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Dahlström, Christina
Publications (10 of 33) Show all publications
Blomquist, N., Alimadadi, M., Hummelgård, M., Dahlström, C., Olsen, M. & Olin, H. (2019). Effects of Geometry on Large-scale Tube-shear Exfoliation of Multilayer Graphene and Nanographite in Water. Scientific Reports, 9(1), Article ID 8966.
Open this publication in new window or tab >>Effects of Geometry on Large-scale Tube-shear Exfoliation of Multilayer Graphene and Nanographite in Water
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2019 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, no 1, article id 8966Article in journal (Refereed) Published
Abstract [en]

Industrially scalable methods for the production of graphene and other nanographites are needed to achieve cost-efficient commercial products. At present, there are several available routes for the production of these materials but few allow large-scale manufacturing and environmentally friendly low-cost solvents are rarely used. We have previously demonstrated a scalable and low-cost industrial route to produce nanographites by tube-shearing in water suspensions. However, for a deeper understanding of the exfoliation mechanism, how and where the actual exfoliation occurs must be known. This study investigates the effect of shear zone geometry, straight and helical coil tubes, on this system based on both numerical simulation and experimental data. The results show that the helical coil tube achieves a more efficient exfoliation with smaller and thinner flakes than the straight version. Furthermore, only the local wall shear stress in the turbulent flow is sufficient for exfoliation since the laminar flow contribution is well below the needed range, indicating that exfoliation occurs at the tube walls. This explains the exfoliation mechanism of water-based tube-shear exfoliation, which is needed to achieve scaling to industrial levels of few-layer graphene with known and consequent quality.

National Category
Natural Sciences
Identifiers
urn:nbn:se:miun:diva-36084 (URN)10.1038/s41598-019-45133-y (DOI)2-s2.0-85067662886 (Scopus ID)
Available from: 2019-05-06 Created: 2019-05-06 Last updated: 2019-07-10Bibliographically approved
Yang, J., Dahlström, C., Edlund, H., Lindman, B. & Norgren, M. (2019). pH-responsive cellulose–chitosan nanocomposite films with slow release of chitosan. Cellulose (London), 26(6), 3763-3776
Open this publication in new window or tab >>pH-responsive cellulose–chitosan nanocomposite films with slow release of chitosan
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2019 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 26, no 6, p. 3763-3776Article in journal (Refereed) Published
Abstract [en]

Cellulose–chitosan films were preparedusing a physical method in which cellulose andchitosan were separately dissolved via freeze thawingin LiOH/urea and mixed in different proportions, theresulting films being cast and regenerated in water/ethanol. X-ray diffraction and Fourier transforminfrared spectroscopy (FT-IR) spectroscopy verifiedthe composition changes in the nanocomposites due todifferent mixing ratios between the polymers. Tensilestress–strain measurements indicated that the mechan-ical performance of the cellulose–chitosan nanocom-posites slightly worsened with increasing chitosancontent compared with that of films comprisingcellulose alone. Field emission scanning electronmicroscopy revealed the spontaneous formation ofnanofibers in the films; these nanofibers were subse-quently ordered into lamellar structures. Water uptakeand microscopy analysis of film thickness changesindicated that the swelling dramatically increased atlower pH and with increasing chitosan content, thisbeing ascribed to the Gibbs–Donnan effect. Slowmaterial loss appeared at acidic pH, as indicated by aloss of weight, and quantitative FT-IR analysisconfirmed that chitosan was the main componentreleased.Asample containing 75% chitosan reached amaximum swelling ratio and weight loss of 1500%and 55 wt%, respectively, after 12 h at pH 3. Thestudy presents a novel way of preparing pH-responsivecellulose–chitosan nanocomposites with slow-releasecharacteristics using an environmentally friendlyprocedure and without any chemical reactions.

Keywords
Cellulose dissolution, Chitosan dissolution, pH responsive, Gibbs–Donnan equilibrium, Nanocomposite, Slow release
National Category
Other Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-35778 (URN)10.1007/s10570-019-02357-5 (DOI)000464849500011 ()2-s2.0-85062686323 (Scopus ID)
Funder
Swedish Research Council Formas, 942-2015-251
Available from: 2019-03-12 Created: 2019-03-12 Last updated: 2019-09-03Bibliographically approved
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
Forsberg, V., Maslik, J., Andersson, H., Hummelgård, M., Dahlström, C., Toivakka, M., . . . Norgren, M. (2018). Printability of functional inkjet inks onto commercial inkjet substrates and a taylor made pigmented coated paper. In: : . Paper presented at E-MRS, European Materials Research Society Spring Meeting 2018, Strasbourg, France, June 18-22, 2018. Strasbourg
Open this publication in new window or tab >>Printability of functional inkjet inks onto commercial inkjet substrates and a taylor made pigmented coated paper
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2018 (English)Conference paper, Poster (with or without abstract) (Other academic)
Abstract [en]

Printed electronics are of increasing interest. The substrates used have primarily been plastics although the interest for cellulose-based substrates is increasing due to the environmental aspect as well as cost. The requirements of substrates for electronically active inks differs from graphical inks and therefore we have investigated a custom-made pigment based coated paper and compared it to commercial photo-papers and a coated PE film.

Our goal with the study of different substrates was to select the most suitable substrate to print water based 2D materials inkjet inks for flexible electronics.

The discovery of graphene, a layered material achieved from the exfoliation of graphite, has resulted in the study of other materials with similar properties to cover areas where graphene could not be used due to the absence of a bandgap in the material. For example in thin film transistors (TFT) a semiconductor layer is essential to enable turn on and off the device. This semiconductor layer can be achieved using various materials but particular interest have been dedicated to abundant and cheap 2D materials such as the transition metal dichalcogenide (TMD) molybdenum disulfide (MoS2). To date, most of the dispersions based on TMDs use organic solvents or water solutions of surfactants. Previously we focus on the study of environmental friendly inks produced by liquid phase exfoliation (LPE) of MoS2 in water using cellulose stabilizers such as ethyl cellulose (EC), cellulose nanofibrils (CNF) and nanofibrilcellulose (NFC). We have study various aspects of the ink fabrication includi  ng pH range, the source of MoS2, nanosheets thickness, particle size distribution,  ink stabilizers, ink concentration, viscosity and surface tension. These inks have very low concentration requiring a number of printing passes to cover the substrate. Therefore the substrate selection is crucial as a large amount of solvent is to be absorb by the substrate. Our goal was to use such an ink to print electrodes of MoS2 into a paper substrate after substrate selection.

Commercial photo papers, a commercial coated PE film and a tailor made multilayer pigment coated paper substrate were used for the substrate selection analysis.  We print the substrates using a DIMATIX inkjet printer with a 10 pL printing head using the distillated water waveform supplied by the printer manufacturer. The voltage used was 23V and 4 nozzles were used for the print outs. The inkjet ink used was the organic PEDOT:PSS. We printed lines ranging from 1 pixel to 20 pixels with 1, 2 and 3 printing passes. The printing quality was evaluated through measurements of the waviness of the printed lines measured after imaging the printed samples with a SEM microscope. The line width measurement was done using the software from the SEM.

We also evaluated the structure of the coatings using SEM and topography measurements. The ink penetration through the substrates was evaluated using Raman Spectroscopy. For the pigmented coated sample we measured 4% of ink penetration through the substrate for the 1pxl printed line printed once onto the paper.  Cross-section SEM images of the printed lines were made to visualize the ink penetration into the substrate.

Regarding the electrical conductivity of the printed samples, the differences in resistivity varying the width of the printed lines and the number of printed passes were evaluated. The resistivity of the printed electrodes was evaluated using the 2-points probe method. Before the resistivity measurements, the printed substrates were heated at 50°C and 100°C for 30 minutes in an oven.

We choose the PEDOT:PSS ink because it is a low price ink compared to metal nanoparticles inks for printed electronics. The print outs had low resistivity at a few printing passes with no need for sintering at high temperatures. The MoS2 ink has a very high resistance at a few printing passes due to lower coverage of the substrate therefore for this ink these measurements were not possible to be made. The main pigment composition of the paper coatings of the substrates was evaluated using FT-IR and EDX, these data plus the coating structure evaluated by SEM was related to the print quality.

The best in test papers were used to print MoS2 electrodes. After the printing tests, another step for the optimization of the MoS2 ink properties shall be carried out in future studies for better print quality. We also evaluated the surface energy of the substrates through contact angle measurements to match the surface tension of the PEDOT:PSS ink and later the MoS2 ink. Although the pigmented coated printing substrate did not show better results than the commercial photo papers and PE foil in terms of line quality, it shows the lowest resistivity and sufficient results for low cost recyclable electronics, which do not require high conductivity. Nevertheless, the substrate was very thin and it could even be used in magazines as traditional lightweight coated papers (LWC) are used but with the additional of a printed electronic feature.

Place, publisher, year, edition, pages
Strasbourg: , 2018
Keywords
Z-depth Raman penetration, substrates printed electronics, 2D materials, transparent electronics
National Category
Physical Sciences Chemical Sciences Materials Engineering Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-34034 (URN)
Conference
E-MRS, European Materials Research Society Spring Meeting 2018, Strasbourg, France, June 18-22, 2018
Funder
Knowledge Foundation, 2600364
Note

Proceedings will be published on the Elsevier Journal Thin Solid Films. 

Available from: 2018-06-29 Created: 2018-06-29 Last updated: 2019-01-16Bibliographically approved
Alimohammadzadeh, R., Osong, S. H., Dahlström, C. & Cordova, A. (2018). Scalable Improvement of the Strength Properties of Chemimechanical Pulp Fibers by Eco-Friendly Catalysis. In: IMPC 2018: . Paper presented at International Mechanical Pulping Conference (IMPC) 2018, May 27-30, 2018, Trondheim, Norway. Trondheim, Norway
Open this publication in new window or tab >>Scalable Improvement of the Strength Properties of Chemimechanical Pulp Fibers by Eco-Friendly Catalysis
2018 (English)In: IMPC 2018, Trondheim, Norway, 2018Conference paper, Published paper (Refereed)
Abstract [en]

The sustainable improvement of the strength properties of chemimechanical pulp by eco-friendlycatalysis is disclosed. Significant research activities have been performed on the use of cationic starchand polyelectrolyte complexes for improving the strength properties of cellulose-based materials. Herewe apply an eco-friendly strategy based on catalysis for significantly improving the strength propertiesof sheets made from chemimechanical pulp (CTMP) and bleeched sulphite pulp (BSP) using sustainablepolyelectrolyte complexes as the strength additives and organocatalysis. This surface engineeringstrategy significantly increased the strength properties of the assembled sheets (up to 100% in the caseof Z-strength). We also developed a catalytic selective colour marking of the cationic potato starch (CS)and carboxymethylcellulose (CMC) in order to elucidated how the specific strength additives aredistributed on the sheets. It revealed that the strength additives were more evenly distributed on thesheets made from CTMP as compared to BSP sheets. This is most likely attributed to the presence oflignin in the former lignocellulosic material. It also contributes to the increase in strength (up to 100%,Z-strength) for the CTMP derived sheets. The selective colour marking method also revealed that morestrength additives had been bound to the pulps in the presence of the catalyst.

Place, publisher, year, edition, pages
Trondheim, Norway: , 2018
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:miun:diva-34682 (URN)
Conference
International Mechanical Pulping Conference (IMPC) 2018, May 27-30, 2018, Trondheim, Norway
Available from: 2018-10-08 Created: 2018-10-08 Last updated: 2018-10-08Bibliographically 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
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