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Andersson, Richard L.ORCID iD iconorcid.org/0000-0002-0236-5420
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Publications (10 of 28) Show all publications
Birdsong, B. K., Hoogendoorn, B. W., Nilsson, F., Andersson, R. ., Capezza, A. J., Hedenqvist, M. S., . . . Olsson, R. (2023). Large-scale synthesis of 2D-silica (SiOx) nanosheets using graphene oxide (GO) as a template material. Nanoscale, 15(31), 13037-13048
Open this publication in new window or tab >>Large-scale synthesis of 2D-silica (SiOx) nanosheets using graphene oxide (GO) as a template material
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2023 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 15, no 31, p. 13037-13048Article in journal (Refereed) Published
Abstract [en]

Graphene oxide (GO) was used in this study as a template to successfully synthesize silicon oxide (SiOx) based 2D-nanomaterials, adapting the same morphological features as the GO sheets. By performing a controlled condensation reaction using low concentrations of GO (<0.5 wt%), the study shows how to obtain 2D-nanoflakes, consisting of GO-flakes coated with a silica precursor that were ca. 500 nm in lateral diameter and ca. 1.5 nm in thickness. XPS revealed that the silanes had linked covalently with the GO sheets at the expense of the oxygen groups present on the GO surface. The GO template was shown to be fully removable through thermal treatment without affecting the nanoflake morphology of the pure SiOx-material, providing a methodology for large-scale preparation of SiOx-based 2D nanosheets with nearly identical dimensions as the GO template. The formation of SiOx sheets using a GO template was investigated for two different silane precursors, (3-aminopropyl) triethoxysilane (APTES) and tetraethyl orthosilicate (TEOS), showing that both precursors were capable of accurately templating the graphene oxide template. Molecular modeling revealed that the choice of silane affected the number of layers coated on the GO sheets. Furthermore, rheological measurements showed that the relative viscosity was significantly affected by the specific surface area of the synthesized particles. The protocol used showed the ability to synthesize these types of nanoparticles using a common aqueous alcohol solvent, and yield larger amounts (∼1 g) of SiOx-sheets than what has been previously reported.

Place, publisher, year, edition, pages
Royal Society of Chemistry (RSC), 2023
National Category
Materials Chemistry
Identifiers
urn:nbn:se:kth:diva-338513 (URN)10.1039/d3nr01048a (DOI)001033054400001 ()37492887 (PubMedID)2-s2.0-85167336014 (Scopus ID)
Note

QC 20231114

Available from: 2023-11-14 Created: 2023-11-14 Last updated: 2024-02-29Bibliographically approved
Ye, X., Capezza, A. J., Davoodi, S., Wei, X.-F., Andersson, R. ., Chumakov, A., . . . Lendel, C. (2022). Robust Assembly of Cross-Linked Protein Nanofibrils into Hierarchically Structured Microfibers. ACS Nano, 16(8), 12471-12479
Open this publication in new window or tab >>Robust Assembly of Cross-Linked Protein Nanofibrils into Hierarchically Structured Microfibers
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2022 (English)In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 16, no 8, p. 12471-12479Article in journal (Refereed) Published
Abstract [en]

Natural, high-performance fibers generally have hierarchically organized nanosized building blocks. Inspired by this, whey protein nanofibrils (PNFs) are assembled into microfibers, using flow-focusing. By adding genipin as a nontoxic cross-linker to the PNF suspension before spinning, significantly improved mechanical properties of the final fiber are obtained. For curved PNFs, with a low content of cross-linker (2%) the fiber is almost 3 times stronger and 4 times stiffer than the fiber without a cross-linker. At higher content of genipin (10%), the elongation at break increases by a factor of 2 and the energy at break increases by a factor of 5. The cross-linking also enables the spinning of microfibers from long straight PNFs, which has not been achieved before. These microfibers have higher stiffness and strength but lower ductility and toughness than those made from curved PNFs. The fibers spun from the two classes of nanofibrils show clear morphological differences. The study demonstrates the production of protein-based microfibers with mechanical properties similar to natural protein-based fibers and provides insights about the role of the nanostructure in the assembly process. 

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2022
Keywords
amyloid, cross-linking, flow-focusing, hierarchal assembly, protein nanofibrils, Microfibers, Proteins, Spinning (fibers), Cross linking, Cross-linked proteins, Crosslinker, Flow focusing, Genipin, Micro-fiber, Robust assembly, Nanofibers, iridoid, nanomaterial, protein, tensile strength, Iridoids, Nanostructures
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-326794 (URN)10.1021/acsnano.2c03790 (DOI)000835301400001 ()35904348 (PubMedID)2-s2.0-85136139287 (Scopus ID)
Note

QC 20230515

Available from: 2023-05-15 Created: 2023-05-15 Last updated: 2023-05-15Bibliographically approved
Zirignon, J.- . C., Capezza, A. J., Xiao, X., Richard L., R. ., Forslund, M., Dinér, P. & Olsson, R. (2021). Experimental review of PEI electrodeposition onto copper substrates for insulation of complex geometries. RSC Advances, 11(55), 34599-34604
Open this publication in new window or tab >>Experimental review of PEI electrodeposition onto copper substrates for insulation of complex geometries
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2021 (English)In: RSC Advances, E-ISSN 2046-2069, Vol. 11, no 55, p. 34599-34604Article, review/survey (Refereed) Published
Abstract [en]

Polyetherimide (PEI) was used for coating copper substrates via electrophoretic deposition (EPD) for electrical insulation. Different substrate preparation and electrical field application techniques were compared, demonstrating that the use of a pulsed voltage of 20 V allowed for the best formation of insulating coatings in the 2-6 mu m thickness range. The results indicate that pulsed EPD is the best technique to effectively coat conductive substrates with superior surface finish coatings that could pass a dielectric withstand test at 10 kV mm(-1), which is of importance within the EV automotive industry.

Place, publisher, year, edition, pages
Royal Society of Chemistry (RSC), 2021
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:kth:diva-304787 (URN)10.1039/d1ra05448a (DOI)000711116800001 ()2-s2.0-85120076233 (Scopus ID)
Note

QC 20220322

Available from: 2021-11-24 Created: 2021-11-24 Last updated: 2024-03-18Bibliographically approved
Pourrahimi, A. M., Andersson, R. ., Tjus, K., Ström, V., Björk, A. & Olsson, R. T. (2019). Making an ultralow platinum content bimetallic catalyst on carbon fibres for electro-oxidation of ammonia in wastewater. Sustainable Energy & Fuels, 3(8), 2111-2124
Open this publication in new window or tab >>Making an ultralow platinum content bimetallic catalyst on carbon fibres for electro-oxidation of ammonia in wastewater
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2019 (English)In: Sustainable Energy & Fuels, E-ISSN 2398-4902, Vol. 3, no 8, p. 2111-2124Article in journal (Refereed) Published
Abstract [en]

Electrocatalysis of wastewater containing ammonia is a promising alternative to chemical and biological water purification for several reasons, one being that energy-rich hydrogen gas is generated as a by-product while the reaction can be strictly controlled to meet demands. An objective has been to reduce the loading of expensive platinum (Pt) in the catalyst electrodes, and to reduce the poisoning of the metal surface during the electrolysis. Herein, the co-deposition of a copper-platinum (Cu-Pt) bimetallic alloy onto carbon filaments, stripped from their polymeric coating, is shown to give an electrocatalytic performance superior to that of pure Pt at a content of less than 3 wt% Pt. The key to the enhanced performance was to take advantage of micrometer-sized carbon filaments to distribute a very large bimetallic alloy surface uniformly over the filaments. The Cu-Pt-alloy-coated filaments also suffer less electrode poisoning than pure Pt, and are bonded more strongly to the carbon fibre due to better mechanical interlocking between the bimetallic alloy and the carbon filaments. High-resolution electron microscopy studies combined with a tuned electro-deposition process made it possible to tailor the catalyst micro/nano morphology to reach a uniform coverage, surrounding the entire carbon filaments. The results are promising steps towards large-scale wastewater treatment, combined with clean energy production from regenerated hydrogen.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2019
National Category
Other Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-255760 (URN)10.1039/c9se00161a (DOI)000476912900020 ()2-s2.0-85069762947 (Scopus ID)
Note

QC 20190809

Available from: 2019-08-09 Created: 2019-08-09 Last updated: 2024-03-15Bibliographically approved
Antonio, C., Andersson, R. ., Ström, V., Wu, Q., Sacchi, B., Farris, S., . . . Olsson, R. T. (2019). Preparation and Comparison of Reduced Graphene Oxide and Carbon Nanotubes as Fillers in Conductive Natural Rubber for Flexible Electronics. Omega, 4(2)
Open this publication in new window or tab >>Preparation and Comparison of Reduced Graphene Oxide and Carbon Nanotubes as Fillers in Conductive Natural Rubber for Flexible Electronics
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2019 (English)In: Omega, ISSN 0030-2228, E-ISSN 1541-3764, Vol. 4, no 2Article in journal (Refereed) Published
Abstract [en]

Conductive natural rubber (NR) nanocomposites were prepared by solvent-casting suspensions of reduced graphene oxide(rGO) or carbon nanotubes (CNTs), followed by vulcanization of the rubber composites. Both rGO and CNT were compatible as fillers in the NR as well as having sufficient intrinsic electrical conductivity for functional applications. Physical (thermal) and chemical reduction of GO were investigated, and the results of the reductions were monitored by X-ray photoelectron spectroscopy for establishing a reduction protocol that was useful for the rGO nanocomposite preparation. Field-emission scanning electron microscopy showed that both nanofillers were adequately dispersed in the main NR phase. The CNT composite displays a marked mechanical hysteresis and higher elongation at break, in comparison to the rGO composites for an equal fraction of the carbon phase. Moreover, the composite conductivity was always ca. 3-4 orders of magnitude higher for the CNT composite than for the rGO composites, the former reaching a maximum conductivity of ca. 10.5 S/m, which was explained by the more favorable geometry of the CNT versus the rGO sheets. For low current density applications though, both composites achieved the necessary percolation and showed the electrical conductivity needed for being applied as flexible conductors for a light-emitting diode. 

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
National Category
Natural Sciences
Identifiers
urn:nbn:se:kth:diva-246150 (URN)10.1021/acsomega.8b03630 (DOI)000460237300107 ()31459561 (PubMedID)2-s2.0-85061903645 (Scopus ID)
Note

QC 20190318

Available from: 2019-03-14 Created: 2019-03-14 Last updated: 2024-03-18Bibliographically approved
Paulraj, T., Riazanova, A., Yao, K., Andersson, R. ., Mullertz, A. & Svagan, A. J. (2017). Bioinspired Layer-by-Layer Microcapsules Based on Cellulose Nanofibers with Switchable Permeability. Biomacromolecules, 18(4), 1401-1410
Open this publication in new window or tab >>Bioinspired Layer-by-Layer Microcapsules Based on Cellulose Nanofibers with Switchable Permeability
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2017 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 18, no 4, p. 1401-1410Article in journal (Refereed) Published
Abstract [en]

Green, all-polysaccharide based microcapsules with mechanically robust capsule walls and fast, stimuli-triggered, and switchable permeability behavior show great promise in applications based on selective and timed permeability. Taking a cue from nature, the build-up and composition of plant primary cell walls inspired the capsule wall assembly, because the primary cell walls in plants exhibit high mechanical properties despite being in a highly hydrated state, primarily owing to cellulose microfibrils. The micro capsules (16 +/- 4 mu m in diameter) were fabricated using the layer-by-layer technique on sacrificial CaCO3 templates, using plant polysaccharides (pectin, cellulose nanofibers, and xyloglucan) only. In water, the capsule wall was permeable to labeled dextrans with a hydrodynamic diameter of similar to 6.6 nm. Upon exposure to NaC1, the porosity of the capsule wall quickly changed allowing larger molecules (similar to 12 nm) to permeate. However, the porosity could be restored to its original state by removal of NaCl, by which permeants became trapped inside the capsule's core. The high integrity of cell wall was due to the CNF and the ON/OFF alteration of the permeability properties, and subsequent loading/unloading of molecules, could be repeated several times with the same capsule demonstrating a robust microcontainer with controllable permeability properties.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2017
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-207697 (URN)10.1021/acs.biomac.7b00126 (DOI)000399061100036 ()28323423 (PubMedID)2-s2.0-85017647489 (Scopus ID)
Note

QC 20170531

Available from: 2017-05-31 Created: 2017-05-31 Last updated: 2022-10-18Bibliographically approved
Wu, Q., Sundborg, H., Andersson, R. ., Peuvot, K., Guex, L., Nilsson, F., . . . Olsson, R. T. (2017). Conductive biofoams of wheat gluten containing carbon nanotubes, carbon black or reduced graphene oxide. RSC Advances, 7(30), 18260-18269
Open this publication in new window or tab >>Conductive biofoams of wheat gluten containing carbon nanotubes, carbon black or reduced graphene oxide
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2017 (English)In: RSC Advances, E-ISSN 2046-2069, Vol. 7, no 30, p. 18260-18269Article in journal (Refereed) Published
Abstract [en]

Conductive biofoams made from glycerol-plasticized wheat gluten (WGG) are presented as a potential substitute in electrical applications for conductive polymer foams from crude oil. The soft plasticised foams were prepared by conventional freeze-drying of wheat gluten suspensions with carbon nanotubes (CNTs), carbon black (CB) or reduced graphene oxide (rGO) as the conductive filler phase. The change in conductivity upon compression was documented and the results show not only that the CNT-filled foams show a conductivity two orders of magnitude higher than foams filled with the CB particles, but also that there is a significantly lower percolation threshold with percolation occurring already at 0.18 vol%. The rGO-filled foams gave a conductivity inferior to that obtained with the CNTs or CB particles, which is explained as being related to the sheet-like morphology of the rGO flakes. An increasing amount of conductive filler resulted in smaller pore sizes for both CNTs and CB particles due to their interference with the ice crystal formation before the lyophilization process. The conductive WGG foams with CNTs were fully elastic with up to 10% compressive strain, but with increasing compression up to 50% strain the recovery gradually decreased. The data show that the conductivity strongly depends on the type as well as the concentration of the conductive filler, and the conductivity data with different compressions applied to these biofoams are presented for the first time.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2017
Keywords
Carbon black, Carbon nanotubes, Compaction, Crude oil, Fillers, Graphene, Nanotubes, Pore size, Solvents, Yarn, Compressive strain, Conductive fillers, Conductive Polymer, Electrical applications, Orders of magnitude, Percolation thresholds, Reduced graphene oxides, Reduced graphene oxides (RGO), Foams
National Category
Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-207441 (URN)10.1039/c7ra01082f (DOI)000399005500011 ()2-s2.0-85016468994 (Scopus ID)
Note

Funding details: EIT, European Institute of Innovation and Technology; Funding details: 243-2011-1436, Svenska Forskningsrådet Formas; Funding text: This work was financed by the Swedish Research Council Formas (No. 243-2011-1436). R. L. Andersson acknowledges the support from: European Institute of Innovation and Technology (EIT)-KIC InnoEnergy, Swedish Centre for Smart Grids and Energy Storage (SweGRIDS) and ABB AB.

QC 20170523

Available from: 2017-05-23 Created: 2017-05-23 Last updated: 2023-03-02Bibliographically approved
Guex, L. G., Sacchi, B., Peuvot, K. F., Andersson, R. L., Pourrahimi, A. M., Ström, V., . . . Olsson, R. T. (2017). Experimental review: chemical reduction of graphene oxide (GO) to reduced graphene oxide (rGO) by aqueous chemistry. Nanoscale, 9(27), 9562-9571
Open this publication in new window or tab >>Experimental review: chemical reduction of graphene oxide (GO) to reduced graphene oxide (rGO) by aqueous chemistry
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2017 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 9, no 27, p. 9562-9571Article, review/survey (Refereed) Published
Abstract [en]

The electrical conductivity of reduced graphene oxide (rGO) obtained from graphene oxide (GO) using sodium borohydride (NaBH4) as a reducing agent has been investigated as a function of time (2 min to 24 h) and temperature (20 degrees C to 80 degrees C). Using a 300 mM aqueous NaBH4 solution at 80 degrees C, reduction of GO occurred to a large extent during the first 10 min, which yielded a conductivity increase of 5 orders of magnitude to 10 S m(-1). During the residual 1400 min of reaction, the reduction rate decreased significantly, eventually resulting in a rGO conductivity of 1500 S m(-1). High resolution XPS measurements showed that C/O increased from 2.2 for the GO to 6.9 for the rGO at the longest reaction times, due to the elimination of oxygen. The steep increase in conductivity recorded during the first 8-12 min of reaction was mainly due to the reduction of C-O (e.g., hydroxyl and epoxy) groups, suggesting the preferential attack of the reducing agent on C-O rather than C=O groups. In addition, the specular variation of the percentage content of C-O bond functionalities with the sum of Csp(2) and Csp(3) indicated that the reduction of epoxy or hydroxyl groups had a greater impact on the restoration of the conductive nature of the graphite structure in rGO. These findings were reflected in the dramatic change in the structural stability of the rGO nanofoams produced by freeze-drying. The reduction protocol in this study allowed to achieve the highest conductivity values reported so far for the aqueous reduction of graphene oxide mediated by sodium borohydride. The 4-probe sheet resistivity approach used to measure the electrical conductivity is also, for the first time, presented in detail for filtrate sheet assemblies' of stacked GO/rGO sheets.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2017
National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:kth:diva-211329 (URN)10.1039/c7nr02943h (DOI)000405387100035 ()28664948 (PubMedID)2-s2.0-85024119687 (Scopus ID)
Funder
SweGRIDS - Swedish Centre for Smart Grids and Energy Storage
Note

QC 20170731

Available from: 2017-07-31 Created: 2017-07-31 Last updated: 2024-03-15Bibliographically approved
Wåhlander, M., Nilsson, F., Andersson, R. L., Carlmark, A., Hillborg, H. & Malmström, E. (2017). Reduced and Surface-Modified Graphene Oxide with Nonlinear Resistivity. Macromolecular rapid communications, 38(16), Article ID 1700291.
Open this publication in new window or tab >>Reduced and Surface-Modified Graphene Oxide with Nonlinear Resistivity
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2017 (English)In: Macromolecular rapid communications, ISSN 1022-1336, E-ISSN 1521-3927, Vol. 38, no 16, article id 1700291Article in journal (Refereed) Published
Abstract [en]

Field-grading materials (FGMs) are used to reduce the probability for electrical breakdowns in critical regions of electrical components and are therefore of great importance. Usually, FGMs are heavily filled (40 vol.%) with semi-conducting or conducting particles. Here, polymer-grafted reduced graphene oxide (rGO) is used as a filler to accomplish percolated networks at very low filling ratios (<2 vol.%) in a semi-crystalline polymer matrix: poly(ethylene-co-butyl acrylate) (EBA). Various simulation models are used to predict the percolation threshold and the flake-to-flake distances, to complement the experimental results. A substantial increase in thermal stability of rGO is observed after surface modification, either by silanization or subsequent polymerizations. The non-linear DC resistivity of neat and silanized rGO and its trapping of charge-carriers in semi-crystalline EBA are demonstrated for the first time. It is shown that the polymer-grafted rGO improve the dispersibility in the EBA-matrix and that the graft length controls the inter-flake distances (i.e. charge-carrier hopping distances). By the appropriate selection of graft lengths, both highly resistive materials at 10 kV mm-1 and FGMs with a large and distinct drop in resistivity (six decades) are obtained, followed by saturation. The nonlinear drop in resistivity is attributed to narrow inter-flake distance distributions of grafted rGO.

Place, publisher, year, edition, pages
John Wiley & Sons, 2017
Keywords
tuning of properties, non-linear resistivity, polymer-grafting, field-grading, rGO
National Category
Polymer Chemistry
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-204040 (URN)10.1002/marc.201700291 (DOI)000407849000013 ()28691386 (PubMedID)2-s2.0-85022346084 (Scopus ID)
Funder
SweGRIDS - Swedish Centre for Smart Grids and Energy Storage
Note

QC 20170323. QC 20191105

Available from: 2017-03-23 Created: 2017-03-23 Last updated: 2024-03-15Bibliographically approved
Wåhlander, M., Nilsson, F., Andersson, R. L., Cobo Sanchez, C., Taylor, N., Carlmark, A., . . . Malmström, E. (2017). Tailoring Dielectric Properties using Designed Polymer-Grafted ZnO Nanoparticles in Silicone Rubber. Journal of Materials Chemistry A, 5, 14241-14258, Article ID C6TA11237D.
Open this publication in new window or tab >>Tailoring Dielectric Properties using Designed Polymer-Grafted ZnO Nanoparticles in Silicone Rubber
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2017 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 5, p. 14241-14258, article id C6TA11237DArticle in journal (Refereed) Published
Abstract [en]

Polymer grafts were used to tailor the interphases between ZnO nanoparticles (NPs) and silicone matrices. The final electrical properties of the nanocomposites were tuned by the grafted interphases, by controlling the inter-particle distance and the NP-morphology. The nanocomposites can be used in electrical applications where control of the resistivity is desired. Hansen's solubility parameters were used to select a semi-compatible polymer for grafting to obtain anisotropic NP morphologies in silicone, and the grafted NPs self-assembled into various morphologies inside the silicone matrices. The morphologies in the semi-compatible nanocomposites could be tuned by steering the graft length of poly(n-butyl methacrylate) via entropic matrix-graft wetting using surface-initiated atom-transfer radical polymerization. Image analysis models were developed to calculate the radius of primary NPs, the fraction of aggregates, the dispersion, and the face-to-face distance of NPs. The dielectric properties of the nanocomposites were related to the morphology and the face-to-face distance of the NPs. The dielectric losses, above 100 Hz, for nanocomposites with grafted NPs were approximately one decade lower than those of pristine NPs. The isotropic nanocomposites increased the resistivity up to 100 times compared to that of neat silicone rubber, due to the trapping of charge carriers by the interphase of dispersed NPs and nanoclusters. On the other hand, the resistivity of anisotropic nanocomposites decreased 10–100 times when the inter-particle distance in continuous agglomerates was close to the hopping distance of charge carriers. The electrical breakdown strength increased for compatible isotropic nanocomposites, and the temperature dependence of the resistivity and the activation energy were ∼50% lower in the nanocomposites with grafted NPs. These flexible dielectric nanocomposites are promising candidates for low-loss high-voltage transmission cable accessories, mobile electronic devices, wearables and sensors.

Place, publisher, year, edition, pages
RSC Publishing, 2017
Keywords
tailoring nanoparticle arrangement, polymer grafting, tuning of dielectric properties
National Category
Materials Chemistry Polymer Chemistry
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-204038 (URN)10.1039/C6TA11237D (DOI)000405190000036 ()2-s2.0-85023756284 (Scopus ID)
Funder
SweGRIDS - Swedish Centre for Smart Grids and Energy StorageSwedish Foundation for Strategic Research , SM14-0034
Note

QC 20170323

Available from: 2017-03-23 Created: 2017-03-23 Last updated: 2024-03-15Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-0236-5420

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