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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
Ibrahem, I., Iqbal, M. N., Verho, O., Eivazihollagh, A., Olsén, P., Edlund, H., . . . Johnston, E. V. (2018). Copper Nanoparticles on Controlled Pore Glass and TEMPO for the Aerobic Oxidation of Alcohols. ChemNanoMat, 4(1), 71-75
Open this publication in new window or tab >>Copper Nanoparticles on Controlled Pore Glass and TEMPO for the Aerobic Oxidation of Alcohols
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2018 (English)In: ChemNanoMat, ISSN 2199-692X, Vol. 4, no 1, p. 71-75Article in journal (Refereed) Published
Abstract [en]

Herein, we report on the facile synthesis of a heterogeneous copper nanocatalyst and its combination with 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) for the aerobic oxidation of alcohols to their corresponding carbonyl compounds. This low cost copper nanocatalyst was found to exhibit excellent recyclability, making it a highly attractive catalytic system from an economical and environmental point of view. Extensive characterization of the catalyst by a number of techniques revealed that it was comprised of well-dispersed Cu(I/II) nanoparticles with an average size of around 6nm.

Keywords
Alcohol oxidation, Copper nanoparticles, Green chemistry, Heterogeneous catalysis, TEMPO
National Category
Chemical Sciences
Identifiers
urn:nbn:se:miun:diva-32328 (URN)10.1002/cnma.201700309 (DOI)000419237800011 ()2-s2.0-85033664510 (Scopus ID)
Note

Version of record online: 14 November 2017

Available from: 2017-12-07 Created: 2017-12-07 Last updated: 2018-06-28Bibliographically approved
Lundberg, M., Norgren, M. & Edlund, H. (2018). Crill Measurements For Improved Fines Material Control. 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 >>Crill Measurements For Improved Fines Material Control
2018 (English)In: IMPC 2018, Trondheim, Norway, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Finding the characterization method that best matches the pulping process is crucial in enabling the monitoring and control of pulp and final-product properties. Control of optimal process parameters in the production line are thus dependent on reliable and valid results. The Crill method is an analogue method based on the relationship between the interactions of lights of two different wavelengths (UV and IR) with the particles in the pulp. By comparing the specific UV and IR surfaces, the crill value is calculated. The crill method has been used in two studies with the aims to validate the crill measurement in a high yield pulping (HYP) process by focusing on refining and control of crill value of different pulp streams. The results indicate that the crill method can be used to monitor fibre treatment in refining processes. Moreover, by controlling pulp streams with regards to crill value, improvements of pulp strength and retention on the paper machine (PM) can be achieved.

Place, publisher, year, edition, pages
Trondheim, Norway: , 2018
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:miun:diva-34678 (URN)
Conference
International Mechanical Pulping Conference (IMPC) 2018, May 27-30, 2018, Trondheim, Norway
Available from: 2018-10-09 Created: 2018-10-09 Last updated: 2018-10-09Bibliographically approved
Fiskari, J., Ferritsius, R., Osong, S. H., Persson, A., Höglund, T. & Norgren, M. (2018). Deep Eutectic Solvent Treatment to Low-Energy TMP to Produce Fibers for Papermaking. 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 >>Deep Eutectic Solvent Treatment to Low-Energy TMP to Produce Fibers for Papermaking
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2018 (English)In: IMPC 2018, Trondheim, Norway, 2018Conference paper, Published paper (Refereed)
Abstract [en]

The aim of this research was to gain a better understanding on whether a novel process based on low-energy thermo-mechanical pulp (TMP) process followed by a chemical treatment with deep eutectic solvents (DESs) could produce fibers suitable for papermaking. In full scale production, these fibers could be produced at a much lower capital and operational costs, especially when utilizing existing TMP plants which are under the threat to be shut down or have already been shut down due to a decreasing demand for newsprint and other wood-containing papers.The efficiency of several DES treatments under various temperatures and times were evaluated by carrying out experiments in standard Teflon-lined autoclaves. A few tests were also performed in a unique nonstandard flow extractor. Pulp samples were characterized for their cellulose, hemicellulose and lignin contents. Moreover, tensile index was measured both before and after pulp refining. Depending on the solvent, the response of mechanical pulp varied, especially in terms of hemicellulose dissolution. Lactic acid, oxalic acid and urea, all in combination with choline chloride ([Ch]Cl) as the hydrogen bond acceptor, dissolved about 50% of the lignin of the low-energy TMP fibers under the tested conditions. The mixture of malic acid and [Ch]Cl was less effective in lignin dissolution. The mixture of urea and [Ch]Cl exhibited only a minor loss in hemicellulose content, when compared to the other tested DESs. Although 50% of the lignin was dissolved with minor loss in hemicellulose no improvement in tensile strength was observed, as it was rather the opposite. Another benefit with the mixture of urea and [Ch]Cl was that this DES did not appear to be corrosive to stainless steel. All other tested DESs—which were also quite acidic—were observed to be corrosive. Moreover, this DES-related corrosion was found to intensify at elevated temperatures.When chips were used as starting material with otherwise the same conditions almost no lignin was dissolved. This suggests that low-energy mechanical pulp is likely to be a good starting material for extracting lignin using DESs.

Place, publisher, year, edition, pages
Trondheim, Norway: , 2018
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:miun:diva-34679 (URN)
Conference
International Mechanical Pulping Conference (IMPC) 2018, May 27-30, 2018, Trondheim, Norway
Available from: 2018-10-09 Created: 2018-10-09 Last updated: 2018-10-09Bibliographically approved
Eivazihollagh, A., Bäckström, J., Norgren, M. & Edlund, H. (2018). Electrochemical recovery of copper complexed by DTPA and C12-DTPA from aqueous solution using a membrane cell. Journal of chemical technology and biotechnology (1986), 93(5), 1421-1431
Open this publication in new window or tab >>Electrochemical recovery of copper complexed by DTPA and C12-DTPA from aqueous solution using a membrane cell
2018 (English)In: Journal of chemical technology and biotechnology (1986), ISSN 0268-2575, E-ISSN 1097-4660, Vol. 93, no 5, p. 1421-1431Article in journal (Refereed) Published
Abstract [en]

BACKGROUND

The electrochemical recovery of copper from DTPA and C12-DTPA (a surface-active derivative of DTPA) complex solutions was investigated in a membrane flow cell. Electrolysis time, solution flow rate, applied current density, and solution pH were evaluated.

RESULTS

The chelating surfactant C12-DTPA can promote the kinetics of copper electrodeposition more than DTPA depending on the experimental conditions. At a current density of 30 A m–2, a solution flow rate of 0.6 L min–1, and pH 10 after 180 min treatment, the copper recovery and current efficiency were 50% and 43.3%, respectively, in the Cu(II)-DTPA system and about 65% and 53.6%, respectively, in the Cu(II)-C12-DTPA system. The differences in the amount of recovery could be explained in terms of differences in the diffusion of copper complexes with DTPA and C12-DTPA to the cathode, as well as their solution behavior and pH-dependent conditional stability constants (log10 K’CuDTPA3-).

CONCLUSION

Electrochemical methods could be effectively combined with foam flotation for the chelating surfactant C12-DTPA, to recover copper and C12-DTPA. This makes the overall treatment more sustainable, and can be helpful in complying with the increasingly stringent environmental regulations

National Category
Chemical Sciences
Identifiers
urn:nbn:se:miun:diva-32251 (URN)10.1002/jctb.5510 (DOI)000429714500022 ()
Note

Available from: 2017-12-05 Created: 2017-12-05 Last updated: 2018-06-28Bibliographically approved
Forsberg, V. & Norgren, M. (2018). Green materials for inkjet printing of 2D materials and transparent electronics. In: : . Paper presented at 10th Anniversary Symposium on Liquid Phase Exfoliation, Irland, August 2, 2018.
Open this publication in new window or tab >>Green materials for inkjet printing of 2D materials and transparent electronics
2018 (English)Conference paper, Poster (with or without abstract) (Other (popular science, discussion, etc.))
National Category
Materials Chemistry Paper, Pulp and Fiber Technology Polymer Technologies
Identifiers
urn:nbn:se:miun:diva-34234 (URN)
Conference
10th Anniversary Symposium on Liquid Phase Exfoliation, Irland, August 2, 2018
Projects
KM2 Sol
Funder
Knowledge Foundation
Available from: 2018-08-13 Created: 2018-08-13 Last updated: 2018-08-16Bibliographically approved
Medronho, B., Filipe, A., Costa, C., Romano, A., Lindman, B., Edlund, H. & Norgren, M. (2018). Microrheology of novel cellulose stabilized oil-in-water emulsions. Journal of Colloid and Interface Science, 531(1 December 2018), 225-232
Open this publication in new window or tab >>Microrheology of novel cellulose stabilized oil-in-water emulsions
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2018 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 531, no 1 December 2018, p. 225-232Article in journal (Refereed) Published
Abstract [en]

Diffusing wave spectroscopy (DWS) is a powerful optical technique suitable to investigate turbid samples in a nondestructive and reproducible way, providing information on the static and dynamic properties of the system. This includes the relative displacement of emulsion droplets over time and changes in the viscoelastic properties. Here, novel and promising cellulose-based oil-in-water (O/W) emulsions were prepared and studied, for the first time, by DWS. Cellulose plays the role of a novel eco-friendly emulsifying agent. The hydrolysis time of cellulose was observed to affect the average size of the emulsion droplets and their stability; the longer the hydrolysis time, the more dispersed and stable the emulsions were found to be. Additionally, a good complementarity between the microrheology (DWS) and macrorheology (mechanical rheometer) data was found. Our work suggests that DWS is a highly attractive method to investigate the stability, aging and microrheology properties of cellulose-based emulsions, providing valuable insights on their microstructure. This technique is thus highly appealing for the characterization and design of novel emulsion formulations.

Keywords
Diffusing wave spectroscopy, Cellulose, Emulsions, Microrheology
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-34407 (URN)10.1016/j.jcis.2018.07.043 (DOI)000444067300025 ()30032009 (PubMedID)2-s2.0-85050164802 (Scopus ID)
Available from: 2018-09-13 Created: 2018-09-13 Last updated: 2018-09-28
Forsberg, V., Andersson, H., Engholm, M., Thungström, G., Zhang, R., Hummelgård, M., . . . Norgren, M. (2018). Photodetector of multilayer exfoliated MoS2 deposited on polyimide films. In: : . Paper presented at 20th International Workshop on Radiation Imaging Detectors, Sundsvall, 24-28 June, 2018.
Open this publication in new window or tab >>Photodetector of multilayer exfoliated MoS2 deposited on polyimide films
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2018 (English)Conference paper, Poster (with or without abstract) (Other academic)
Abstract [en]

We fabricated a photodetector based on multilayer molybdenum disulfide (MoS2) by micromechanical cleavage of a molybdenite crystal using a polyimide film. We deposited 40 nm of gold by vacuum sputtering and copper tape was used for the contacts.  Without any surface treatment, we achieved high responsivity at different incident optical power. The calculated responsivity was 23 mA/W of incident optical power in the range between 400 and 800 nm. For the responsivity measurement it was estimated that MoS2 have a bandgap of 1.6 eV, which lies between monolayer and multilayer films. The thickness of the MoS2 thin film was determined by Raman spectroscopy evaluating the difference between the in plane  and out of plane  Raman modes. The measurement of IV curves indicated Ohmic contacts in respect to the Au regardless of the incident optical power. Our device fabrication was much simpler than previous reported devices and can be used to test the light absorption and luminescence capabilities of exfoliated MoS2.

Keywords
Photodetector, MoS2
National Category
Chemical Engineering Materials Engineering Physical Sciences
Identifiers
urn:nbn:se:miun:diva-34035 (URN)
Conference
20th International Workshop on Radiation Imaging Detectors, Sundsvall, 24-28 June, 2018
Funder
Knowledge Foundation, 2600364
Available from: 2018-06-29 Created: 2018-06-29 Last updated: 2018-08-16Bibliographically approved
Lundberg, M., Norgren, M. & Edlund, H. (2018). Validation of crill measurements in a high-yield pulp refining process for improved fines material control. Nordic Pulp & Paper Research Journal, 33(2), 200-209
Open this publication in new window or tab >>Validation of crill measurements in a high-yield pulp refining process for improved fines material control
2018 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 33, no 2, p. 200-209Article in journal (Refereed) Published
Abstract [en]

In high-yield pulp (HYP) refining, fine material is created by peeling action on the fibre surface. This fine material is usually characterized using conventional camera technology and image analysis. The smallest particles, the crill, also created in the refining process are too small to be visible in a camera image, and are therefore measured using light sources in the UV and IR wavelength spectrum. This research sought to determine whether the crill could be characterized in the presence of large fines material in a HYP refining process, and the results indicated that the larger fines material had little impact. In addition, the variation in crill measurements declined as the fibre treatment increased and remained low and stable during an extended period. Due to the great need to monitor and control pulp processes using rapid online measurements, cost-reduction actions at mills running close to specification targets put high demands on the measuring devices characterizing the production. The outcome of this study enables the use of the crill method to improve our knowledge of fibre treatment and its contribution to fibre adhesion in complex refining processes. Finally, combining conventional camera technology and the crill method could improve the overall fines material control.

Keywords
crill, fibre adhesion, fibre characterization, fines, refining, validation
National Category
Chemical Engineering
Identifiers
urn:nbn:se:miun:diva-34409 (URN)10.1515/npprj-2018-3019 (DOI)000450922400005 ()2-s2.0-85048741976 (Scopus ID)
Available from: 2018-09-13 Created: 2018-09-13 Last updated: 2018-12-11Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0003-3407-7973

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