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Zhao, W., Sugunan, A., Gillgren, T., Larsson, J. A., Zhang, Z.-B., Zhang, S.-L., . . . Ahniyaz, A. (2022). Surfactant-free starch-graphene composite films as simultaneous oxygen and water vapour barriers. npj 2D Materials and Applications, 6(1), Article ID 20.
Open this publication in new window or tab >>Surfactant-free starch-graphene composite films as simultaneous oxygen and water vapour barriers
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2022 (English)In: npj 2D Materials and Applications, ISSN 2397-7132, Vol. 6, no 1, article id 20Article in journal (Refereed) Published
Abstract [en]

A single coating formulation for multifunctional composites, such as a gas barrier against both oxygen and water vapour, is the holy grail for the packaging industry. Since the last decade, graphene has been touted as the ideal barrier material in composites due to its morphology and impermeability to all gases. However, this prospect is limited by either poor dispersion of graphene or excess surfactants to aid the dispersion, both leading to shortcuts that allow gas permeation through the composite. Here, we demonstrate a combined gas barrier with starch-graphene composite films made from a single formulation of surfactant-free starch nanoparticle-stabilized graphene dispersion (2.97 mg mL−1). Hence, the incorporated graphene reduces the permeability of both the oxygen and the water vapour by over 70% under all the relative humidity conditions tested. Moreover, these films are foldable and electrically conductive (9.5 S m−1). Our surfactant-free approach of incorporating graphene into an industrially important biopolymer is highly relevant to the packaging industry, thus offering cost-effective and water-based solution depositions of multifunctional composite films for wide-ranging applications, such as gas barriers in food packaging. © 2022, The Author(s).

Place, publisher, year, edition, pages
Nature Research, 2022
Keywords
Biopolymers, Composite films, Conductive films, Cost effectiveness, Dispersions, Gas permeable membranes, Oxygen, Starch, Surface active agents, Water vapor, Barrier material, Coating formulations, Gas barrier, Graphene composites, Multifunctional composites, Oxygen vapors, Packaging industry, Surfactant-free, Water vapour, Water vapour barrier, Graphene
National Category
Polymer Technologies
Identifiers
urn:nbn:se:ri:diva-59006 (URN)10.1038/s41699-022-00292-x (DOI)2-s2.0-85126771096 (Scopus ID)
Note

Funding details: Stiftelsen för Strategisk Forskning, SSF, FID-15-0105; Funding text 1: This work was financially supported by the Swedish Foundation for Strategic Research (SSF, grant no. FID-15-0105) and BillerudKorsnäs AB. The authors thank Karin Hallstensson for support with the SEM imaging, Mikael Sundin for performing the XPS analysis and Marie Ernstsson for interpreting the data, Andreas Fall and Niklas Nordgren for insightful discussions and review of the manuscript.; Funding text 2: This work was financially supported by the Swedish Foundation for Strategic Research (SSF, grant no. FID-15-0105) and BillerudKorsna?s AB. The authors thank Karin Hallstensson for support with the SEM imaging, Mikael Sundin for performing the XPS analysis and Marie Ernstsson for interpreting the data, Andreas Fall and Niklas Nordgren for insightful discussions and review of the manuscript.

Available from: 2022-04-21 Created: 2022-04-21 Last updated: 2023-05-09Bibliographically approved
Majee, S., Zhao, W., Sugunan, A., Gillgren, .. ., Larsson, J. A., Brooke, R., . . . Ahniyaz, A. (2021). Highly Conductive Films by Rapid Photonic Annealing of Inkjet Printable Starch–Graphene Ink. Advanced Materials Interfaces, 9(5), Article ID 2101884.
Open this publication in new window or tab >>Highly Conductive Films by Rapid Photonic Annealing of Inkjet Printable Starch–Graphene Ink
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2021 (English)In: Advanced Materials Interfaces, ISSN 2196-7350, Vol. 9, no 5, article id 2101884Article in journal (Refereed) Published
Abstract [en]

A general formulation engineering method is adopted in this study to produce a highly concentrated (≈3 mg mL−1) inkjet printable starch–graphene ink in aqueous media. Photonic annealing of the starch–graphene ink is validated for rapid post-processing of printed films. The experimental results demonstrate the role of starch as dispersing agent for graphene in water and photonic pulse energy in enhancing the electrical properties of the printed graphene patterns, thus leading to an electrical conductivity of ≈2.4 × 104 S m−1. The curing mechanism is discussed based on systematic material studies. The eco-friendly and cost-efficient approach presented in this work is of technical potential for the scalable production and integration of conductive graphene inks for widespread applications in printed and flexible electronics. 

Place, publisher, year, edition, pages
John Wiley and Sons Inc, 2021
Keywords
Conductive films, Flexible electronics, Graphene, Ink, Aqueous media, Curing mechanism, Dispersing agent, Electrical conductivity, Engineering methods, Formulation engineering, Graphene inks, Ink jet, Post-processing, Pulse energies, Starch
National Category
Materials Chemistry
Identifiers
urn:nbn:se:ri:diva-58169 (URN)10.1002/admi.202101884 (DOI)2-s2.0-85122063587 (Scopus ID)
Note

Funding details: Stiftelsen för Strategisk Forskning, SSF, FID‐15‐0105; Funding text 1: This work was financially supported by the Swedish Foundation for Strategic Research (SSF, grant no. FID‐15‐0105) and BillerudKorsnäs AB. The authors would like to thank Karin Hallstensson for support with the SEM measurements. The authors are also thankful to Mohammad Yusuf Mulla for supporting in the fabrication of the demonstration circuit.

Available from: 2022-01-14 Created: 2022-01-14 Last updated: 2024-03-03Bibliographically approved
Zhao, W., Sugunan, A., Gillgren, T., Larsson, J., Zhang, Z.-B., Zhang, S.-L., . . . Ahniyaz, A. (2021). Surfactant-Free Stabilization of Aqueous Graphene Dispersions Using Starch as a Dispersing Agent. ACS Omega, 6(18), 12050-12062
Open this publication in new window or tab >>Surfactant-Free Stabilization of Aqueous Graphene Dispersions Using Starch as a Dispersing Agent
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2021 (English)In: ACS Omega, E-ISSN 2470-1343, Vol. 6, no 18, p. 12050-12062Article in journal (Refereed) Published
Abstract [en]

Attention to graphene dispersions in water with the aid of natural polymers is increasing with improved awareness of sustainability. However, the function of biopolymers that can act as dispersing agents in graphene dispersions is not well understood. In particular, the use of starch to disperse pristine graphene materials deserves further investigation. Here, we report the processing conditions of aqueous graphene dispersions using unmodified starch. We have found that the graphene content of the starch-graphene dispersion is dependent on the starch fraction. The starch-graphene sheets are few-layer graphene with a lateral size of 3.2 μm. Furthermore, topographical images of these starch-graphene sheets confirm the adsorption of starch nanoparticles with a height around 5 nm on the graphene surface. The adsorbed starch nanoparticles are ascribed to extend the storage time of the starch-graphene dispersion up to 1 month compared to spontaneous aggregation in a nonstabilized graphene dispersion without starch. Moreover, the ability to retain water by starch is reduced in the presence of graphene, likely due to environmental changes in the hydroxyl groups responsible for starch-water interactions. These findings demonstrate that starch can disperse graphene with a low oxygen content in water. The aqueous starch-graphene dispersion provides tremendous opportunities for environmental-friendly packaging applications. © 2021 American Chemical Society.

Place, publisher, year, edition, pages
American Chemical Society, 2021
National Category
Physical Chemistry
Identifiers
urn:nbn:se:ri:diva-53478 (URN)10.1021/acsomega.1c00699 (DOI)2-s2.0-85106450176 (Scopus ID)
Note

Funding details: Stiftelsen för Strategisk Forskning, SSF, FID-15-0105; Funding text 1: This work was financially supported by the Swedish Foundation for Strategic Research (SSF, grant no. FID-15-0105) and BillerudKorsnäs AB. The authors thank Karin Hallstensson for support with the SEM/STEM imaging.

Available from: 2021-06-17 Created: 2021-06-17 Last updated: 2023-05-26Bibliographically approved
Baresel, C., Schaller, V., Jonasson, C., Johansson, C., Bordes, R., Chauhan, V., . . . Welling, S. (2019). Functionalized magnetic particles for water treatment. Heliyon, 5(8), Article ID e02325.
Open this publication in new window or tab >>Functionalized magnetic particles for water treatment
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2019 (English)In: Heliyon, E-ISSN 2405-8440, Vol. 5, no 8, article id e02325Article in journal (Refereed) Published
Abstract [en]

In this study, we have taken the concept of water treatment by functionalized magnetic particles one step forward by integrating the technology into a complete proof of concept, which included the preparation of surface modified beads, their use as highly selective absorbents for heavy metals ions (Zinc, Nickel), and their performance in terms of magnetic separation. The separation characteristics were studied both through experiments and by simulations. The data gathered from these experimental works enabled the elaboration of various scenarios for Life Cycle Analysis (LCA). The LCA showed that the environmental impact of the system is highly dependent on the recovery rate of the magnetic particles. The absolute impact on climate change varied significantly among the scenarios studied and the recovery rates. The results support the hypothesis that chelation specificity, magnetic separation and bead recovery should be optimized to specific targets and applications. 

Place, publisher, year, edition, pages
Elsevier Ltd, 2019
Keywords
Chemical engineering, Environmental science, Life cycle assessment, Magnetic particle, Materials chemistry, Nanotechnology, Pollutant, Water treatment
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-39844 (URN)10.1016/j.heliyon.2019.e02325 (DOI)2-s2.0-85070906522 (Scopus ID)
Note

This work was supported by VINNOVA , the Swedish Governmental Agency for Innovation, within the call Innovationer för ett hållbart samhälle: miljö och transport.

Available from: 2019-10-01 Created: 2019-10-01 Last updated: 2024-03-04Bibliographically approved
Zhao, W., Sugunan, A., Zhang, Z.-B. & Ahniyaz, A. (2019). Graphene and Flavin Mononucleotide Interaction in Aqueous Graphene Dispersions. The Journal of Physical Chemistry C, 123(43), 26282-26288
Open this publication in new window or tab >>Graphene and Flavin Mononucleotide Interaction in Aqueous Graphene Dispersions
2019 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 123, no 43, p. 26282-26288Article in journal (Refereed) Published
Abstract [en]

A fundamental understanding of the interaction between graphene and a stabilizer is needed for the development of stable aqueous graphene dispersions. Here, we studied the interaction of graphene with the FMN in water. The UV-vis absorption spectra revealed blue shifts of the FMN absorption bands II (374 nm) and I (445 nm) in the presence of graphene. Furthermore, Fourier transform IR anal. showed that the graphene also upshifted the FMN vibration modes C10a=N1 and C4a=N5, which correspond to the FMN isoalloxazine binding sites N(1) and N(5), resp. In addition, thermogravimetric anal. showed that the thermal stability of graphene was enhanced by the adsorbed FMN, which supports the strong interaction. These results confirm that FMN adsorbs on the graphene surface in parallel conformation and hinders hydrogen bonding at the FMN isoalloxazine binding sites.

Place, publisher, year, edition, pages
American Chemical Society, 2019
Keywords
flavin mononucleotide interaction graphene aqueous dispersion
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-40649 (URN)10.1021/acs.jpcc.9b06442 (DOI)2-s2.0-85074434371 (Scopus ID)
Available from: 2019-11-08 Created: 2019-11-08 Last updated: 2023-05-09Bibliographically approved
Fall, A., Zhao, W., Blademo, Å., Bodelsson, J., Sugunan, A., Nordgren, N., . . . Gillgren, T. (2019). Hybrid Materials of Nanocellulose and Graphene. In: International Conference on Nanotechnology for Renewable Materials 2019: . Paper presented at International Conference on Nanotechnology for Renewable Materials 2019. Chiba. 3 June 2019 through 7 June 2019 (pp. 1069-1080). TAPPI Press, 2
Open this publication in new window or tab >>Hybrid Materials of Nanocellulose and Graphene
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2019 (English)In: International Conference on Nanotechnology for Renewable Materials 2019, TAPPI Press , 2019, Vol. 2, p. 1069-1080Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
TAPPI Press, 2019
National Category
Materials Engineering
Identifiers
urn:nbn:se:ri:diva-68229 (URN)2-s2.0-85073798897 (Scopus ID)
Conference
International Conference on Nanotechnology for Renewable Materials 2019. Chiba. 3 June 2019 through 7 June 2019
Available from: 2023-12-06 Created: 2023-12-06 Last updated: 2023-12-06Bibliographically approved
Gavilán, H., Kowalski, A., Heinke, D., Sugunan, A., Sommertune, J., Varón, M., . . . Morales, M. P. (2017). Colloidal Flower-Shaped Iron Oxide Nanoparticles: Synthesis Strategies and Coatings. Particle & particle systems characterization, 34(7), Article ID 1700094.
Open this publication in new window or tab >>Colloidal Flower-Shaped Iron Oxide Nanoparticles: Synthesis Strategies and Coatings
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2017 (English)In: Particle & particle systems characterization, ISSN 0934-0866, E-ISSN 1521-4117, Vol. 34, no 7, article id 1700094Article in journal (Refereed) Published
Abstract [en]

The assembly of magnetic cores into regular structures may notably influence the properties displayed by a magnetic colloid. Here, key synthesis parameters driving the self-assembly process capable of organizing colloidal magnetic cores into highly regular and reproducible multi-core nanoparticles are determined. In addition, a self-consistent picture that explains the collective magnetic properties exhibited by these complex assemblies is achieved through structural, colloidal, and magnetic means. For this purpose, different strategies to obtain flower-shaped iron oxide assemblies in the size range 25–100 nm are examined. The routes are based on the partial oxidation of Fe(OH)2, polyol-mediated synthesis or the reduction of iron acetylacetonate. The nanoparticles are functionalized either with dextran, citric acid, or alternatively embedded in polystyrene and their long-term stability is assessed. The core size is measured, calculated, and modeled using both structural and magnetic means, while the Debye model and multi-core extended model are used to study interparticle interactions. This is the first step toward standardized protocols of synthesis and characterization of flower-shaped nanoparticles.

Keywords
colloids, magnetic properties, magnetite, nanoflowers, self-assembly, Association reactions, Iron, Iron compounds, Iron oxides, Magnetic cores, Magnetism, Nanoparticles, Self assembly, Synthesis (chemical), Inter-particle interaction, Iron acetylacetonate, Iron oxide nanoparticle, Long term stability, Polyol-mediated synthesis, Self assembly process, Synthesis and characterizations, Synthesis parameters, Nanomagnetics
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-30284 (URN)10.1002/ppsc.201700094 (DOI)2-s2.0-85020161573 (Scopus ID)
Note

 This work was partially supported by the European Commission Framework Program 7 (NanoMag project, NO 604448) and by the Spanish Ministry of Economy and Competitiveness (Mago project, No. MAT2014-52069-R).

Available from: 2017-08-11 Created: 2017-08-11 Last updated: 2023-05-08Bibliographically approved
Lobov, G. S., Marinins, A., Etcheverry, S., Zhao, Y., Vasileva, E., Sugunan, A., . . . Popov, S. (2017). Direct birefringence and transmission modulation via dynamic alignment of P3HT nanofibers in an advanced opto-fluidic component. Optical Materials Express, 7(1), 52-61
Open this publication in new window or tab >>Direct birefringence and transmission modulation via dynamic alignment of P3HT nanofibers in an advanced opto-fluidic component
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2017 (English)In: Optical Materials Express, ISSN 2159-3930, E-ISSN 2159-3930, Vol. 7, no 1, p. 52-61Article in journal (Refereed) Published
Abstract [en]

Poly-3-hexylthiophene (P3HT) nanofibers are semiconducting high-aspect ratio nanostructures with anisotropic absorption and birefringence properties found at different regions of the optical spectrum. In addition, P3HT nanofibers possess an ability to be aligned by an external electric field, while being dispersed in a liquid. In this manuscript we show that such collective ordering of nanofibers, similar to liquid crystal material, significantly changes the properties of transmitted light. With a specially fabricated opto-fluidic component, we monitored the phase and transmission modulation of light propagating through the solution of P3HT nanofibers, being placed in the electric field with strength up to 0.1 V/μm. This report describes a technique for light modulation, which can be implemented in optical fiber-based devices or on-chip integrated components.

Keywords
Absorption spectroscopy, Aspect ratio, Birefringence, Electric fields, Light modulation, Liquid crystals, Modulation, Nanofibers, Optical fiber fabrication, Optical fibers, Anisotropic absorption, Birefringence property, External electric field, Fiber-based device, High aspect ratio nano-structures, Liquid crystal materials, Poly-3-hexylthiophene, Transmission modulation, Light transmission
National Category
Physical Sciences
Identifiers
urn:nbn:se:ri:diva-29201 (URN)10.1364/OME.7.000052 (DOI)2-s2.0-85008157720 (Scopus ID)
Note

Export Date: 3 April 2017; Article

Available from: 2017-04-03 Created: 2017-04-03 Last updated: 2023-05-08Bibliographically approved
Bender, P., Bogart, L. K., Posth, O., Szczerba, W., Rogers, S. E., Castro, A., . . . Johansson, C. (2017). Structural and magnetic properties of multi-core nanoparticles analysed using a generalised numerical inversion method. Scientific Reports, 7, Article ID 45990.
Open this publication in new window or tab >>Structural and magnetic properties of multi-core nanoparticles analysed using a generalised numerical inversion method
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2017 (English)In: Scientific Reports, E-ISSN 2045-2322, Vol. 7, article id 45990Article in journal (Refereed) Published
Abstract [en]

The structural and magnetic properties of magnetic multi-core particles were determined by numerical inversion of small angle scattering and isothermal magnetisation data. The investigated particles consist of iron oxide nanoparticle cores (9 nm) embedded in poly(styrene) spheres (160 nm). A thorough physical characterisation of the particles included transmission electron microscopy, X-ray diffraction and asymmetrical flow field-flow fractionation. Their structure was ultimately disclosed by an indirect Fourier transform of static light scattering, small angle X-ray scattering and small angle neutron scattering data of the colloidal dispersion. The extracted pair distance distribution functions clearly indicated that the cores were mostly accumulated in the outer surface layers of the poly(styrene) spheres. To investigate the magnetic properties, the isothermal magnetisation curves of the multi-core particles (immobilised and dispersed in water) were analysed. The study stands out by applying the same numerical approach to extract the apparent moment distributions of the particles as for the indirect Fourier transform. It could be shown that the main peak of the apparent moment distributions correlated to the expected intrinsic moment distribution of the cores. Additional peaks were observed which signaled deviations of the isothermal magnetisation behavior from the non-interacting case, indicating weak dipolar interactions.

National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-29602 (URN)10.1038/srep45990 (DOI)2-s2.0-85017457020 (Scopus ID)
Available from: 2017-05-16 Created: 2017-05-16 Last updated: 2023-05-08Bibliographically approved
Lobov, G. S., Zhao, Y., Marinins, A., Yan, M., Li, J., Sugunan, A., . . . Popov, S. (2016). Dynamic manipulation of optical anisotropy of suspended Poly-3-hexylthiophene nanofibers. Advanced Optical Materials, 4(10), 1651-1656
Open this publication in new window or tab >>Dynamic manipulation of optical anisotropy of suspended Poly-3-hexylthiophene nanofibers
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2016 (English)In: Advanced Optical Materials, ISSN 2162-7568, E-ISSN 2195-1071, Vol. 4, no 10, p. 1651-1656Article in journal (Refereed) Published
Abstract [en]

Poly-3-hexylthiophene (P3HT) nanofibers are 1D crystalline semiconducting nanostructures, which are known for their application in photovoltaics. Due to the internal arrangement, P3HT nanofibers possess optical anisotropy, which can be enhanced on a macroscale if nanofibers are aligned. Alternating electric field, applied to a solution with dispersed nanofibers, causes their alignment and serves as a method to produce solid layers with ordered nanofibers. The transmission ellipsometry measurements demonstrate the dichroic absorption and birefringence of ordered nanofibers in a wide spectral range of 400–1700 nm. Moreover, the length of nanofibers has a crucial impact on their degree of alignment. Using electric birefringence technique, it is shown that external electric field applied to the solution with P3HT nanofibers can cause direct birefringence modulation. Dynamic alignment of dispersed nanofibers changes the refractive index of the solution and, therefore, the polarization of transmitted light. A reversible reorientation of nanofibers is organized by using a quadrupole configuration of poling electrodes. With further development, the described method can be used in the area of active optical fiber components, lab-on-chip or sensors. It also reveals the potential of 1D conducting polymeric structures as objects whose highly anisotropic properties can be implemented in electro-optical applications.​.

Keywords
anisotropic optical materials, electrooptical materials, nanofibers, optical properties, polymers, Anisotropy, Birefringence, Electric fields, Optical anisotropy, Optical fibers, Refractive index, Alternating electric field, Electric birefringence, Electro-optical applications, External electric field, Quadrupole configuration, Semiconducting nanostructures, Transmission ellipsometry
National Category
Atom and Molecular Physics and Optics Condensed Matter Physics Composite Science and Engineering Materials Chemistry
Identifiers
urn:nbn:se:ri:diva-27605 (URN)10.1002/adom.201600226 (DOI)2-s2.0-84979574389 (Scopus ID)
Available from: 2016-12-22 Created: 2016-12-21 Last updated: 2023-05-08Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-3186-6507

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