforms such as Rhamnogalacturonan-I (RG-I). In the gastro-intestinal tract the RG-I is only degraded by the action of the colonic microflora. For assessment of potential drug delivery properties, RG-I based microcapsules (~1 μm in diameter) were prepared by an interfacial poly-addition reaction. The cross-linked capsules were loaded with a fluorescent dye (model drug). The capsules showed negligible and very little in vitro release when subjected to media simulating gastric and intestinal fluids, respectively. However, upon exposure to a cocktail of commercial RG-I cleaving enzymes, ~ 9 times higher release was observed, demonstrating that the capsules can be opened by enzymatic degradation. The combined results suggest a potential platform for targeted drug delivery in the terminal gastro-intestinal tract.

  • 79.
    Tang, Hu
    et al.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Butchosa, Nuria
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Bulone, Vincent
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Transparent, hazy and strong macroscopic ribbon of oriented cellulose nanofibrils bearing poly(ethylene glycol)Manuskript (preprint) (Övrigt vetenskapligt)
  • 80.
    Tang, Hu
    et al.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Butchosa, Nuria
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Biokompositer.
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    A Transparent, Hazy, and Strong Macroscopic Ribbon of Oriented Cellulose Nanofibrils Bearing Poly(ethylene glycol)2015Ingår i: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 27, nr 12, s. 2070-2076Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A macroscopic ribbon of oriented cellulose nanofibrils bearing polyethylene glycol is fabricated by stretching the cellulose nanofibrils network structure in the hydrogel state. The covalently grafted polyethylene glycol on the nanofibril surface facilitates the alignment and compartmentalization of individual nanofibrils in the ribbon. The ribbon has ultrahigh tensile strength (576 +/- 54 MPa), modulus (32.3 +/- 5.7 GPa), high transparency, and haze.

  • 81.
    Yao, Kun
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Meng, Qijun
    Bulone, Vincent
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Flexible and Responsive Chiral Nematic Cellulose Nanocrystal/Poly(ethylene glycol) Composite Films with Uniform and Tunable Structural Color2017Ingår i: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 29, nr 28, artikel-id 1701323Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The fabrication of responsive photonic structures from cellulose nanocrystals (CNCs) that can operate in the entire visible spectrum is challenging due to the requirements of precise periodic modulation of the pitch size of the self-assembled multilayer structures at the length scale within the wavelength of the visible light. The surface charge density of CNCs is an important factor in controlling the pitch size of the chiral nematic structure of the dried solid CNC films. The assembly of poly(ethylene glycol) (PEG) together with CNCs into smaller chiral nematic domains results in solid films with uniform helical structure upon slow drying. Large, flexible, and flat photonic composite films with uniform structure colors from blue to red are prepared by changing the composition of CNCs and PEG. The CNC/PEG(80/20) composite film demonstrates a reversible and smooth structural color change between green and transparent in response to an increase and decrease of relative humidity between 50% and 100% owing to the reversible swelling and dehydration of the chiral nematic structure. The composite also shows excellent mechanical and thermal properties, complementing the multifunctional property profile.

  • 82. Zhang, L.
    et al.
    Li, X. L.
    Zhou, Qi
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Zhang, X. F.
    Chen, R. Q.
    Transition from triple helix to coil of Lentinan in solution measured by SEC, viscometry, and C-13 NMR2002Ingår i: Polymer journal, ISSN 0032-3896, E-ISSN 1349-0540, Vol. 34, nr 6, s. 443-449Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lentinan, beta-(1 --> 3)-D-glucan with (1 --> 6) branching, was isolated from Lentinus edodes. Weight-average molecular weight M-w radius of gyration < s(2) > (1/2) and intrinsic viscosity [eta] of Lentinan in 0.2 M NaCl aqueous solution, dimethylsulfoxide (DMSO) and water/DMSO mixtures were measured by light scattering (LS), size exclusion chromatography (SEC) combined with LS, and viscometry. The results indicated that the glucan exists mainly as triple-helical chains in 0.2 M NaCl aqueous solution and water/DMSO mixtures with over 20 wt% water content, and as single-flexible chain in DMSO. The data from SEC-LS, viscosity and C-13 NMR measurements proved strongly that the helix-coil conformation transition occurred in a narrow range from 80 to 85 wt% DMSO aqueous solution, accompanying with obvious changes of M-w, < s(2) >(1/2)(z), [eta] as well as signals of C6 and C6(s). The transition of Lentinan in water/DMSO mixture was irreversible. The difference in C-13 NMR spectra for the triple-helical and coil conformations was the disappearance of the signals of C3 in beta-(1 --> 3)- linked backbone and the enhancement in relative intensities of glucose substituted C6s in the helix state, as well as the appearance of an asymmetric and broad peak of C6 in the intermediate of the conformation change. This suggests that the immobilization of the backbone by binding with intra and intermolecular hydrogen bonds resulted in the loss of the signals of its carbon atoms in the triple helix state. An overcoating cylinder model composed of the beta-(1 --> 3)- linked backbone as helix core and the side chains as rotatable overcoat was proposed to illustrate the triple-helical conformation and its transition in the solution.

  • 83. Zhang, L. N.
    et al.
    Zhang, M.
    Zhou, Qi
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Chen, J. H.
    Zeng, F. B.
    Solution properties of antitumor sulfated derivative of alpha-(1 -> 3)-D-glucan from Ganoderma lucidum2000Ingår i: Bioscience, biotechnology and biochemistry, ISSN 0916-8451, E-ISSN 1347-6947, Vol. 64, nr 10, s. 2172-2178Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Four fractions of a water-insoluble alpha-(1-->3)-D-glucan GL extracted from fruiting bodies of Ganoderma lucidum were dissolved in 0.25 M LiCl/DMsO, and then reacted with sulfur trioxide-pyridine complex at 80 degreesC to synthesize a series of water-soluble sulfated derivatives S-GL. The degree of substitution of DS was measured by using IR infrared spectra, elemental analysis, and C-13 NMR to be 1.2-1.6 in the non-selective sulfation. Weight-average molecular weight M, and intrinsic viscosity [eta] of the sulfated derivatives S-GL were measured by multi-angle laser light scattering and viscometry. The M-w value (2.4 x 10(4)) of sulfated glucan S-GL-1 was much lower than that (44.5 x 10(4)) of original alpha-(1-->3)-D-glucan GL-1. The Mark-Houwink equation and average value of characteristic ratio C-infinity for the S-GL in 0.2 M NaCl aqueous solution at 25 degreesC were found to be: [eta] =1.32 x 10(-3) M-w(1.06) (cm(3) g(-1)) and 16, respectively, in the M-w range from 1.1 x 10(4) to 2.4 x 10(4). It indicated that the sulfated derivatives of the alpha-(1-->3)-D-glucan in the aqueous solution behave as an expanded chain, owing to intramolecular hydrogen bonding or interaction between charge groups. Interestingly, two sulfated derivatives synthesized from the alpha-(1-->3)-D-glucan and curdlan, a beta-(1-->3)-D-glucan, all had significant higher antitumor activity against Ehrlich ascites carcinoma (EAC) than the originals. The effect of expanded chains of the sulfated glucan in the aqueous solution on the improvement of the antitumor activity could not be negligible.

  • 84. Zhang, L. N.
    et al.
    Zhang, X. F.
    Zhou, Qi
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Zhang, P. Y.
    Zhang, M.
    Li, X. L.
    Triple helix of beta-D-glucan from Lentinus Edodes in 0.5 M NaCl aqueous solution characterized by light scattering2001Ingår i: Polymer journal, ISSN 0032-3896, E-ISSN 1349-0540, Vol. 33, nr 4, s. 317-321Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    beta-(1 -->3)-D-glucan with (1 -->6) branching (L-FV-I) from Lentinus edodes in water was degraded into seven fractions of different molecular weights by ultrasonic irradiation. Weight-average molecular weight M,, radius of gyration (1/2)(5) and intrinsic viscosity [eta] of the beta -D-glucan and its fractions in 0.5 M NaCl aqueous solution and dimethylsulfoxide (DMSO) were studied by multi-angle laser light scattering (MALLS), GPC combined with MALLS, and viscometry. M, dependence of [eta] for the glucan in 0.5 M NaCl aqueous solution was represented approximately by [eta] =7.69 x 10(-6) M-w(1.32) (cm(3) g(-1)) at M-w from 1.87 X 10(5) to 1.20 X 10(6) at 25 degreesC. GPC chromatograms of the glucans in aqueous solution contained two peaks, a main peak corresponding to triple-stranded chains with molecular weight M-w,M-m, and small second peak corresponding to fragments of single chains with M-w,M-s (about 20 +/-5% content). Analysis of M-w,M-m and (1/2)(z,m) in term of the known theory for wormlike chains yielded 2180 +/- 100 nm(-1), 120 +/- 10 nm and 0.31 nm for molar mass per unit contour length M-L, persistence length q, and contour length h per main-chain glucose residue, respectively, which agree closely with theory data of triple-helical chains and reported parameters for triple-helix schizophyllan in 0.01 M NaOH aqueous solution. The ratios of M-w,M-m, in 0.5 M NaCl to M, in DMSO were calculated to be roughly 3. The predominant species of the glucan in 0.5 M NaCl aqueous solution exist as triple-helical chains with high rigidity, and in DMSO as single-flexible chains.

  • 85. Zhang, L
    et al.
    Zhou, JP
    Huang, J
    Gong, P
    Zhou, Q
    Zheng, LS
    Du, YM
    Biodegradability of regenerated cellulose films coated with polyurethane/natural polymers interpenetrating polymer networks1999Ingår i: Industrial & Engineering Chemistry Research, Vol. 38, nr 11, s. 4284-4289Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Interpenetrating polymer network (IPN) coatings synthesized from castor- oil-based polyurethane (PU) with chitosan, nitrocellulose, or elaeostearin were coated on regenerated cellulose (RC) film for curing at 80-100 °C for 2-5 min, providing biodegradable, water-resistant cellulose films coded, respectively, as RCCH, RCNC, and RCEs. The coated films were buried in natural soil for decaying and inoculated with a spore suspension of fungi on the agar medium, respectively, to test biodegradability. The viscosity- average molecular weight, M(n), and the weight of the degraded films decreased sharply with the progress of degradation. The degradation half- lifes, t(1/2), of the films in soil at 30 °C were found to be 19 days for RC, 25 days for RCNC, 32 days for RCCH, and 45 days for the RCEs films. Scanning electron microscopy (SEM) showed that the extent of decay followed in the order RC > RCNC > RCCH > RCEs. SEM, infrared (IR), high-performance liquid chromatography (HPLC), and CO2 evolution results indicated that the microorganisms directly attacked the water-resistant coating layer and then penetrated into the cellulose to speedily metabolize, while accompanying with producing CO2, H2O, glucose cleaved from cellulose, and small molecules decomposed from the coatings.

    Interpenetrating polymer network (IPN) coatings synthesized from castor-oil-based polyurethane (PU) with chitosan, nitrocellulose, or elaeostearin were coated on regenerated cellulose (RC) film for curing at 80-100°C for 2-5 min, providing biodegradable, water-resistant cellulose films coded, respectively, as RCCH, RCNC, and RCEs. The coated films were buried in natural soil for decaying and inoculated with a spore suspension of fungi on the agar medium, respectively, to test biodegradability. The viscosity-average molecular weight, Mη, and the weight of the degraded films decreased sharply with the process of degradation. The degradation half-lifes, t1/2, of the films in soil at 30°C were found to be 19 days for RC, 25 days for RCNC, 32 days for RCCH, and 45 days for the RCEs films. Scanning electron microscopy (SEM) showed that the extent of decay followed in the order RC > RCNC > RCCH > RCEs. SEM, infrared (IR), high-performance liquid chromatography (HPLC), and CO2 evolution results indicated that the microorganisms directly attacked the water-resistant coating layer and then penetrated into the cellulose to speedily metabolize, while accompanying with producing CO2, H2O, glucose cleaved from cellulose, and small molecules decomposed from the coatings.

  • 86.
    Zhang, L
    et al.
    Wuhan University, China .
    Zhou, Qi
    Wuhan University, China .
    Effects of molecular weight of nitrocellulose on structure and properties of polyurethane nitrocellulose IPNs1999Ingår i: Journal of Polymer Science Part B-Polymer Physics, Vol. 37, nr 14, s. 1623-1631Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Semi-interpenetrating polymer network (semi-IPN) coatings were prepared by using castor oil-based polyurethane (PU) and nitrocellulose (NC) with various viscosity-average molecular weights (Mη) from 6 × 104 to 42 × 104, and coated on a regenerated cellulose (RC) film to obtain water-resistant film. The PU/NC coatings and coated films, which were cured at 80°C for 5 min and 2 min, respectively, were investigated by infrared (IR) and ultraviolet (UV) spectroscopy, X-ray diffraction, swelling test, strength test, dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The results show that the crosslink densities of the PU/NC semi-IPNs were smaller than that of pure PU, and decreased with the decrease of Mη of nitrocellulose (NC Mη), indicating NC molecules cohered intimately with PU, and hindered the PU network formation. The physical and mechanical properties of the films coated with PU/NC coatings were significantly improved. With the increase of NC Mη, the strength and thermal stability of the coated films increased, but the pliability, water resistivity, and optical transmission decreased slowly. The PU/NC coating with low NC Mη more readily penetrated into the RC film, and reacted with cellulose, resulting in a strong interfacial bonding and dense surface caused by intimate blend of PU/NC in the coated films.

  • 87. Zhang, L
    et al.
    Zhou, Qi
    Wuhan University, China.
    Water-resistant film from polyurethane/nitrocellulose coating to regenerated cellulose1997Ingår i: Industrial & Engineering Chemistry Research, Vol. 36, nr 7, s. 2651-2656Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Water-resistant films were obtained from polyurethane (PU)/nitrocellulose coating to regenerated cellulose films, which were prepared by coagulating cellulose cuoxam solution. The PU/nitrocellulose coating layer was cured at 80 degrees C for 2 min and formed semi-interpenetrating polymer networks (semi-IPNs) structure. The tensile strength (sigma(b)), water resistivity (R), water vapor permeability (P), and light transmittance of the coated films changed with nitrocellulose content in the coating, and the best values (such as sigma(b), 679 kg.cm(-2); R, 53%; P, 0.004 g.cm(-2).day(-1)) were attained at 33 wt % nitrocellulose. The TEM, EPMA, DTA, IRI and UV results-showed that the coated films have strong interfacial bonding, which is caused by covalent and hydrogen bonds between the cellulose film and the semi-IPNs coating. The biodegradation half-life t(1/2) of the coated films in soil at 20-30 degrees C was given to be 58 days, and after about 6 months the coated films were almost completely decomposed by microorganisms. SEM and the kinetics of decay studied on the biodegradability were discussed. The water-resistant films coated with PU/nitrocellulose have promising application where biodegradation is important.

  • 88. Zhang, L.
    et al.
    Zhou, Qi
    Gong, P.
    Method for prepn. of biological degradability regenerative cellulose waterproof film and cellulose products1998Patent (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    A process for preparing water-proof regenerated cellulose film and water-proof cellulose products freatures use of biodegradable water-proof paint which is composed of pre-polymer of polyurthane, nitrocellulose, SO1-17 liquid, ethyl acetate and less N, N -dimethyl ethanolamine. Its technological steps include coating the surface of regenerated fibre film or cellulose product with and solidifying at 70-90 deg. C for 1-5 min. Obtained products have obviousely improved water-proof nature and tension strength over than 350 kg/sq. cm after immersed in water. The water vapour penetrating it is 0.004-0.005 g.sq. cm. d. It is fully biodegradable.

  • 89.
    Zhou, Juan
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Butchosa, Nuria
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Jayawardena, H. Surangi N.
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Yan, Mingdi
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Ramström, Olof
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Glycan-Functionalized Fluorescent Chitin Nanocrystals for Biorecognition Applications2014Ingår i: Bioconjugate chemistry, ISSN 1043-1802, E-ISSN 1520-4812, Vol. 25, nr 4, s. 640-643Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new platform based on chitin nanocrystals has been developed for biorecognition applications. TEMPO-oxidized chitin nanocrystals (TCNs) were labeled with a fluorescent imidazoisoquinolinone dye, and simultaneously conjugated with carbohydrate ligands, resulting in dually functionalized TCNs. The biorecognition properties of the nanocrystals were probed with lectins and bacteria, resulting in selective interactions with their corresponding cognate carbohydrate-binding proteins, as visualized by optical, fluorescence, STEM, and TEM imaging. This represents a new approach to multifunctional nanomaterials based on naturally occurring polymers, holding high potential for biomedical applications.

  • 90.
    Zhou, Juan
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Butchosa, Núria
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Jayawardena, H. Surangi N.
    University of Massachusetts, United States .
    Park, JaeHyeung
    University of Massachusetts, United States .
    Zhou, Qi
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center. KTH, Skolan för bioteknologi (BIO), Centra, Albanova VinnExcellence Center for Protein Technology, ProNova.
    Yan, Mingdi
    KTH, Skolan för kemivetenskap (CHE), Kemi. University of Massachusetts, United States .
    Ramström, Olof
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Synthesis of Multifunctional Cellulose Nanocrystals for Lectin Recognition and Bacterial Imaging2015Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 16, nr 4, s. 1426-1432Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Multifunctional cellulose nanocrystals have been synthesized and applied as a new type of glyconanomaterial in lectin binding and bacterial imaging. The cellulose nanocrystals were prepared by TEMPO-mediated oxidation and acidic hydrolysis, followed by functionalization with a quinolone fluorophore and carbohydrate ligands. The cellulose nanocrystals were subsequently applied in interaction studies with carbohydrate-binding proteins and in bacterial imaging. The results show that the functional cellulose nanocrystals could selectively recognize the corresponding cognate lectins. In addition, mannosylated nanocrystals were shown to selectively interact with FimH-presenting E. coli, as detected by TEM and confocal fluorescence microscopy. These glyconanomaterials provide a new application of cellulose nanocrystals in biorecognition and imaging.

  • 91.
    Zhou, Juan
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi.
    Robles, Nuria
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Zhou, Qi
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Ramström, Olof
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Yan, Mingdi
    Dually functionalized chitin nanocrystals for biorecognition applications2013Ingår i: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 246, s. 192-POLY-Artikel i tidskrift (Övrigt vetenskapligt)
  • 92.
    Zhou, Qi
    et al.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Baumann, M. J.
    Brumer, Harry
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Teeri, Tuula T.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    The influence of surface chemical composition on the adsorption of xyloglucan to chemical and mechanical pulps2006Ingår i: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 63, nr 4, s. 449-458Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Adsorption kinetics of xyloglucan (XG) onto bleached chemical and mechanical wood pulps were studied to better understand the application of this plant polysaccharide to the modification of key industrial cellulosic materials. Bleached pulps prepared by the kraft process adsorbed significantly larger amounts of xyloglucan than did thermomechanical pulps (TMP) and chemi-thermomechanical pulps (CTMP). The ability of pulps to adsorb xyloglucan was intimately related to the surface amounts Of Cellulose, lignin and extractives, as determined by electron spectroscopy for chemical analysis (ESCA). The distribution of absorbed XG on bleached Pulp fibers was examined with an XG-fluorescein conjugate (XG-FITC), which was prepared by xyloglucan endotransglycosylase (XET, EC 2.4.1.207)-mediated incorporation of fluoresce-inlabeled xyloglucan oligosaccharides (XGO-FITC) into XG. Fluorescence microscopy revealed that XG-FITC preferentially adsorbed on fiber surfaces, and was adsorbed in higher amounts to chemical pulps than mechanical pulps, as observed for the unmodified parent polysaccharide. Addition of hybrid aspen XET (PttXET16A) and XGO-FITC to bleached and unbleached mechanical Pulps indicated that the amount of enzyme-accessible xyloglucan presented on TMP and CTMP surfaces is low.

  • 93.
    Zhou, Qi
    et al.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Baumann, Martin J.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Piispanen, Peter S.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Teeri, Tuula T.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Brumer, Harry
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Xyloglucan and xyloglucan endo-transglycosylases (XET): Tools for ex vivo cellulose surface modification2006Ingår i: Biocatalysis and Biotransformation, ISSN 1024-2422, E-ISSN 1029-2446, Vol. 24, nr 1-2, s. 107-120Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Wood fibres constitute a renewable raw material for the production of novel biomaterials. The development of efficient methods for cellulose surface modification is essential for expanding the properties of wood fibres for increased reactivity and compatibility with other materials. By combining the high affinity between xyloglucan and cellulose, the unique mechanistic property of xyloglucan endo-transglycosylases (XET, EC 2.4.1.207) to catalyze polysaccharide-oligosaccharide coupling reactions, and traditional carbohydrate synthesis, a new system for the attachment of a wide variety of functional groups to wood pulps has been generated. An overview of recent developments is presented in the context of the structure, physical properties, and historical applications of xyloglucan.

  • 94.
    Zhou, Qi
    et al.
    KTH, Skolan för bioteknologi (BIO), Centra, Albanova VinnExcellence Center for Protein Technology, ProNova.
    Baumann, Martin J.
    KTH, Skolan för bioteknologi (BIO), Centra, Albanova VinnExcellence Center for Protein Technology, ProNova.
    Teeri, Tuula T.
    KTH, Skolan för bioteknologi (BIO), Centra, Albanova VinnExcellence Center for Protein Technology, ProNova.
    Brumer, Harry
    KTH, Skolan för bioteknologi (BIO), Centra, Albanova VinnExcellence Center for Protein Technology, ProNova.
    Xyloglucan and xyloglucan endo-transglycosylases (XET): Tools for ex vivo cellulose surface modification2006Konferensbidrag (Refereegranskat)
  • 95.
    Zhou, Qi
    et al.
    KTH, Skolan för bioteknologi (BIO), Centra, Albanova VinnExcellence Center for Protein Technology, ProNova. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    CHAPTER 9 PLA-nanocellulose Biocomposites2015Ingår i: Poly(lactic acid) Science and Technology: Processing, Properties, Additives and Applications, The Royal Society of Chemistry , 2015Kapitel i bok, del av antologi (Refereegranskat)
  • 96.
    Zhou, Qi
    et al.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Brumer, Harry
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Teeri, Teeri T.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Stolt, J. P.
    Oedberg, L. G.
    Copolymer, modified polymer carbohydrate material, modified buld polymer, composite material, and methods of preparation2006Patent (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    The present invention relates to a novel group of copolymers comprising a soluble carbohydrate polymer (SCP), which typically is a non-starch carbohydrate, and a macromolecule covalently attached to the SCP. The macromolecule may e.g. be a hydrophobic copolymer, a polyelectrolyte polymer or a biodegradable polymer. The present invention furthermore relates to a method of preparing the copolymer, products comprising the copolymer, and to methods of preparing the products comprising the copolymer. The products comprising a copolymer are for example a polymeric carbohydrate material (PCM) modified by attachment of a copolymer, and a composite material comprising the modified PCM.

  • 97.
    Zhou, Qi
    et al.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Brumer, Harry
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Teeri, Tuula T.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Self-Organization of Cellulose Nanocrystals Adsorbed with Xyloglucan Oligosaccharide-Poly(ethylene glycol)-Polystyrene Triblock Copolymer2009Ingår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 42, nr 15, s. 5430-5432Artikel i tidskrift (Refereegranskat)
  • 98.
    Zhou, Qi
    et al.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Butchosa, Núria
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Nanocellulose-based Green Nanocomposite Materials2016Ingår i: Biodegradable Green Composites, John Wiley & Sons, 2016, s. 118-148Kapitel i bok, del av antologi (Refereegranskat)
  • 99.
    Zhou, Qi
    et al.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Greffe, Lionel
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Baumann, Martin
    KTH, Skolan för bioteknologi (BIO).
    Malmström, Eva
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik.
    Teeri, Tuula T.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Brumer, Harry
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Use of xyloglucan as a molecular anchor for the elaboration of polymers from cellulose surfaces: A general route for the design of biocomposites2005Ingår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 38, nr 9, s. 3547-3549Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The controlled graft copolymerization of methyl methacrylate (MMA) on cellulose fibers through a combination of the XET and atom transfer radical polymerization (ATRP) was investigated. It was found that graft polymerization of MMA on the initiator-laden filter paper under appropriate ATRP conditions yielded fibers that had altered surface properties. Controlled ATRP carried out using an initiator specifically immobilized on cellulose fibers through the XG/XET system provided a new route for the generation of biocomposite materials. The method provided a novel approach for the immobilization of polymerization initiators on cellulose, which was complementary to previously established chemical routes.

  • 100.
    Zhou, Qi
    et al.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Malm, Erik
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Nilsson, Helena
    Larsson, Per Tomas
    Iversen, Tommy
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Biokompositer.
    Bulone, Vincent
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Biomimetic design of cellulose-based nanostructured composites using bacterial cultures2009Ingår i: Polymer Preprints, ISSN 0032-3934, Vol. 50, nr 2, s. 7-8Artikel i tidskrift (Refereegranskat)
123 51 - 100 av 107
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