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  • 1.
    Aadland, Reidun C.
    et al.
    Norwegian University of Science and Technology (NTNU), Norway.
    Dziuba, Carter J.
    University of Calgary, Canada.
    Heggset, Ellinor B.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Syverud, Kristin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Torsæter, Ole
    Norwegian University of Science and Technology (NTNU), Norway.
    Holt, Thorleif
    SINTEF, Norway.
    Gates, Ian D.
    University of Calgary, Canada.
    Bryant, Steven L.
    University of Calgary, Canada.
    Identification of nanocellulose retention characteristics in porous media2018In: Nanomaterials, ISSN 2079-4991, Vol. 8, no 7, article id 547Article in journal (Refereed)
    Abstract [en]

    The application of nanotechnology to the petroleum industry has sparked recent interest in increasing oil recovery, while reducing environmental impact. Nanocellulose is an emerging nanoparticle that is derived from trees or waste stream from wood and fiber industries. Thus, it is taken from a renewable and sustainable source, and could therefore serve as a good alternative to current Enhanced Oil Recovery (EOR) technologies. However, before nanocellulose can be applied as an EOR technique, further understanding of its transport behavior and retention in porous media is required. The research documented in this paper examines retention mechanisms that occur during nanocellulose transport. In a series of experiments, nanocellulose particles dispersed in brine were injected into sandpacks and Berea sandstone cores. The resulting retention and permeability reduction were measured. The experimental parameters that were varied include sand grain size, nanocellulose type, salinity, and flow rate. Under low salinity conditions, the dominant retention mechanism was adsorption and when salinity was increased, the dominant retention mechanism shifted towards log-jamming. Retention and permeability reduction increased as grain size decreased, which results from increased straining of nanocellulose aggregates. In addition, each type of nanocellulose was found to have significantly different transport properties. Experiments with Berea sandstone cores indicate that some pore volume was inaccessible to the nanocellulose. As a general trend, the larger the size of aggregates in bulk solution, the greater the observed retention and permeability reduction. Salinity was found to be the most important parameter affecting transport. Increased salinity caused additional aggregation, which led to increased straining and filter cake formation. Higher flow rates were found to reduce retention and permeability reduction. Increased velocity was accompanied by an increase in shear, which is believed to promote breakdown of nanocellulose aggregates. © 2018 by the authors.

  • 2.
    Aarstad, Olav
    et al.
    NTNU Norwegian University of Science and Technology, Norway.
    Heggset, Ellinor B
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Pedersen, Ina Sander
    NTNU Norwegian University of Science and Technology, Norway.
    Björnöy, Sindre H.
    NTNU Norwegian University of Science and Technology, Norway.
    Syverud, Kristin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Strand, Berit L.
    NTNU Norwegian University of Science and Technology, Norway.
    Mechanical properties of composite hydrogels of alginate and cellulose nanofibrils2017In: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 9, no 8, article id 378Article in journal (Refereed)
    Abstract [en]

    Alginate and cellulose nanofibrils (CNF) are attractive materials for tissue engineering and regenerative medicine. CNF gels are generally weaker and more brittle than alginate gels, while alginate gels are elastic and have high rupture strength. Alginate properties depend on their guluronan and mannuronan content and their sequence pattern and molecular weight. Likewise, CNF exists in various qualities with properties depending on, e.g., morphology and charge density. In this study combinations of three types of alginate with different composition and two types of CNF with different charge and degree of fibrillation have been studied. Assessments of the composite gels revealed that attractive properties like high rupture strength, high compressibility, high gel rigidity at small deformations (Young’s modulus), and low syneresis was obtained compared to the pure gels. The effects varied with relative amounts of CNF and alginate, alginate type, and CNF quality. The largest effects were obtained by combining oxidized CNF with the alginates. Hence, by combining the two biopolymers in composite gels, it is possible to tune the rupture strength, Young’s modulus, syneresis, as well as stability in physiological saline solution, which are all important properties for the use as scaffolds in tissue engineering.

  • 3.
    Brod, E
    et al.
    NIBIO, Norwegian Institute of Bioeconomy Research, Norway.
    Toven, K
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Haraldsen, TK
    NIBIO, Norwegian Institute of Bioeconomy Research, , Norway.
    Krogstad, T
    Norwegian University of Life Sciences, Norway.
    Unbalanced nutrient ratios in pelleted compound recycling fertilizers2018In: Soil use and management, ISSN 0266-0032, E-ISSN 1475-2743, Vol. 34, no 1, p. 18-27Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to contribute to the development of pelleted compound recycling fertilizers with favourable handling and spreading characteristics and balanced nutrient ratios by combining nitrogen (N)- and phosphorus (P)-rich waste resources (meat bone meal, fish sludge or food waste) with potassium (K)-rich bottom wood ash. Pelleted compound recycling fertilizers with good durability and low dusting tendency were produced by roll-pelleting preheated waste resources at a suitable moisture content. However, the nutrient ratios in the final products were insufficiently balanced, with too low N concentrations relative to P and K to meet crop demands. In a bioassay using barley (Hordeum vulgare) and a nutrient-deficient sand/peat mixture, the relative agronomic effectiveness (RAE) of pelleted compound recycling fertilizers and reference recycling fertilizers was 22-42% of that of mineral compound fertilizer. Growth limitation was due to reduced N availability (mineral fertilizer equivalent - MFE=35-57%) or reduced P availability (MFE=20-115%), with the greatest P fertilizer value obtained for digestate based on dairy manure and fish sludge. Availability of K in bottom wood ash was masked by the experimental soil.

  • 4.
    Brodin, F.W
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Celaya Romeo, Javier
    Toven, K.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Dewatered pyrolysis oil as fuel component in marine fuel blends2016In: European Biomass Conference and Exhibition: Proceedings, 2016, no 24thEUBCE, p. 1122-1124Conference paper (Other academic)
    Abstract [en]

    Forest-based fast pyrolysis liquids constitute a potential low-sulphur fuel alternative for the marine sector. However, it is a challenge to meet the marine fuel quality demands set by current infrastructure, engines and fuels standards. The aim of this work has been to explore the potential for producing a new and more sustainable marine fuel quality. This new fuel quality is based on upgraded pyrolysis oil which is used as a fuel component in three-component blends. Low-water containing pine pyrolysis oil samples were formed by vacuum-assisted dewatering and in the next step three-component blends were prepared by mixing pyrolysis oil with bio-diesel and nbutanol. The results showed that less amount of butanol is required to form homogenous and storage stable blends when using dewatered pyrolysis oil as a blend component as compared to using crude pyrolysis oil. Dewatering also reduced the corrosiveness dramatically indicating that fuel blends based on dewatered pyrolysis oils are more compatible with marine engines than fuel blend based on crude pyrolysis oil.

  • 5.
    Brodin, Magnus
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Vallejos, Maria
    Instituto de Materiales de Misiones (IMAM), Argentina.
    Opedal, Mihaela Tanase
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Area, Maria C.
    Instituto de Materiales de Misiones (IMAM), Argentina.
    Chinga-Carrasco, Gary
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Lignocellulosics as sustainable resources for production of bioplastics: a review2017In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 162, p. 646-664Article, review/survey (Refereed)
    Abstract [en]

    The bio-based economy requires a sustainable utilization of bioresources for production of a range of products, including pulp, paper, chemicals, biofuel and bioplastics. Currently, various types of bioplastics are produced industrially, competing in performance and price with the conventional fossil-oil based plastics. However, there is also a major interest in utilizing non-food crops, such as lignocellulosics, for production of drop-in polymers or new dedicated bioplastics. Lignocellulosic resources have a potential to replace plastics and materials, which have been traditionally based on fossil resources. This is important, as the development of high performance bio-based and renewable materials is one important factor for sustainable growth of the bio-based industry. However, production of bioplastics from forestry biomass requires a dedicated fractionation into the major components, i.e. cellulose, hemicelluloses and lignin, effective purification processes and cost-effective routes for conversion into monomers and platform molecules, utilized as a basis for bioplastics production. These processes are now technologically demanding and not profitable. The intention of this work was thus to review the current advances that have been made during the years within fractionation and purification of lignocelluloses and the processes that may feasible for production of bioplastics, based on wood components.

  • 6.
    Campodoni, Elisabetta
    et al.
    Institute of Science and Technology for Ceramics-National Research Council (ISTEC-CNR), Italy.
    Heggset, Elinor B.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Rashad, Ahmad
    University of Bergen, Norway.
    Ramírez-Rodríguez, Gloria B.
    Universidad de Granada, Spain.
    Mustafa, Kamal
    University of Bergen, Norway.
    Syverud, Kristin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI. Norwegian University of Science and Technology, Norway.
    Tampieri, Anna
    Institute of Science and Technology for Ceramics-National Research Council (ISTEC-CNR), Italy.
    Sandri, Monica
    Institute of Science and Technology for Ceramics-National Research Council (ISTEC-CNR), Italy.
    Polymeric 3D scaffolds for tissue regeneration: Evaluation of biopolymer nanocomposite reinforced with cellulose nanofibrils2019In: Materials science & engineering. C, biomimetic materials, sensors and systems, ISSN 0928-4931, E-ISSN 1873-0191, Vol. 94, p. 867-878Article in journal (Refereed)
    Abstract [en]

    Biopolymers such as gelatin (Gel) and cellulose nanofibrils (CNF) have many of the essential requirements for being used as scaffolding materials in tissue regeneration; biocompatibility, surface chemistry, ability to generate homogeneous hydrogels and 3D structures with suitable pore size and interconnection, which allows cell colonization and proliferation. The purpose of this study was to investigate whether the mechanical behaviour of the Gel matrix can be improved by means of functionalization with cellulose nanofibrils and proper cross-linking treatments. Blending processes were developed to achieve a polymer nanocomposite incorporating the best features of both biopolymers: biomimicry of the Gel and structural reinforcement by the CNF. The designed 3D structures underline interconnected porosity achieved by freeze-drying process, improved mechanical properties and chemical stability that are tailored by CNF addition and different cross-linking approaches. In vitro evaluations reveal the preservation of the biocompatibility of Gel and its good interaction with cells by promoting cell colonization and proliferation. The results support the addition of cellulose nanofibrils to improve the mechanical behaviour of 3D porous structures suitable as scaffolding for tissue regeneration.

  • 7. Celaya Romeo, Javier
    et al.
    Brodin, F.W.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Toven, K.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Pyrolysis oil based fuel emulsions for marine engines2016In: European Biomass Conference and Exhibition: Proceedings, 2016, no 24thEUBCE, p. 1740-1745Conference paper (Other academic)
    Abstract [en]

    The International Convention for the Prevention of Pollution from Ships (MARPOL) is reducing the allowed amount of sulphur in marine fuels and these reductions will continue in the future. Bio-oil is a sulphur-free liquid fuel and it constitutes a potential biofuel for the marine sector because it may be produced at industrial scale through pyrolysis of residues coming from the wood processing industry. Due to some of its challenging characteristics, it cannot substitute conventional fuels directly or be blended with them, but it might be used as a component of an emulsified drop-in fuel. The objective of this work is to determine the best conditions to produce an emulsified marine drop-in fuel. These conditions include the percentages of each component (marine gas oil or biodiesel, bio-oil, surfactant, type and combination of surfactants and the hydrophilic-lipophilic value (HLB) of the surfactant blend. Stability of the emulsions has been analysed by light scattering and visual observation at different times. This work forms part of the ReShip Project partly funded by the Research Council of Norway (The ENERGIX programme).

  • 8.
    Chinga-Carrasco, Gary
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Potential and Limitations of Nanocelluloses as Components in Biocomposite Inks for Three-Dimensional Bioprinting and for Biomedical Devices.2018In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 19, no 3, p. 701-711Article in journal (Refereed)
    Abstract [en]

    Three-dimensional (3D) printing has rapidly emerged as a new technology with a wide range of applications that includes biomedicine. Some common 3D printing methods are based on the suitability of biopolymers to be extruded through a nozzle to construct a 3D structure layer by layer. Nanocelluloses with specific rheological characteristics are suitable components to form inks for 3D printing. This review considers various nanocelluloses that have been proposed for 3D printing with a focus on the potential advantages, limitations, and requirements when used for biomedical devices and when used in contact with the human body.

  • 9.
    Chinga-Carrasco, Gary
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Ehman, Nanci V.
    Instituto de Materiales de Misiones (IMAM), Misiones Argentina.
    Pettersson, Jennifer
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Vallejos, Maria E.
    Instituto de Materiales de Misiones (IMAM), Misiones Argentina.
    Brodin, Malin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Felissia, Fernando E.
    Instituto de Materiales de Misiones (IMAM), Misiones Argentina.
    Håkansson, Joakim
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Area, Maria C.
    Instituto de Materiales de Misiones (IMAM), Misiones Argentina.
    Pulping and Pretreatment Affect the Characteristics of Bagasse Inks for Three-dimensional Printing2018In: ACS Sustainable Chemistry and Engineering, ISSN 2168-0485, Vol. 6, no 3, p. 4068-4075Article in journal (Refereed)
    Abstract [en]

    Bagasse is an underutilized agro-industrial residue with great potential as raw material for the production of cellulose nanofibrils (CNF) for a range of applications. In this study, we have assessed the suitability of bagasse for production of CNF for three-dimensional (3D) printing. First, pulp fibers were obtained from the bagasse raw material using two fractionation methods, i.e. soda and hydrothermal treatment combined with soda. Second, the pulp fibers were pretreated by TEMPO-mediated oxidation using two levels of oxidation for comparison purposes. Finally, the CNF were characterized in detail and assessed as inks for 3D printing. The results show that CNF produced from fibers obtained by hydrothermal and soda pulping were less nanofibrillated than the corresponding material produced by soda pulping. However, the CNF sample obtained from soda pulp was cytotoxic, apparently due to a larger content of silica particles. All the CNF materials were 3D printable. We conclude that the noncytotoxic CNF produced from hydrothermally and soda treated pulp can potentially be used as inks for 3D printing of biomedical devices. 

  • 10.
    Courtade, Gaston
    et al.
    NTNU Norwegian University of Science and Technology, Norway.
    Forsberg, Zarah
    NMBU Norwegian University of Life Sciences, Norway.
    Heggset, Ellinor B
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Eijsink, Vincent G H
    NMBU Norwegian University of Life Sciences, Norway.
    Aachmann, Finn L
    NTNU Norwegian University of Science and Technology, Norway.
    The carbohydrate-binding module and linker of a modular lytic polysaccharide monooxygenase promote localized cellulose oxidation.2018In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 293, no 34, p. 13006-13015Article in journal (Refereed)
    Abstract [en]

    Lytic polysaccharide monooxygenases (LPMOs) are copper-dependent enzymes that catalyze the oxidative cleavage of polysaccharides such as cellulose and chitin, a feature that makes them key tools in industrial biomass conversion processes. The catalytic domains of a considerable fraction of LPMOs and other carbohydrate-active enzymes (CAZymes) are tethered to carbohydrate-binding modules (CBMs) by flexible linkers. These linkers preclude X-ray crystallographic studies, and the functional implications of these modular assemblies remain partly unknown. Here, we used NMR spectroscopy to characterize structural and dynamic features of full-length modular ScLPMO10C from Streptomyces coelicolor We observed that the linker is disordered and extended, creating distance between the CBM and the catalytic domain and allowing these domains to move independently of each other. Functional studies with cellulose nanofibrils revealed that most of the substrate-binding affinity of full-length ScLPMO10C resides in the CBM. Comparison of the catalytic performance of full-length ScLPMO10C and its isolated catalytic domain revealed that the CBM is beneficial for LPMO activity at lower substrate concentrations and promotes localized and repeated oxidation of the substrate. Taken together, these results provide a mechanistic basis for understanding the interplay between catalytic domains linked to CBMs in LPMOs and CAZymes in general.

  • 11.
    Filgueira, Daniel
    et al.
    University of Vigo, Spain.
    Holmen, Solveig
    NTNU, Norway.
    Melbø, Johnny K.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Moldes, Diego
    University of Vigo, Spain.
    Echtermeyer, Andreas T.
    NTNU, Norway.
    Chinga-Carrasco, Gary
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    3D printable filaments made of biobased polyethylene biocomposites2018In: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 10, no 3, article id 314Article in journal (Refereed)
    Abstract [en]

    Two different series of biobased polyethylene (BioPE) were used for the manufacturing of biocomposites, complemented with thermomechanical pulp (TMP) fibers. The intrinsic hydrophilic character of the TMP fibers was previously modified by grafting hydrophobic compounds (octyl gallate and lauryl gallate) by means of an enzymatic-assisted treatment. BioPE with low melt flow index (MFI) yielded filaments with low void fraction and relatively low thickness variation. The water absorption of the biocomposites was remarkably improved when the enzymatically-hydrophobized TMP fibers were used. Importantly, the 3D printing of BioPE was improved by adding 10% and 20% TMP fibers to the composition. Thus, 3D printable biocomposites with low water uptake can be manufactured by using fully biobased materials and environmentally-friendly processes.

  • 12.
    Filgueira, Daniel
    et al.
    University of Vigo, Spain.
    Holmen, Solveig
    NTNU, Norway.
    Melbø, Johnny K.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Moldes, Diego
    University of Vigo, Spain.
    Echtermeyer, Andreas T.
    NTNU, Norway.
    Chinga-Carrasco, Gary
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Enzymatic-Assisted Modification of Thermomechanical Pulp Fibers to Improve the Interfacial Adhesion with Poly(lactic acid) for 3D Printing2017In: ACS Sustainable Chemistry and Engineering, ISSN 2168-0485, Vol. 5, no 10, p. 9338-9346Article in journal (Refereed)
    Abstract [en]

    The present study is about the enzymatic modification of thermomechanical pulp (TMP) fibers for reduction of water uptake and their use in bio-based filaments for 3D printing. Additionally, TMP was used as a fiber reinforcing material and poly(lactic acid) (PLA) as the polymer matrix. The hydrophilic TMP fibers were treated via laccase-assisted grafting of octyl gallate (OG) or lauryl gallate (LG) onto the fiber surface. The modified TMP fibers showed remarkable hydrophobic properties, as demonstrated by water contact angle measurements. Filaments reinforced with OG-treated fibers exhibited the lowest water absorption and the best interfacial adhesion with the PLA matrix. Such higher chemical compatibility between the OG-treated fibers and the PLA enabled better stress transfer from the matrix to the fibers during mechanical testing, which led to the manufacture of strong filaments for 3D printing. All of the manufactured filaments were 3D-printable, although the filaments containing OG-treated fibers yielded the best results. Hence, laccase-mediated grafting of OG onto TMP fibers is a sustainable and environmentally friendly pathway for the manufacture of fully bio-based filaments for 3D printing.

  • 13.
    Heggset, Ellinor B
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Chinga-Carrasco, Gary
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Syverud, Kristin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI. Norwegian University of Science and Technology (NTNU), Norway.
    Temperature stability of nanocellulose dispersions2017In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 157, p. 114-121Article in journal (Refereed)
    Abstract [en]

    Cellulose nanofibrils (CNF) have potential as rheology modifiers of water based fluids, e.g. drilling fluids for use in oil wells or as additives in injection water for enhanced oil recovery (EOR). The temperature in oil wells can be high (>100 °C), and the retention time long; days for drilling fluids and months for EOR fluids. Hence, it is important to assess the temperature stability over time of nanocellulose dispersions to clarify their suitability as rheology modifiers of water based fluids at such harsh conditions. Dispersions of CNF produced mechanically, by using TEMPO mediated oxidation and by using carboxymethylation as pretreatment, in addition to cellulose nanocrystals (CNC), have been subjected to heat aging. Temperature stability was best for CNC and for mechanically produced CNF that were stable after heating to 140 °C for three days. The effect of additives was evaluated; cesium formate and sodium formate increased the temperature stability of the dispersions, while there was no effect of using phosphate buffer.

  • 14.
    Hill, Jan
    et al.
    QualTech AB, Sweden.
    Johansson, Lars
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Mörseburg, Kathrin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    ATMP pulping of Norway spruce: Pulp property development and energy efficiency2017In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 32, no 1, p. 70-86Article in journal (Refereed)
    Abstract [en]

    ATMP pilot refining trials on Norway spruce were conducted. The ATMP configuration consists of selective wood disintegration and targeted application of chemicals when defibration already is initiated in order to achieve energy-efficient final fibre separation and development. ATMP was compared to TMP and RTS. The TMP like character was maintained despite of differences in pre-treatment, chemicals and primary stage refining energies. The fractional composition of the pulps was, however, altered. Bauer McNett R14 fraction exhibited the largest differences followed by P200 fraction. Thus different process alternatives produced pulps with different fingerprints. The amount of the R14 fibres is important as these tend to cause surface roughness impairing printability. Regardless of strategy, the ATMP pulp properties at equal tensile index (44 Nm/g) were equal or superior to those achieved by TMP or RTS refining. The main difference was the required specific energy input, ranging from 1.71 (TMP) to 1.05 MWh/BDT (ATMP with bisulphite addition). Primary stage refining was explored from multiple trials with the same process configuration and chemistry. The higher the specific energy applied the better is the energy efficiency. Furthermore established refining theories appear inadequate in describing the differences between process alternatives with respect to energy efficiency and pulp property development.

  • 15.
    Jack, Alison A.
    et al.
    Cardiff University School of Dentistry, UK.
    Nordli, Henriette R.
    NTNU, Norway.
    Powell, Lydia C.
    Cardiff University School of Dentistry, UK.
    Powell, Kate A.
    Cardiff University School of Dentistry, UK.
    Kishnani, Himanshu
    Cardiff University School of Dentistry, UK.
    Johnsen, Per Olav
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Pukstad, Brita
    Trondheim University Hospital, Norway.
    Thomas, David W.
    Cardiff University School of Dentistry, UK.
    Chinga-Carrasco, Gary
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Hill, Katja E.
    Cardiff University School of Dentistry, UK.
    The interaction of wood nanocellulose dressings and the wound pathogen P. aeruginosa2017In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 157, p. 1955-1962Article in journal (Refereed)
    Abstract [en]

    Chronic wounds pose an increasingly significant worldwide economic burden (over £1 billion per annum in the UK alone). With the escalation in global obesity and diabetes, chronic wounds will increasingly be a significant cause of morbidity and mortality. Cellulose nanofibrils (CNF) are highly versatile and can be tailored with specific physical properties to produce an assortment of three-dimensional structures (hydrogels, aerogels or films), for subsequent utilization as wound dressing materials. Growth curves using CNF (diameter <20 nm) in suspension demonstrated an interesting dose-dependent inhibition of bacterial growth. In addition, analysis of biofilm formation (Pseudomonas aeruginosa PAO1) on nanocellulose aerogels (20 g/m2) revealed significantly less biofilm biomass with decreasing aerogel porosity and surface roughness. Importantly, virulence factor production by P. aeruginosa in the presence of nanocellulose materials, quantified for the first time, was unaffected (p > 0.05) over 24 h. These data demonstrate the potential of nanocellulose materials in the development of novel dressings that may afford significant clinical potential.

  • 16.
    Kumar, Vinay
    et al.
    Åbo Akademi University, Finland.
    Ottesen, Vegar
    NTNU, Norway.
    Syverud, Kristin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Gregersen, Öyvind Weiby
    NTNU, Norway.
    Toivakka, Martti
    Åba Akademi University, Finland.
    Coatability of cellulose nanofibril suspensions: Role of rheology and water retention2017In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 12, no 4, p. 7656-7679Article in journal (Refereed)
    Abstract [en]

    Cellulose nanofibril (CNF) suspensions are not easily coatable because of their excessively high viscosity and yield stress, even at low solids concentrations. In addition, CNF suspensions vary widely in their properties depending on the production process used, which can affect their processability. This work reports roll-to-roll coating of three different types of CNF suspensions with a slot-die, and the influence of rheology and water retention on coatability is addressed. The impact of CMC addition on the high and low shear rate rheology, water retention, coatability, and final coating quality of these suspensions is reported. All three CNF suspensions were coated successfully using the slot-die coating process. CMC addition further improved the coatability by positively influencing both the low and high shear rate viscosity and water retention of the CNF suspensions. All CNF coatings significantly improved the air, heptane vapor, grease and oil barrier, while reducing the water vapor transmission rate to some extent.

  • 17.
    Mihiretu, Gezahegn T.
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI. Stellenbosch University, South Africa.
    Brodin, Malin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Chimphango, Annie F.
    Stellenbosch University, South Africa.
    ֘yaas, Karin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Hoff, Bård H
    Norwegian University of Science and Technology (NTNU), Norway.
    Görgens, Johann F.
    Stellenbosch University, South Africa.
    Single-step microwave-assisted hot water extraction of hemicelluloses from selected lignocellulosic materials: A biorefinery approach2017In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 241, p. 669-680Article in journal (Refereed)
    Abstract [en]

    The viability of single-step microwave-induced pressurized hot water conditions for co-production of xylan-based biopolymers and bioethanol from aspenwood sawdust and sugarcane trash was investigated. Extraction of hemicelluloses was conducted using microwave-assisted pressurized hot water system. The effects of temperature and time on extraction yield and enzymatic digestibility of resulting solids were determined. Temperatures between 170–200 °C for aspenwood and 165–195 °C for sugarcane trash; retention times between 8–22 min for both feedstocks, were selected for optimization purpose. Maximum xylan extraction yields of 66 and 50%, and highest cellulose digestibilities of 78 and 74%, were attained for aspenwood and sugarcane trash respectively. Monomeric xylose yields for both feedstocks were below 7%, showing that the xylan extracts were predominantly in non-monomeric form. Thus, single-step microwave-assisted hot water method is viable biorefinery approach to extract xylan from lignocelluloses while rendering the solid residues sufficiently digestible for ethanol production.

  • 18.
    Molnes, Silje N.
    et al.
    University of Stavanger, Norway ; Norwegian University of Science and Technology (NTNU), Norway.
    Mamonov, Aleksandr
    University of Stavanger, Norway.
    Paso, Kristofer G.
    Norwegian University of Science and Technology (NTNU), Norway.
    Strand, Skule
    University of Stavanger, Norway.
    Syverud, Kristin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI. Norwegian University of Science and Technology (NTNU), Norway.
    Investigation of a new application for cellulose nanocrystals: a study of the enhanced oil recovery potential by use of a green additive2018In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 25, no 4, p. 2289-2301Article in journal (Refereed)
    Abstract [en]

    Cellulose nanocrystals (CNC) were investigated for use in a potential new application, enhanced oil recovery. Core flooding experiments were performed on outcrop sandstone cores using CNC particles dispersed in low salinity brine (CNC-LS). Core flooding experiments performed on fully water-saturated cores confirm that a majority of viscosity-generating CNC particles successfully traverse the cores at temperature conditions ranging from 60 to 120 A degrees C. Oil recovery tests performed on crude oil saturated sandstone cores at 60 and 90 A degrees C show that when CNC-LS is applied in tertiary mode, ultimate oil recovery increases. During tertiary CNC-LS injection, CNC particles exacerbate differential pressure fluctuations, a phenomenon attributable to log jamming in pore throats, causing remobilisation of oil trapped within pore space regions. Results from the current work indicate that CNC particles dispersed in low saline brine remain promising for implementation in enhanced oil recovery operations.

  • 19.
    Molnes, Silje N.
    et al.
    Norwegian University of Science and Technology, Norway ; University of Stavanger, Norway.
    Paso, Kristofer G.
    Norwegian University of Science and Technology, Norway.
    Strand, Skule
    University of Stavanger, Norway.
    Syverud, Kristin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI. Norwegian University of Science and Technology, Norway.
    The effects of pH, time and temperature on the stability and viscosity of cellulose nanocrystal (CNC) dispersions: implications for use in enhanced oil recovery2017In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 24, no 10, p. 4479-4491Article in journal (Refereed)
    Abstract [en]

    Cellulose nanocrystals (CNC) are currently being investigated as potential additives for enhanced oil recovery (EOR). Presented in this paper is a study investigating the effects of different physical and chemical environments that low concentration CNC dispersions may be subjected to at oil reservoir conditions. Different concentrations of CNC dispersed in de-ionized water and in a 1000 ppm NaCl brine were subjected to variations in pH and temperature, and the results showed that the dispersions remained stable in the pH range expected in oil reservoirs (between 5 and 9). Stable dispersions were also observed when heated to temperatures ranging from 50 to 90 °C. At extended heat aging at 90 and 120 °C for seven days; beginning degradation was observed for both types of CNC dispersions; with viscosity increase and pH decrease as the most important indicators. CNC dispersed in 1000 ppm NaCl brine was generally more heat tolerant than the CNC dispersed in de-ionized water. The increase in viscosity during heat aging can be very interesting for EOR applications. A fluid that increases its viscosity with heat and time will be easier to inject due to a low initial viscosity, and when the viscosity increases in the porous reservoir, the effect can be a stable waterfront and less viscous fingering, which again can lead to increased sweep efficiency and better oil recovery.

  • 20.
    Ottesen, Vegar
    et al.
    Norwegian university of science and technology, Norway.
    Roede, Erik Dobloug
    Norwegian university of science and technology, Norway.
    Syverud, Kristin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI. Norwegian university of science and technology, Trondheim, Norway.
    Gregersen, Øyvind Weiby
    Norwegian university of science and technology, Norway.
    Focused ion beam tomography as a means for characterization of CNF in a paper matrix2017In: 16th Fundamental Research symposium, 2017, p. 595-609Conference paper (Refereed)
  • 21.
    Rashad, Ahmad
    et al.
    University of Bergen, Norway.
    Mohamed-Ahmed, Samih
    University of Bergen, Norway.
    Ojansivu, Miina
    University of Bergen, Norway; University of Tampere, Finland.
    Berstad, Kaia
    University of Bergen, Norway.
    Yassin, Mohammad
    University of Bergen, Norway.
    Kivijärvi, Tove
    KTH Royal Institute of Technology, Sweden.
    Heggset, Ellinor
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Syverud, Kristin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI. NTNU Norwegian University of Science and Technology, Norway.
    Mustafa, Kamal
    University of Bergen, Norway.
    Coating 3D Printed Polycaprolactone Scaffolds with Nanocellulose Promotes Growth and Differentiation of Mesenchymal Stem Cells2018In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 19, no 11, p. 4307-4319Article in journal (Refereed)
    Abstract [en]

    3D printed polycaprolactone (PCL) has potential as a scaffold for bone tissue engineering, but the hydrophobic surface may hinder optimal cell responses. The surface properties can be improved by coating the scaffold with cellulose nanofibrils material (CNF), a multiscale hydrophilic biocompatible biomaterial derived from wood. In this study, human bone marrow-derived mesenchymal stem cells were cultured on tissue culture plates (TCP) and 3D printed PCL scaffolds coated with CNF. Cellular responses to the surfaces (viability, attachment, proliferation, and osteogenic differentiation) were documented. CNF significantly enhanced the hydrophilic properties of PCL scaffolds and promoted protein adsorption. Live/dead staining and lactate dehydrogenase release assays confirmed that CNF did not inhibit cellular viability. The CNF between the 3D printed PCL strands and pores acted as a hydrophilic barrier, enhancing cell seeding efficiency, and proliferation. CNF supported the formation of a well-organized actin cytoskeleton and cellular production of vinculin protein on the surfaces of TCP and PCL scaffolds. Moreover, CNF-coated surfaces enhanced not only alkaline phosphatase activity, but also collagen Type-I and mineral formation. It is concluded that CNF coating enhances cell attachment, proliferation, and osteogenic differentiation and has the potential to improve the performance of 3D printed PCL scaffolds for bone tissue engineering.

  • 22.
    Rashad, Amad
    et al.
    University of Bergen, Norway.
    Mustafa, Kamal
    University of Bergen, Norway.
    Heggset, Ellinor B
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Syverud, Kristin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI. Norwegian University of Science and Technology (NTNU), Norway.
    Cytocompatibility of Wood-Derived Cellulose Nanofibril Hydrogels with Different Surface Chemistry2017In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 18, no 4, p. 1238-1248Article in journal (Refereed)
    Abstract [en]

    The current study aims to demonstrate the influence of the surface chemistry of wood-derived cellulose nanofibril (CNF) hydrogels on fibroblasts for tissue engineering applications. TEMPO-mediated oxidation or carboxymethylation pretreatments were employed to produce hydrogels with different surface chemistry. This study demonstrates the following: first, the gelation of CNF with cell culture medium and formation of stable hydrogels with improved rheological properties; second, the response of mouse fibroblasts cultured on the surface of the hydrogels or sandwiched within the materials with respect to cytotoxicity, cell attachment, proliferation, morphology, and migration. Indirect cytotoxicity tests showed no toxic effect of either hydrogel. The direct contact with the carboxymethylated hydrogel adversely influenced the morphology of the cells and limited their spreading, while typical morphology and spreading of cells were observed with the TEMPO-oxidized hydrogel. The porous fibrous structure may be a key to cell proliferation and migration in the hydrogels.

  • 23.
    Rusu, Caterina
    et al.
    NTNU, Norway.
    Brodin, Malin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Hausvik, Tor Inge
    Berry Alloc, Norway.
    Hindersland, Leif Kåre
    Berry Alloc, Norway.
    Chinga-Carrasco, Gary
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Einarsrud, Mary Anne
    NTNU, Norway.
    Lein, Hilde
    NTNU, Norway.
    The potential of functionalized ceramic particles in coatings for improved scratch resistance2018In: Coatings, ISSN 2079-6412, Vol. 8, no 6, article id 224Article in journal (Refereed)
    Abstract [en]

    The top layer of a typical high pressure floor laminate (HPL) consists of a melamine formaldehyde (MF) impregnated special wear layer (overlay) with alumina particles. This top layer plays a crucial role in determining the mechanical properties of the laminate. For HPLs, scratch resistance and scratch visibility are particularly important properties. This study aimed to improve the mechanical properties, particularly the scratch resistance, by adjusting the composition of the overlay. Laminates containing alumina particles were prepared and tested. These alumina particles were additionally functionalized with a silane coupling agent to ensure better adhesion between the particles and the resin. The functionalized particles led to enhanced scratch resistance of the laminates as well as improved dispersion of the particles within the resin. Micro scratch testing revealed that by using functionalized particles, the scratch surface damage was reduced and the recovery characteristics of the surface layer were improved. Higher scratch resistance and scratch hardness were thus obtained, along with a reduced scratch visibility.

  • 24.
    Sun, Fengzhen
    et al.
    Uppsala University, Sweden.
    Nordli, Henriette R.
    Norwegian University of Science and Technology (NTNU), Norway.
    Pukstad, Brita
    Norwegian University of Science and Technology (NTNU), Norway ; Trondheim University Hospital, Norway.
    Gamstedt, E. Kristofer
    Uppsala University, Sweden.
    Chinga-Carrasco, Gary
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Mechanical characteristics of nanocellulose-PEG bionanocomposite wound dressings in wet conditions2017In: Journal of The Mechanical Behavior of Biomedical Materials, ISSN 1751-6161, E-ISSN 1878-0180, Vol. 69, p. 377-384Article in journal (Refereed)
    Abstract [en]

    Wood nanocellulose has been proposed for wound dressing applications partly based on its capability to form translucent films with good liquid absorption capabilities. Such properties are adequate for non-healing and chronic wounds where adequate management of exudates is a requirement. In addition, the translucency will allow to follow the wound development without the necessity to remove the dressing from the wound. Understanding the mechanical properties of nanocellulose films and dressings are also most important for tailoring optimizing wound dressing structures with adequate strength, conformability, porosity and exudate management. Mechanical properties are usually assessed in standard conditions (50% relative humidity, RH), which is not relevant in a wound management situation. In this study we have assessed the mechanical properties of three nanocellulose grades varying in the degree of nanofibrillation. The effect of nanofibrillation and of polyethylene glycol (PEG) addition, on the tensile strength, elongation and elastic modulus were assessed after 24 h in water and in phosphate-buffered saline (PBS). The results reveal the behavior of the nanocellulose dressings after wetting and shed light into the development of mechanical properties in environments, which are relevant from a wound management point of view.

  • 25.
    Tanase-Opedal, Mikaela
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Eriksen, Öyvind
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Toven, Kai
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Increase accessibility for enzymatic hydrolysis of Norway spruce by organosolv pre-treatment in a novel reactor2018In: The 8th Nordic Wood Biorefinery Conference: NWBC 2018: proceedings / [ed] Hytönen Eemeli, Vepsäläinen Jessica, Espoo: VTT Technical Research Centre of Finland , 2018, p. 177-177Conference paper (Refereed)
  • 26.
    Tarrés, Q.
    et al.
    University of Girona, Italy.
    Melbø, Johnny Kvakland
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Delgado-Aguilar, M.
    University of Girona, Italy.
    Espinach, F. X.
    University of Girona, Italy.
    Mutjé, P.
    University of Girona, Italy.
    Chinga-Carrasco, Gary
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Bio-polyethylene reinforced with thermomechanical pulp fibers: Mechanical and micromechanical characterization and its application in 3D-printing by fused deposition modelling2018In: Composites Part B: Engineering, ISSN 1359-8368, E-ISSN 1879-1069, Vol. 153, p. 70-77Article in journal (Refereed)
    Abstract [en]

    Two biobased polyethylenes (BioPE) and thermomechanical pulp (TMP) fibers were used to produce biocomposites. The impact of TMP fibers on the mechanical properties was assessed in detail. An increase on the viscosity of the melted biocomposites was quantified and was related to the incorporation of the TMP fibers (0–30% w/w). The impact of polyethylene functionalized with maleic anhydride (MAPE) on the mechanical properties was quantified. Compared to neat BioPEs, a maximum increase of tensile strength between 115 and 127% was obtained, for the biocomposites containing 6% w/w of MAPE and 30% w/w TMP fibers. The formulated biocomposites containing 10 and 20% TMP fibers were three-dimensional (3D) printed, by fused deposition modelling. We confirmed that TMP fibers facilitated the 3D printing and correspondingly improved the mechanical properties of the biocomposite materials.

  • 27.
    Torstensen, Jonathan Ø
    et al.
    Norwegian University of Science and Technology (NTNU), Norway.
    Johnsen, Per Olav
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Riis, Henrik
    University of Oslo, Norway.
    Spontak, Richard J.
    North Carolina State University, US.
    Deng, Liyuan
    Norwegian University of Science and Technology (NTNU), Norway.
    Gregersen, Öyvind
    Norwegian University of Science and Technology (NTNU), Norway.
    Syverud, K.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI. Norwegian University of Science and Technology (NTNU), Norway.
    Preparation of cellulose nanofibrils for imaging purposes: comparison of liquid cryogens for rapid vitrification2018In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 25, no 8, p. 4269-4274Article in journal (Refereed)
    Abstract [en]

    Artifact-free imaging of cellulose nanofibrils (CNFs) from aqueous nanocellulose suspensions is nontrivial due to frequent irreversible agglomeration and structure damage during the course of sample preparation, especially as water is solidified prior to freeze-drying. In this study, we have examined the morphologies of CNF suspensions prepared by rapid vitrification in two different liquid cryogens—nitrogen and ethane—followed by freeze-drying. Results obtained by scanning electron microscopy confirm that vitrification in liquid ethane not only greatly improves the survivability of fine-scale CNF structural elements but also significantly reduces the propensity for CNF to agglomerate.

  • 28.
    Torstensen, Jonathan Ø
    et al.
    Norwegian University of Science and Technology, Norway.
    Liu, Ming
    North Carolina State University, USA.
    Jin, Soo-Ah
    North Carolina State University, USA.
    Deng, Liyuan
    Norwegian University of Science and Technology, Norway.
    Hawari, Ayman I
    North Carolina State University, USA.
    Syverud, Kristin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI. Norwegian University of Science and Technology, Norway.
    Spontak, Richard J
    North Carolina State University, USA.
    Gregersen, Øyvind W
    Norwegian University of Science and Technology, Norway.
    Swelling and Free-Volume Characteristics of TEMPO-Oxidized Cellulose Nanofibril Films.2018In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602Article in journal (Refereed)
    Abstract [en]

    Cellulose nanofibrils (CNFs) are becoming increasingly ubiquitous in diverse technologies requiring sustainable nanoscale species to form or modify films. The objective of the present study is to investigate the swelling behavior and accompanying free volume of self-standing TEMPO-oxidized (TO) CNF films in the presence of water vapor. For this purpose, we have performed time-resolved swelling experiments on films, prepared according to different experimental protocols, at 90% relative humidity (RH) and ambient temperature. Corresponding free-volume characteristics are elucidated by positron annihilation lifetime spectroscopy (PALS) conducted at ambient temperature and several RH levels. Increasing the drying temperature of the films (from ambient to 50 °C) is observed to promote an increase in film density, which serves to reduce bulk swelling. These elevated drying temperatures likewise cause the free-volume pore size measured by PALS to decrease, while the corresponding total free-volume fraction remains nearly constant. Similarly, dispersion of TO-CNF into aqueous suspensions by ultrasonication prior to film formation increases both the total free-volume fraction and pore size but reduces the size of individual nanofibrils with little net change in bulk swelling. The swelling and concurrent free-volume measurements reported here generally reveal an increase in the free volume of TO-CNF films with increasing RH.

  • 29.
    Valdebenito, Fabiola
    et al.
    Universidad de la Frontera, Chile.
    García, Rafael
    Universidad de Concepción, Chile.
    Cruces, Karen
    Universidad de Concepción, Chile.
    Ciudad, Gustavo
    Universidad de la Frontera, Chile.
    Chinga-Carrasco, Gary
    RISE - Research Institutes of Sweden, Bioeconomy, PFI. Universidad de la Frontera, Chile.
    Habibi, Youssef
    Luxembourg Institute of Science and Technology (LIST), Luxembourg.
    CO2 Adsorption of Surface-Modified Cellulose Nanofibril Films Derived from Agricultural Wastes2018In: ACS Sustainable Chemistry and Engineering, ISSN 2168-0485, Vol. 6, no 10, p. 12603-12612Article in journal (Refereed)
    Abstract [en]

    The present work demonstrates a simple and straightforward chemical modification of cellulose nanofibril (CNF) films in order to produce CO2 adsorbent materials. The CNF films were obtained from two agricultural residues, i.e. corn husks and oat hulls. CNF from kraft pulp was used for comparison purposes. Controlled surface silylation was conducted on the preformed CNF films in aqueous media under mild conditions using three aminosilanes bearing mono, di, and triamine groups. The success of the grafting of the aminosilanes on the CNF films was demonstrated by Fourier transform infrared and X-ray photoelectron spectroscopy analyses. The results of the contact angle measurements and field emission scanning electron microscopy coupled with energy dispersive spectroscopy showed homogeneous coverage by the amino groups on the surface of the modified CNF films, particularly with the diaminosilane N-[3-(trimethoxysilyl)propyl]ethylenediamine (DAMO). The produced films were thermally stable, and when subjected to 99.9% CO2 flow at 25 °C, these modified films showed good adsorption of CO2. Indeed, after 3 h of exposure the adsorbed concentration of CO2 of the CNF films modified with DAMO was 0.90, 1.27, and 2.11 mmol CO2 g-1 polymer for CNF films from corn husks, oat hulls, and kraft pulp, respectively.

  • 30.
    Valdebenito, Fabiola
    et al.
    Center for Advanced Polymers Research, Chile ; La Frontera University, Chile .
    Pereira, Miguel
    University of Concepcion, Chile.
    Ciudad, Gustavo
    La Frontera University, Chile .
    Azocar, Laura
    La Frontera University, Chile.
    Briones, Rodrigo
    Center for Advanced Polymers Research, Chile .
    Chinga-Carrasco, Gary
    RISE - Research Institutes of Sweden, Bioeconomy, PFI. La Frontera University, Chile.
    On the nanofibrillation of corn husks and oat hulls fibres2017In: Industrial crops and products (Print), ISSN 0926-6690, E-ISSN 1872-633X, Vol. 95, p. 528-534Article in journal (Refereed)
    Abstract [en]

    Cellulose nanofibrils (CNF) were isolated from agro-industrial waste (corn husks and oat hulls) and market kraft pulp fibres, and a detailed comparative study was performed. Initially, the raw materials were subjected to a conventional pulping process to remove lignin and hemicelluloses. The chemical pre-treatment was based on 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-mediated oxidation and the mechanical treatment was carried out with a high-pressure homogenizer. An extensive characterization of the raw material and of the nanofibrillated celluloses was performed, considering structural and chemical aspects. CNF films were produced for their characterization by optical methods, laser profilometry (LP), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Considering the same pulping and chemical pre-treatment, the analyses indicated that the oxidized corn husks fibres had higher carboxylate content and thus a larger tendency to nanofibrillate compared to the oat hulls fibres. The obtained content of carboxylic acids was directly proportional to the content of cellulose in the assessed samples, confirming the selectivity of the TEMPO-mediated oxidation. The fibrillated corn husks material had a minor fraction of residual fibres (<4%) and homogeneous nanofibril width distribution (<20 nm), which is a major achievement. The homogeneous CNF morphology was confirmed by AFM analysis. Hence, this study demonstrates that the assessed agro-industrial wastes are sustainable resources for production of CNF, which may have a wide range of value-added applications.

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