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Harder, C., Betker, M., Alexakis, A. E., Bulut, Y., Sochor, B., Söderberg, D., . . . Roth, S. V. (2024). Poly(sobrerol methacrylate) Colloidal Inks Sprayed onto Cellulose Nanofibril Thin Films for Anticounterfeiting Applications. ACS Applied Nano Materials, 7(9), 10840-10851
Open this publication in new window or tab >>Poly(sobrerol methacrylate) Colloidal Inks Sprayed onto Cellulose Nanofibril Thin Films for Anticounterfeiting Applications
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2024 (English)In: ACS Applied Nano Materials, E-ISSN 2574-0970, Vol. 7, no 9, p. 10840-10851Article in journal (Refereed) Published
Abstract [en]

The colloidal layer formation on porous materials is a crucial step for printing and applying functional coatings, which can be used to fabricate anticounterfeiting paper. The deposition of colloidal layers and subsequent thermal treatment allows for modifying the hydrophilicity of the surface of a material. In the present work, wood-based colloidal inks are applied by spray deposition on spray-deposited porous cellulose nanofibrils (CNF) films. The surface modification by thermal annealing of the fabricated colloid-cellulose hybrid thin films is investigated in terms of layering and hydrophobicity. The polymer colloids in the inks are core-shell nanoparticles with different sizes and glass transition temperatures (T-g), thus enabling different and low thermal treatment temperatures. The ratio between the core polymers, poly(sobrerol methacrylate) (PSobMA), and poly(-butyl methacrylate) (PBMA) determines the T-g and hence allows for tailoring of the T-g. The layer formation of the colloidal inks on the porous CNF layer depends on the imbibition properties of the CNF layer which is determined by their morphology. The water adhesion of the CNF layer decreases due to the deposition of the colloids and thermal treatment except for the colloids with a size smaller than the void size of the porous CNF film. In this case, the colloids are imbibed into the CNF layer when T-g of the colloids is reached and the polymer chains transit in a mobile phase. Tailored aggregate and nanoscale-embedded hybrid structures are achieved depending on the colloid properties. The imbibition of these colloids into the porous CNF films is verified with grazing incidence small-angle X-ray scattering. This study shows a route for tuning the nanoscale structure and macroscopic physicochemical properties useful for anticounterfeiting paper.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2024
Keywords
cellulose nanofibrils, thin films, wetting, colloids, colloidal films, surface energy, GISAXS
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-347168 (URN)10.1021/acsanm.4c01302 (DOI)001227987300001 ()2-s2.0-85192139557 (Scopus ID)
Note

QC 20240604

Available from: 2024-06-04 Created: 2024-06-04 Last updated: 2024-06-04Bibliographically approved
Ribca, I., Sochor, B., Betker, M., Roth, S. V., Lawoko, M., Sevastyanova, O., . . . Johansson, M. (2023). Impact of lignin source on the performance of thermoset resins. European Polymer Journal, 194, 112141-112141, Article ID 112141.
Open this publication in new window or tab >>Impact of lignin source on the performance of thermoset resins
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2023 (English)In: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 194, p. 112141-112141, article id 112141Article in journal (Refereed) Published
Abstract [en]

A series of different technical hardwood lignin-based resins have been successfully synthesized, characterized, and utilised to produce thiol-ene thermoset polymers. Firstly, technical lignin was fractionated and allylated, whereafter it was crosslinked with a trifunctional thiol. Structural and morphological characteristics of the lignin fractions were studied by 1H NMR, 31P NMR, SEC, FTIR, DSC, TGA, and WAXS. The hardwood lignin fractions have a high content of C5-substituted OH groups. The WAXS studies on lignin fractions revealed the presence of two π-π stacking conformations, sandwiched (4.08–4.25 Å) and T-shaped (6.52–6.91 Å). The presence of lignin superstructures with distances/sizes between 10.5 and 12.8 Å was also identified. The curing reaction of the thermosets was investigated by RT-FTIR. Almost all thermosets (excepting one fraction) reached 95% of the thiol conversion in less than 17 h, revealing the enhanced reactivity of the allylated hardwood lignin samples.

The mechanical properties of the thermosets were investigated by DMA. The curing performance, as well as the final thermoset properties, have been correlated to variations in chemical composition and morphological differences of lignin fractions. The described results clearly demonstrate that technical hardwood lignins can be utilized for these applications, but also that significant differences compared to softwood lignins have to be considered for material design.

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Hardwood lignin, Solvent fractionation, Allylation, Thiol-ene thermosets, Wide-angle X-ray scattering, π-π stacking interactions
National Category
Materials Chemistry Polymer Technologies Polymer Chemistry Paper, Pulp and Fiber Technology
Research subject
Chemistry
Identifiers
urn:nbn:se:kth:diva-327220 (URN)10.1016/j.eurpolymj.2023.112141 (DOI)001000190100001 ()2-s2.0-85159278832 (Scopus ID)
Funder
KTH Royal Institute of Technology
Note

QC 20230524

Available from: 2023-05-22 Created: 2023-05-22 Last updated: 2023-06-26Bibliographically approved
Betker, M., Harder, C., Erbes, E., Heger, J. E., Alexakis, A. E., Sochor, B., . . . Roth, S. V. (2023). Sprayed Hybrid Cellulose Nanofibril-Silver Nanowire Transparent Electrodes for Organic Electronic Applications. ACS Applied Nano Materials, 6(14), 13677-13688
Open this publication in new window or tab >>Sprayed Hybrid Cellulose Nanofibril-Silver Nanowire Transparent Electrodes for Organic Electronic Applications
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2023 (English)In: ACS Applied Nano Materials, E-ISSN 2574-0970, Vol. 6, no 14, p. 13677-13688Article in journal (Refereed) Published
Abstract [en]

In times of climate change and resource scarcity, researchers are aiming to find sustainable alternatives to synthetic polymers for the fabrication of biodegradable, eco-friendly, and, at the same time, high-performance materials. Nanocomposites have the ability to combine several favorable properties of different materials in a single device. Here, we evaluate the suitability of two kinds of inks containing silver nanowires for the fast, facile, and industrial-relevant fabrication of two different types of cellulose-based silver nanowire electrodes via layer-by-layer spray deposition only. The Type I electrode has a layered structure, which is composed of a network of silver nanowires sprayed on top of a cellulose nanofibrils layer, while the Type II electrode consists of a homogeneous mixture of silver nanowires and cellulose nanofibrils. A correlation between the surface structure, conductivity, and transparency of both types of electrodes is established. We use the Haacke figure of merit for transparent electrode materials to demonstrate the favorable influence of cellulose nanofibrils in the spray ink by identifying Type II as the electrode with the lowest sheet resistance (minimum 5 ± 0.04 Ω/sq), while at the same time having a lower surface roughness and shorter fabrication time than Type I. Finally, we prove the mechanical stability of the Type II electrode by bending tests and its long-time stability under ambient conditions. The results demonstrate that the mixed spray ink of silver nanowires and cellulose nanofibrils is perfectly suitable for the fast fabrication of highly conductive organic nanoelectronics on an industrial scale.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2023
Keywords
flexible electrodes, GISAXS, nanocellulose, nanocomposites, silver nanowires, spray deposition, thin films
National Category
Materials Chemistry
Identifiers
urn:nbn:se:kth:diva-335715 (URN)10.1021/acsanm.3c02496 (DOI)001024815000001 ()2-s2.0-85165907980 (Scopus ID)
Note

QC 20230911

Available from: 2023-09-11 Created: 2023-09-11 Last updated: 2023-09-11Bibliographically approved
Chen, Q., Betker, M., Harder, C., Brett, C. J., Schwartzkopf, M., Ulrich, N. M., . . . Roth, S. V. (2022). Biopolymer-Templated Deposition of Ordered and Polymorph Titanium Dioxide Thin Films for Improved Surface-Enhanced Raman Scattering Sensitivity. Advanced Functional Materials, 32(6), Article ID 2108556.
Open this publication in new window or tab >>Biopolymer-Templated Deposition of Ordered and Polymorph Titanium Dioxide Thin Films for Improved Surface-Enhanced Raman Scattering Sensitivity
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2022 (English)In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 32, no 6, article id 2108556Article in journal (Refereed) Published
Abstract [en]

Titanium dioxide (TiO2) is an excellent candidate material for semiconductor metal oxide-based substrates for surface-enhanced Raman scattering (SERS). Biotemplated fabrication of TiO2 thin films with a 3D network is a promising route for effectively transferring the morphology and ordering of the template into the TiO2 layer. The control over the crystallinity of TiO2 remains a challenge due to the low thermal stability of biopolymers. Here is reported a novel strategy of the cellulose nanofibril (CNF)-directed assembly of TiO2/CNF thin films with tailored morphology and crystallinity as SERS substrates. Polymorphous TiO2/CNF thin films with well-defined morphology are obtained by combining atomic layer deposition and thermal annealing. A high enhancement factor of 1.79 × 106 in terms of semiconductor metal oxide nanomaterial (SMON)-based SERS substrates is obtained from the annealed TiO2/CNF thin films with a TiO2 layer thickness of 10 nm fabricated on indium tin oxide (ITO), when probed by 4-mercaptobenzoic acid molecules. Common SERS probes down to 10 nm can be detected on these TiO2/CNF substrates, indicating superior sensitivity of TiO2/CNF thin films among SMON SERS substrates. This improvement in SERS sensitivity is realized through a cooperative modulation of the template morphology of the CNF network and the crystalline state of TiO2.

Place, publisher, year, edition, pages
Wiley, 2022
Keywords
Biomolecules, Biopolymers, Cellulose, Crystallinity, Indium compounds, Magnetic semiconductors, Metals, Morphology, Nanostructured materials, Oxide semiconductors, Raman scattering, Substrates, Surface scattering, Thermodynamic stability, Thin films, Tin oxides, Titanium dioxide, X ray scattering
National Category
Other Physics Topics
Identifiers
urn:nbn:se:kth:diva-312836 (URN)10.1002/adfm.202108556 (DOI)000711528400001 ()2-s2.0-85118229976 (Scopus ID)
Note

QC 20220524

Available from: 2022-05-24 Created: 2022-05-24 Last updated: 2022-06-25Bibliographically approved
Chen, Q., Sochor, B., Chumakov, A., Betker, M., Ulrich, N. M., Toimil-Molares, M. E., . . . Roth, S. V. (2022). Cellulose-Reinforced Programmable and Stretch-Healable Actuators for Smart Packaging. Advanced Functional Materials, 32(49), 2208074, Article ID 2208074.
Open this publication in new window or tab >>Cellulose-Reinforced Programmable and Stretch-Healable Actuators for Smart Packaging
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2022 (English)In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 32, no 49, p. 2208074-, article id 2208074Article in journal (Refereed) Published
Abstract [en]

Biomimetic actuators are promising candidates for smart soft robotics. The applications of state-of-the-art actuators require the combination of programmable stimuli-responsiveness, excellent robustness, and efficient self-healing ability in a wide-range of working conditions. However, these properties may be mutually exclusive. Inspired by biological tissues, two kinds of polyelectrolytes including polyvinyl alcohol (PVA) and polystyrene sulfonate (PSS) are exploited as the fillers of cellulose nanofibrils (CNFs) for the fabrication of the CNF/PVA/PSS (CAS) film via the assembly of the physically-crosslinked network through multiple H-bonding and electrostatic interactions. Achieved by a casting-evaporation strategy, internal stress is stored within the polymer matrix and transforms into reversible anisotropic bending deformations in response to a humidity gradient. The speed, direction, and pitch of the bending can be programmed by tailoring the internal stresses and geometry of the samples. Moreover, the H-bonded network also contributes to the effective energy dissipation toward high toughness during tensile stretching, as well as self-healing ability during moisture saturation of the CAS films. This enables the fabrication of a humidity-sensitive flower-shaped actuator and self-healable packaging paper. This study presents a biomimetic strategy for the fabrication of multi-functional soft robotics, which holds great promise for applications in the fields of biosensors and smart packaging. 

Place, publisher, year, edition, pages
Wiley, 2022
Keywords
actuations, healing, humidity responses, stretching, toughness, Biomimetics, Cellulose, Energy dissipation, Polyelectrolytes, Robotics, Self-healing materials, Actuation, Biomimetic actuators, Cellulose nanofibrils, Humidity response, Poly(styrene sulfonate), Self-healing abilities, Smart Packaging, Soft robotics, State of the art, Actuators, Bending, Construction, Packaging, Robots
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-328110 (URN)10.1002/adfm.202208074 (DOI)000863022500001 ()2-s2.0-85139214411 (Scopus ID)
Note

QC 20230602

Available from: 2023-06-02 Created: 2023-06-02 Last updated: 2023-06-02Bibliographically approved
Gupta, P., Srihari, V., Pandit, P., Betker, M., Schwartzkopf, M., Kumar, D., . . . Roth, S. V. (2022). Oblique angle deposited FeCo multilayered nanocolumnar structure: Magnetic anisotropy and its thermal stability in polycrystalline thin films. Applied Surface Science, 590, 153056, Article ID 153056.
Open this publication in new window or tab >>Oblique angle deposited FeCo multilayered nanocolumnar structure: Magnetic anisotropy and its thermal stability in polycrystalline thin films
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2022 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 590, p. 153056-, article id 153056Article in journal (Refereed) Published
Abstract [en]

Iron-Cobalt (FeCo) columnar, multilayered structure is prepared by depositing several thin FeCo layers by varying the angle between the surface normal and the evaporation direction as 0 (normal) and 60(oblique), alternatively. In situ X-ray scattering and magneto-optical Kerr effect (MOKE) measurements established the evolution of magnetic properties with that of the morphology and structure of the multilayer. The strong shape anisotropy and compressive stress of nanocolumns in alternative FeCo layers resulted in a well-defined uniaxial magnetic anisotropy (UMA) with the easy axis of magnetization along the projection of the tilted nanocolumns in the film plane. The stress in the film provides minimization of magnetoelastic energy along the in-plane column direction, which couples with the columnar shape anisotropy energies and results in the preferential orientation of the magnetic easy axis along the oblique angle deposition direction in the film plane. Drastic reduction in the in-plane UMA after annealing at 450 C is attributed to the merging of columns and removal of stresses after heat treatment. The present study opens a new pathway to produce magnetically anisotropic multilayer structures using single material and thus may have prominent implications for future technological devices.

Place, publisher, year, edition, pages
Elsevier BV, 2022
Keywords
Magnetic anisotropy, Oblique angle deposition, Shape anisotropy, Stress, Magnetoelastic energy, In-situ study
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:kth:diva-312803 (URN)10.1016/j.apsusc.2022.153056 (DOI)000790013300002 ()2-s2.0-85126836734 (Scopus ID)
Note

QC 20220525

Available from: 2022-05-25 Created: 2022-05-25 Last updated: 2022-06-25Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-6465-2188

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