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Dahlström, Christina
Publications (10 of 28) Show all publications
Andres, B., Dahlström, C., Blomquist, N., Norgren, M. & Olin, H. (2018). Cellulose binders for electric double-layer capacitor electrodes: The influence of cellulose quality on electrical properties. Materials & design, 141, 342-349
Open this publication in new window or tab >>Cellulose binders for electric double-layer capacitor electrodes: The influence of cellulose quality on electrical properties
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2018 (English)In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 141, p. 342-349Article in journal (Refereed) Published
Abstract [en]

Cellulose derivatives are widely used as binders and dispersing agents in different applications. Binders composed of cellulose are an environmentally friendly alternative to oil-based polymer binding agents. Previously, we reported the use of cellulose nanofibers (CNFs) as binders in electrodes for electric double-layer capacitors (EDLCs). In addition to good mechanical stability, we demonstrated that CNFs enhanced the electrical performance of the electrodes. However, cellulose fibers can cover a broad range of length scales, and the quality requirements from an electrode perspective have not been thoroughly investigated. To evaluate the influence of fiber quality on electrode properties, we tested seven samples with different fiber dimensions that are based on the same kraft pulp. To capture the length scale from fibers to nanofibrils, we evaluated the performance of the untreated kraft pulp, refined fibers, microfibrillated cellulose (MFC) and CNFs. Electrodes with kraft pulp or refined fibers showed the lowest electrical resistivity. The specific capacitances of all EDLCs were surprisingly similar, but slightly lower for the EDLC with CNFs. The same electrode sample with CNFs also showed a slightly higher equivalent series resistance (ESR), compared to those of the other EDLCs. Graphite dispersions with MFC showed the best dispersion stability. 

Keywords
Cellulose, Electric double-layer capacitor, Graphite, Nanocellulose, Nanocomposite, Supercapacitor
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-32766 (URN)10.1016/j.matdes.2017.12.041 (DOI)000424945300031 ()2-s2.0-85040002856 (Scopus ID)
Available from: 2018-01-30 Created: 2018-01-30 Last updated: 2018-07-19Bibliographically approved
Eivazihollagh, A., Norgren, M., Dahlström, C. & Edlund, H. (2018). Controlled Synthesis of Cu and Cu2O NPs and Incorporation of Octahedral Cu2O NPs in Cellulose II Films. Nanomaterials, 8(4), Article ID 238.
Open this publication in new window or tab >>Controlled Synthesis of Cu and Cu2O NPs and Incorporation of Octahedral Cu2O NPs in Cellulose II Films
2018 (English)In: Nanomaterials, ISSN 2079-4991, Vol. 8, no 4, article id 238Article in journal (Refereed) Published
Abstract [en]

In this study, Cu and Cu2O nanoparticles (NPs) were synthesized through chemical reduction of soluble copper-chelating ligand complexes using formaldehyde as a reducing agent. The influence of various chelating ligands, such as ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and a surface-active derivative of DTPA (C12-DTPA), as well as surfactants (i.e., hexadecyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium chloride (DoTAC), sodium dodecyl sulfate (SDS), and dimethyldodecylamine-N-oxide (DDAO)), on morphology and the composition of produced NPs was investigated. In the absence of surfactants, spherical copper particles with polycrystalline structure could be obtained. X-ray diffraction (XRD) analysis revealed that, in the presence of EDTA, the synthesized NPs are mainly composed of Cu with a crystallite size on the order of 35 nm, while with DTPA and C12-DTPA, Cu2O is also present in the NPs as a minority phase. The addition of ionic surfactants to the copper–EDTA complex solution before reduction resulted in smaller spherical particles, mainly composed of Cu. However, when DDAO was added, pure Cu2O nano-octahedrons were formed, as verified by high-resolution scanning electron microscopy (HR-SEM) and XRD. Furthermore, a hybrid material could be successfully prepared by mixing the octahedral Cu2O NPs with cellulose dissolved in a LiOH/urea solvent system, followed by spin-coating on silica wafers. It is expected that this simple and scalable route to prepare hybrid materials could be applied to a variety of possible applications.

Keywords
copper nanoparticles; cuprous oxide nano-octahedrons; hybrid material; regenerated cellulose; chemical reduction; chelating agent; surfactant
National Category
Nano Technology Chemical Engineering Materials Engineering
Identifiers
urn:nbn:se:miun:diva-33497 (URN)10.3390/nano8040238 (DOI)000434889100059 ()2-s2.0-85045875998 (Scopus ID)
Available from: 2018-04-16 Created: 2018-04-16 Last updated: 2018-07-04Bibliographically approved
Kumar, V., Forsberg, S., Engström, A., Nurmi, M., Dahlström, C. & Toivakka, M. (2017). Conductive carbon-nanocellulose coatings on paper. TAPPI Journal, 16(6), 310-311
Open this publication in new window or tab >>Conductive carbon-nanocellulose coatings on paper
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2017 (English)In: TAPPI Journal, ISSN 0734-1415, Vol. 16, no 6, p. 310-311Article in journal, Editorial material (Other academic) Published
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-31365 (URN)000405492700003 ()
Available from: 2017-08-10 Created: 2017-08-10 Last updated: 2017-12-15Bibliographically approved
Kumar, V., Forsberg, S., Engström, A.-C., Nurmi, M., Dahlström, C. & Toivakka, M. (2017). Conductive carbon-nanocellulose coatings on paper. In: Paper Conference and Trade Show, PaperCon 2017: Renew, Rethink, Redefine the Future. Paper presented at Paper Conference and Trade Show: Renew, Rethink, Redefine the Future, PaperCon 2017, Minneapolis, United States, 23 April 2017 through 26 April 2017 (pp. 26-35). TAPPI Press
Open this publication in new window or tab >>Conductive carbon-nanocellulose coatings on paper
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2017 (English)In: Paper Conference and Trade Show, PaperCon 2017: Renew, Rethink, Redefine the Future, TAPPI Press , 2017, p. 26-35Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
TAPPI Press, 2017
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-32867 (URN)2-s2.0-85041529982 (Scopus ID)9781510847286 (ISBN)
Conference
Paper Conference and Trade Show: Renew, Rethink, Redefine the Future, PaperCon 2017, Minneapolis, United States, 23 April 2017 through 26 April 2017
Available from: 2018-02-20 Created: 2018-02-20 Last updated: 2018-02-20Bibliographically approved
Kumar, V., Forsberg, S., Engström, A.-C., Nurmi, M., Andres, B., Dahlström, C. & Toivakka, M. (2017). Conductive nanographite-nanocellulose coatings on paper. Flexible And Printed Electronics, 2(3), Article ID aa728e.
Open this publication in new window or tab >>Conductive nanographite-nanocellulose coatings on paper
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2017 (English)In: Flexible And Printed Electronics, ISSN 2058-8585, Vol. 2, no 3, article id aa728eArticle in journal (Refereed) Published
Abstract [en]

Paper products with active and functional coatings have attracted interest in recent years to counter the stagnating demand for traditional graphic paper grades. Conductive coatings have potential uses in various energy generation and storage applications, e.g. in batteries, supercapacitors, and photovoltaics. The current work aims to demonstrate large-scale production of flexible low-cost nanographite coatings on paper-based substrate. The large aspect ratio of graphene present in the suspension limits solids content to very low values, which makes it challenging to create thick coating layers required for high conductivity. The use of nanocellulose binder together with a custom-built slot-coating device enables roll-to-roll coating of thick conductive coatings on paper. The rheological and water-retention properties of nanographite-nanocellulose suspensions are reported. The influence of coat weight, carbon black addition, and calendering on coating structure and the resulting conductivity of the coatings is investigated. Impact of humidity and bending/creasing of coated samples on their electrical performance is explored as well. The lowest surface resistances obtained were in the range 1-2 Ohm/square, for 15 g m(-2) coat weight. Increasing the coat weight and calendering nip load resulted in higher conductivity of coatings. Carbon black addition deteriorated the conductivity somewhat, probably due to increased porosity of coatings. Moisture and creasing did not affect significantly the conductivity of high coat weight and calendered samples. The results reported are very encouraging for future research on further improving the electrical performance of such carbon coatings.

Keywords
nanographite, nanofibrillated cellulose, paper electronics, carbon black, calendering, roll-to-roll conductive coating
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-31882 (URN)10.1088/2058-8585/aa728e (DOI)000410630500004 ()2-s2.0-85041007089 (Scopus ID)
Available from: 2017-10-17 Created: 2017-10-17 Last updated: 2018-02-20Bibliographically approved
Eivazihollagh, A., Bäckström, J., Dahlström, C., Carlsson, F., Ibrahem, I., Lindman, B., . . . Norgren, M. (2017). One-pot synthesis of cellulose-templated copper nanoparticles with antibacterial properties. Materials letters (General ed.), 187, 170-172
Open this publication in new window or tab >>One-pot synthesis of cellulose-templated copper nanoparticles with antibacterial properties
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2017 (English)In: Materials letters (General ed.), ISSN 0167-577X, E-ISSN 1873-4979, Vol. 187, p. 170-172Article in journal (Refereed) Published
Abstract [en]

We report a facile in situ synthesis of spherical copper nanoparticles (NPs) templated by a gelled cellulose II matrix under alkaline aqueous reaction conditions. In under 20 min, the hybrid material could be obtained in a one-pot reaction. Field-emission scanning electron microscopy (FE-SEM) revealed that the polycrystalline NPs of 200–500 nm were well distributed in the regenerated cellulose matrix. The average Cu crystallite size was of the order of 20 nm, as estimated from both X-ray diffraction (XRD) and FE-SEM. XRD data also indicated that the composite contained up to approximately 20% Cu2O. In suspensions containing the hybrid material, growth of Escerichia coli and Staphylococcus aureus strains was inhibited by 80% and 95%, respectively, after 72 h. The synthesis procedure offers a general approach to designing various low-cost hybrid materials of almost any shape, and the concept could be extended to utilization areas such as catalysis, functional textiles, and food packaging as well as to electronic applications.

Keywords
One-pot synthesis, Copper nanoparticles, Cellulose, Hybrid material, Antibacterial properties
National Category
Nano Technology Chemical Engineering Composite Science and Engineering
Identifiers
urn:nbn:se:miun:diva-29336 (URN)10.1016/j.matlet.2016.10.026 (DOI)000390628200045 ()2-s2.0-84994876232 (Scopus ID)FSCN (Local ID)FSCN (Archive number)FSCN (OAI)
Projects
NovoCell - Novel use of native cellulose in dispersions and functional biocomposites
Funder
Swedish Research Council Formas, 942-2015-251
Available from: 2016-11-24 Created: 2016-11-24 Last updated: 2018-06-28Bibliographically approved
Forsberg, S., Kumar, V., Engström, A.-C., Maristiina, N., Dahlström, C. & Martti, T. (2016). Effect of calendering and coating formulations on conductivity in paper-based electrodes. In: : . Paper presented at TAPPI Advanced Coating Symposium 2016, October 4-6, 2016, Stockholm.
Open this publication in new window or tab >>Effect of calendering and coating formulations on conductivity in paper-based electrodes
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2016 (English)Conference paper, Oral presentation with published abstract (Refereed)
National Category
Composite Science and Engineering
Identifiers
urn:nbn:se:miun:diva-29691 (URN)
Conference
TAPPI Advanced Coating Symposium 2016, October 4-6, 2016, Stockholm
Available from: 2016-12-20 Created: 2016-12-20 Last updated: 2016-12-20Bibliographically approved
Andres, B., Engström, A.-C., Blomquist, N., Forsberg, S., Dahlström, C. & Olin, H. (2016). Electrode Mass Balancing as an Inexpensive and Simple Method to Increase the Capacitance of Electric Double-Layer Capacitors. PLoS ONE, 11(9), 1-12, Article ID e0163146.
Open this publication in new window or tab >>Electrode Mass Balancing as an Inexpensive and Simple Method to Increase the Capacitance of Electric Double-Layer Capacitors
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2016 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 9, p. 1-12, article id e0163146Article in journal (Refereed) Published
Abstract [en]

Symmetric electric double-layer capacitors (EDLCs) have equal masses of the same active material in both electrodes. However, having equal electrode masses may prevent the EDLC to have the largest possible specific capacitance if the sizes of the hydrated anions and cations in the electrolyte differ because the electrodes and the electrolyte may not be completely utilized. Here we demonstrate how this issue can be resolved by mass balancing. If the electrode masses are adjusted according to the size of the ions, one can easily increase an EDLC's specific capacitance. To that end, we performed galvanostatic cycling to measure the capacitances of symmetric EDLCs with different electrode mass ratios using four aqueous electrolytes-Na2SO4, H2SO4, NaOH, and KOH (all with a concentration of 1 M)-and compared these to the theoretical optimal electrode mass ratio that we calculated using the sizes of the hydrated ions. Both the theoretical and experimental values revealed lower-than-1 optimal electrode ratios for all electrolytes except KOH. The largest increase in capacitance was obtained for EDLCs with NaOH as electrolyte. Specifically, we demonstrate an increase of the specific capacitance by 8.6% by adjusting the electrode mass ratio from 1 to 0.86. Our findings demonstrate that electrode mass balancing is a simple and inexpensive method to increase the capacitance of EDLCs. Furthermore, our results imply that one can reduce the amount of unused material in EDLCs and thus decrease their weight, volume and cost.

Keywords
Mass balancing, capacitance, electric double layer capacitor, EDLC, electrode, electrolyte, electrode mass ratio, ion size ratio
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:miun:diva-29083 (URN)10.1371/journal.pone.0163146 (DOI)000383893200073 ()2-s2.0-84992186879 (Scopus ID)
Available from: 2016-10-10 Created: 2016-10-10 Last updated: 2017-11-30Bibliographically approved
Forsberg, V., Zhang, R., Joakim, B., Dahlström, C., Andres, B., Norgren, M., . . . Olin, H. (2016). Exfoliated MoS2 in Water without Additives. PLoS ONE, 11(4), Article ID 0154522.
Open this publication in new window or tab >>Exfoliated MoS2 in Water without Additives
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2016 (Swedish)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 4, article id 0154522Article in journal (Refereed) Published
Abstract [en]

Many solution processing methods of exfoliation of layered materials have been studied during the last few years; most of them are based on organic solvents or rely on surfactants andother funtionalization agents. Pure water should be an ideal solvent, however, it is generallybelieved, based on solubility theories that stable dispersions of water could not be achievedand systematic studies are lacking. Here we describe the use of water as a solvent and thestabilization process involved therein. We introduce an exfoliation method of molybdenumdisulfide (MoS2) in pure water at high concentration (i.e., 0.14±0.01 g L−1). This was achieved by thinning the bulk MoS2by mechanical exfoliation between sand papers and dis-persing it by liquid exfoliation through probe sonication in water. We observed thin MoS2nanosheets in water characterized by TEM, AFM and SEM images. The dimensions of thenanosheets were around 200 nm, the same range obtained in organic solvents. Electropho-retic mobility measurements indicated that electrical charges may be responsible for the sta-bilization of the dispersions. A probability decay equation was proposed to compare thestability of these dispersions with the ones reported in the literature. Water can be used as asolvent to disperse nanosheets and although the stability of the dispersions may not be ashigh as in organic solvents, the present method could be employed for a number of applications where the dispersions can be produced on site and organic solvents are not desirable.

Keywords
liquid exfoliation; MoS2; solar cells; water exfoliation
National Category
Natural Sciences
Identifiers
urn:nbn:se:miun:diva-27560 (URN)10.1371/journal.pone.0154522 (DOI)000374976200086 ()2-s2.0-85002584946 (Scopus ID)
Projects
Paper Solar Cells
Available from: 2016-04-28 Created: 2016-04-28 Last updated: 2017-11-30Bibliographically approved
Forsberg, V., Zhang, R., Andersson, H., Bäckström, J., Dahlström, C., Norgren, M., . . . Olin, H. (2016). Liquid Exfoliation of Layered Materials in Water for Inkjet Printing. In: Printing for Fabrication 2016: Materials, Applications, and Processes. Paper presented at 32nd International Conference on Digital Printing Technologies (NIP) Printing for Fabrication : Materials, Applications, and Processes, Manchester, UK, September 12-16, 2016. USA: Curran Associates, Inc.
Open this publication in new window or tab >>Liquid Exfoliation of Layered Materials in Water for Inkjet Printing
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2016 (English)In: Printing for Fabrication 2016: Materials, Applications, and Processes, USA: Curran Associates, Inc., 2016Conference paper, Published paper (Refereed)
Abstract [en]

MoS2 is a layered material which is abundant and non-toxic and has been increasingly studied during the last few years as a semiconducting alternative to graphene. While most studies have been performed on single MoS2 nanosheets, for example to demonstrate high-performance electronic transistors, more work is needed to explore the use of MoS2 in printed electronics. The importance of using MoS2 as a printed electronic material could be understood by considering the several orders higher electron mobility in MoS2, even in several nanometer thick layers, compared to the organic and other materials used today. In the few studies performed so far on printing MoS2, the developed dispersions used mainly organic solvents that might be detrimental for the environment. Here, we show an environmentally friendly liquid-based exfoliation method in water where the solution was stabilized by sodium dodecyl sulfate (SDS) surfactant. The dispersions consisted of very thin MoS2 nanosheets with average lateral size of about 150 nm, surface tension of 28 mN m-1 and a shelf life of a year. Although both the concentration and viscosity was less than optimal, we were able to inkjet print the MoS2 solution on paper and on PET films, using multiple printing passes. By tuning the concentration/viscosity, this approach might lead to an environmentally friendly MoS2 ink suitable for printed electronics.

Place, publisher, year, edition, pages
USA: Curran Associates, Inc., 2016
National Category
Materials Chemistry
Identifiers
urn:nbn:se:miun:diva-31651 (URN)978-0-89208-322-0 (ISBN)978-0-89208-323-7 (ISBN)978-0-89208-321-3 (ISBN)
Conference
32nd International Conference on Digital Printing Technologies (NIP) Printing for Fabrication : Materials, Applications, and Processes, Manchester, UK, September 12-16, 2016
Projects
Paper Solar Cells
Funder
Knowledge Foundation
Note

This paper was also publised at the JIST, Journal of imaging and Science and Technology. It was connected to the conference.

Available from: 2017-09-21 Created: 2017-09-21 Last updated: 2017-11-01Bibliographically approved
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