Vegar Ottesen

• Ravlo, Erlend; Sousa, Mirta; Andresen, Lise Lima; Holberg-Petersen, Mona; Klundby, Ingvild & Aas, Per Arne [Show all 14 contributors for this article] (2023). A fast, low-cost, robust and high-throughput method for viral nucleic acid isolation based on NAxtra magnetic nanoparticles. Scientific Reports. ISSN 2045-2322. 13(1), p. 1–7. doi: 10.1038/s41598-023-38743-0. Full text in Research Archive
• Torstensen, Jonathan Økland; Ottesen, Vegar; Rodríguez-Fabià, Sandra; Syverud, Kristin; Johansson, Lars & Lervik, Anders (2022). The influence of temperature on cellulose swelling at constant water density. Scientific Reports. ISSN 2045-2322. 12(1). doi: 10.1038/s41598-022-22092-5. Full text in Research Archive
• Joseph, Prajin; Ottesen, Vegar; Tanase-Opedal, Mihaela & Moe, Størker T. (2022). Morphology of lignin structures on fiber surfaces after organosolv pretreatment. Biopolymers. ISSN 0006-3525. 113(9). doi: 10.1002/bip.23520. Full text in Research Archive
• Ottesen, Vegar & Syverud, Kristin (2020). Swelling of individual cellulose nanofibrils in water, role of crystallinity: an AFM study. Cellulose. ISSN 0969-0239. 28, p. 1–11. doi: 10.1007/s10570-020-03517-8. Full text in Research Archive
• Bhujbal, Swapnil Vilas; Dekov, Maren; Ottesen, Vegar; Dunker, Karen; Lale, Rahmi & Sletmoen, Marit (2020). Effect of design geometry, exposure energy, cytophilic molecules, cell type and load in fabrication of single-cell arrays using micro-contact printing. Scientific Reports. ISSN 2045-2322. 10. doi: 10.1038/s41598-020-72080-w. Full text in Research Archive
• Ottesen, Vegar; Larsson, Per Tomas; Chinga-Carrasco, Gary; Syverud, Kristin & Gregersen, Øyvind Weiby (2019). Mechanical properties of cellulose nanofibril films: effects of crystallinity and its modification by treatment with liquid anhydrous ammonia. Cellulose. ISSN 0969-0239. 26(11), p. 6615–6627. doi: 10.1007/s10570-019-02546-2. Full text in Research Archive Show summary

  The influence of cellulose crystallinity on mechanical properties of cellulose nano-fibrils (CNF) was investigated. Degree of crystallinity (DoC) was modified using liquid anhydrous ammonia. Such treatment changes crystal allomorph from cellulose I to cellulose III, a change which was reversed by subsequent boiling in water. DoC was measured using solid state nuclear magnetic resonance (NMR). Crystalline index (CI) was also measured using wide angle x-ray scattering (WAXS). Cotton linters were used as the raw material. The cotton linter was ammonia treated prior to fibrillation. Reduced DoC is seen to associate with an increased yield point and decreased Young modulus. Young modulus is here defined as the maximal slope of the stress-strain curves. The association between DoC and Young modulus or DoC and yield point are both statistically significant. We cannot conclude there has been an effect on strainability. While mechanical properties were affected, we found no indication that ammonia treatment affected degree of fibrillation. CNF was also studied in air and liquid using atomic force microscopy (AFM). Swelling of the nanofibers was observed, with a mean diameter increase of 48.9 %

• Dai, Zhongde; Ottesen, Vegar; Deng, Jing; Helberg, Ragne M Lilleby & Deng, Liyuan (2019). A Brief Review of Nanocellulose Based Hybrid Membranes for CO2 Separation . Fibers. ISSN 2079-6439. 7:40(5), p. 1–18. doi: 10.3390/FIB7050040. Full text in Research Archive
• Kumar, Vinay; Ottesen, Vegar; Syverud, Kristin; Gregersen, Øyvind Weiby & Toivakka, Martti (2017). Coatability of cellulose nanofibril suspensions: Role of rheology and water retention. BioResources. ISSN 1930-2126. 12(4), p. 7656–7679. doi: 10.15376/biores.12.4.7656-7679. Full text in Research Archive Show summary

  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.

• Ottesen, Vegar; Kumar, Vinay; Toivakka, Martti; Chinga-Carrasco, Gary; Syverud, Kristin & Gregersen, Øyvind Weiby (2017). Viability and properties of roll-to-roll coating of cellulose nanofibrils on recycled paperboard. Nordic Pulp & Paper Research Journal (NPPRJ). ISSN 0283-2631. 32(2), p. 179–188. doi: 10.3183/NPPRJ-2017-32-02-p179-188. Full text in Research Archive Show summary

  Cellulose nanofibrils (CNF) are, due in large part to excellent gas barrier properties, a potential environmentally friendly alternative to inorganic and petrochemical coatings of e.g. paperboard in packaging applications. In the current paper successful roll-to-roll coating of three qualities of CNF is demonstrated on a recycled quality, porous paperboard using a custom-built pilot machine. Single layers of three different thicknesses were applied for each coating. The three CNF qualities used were carboxymethylated CNF (CNF-C), TEMPO- oxidized CNF (CNF-T) and mechanically produced CNF without chemical pre-treatment (CNF-M). All three qualities, which have a range of surface charge, fibril size and fibril size distribution, are shown to produce films that adhere well to the base board. It is revealed that the coating is suspended across surface pores in the base board, as opposed to penetrate into the base board pore structure. Samples were investigated for air and water permeability, gloss, surface roughness and hole density in the coating. Chemically pretreated qualities outperform CNF-M. Addition of 5 wt% carboxy-methyl cellulose (CMC) was shown to reduce hole formation, improve gloss and reduce surface roughness. For thick applications of pre-treated CNF, in particular CNF-C, mechanical strength of the board in and out of the plane increase beyond the un-treated or water treated base board. Possibly a consequence of matter migrating through the base board from the CNF suspension.

• Ottesen, Vegar; Syverud, Kristin & Gregersen, Øyvind Weiby (2016). Mixing of cellulose nanofibrils and individual furnish components: Effects on paper properties and structure. Nordic Pulp & Paper Research Journal (NPPRJ). ISSN 0283-2631. 31(3), p. 441–447. doi: 10.3183/NPPRJ-2016-31-03-p441-447. Full text in Research Archive
• Arnfinnsdottir, Nina Bjørk; Ottesen, Vegar; Lale, Rahmi & Sletmoen, Marit (2015). The Design of Simple Bacterial Microarrays: Development towards Immobilizing Single Living Bacteria on Predefined Micro-Sized Spots on Patterned Surfaces. PLOS ONE. ISSN 1932-6203. 10(6). doi: 10.1371/journal.pone.0128162. Full text in Research Archive

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• Ali, Zeeshan; Ravlo, Erlend; Aas, Per Arne; Hagen, Lars; Erlandsen, Sten Even & Ottesen, Vegar [Show all 9 contributors for this article] (2022). Scalable Production of Silica-coated Magnetic Nanobeads and their Applications in Viral Diagnostics.
• Joseph, Prajin; Ottesen, Vegar; Opedal, Mihaela Tanase & Moe, Størker T. (2021). Organosolv Pretreatment of Nordic Spruce for Biorefinery applications.
• Ottesen, Vegar (2021). Super nanoteknologi fra naturen.
• Ottesen, Vegar (2021). Super nanoteknologi fra naturen.
• Ottesen, Vegar (2021). Forsker på skjerm, Ole Vig videregående skole.
• Ottesen, Vegar (2021). NTNUs koronatest: Utvikling og anvendelse. Show summary

  Foredrag om utvikling av og potensialet til NTNUs korona-tester, etablering av LyBe Scientific og fremtidig horisont for testen.

• Ottesen, Vegar (2021). Aftenposten Forklart Junior. Kan man slutte å bruke plast? [Internet]. https://www.aftenposten.no/podkast/ap/program/100195.
• Ottesen, Vegar (2021). Nanomaterials Characterization by Atomic Force Microscopy.
• Ottesen, Vegar (2021). Nanomaterials Characterization by Electron Microscopy.
• Ottesen, Vegar (2021). Super nanoteknologi fra naturen.
• Ottesen, Vegar (2021). Superrask forskning - Synergi og samarbeid.
• Ottesen, Vegar (2021). Hva er et virus?
• Ottesen, Vegar (2020). Nanotechnology - an Introduction.
• Ottesen, Vegar (2020). Polymeric and biopolymeric nanomaterials - an overview.
• Ottesen, Vegar; Larsson, Per Tomas & Syverud, Kristin (2019). AFM study cellulose nano-fibril swelling in water - Relevance of nanofiber crystallinity.
• Ottesen, Vegar (2019). Kjemisk prosessteknologi – for fremtidens miljø og klima.
• Ottesen, Vegar; Larsson, Per Tomas & Syverud, Kristin (2019). Swelling of Individual Cellulose Nano-Fibrils: Does Crystallinity affect Swellability?
• Ottesen, Vegar & Befring Thomassen, Ellen (2019). Har NTNU-forsker svar på plastproblemet? [Radio]. NRK P3.
• Ottesen, Vegar (2019). Inn med planten - ut med plasten.
• Ottesen, Vegar (2019). PhD Grand Prix 2019 (Konferansier).
• Ottesen, Vegar (2019). Ut med plasten, inn med planten .
• Ottesen, Vegar (2019). Plast og nano fra naturen .
• Ottesen, Vegar (2019). Inn med Planten ut med Plasten.
• Ottesen, Vegar (2019). Nanocellulose og Plast.
• Ottesen, Vegar (2018). Inn med planten – ut med plasten! .
• Ottesen, Vegar (2018). nanocellulose som et alternativ til plast.
• Ottesen, Vegar; Haugen, Randi Wenche & Brattebø, Helge (2018). Hva kan erstatte plast? [TV]. NTNU Kveld.
• Ottesen, Vegar; Larsson, Per Tomas; Chinga-Carrasco, Gary; Syverud, Kristin & Gregersen, Øyvind Weiby (2018). CNF Films: Crystallinity and Ductility.
• Ottesen, Vegar (2018). Sparebank1 - Idekonkurranse Plast. [Internet]. Facebook.
• Ottesen, Vegar (2018). Inn med planten - ut med plasten.
• Ottesen, Vegar (2018). Nano? Inn! Plast? Ut!
• Ottesen, Vegar (2018). Nanocellulose: Tomorrow’s packaging?
• Ottesen, Vegar (2017). Nanocellulose: Plastics Replacer?
• Ottesen, Vegar (2017). Nanocellulose: It's a Wrap!
• Ottesen, Vegar & Opheim, Aagot (2017). Erstatter plast med planter. [Newspaper]. Adresseavisen.
• Syverud, Kristin & Ottesen, Vegar (2017). Prosjekt plast.
• Ottesen, Vegar; Syverud, Kristin & Gregersen, Øyvind Weiby (2017). Nanocellulose - et steg nærmere fremtidens innpakking. Kjemi. ISSN 0023-1983. 4. Show summary

  PLAST som materiale dominerer vår hverdag. Vi finner det i alt fra våre klær, via bygg og transportmidler, til kosmetikk og matinnpakking. Plast har blitt et miljøproblem, men vi er avhengige av produkter som nesten utelukkende er laget av plast – fornybare alternativ kan være nesten umulige å finne. Oljebaserte plastprodukter er altså et betydelig, og voksende, problem. Alternativer trengs, og i enkelte sammenhenger kan potensielle alternativer isoleres fra plantematerialer; nanocellulose er en mulig erstatning for plast og aluminiumslag i flere matinnpakkingsprodukter, som væskekartong. Sammen har en gruppe forskere fra Åbo Akdemi i Finland samt RiSE PFI og NTNU i Trondheim nylig publisert arbeid som demonstrerer en skalerbar teknikk for å legge tynne og hele nanocelluloselag på for eksempel papp. Altså et steg i retning realisering av potensielle alternativ til plast i matinnpakking. Materialets opprinnelsessted? De norske skoger.

• Ottesen, Vegar; Roede, Erik Dobloug; Syverud, Kristin & Gregersen, Øyvind Weiby (2017). Focused Ion Beam Tomography as a Means for Characterization of CNF in a Paper Matrix. Show summary

  A method to study Cellulose Nanofibril (CNF) distribution in three dimensions within a paper matrix in-situ was developed. Focused Ion Beam (FIB)/Scanning Electron Microscopy (SEM) tomography was used to investigate the distribution of cellulose nanofibers in three dimensions within a paper structure. Sufficient resolution and material contrast was obtained using both secondary and back-scattered electrons in volumes as large as 10^3 μm^3. Challenges and approaches to achieve this are discussed, both with respect to the microscopy technique and with respect to image processing and volume reconstruction. A range of recorded images and reconstructed 3D volumes show the technique capable of resolving CNF in a paper matrix. Results presented show CNF within the paper matrix forming capsules enclosing filler particles. These capsules are seen to only infrequently be in physical contact with the enclosed particles. Similar separation between CNF and enclosed filler particles was tested and confirmed in CNF films with 10 wt% added ground calcium carbonate.

• Ottesen, Vegar (2017). Studio 2 «Vi er Plast Entusiaster!». [Radio]. https://radio.nrk.no/serie/studio-2-p2/MKRV20000317/15-03-20. Show summary

  Interviewed about cellulose nanofibrils as an alternative to plastic materials.

• Ottesen, Vegar (2017). PhD Grand Prix 2017 - populærvitenskapelig foredrag på 5 minutter VInnerforedrag.
• Ottesen, Vegar; Kumar, Vinay; Toivakka, Martti; Chinga-Carrasco, Gary; Syverud, Kristin & Gregersen, Øyvind Weiby (2016). CNF i papir - Rull-til-rull bestrykning.
• Ottesen, Vegar; Roede, Erik Dobloug; Syverud, Kristin & Gregersen, Øyvind Weiby (2016). Focused Ion Beam Tomography in the 3D Study of Nanocellulose in Paper.
• Ottesen, Vegar; Syverud, Kristin & Gregersen, Øyvind Weiby (2016). Effects of Premixing CNF with Specific Furnish Components.
• Ottesen, Vegar; Syverud, Kristin & Gregersen, Øyvind Weiby (2016). Bør nanocellulose bindes til en bestemt komponent I furnish?
• Ottesen, Vegar; Syverud, Kristin & Gregersen, Øyvind Weiby (2016). Effects of Cellulose Nanofibril Premixing Strategies for Paper Making. Show summary

  Effects on paper strength, air permeability and filler distribution from CNF premixing with different paper components have been investigated. As a paper additive Cellulose Nano-fibers (CNF) could improve paper strength, permitting the use of more filler or recycled pulp, thereby cutting costs, while retaining paper strength. Various CNF addition strategies may be pursued, it may be added to the complete furnish, it may be pre-flocculated or added to a specific fraction such as the filler or the long fiber fraction. In the event that CNF is pre-mixed with a specific fraction along with retention chemicals it is expected to coat the surface of said fraction, affecting properties like specific surface area (SSA) and surface chemistry of the fraction in question. This, in turn, can be expected to affect the properties of the fraction and subsequently the properties of the resulting paper. While several of the aforementioned strategies can be seen alluded to in patent literature or explored to some degree in scientific literature a comparison or a study of differences is to our knowledge not published. Aiming to address this we have investigated three different addition strategies, premixing mechanically produced CNF with complete furnish, the filler fraction and the long fiber fraction we have found various differences between papers using the different strategies. Structural differences between the strategies are observable with electron microscopy. Tensile strength properties and air permeability also appear affected by the chosen premixing strategy. Results will be presented at TAPPI NANO 2016

• Ottesen, Vegar; Patil, Nilesh; Breiby, Dag Werner; Syverud, Kristin & Gregersen, Øyvind Weiby (2015). Investigations of Cellulose Nano-Fibrils Produced by Homogenization of Pulp Converted to Cellulose III from Cellulose Iβ by Treatment with Liquid Ammonia.
• Ottesen, Vegar; Syverud, Kristin & Gregersen, Øyvind Weiby (2015). Nanocellulose in Paper and Packaging -Interaction Effects.
• Hjorth, Ida; Ottesen, Vegar; Svardal, Lisa Gregusson; Kjærvik, Marit; Bazilchuk, Molly Strimbeck & Schlanbusch, Reidun Dahl [Show all 7 contributors for this article] (2015). En Nanohverdag på Fremmarsj». Teknisk Ukeblad. ISSN 0040-2354.
• Ottesen, Vegar (2014). Naturen kan gi oss svar. Aftenposten Viten. ISSN 2464-3033. Show summary

  Bakterier og andre mikrober danner lett biofilmer på overflater de kommer i kontakt med. En biofilm er et belegg av bakterier eller mikrober, og utvikles på grunn av et samspill mellom overflaten og mikro-organismene.Innimellom er det ønskelig å holde noe klinisk fritt for bakterier eller i det minste minimere deres tilstedeværelse. I en operasjonssal er pasientens liv avhengig av sterilt utstyr og i slakterier, restauranter og annen matindustri er kundens trygghet avhengig av at maten tilberedes på trygt og relativt bakteriefritt miljø.

• Ottesen, Vegar; Syverud, Kristin & Gregersen, Øyvind Weiby (2014). Nanocellulose Properties of Interest for Paper and Packaging. Show summary

  Cellulose Nano-Fibrils (CNF) is a biocompatible nano-material with appealing mechanical and optical properties. The high specific surface area (SSA) of nanofibrils ensure that a large fraction of the polymer chains in each fibril are surface fibrils, meaning numerous surface hydroxyl groups will be available to form bonds between components in the paper, ensuring high density and strength. CNF may be added to conventional paper as a strengthening agent. CNF films may be used as a barrier coating , or CNF sheets may be used in a number of products due to their potential transparency, strength and barrier properties. As a paper additive, CNF as a nanomaterial acts as a material that increase density and form bonds between fibers in the paper, providing a increased strength and stiffness whereas dusting and permeability is reduced.For papers where strength is chiefly limited by inter-fiber bonding strength, increases in excess of 100 % may be achieved by addition of small amounts of CNF. Less, but still significant contributions can be seen for papers whose strength is less dependent on inter-fiber bonding strength. Due to the pore-blocking properties of CNF coupled with Cellulose’s hydrophilic properties, dewatering on the paper machine is a challenge when CNF is used in this fashion. The high density, viz. the low porosity and small pore size (~0.47 nm), of CNF films provide a significant reduction in mass-transport. Applying such a film to a less efficient barrier material, or producing a pure CNF film presents oxygen transfer rates comparable with the best synthetic polymer films produced for this purpose3. Sheets of pure CNF or a CNF composite may transmit over 90 % of incident light with a wavelength of 600 nm. This transparency is due to the high density and small fibril size in sheets of pure CNF or a CNF-based composite, which results in a lower scattering coefficient compared to corresponding conventional fiber based sheets. Transparent sheets such as these may be of interest in packaging applications where the packaged goods, such as foodstuffs or luxury articles, is desired displayed to the end customer. The properties of CNF, whether as a film, a paper additive or a major paper or composite component may be of significant industrial interest due to the unique properties of the material. Acknowledgement: The work is done through NORCEL: The Norwegian Nanocellulose Technology Platform, see www.pfi.no, funded by the Research Council of Norway.

• Arnfinnsdottir, Nina Bjørk; Ottesen, Vegar; Lale, Rahmi & Sletmoen, Marit (2014). Bacterial microarrays obtained by spontaneous adhesion of single bacteria on predefined spots on chemically patterned surfaces.
• Ottesen, Vegar; Gregersen, Øyvind Weiby & Syverud, Kristin (2018). Cellulose Nanofibrils as Paper Additive and Coating Material: Properties, Distribution and Interaction Effects. NTNU. ISSN 978-82-326-3021-9.
• Ottesen, Vegar; Sletmoen, Marit & Arnfinnsdottir, Nina Bjørk (2014). Bacterial Microarrays by Microcontact Printing: Development of a Method for Immobilizing Live Bacteria on Microarrays. NTNU.

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