| 1. |
- Lowe, Robert, 1975-, et al.
(författare)
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Designing for a Wearable Affective Interface for the NAO Robot : A Study of Emotion Conveyance by Touch
- 2018
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Ingår i: Multimodal Technologies and Interaction. - : M D P I AG. - 2414-4088. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- We here present results and analysis from a study of affective tactile communication between human and humanoid robot (the NAO robot). In the present work, participants conveyed eight emotions to the NAO via touch. In this study, we sought to understand the potential for using a wearable affective (tactile) interface, or WAffI. The aims of our study were to address the following: (i) how emotions and affective states can be conveyed (encoded) to such a humanoid robot, (ii) what are the effects of dressing the NAO in the WAffI on emotion conveyance and (iii) what is the potential for decoding emotion and affective states. We found that subjects conveyed touch for longer duration and over more locations on the robot when the NAO was dressed with WAffI than when it was not. Our analysis illuminates ways by which affective valence, and separate emotions, might be decoded by a humanoid robot according to the different features of touch: intensity, duration, location, type. Finally, we discuss the types of sensors and their distribution as they may be embedded within the WAffI and that would likely benefit Human-NAO (and Human-Humanoid) interaction along the affective tactile dimension.
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| 2. |
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| 3. |
- Darabi, Sozan, 1994, et al.
(författare)
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Green Conducting Cellulose Yarns for Machine-Sewn Electronic Textiles
- 2020
-
Ingår i: ACS Applied Materials & Interfaces. - : American Chemical Society (ACS). - 1944-8252 .- 1944-8244. ; 12:50, s. 56403-56412
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Tidskriftsartikel (refereegranskat)abstract
- The emergence of "green"electronics is a response to the pressing global situation where conventional electronics contribute to resource depletion and a global build-up of waste. For wearable applications, green electronic textile (e-textile) materials present an opportunity to unobtrusively incorporate sensing, energy harvesting, and other functionality into the clothes we wear. Here, we demonstrate electrically conducting wood-based yarns produced by a roll-to-roll coating process with an ink based on the biocompatible polymer:polyelectrolyte complex poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). The developed e-textile yarns display a, for cellulose yarns, record-high bulk conductivity of 36 Scm-1, which could be further increased to 181 Scm-1 by adding silver nanowires. The PEDOT:PSS-coated yarn could be machine washed at least five times without loss in conductivity. We demonstrate the electrochemical functionality of the yarn through incorporation into organic electrochemical transistors (OECTs). Moreover, by using a household sewing machine, we have manufactured an out-of-plane thermoelectric textile device, which can produce 0.2 μW at a temperature gradient of 37 K.
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| 4. |
- Darmadi, Iwan, 1990, et al.
(författare)
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Bulk-Processed Pd Nanocube-Poly(methyl methacrylate) Nanocomposites as Plasmonic Plastics for Hydrogen Sensing
- 2020
-
Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; 3:8, s. 8438-8445
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Tidskriftsartikel (refereegranskat)abstract
- Nanoplasmonic hydrogen sensors are predicted to play a key role in safety systems of the emerging hydrogen economy. Pd nanoparticles are the active material of choice for sensor prototype development due to their ability to form a hydride at ambient conditions, which creates the optical contrast. Here, we introduce plasmonic hydrogen sensors made from a thermoplastic nanocomposite material, that is, a bulk material that can be molded with standard plastic processing techniques, such as extrusion and three-dimensional (3D) printing, while at the same time being functionalized at the nanoscale. Specifically, our plasmonic plastic is composed of hydrogensensitive and plasmonically active Pd nanocubes mixed with a poly(methyl methacrylate) matrix, and we optimize it by characterization from the atomic to the macroscopic level. We demonstrate meltprocessed deactivation-resistant plasmonic hydrogen sensors, which retain full functionality even after SO weeks. From a wider perspective, we advertise plasmonic plastic nanocomposite materials for application in a multitude of active plasmonic technologies since they provide efficient scalable processing and almost endless functional material design opportunities via tailored polymer- colloidal nanocrystal combinations.
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| 5. |
- Darmadi, Iwan, 1990, et al.
(författare)
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Bulk-Processed Plasmonic Plastic Nanocomposite Materials for Optical Hydrogen Detection
- 2023
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Ingår i: Accounts of Chemical Research. - 0001-4842 .- 1520-4898. ; 56:13, s. 1850-1861
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Tidskriftsartikel (refereegranskat)abstract
- Conspectus Sensors are ubiquitous, andtheir importanceis only going to increaseacross many areas of modern technology. In this respect, hydrogengas (H-2) sensors are no exception since they allow mitigationof the inherent safety risks associated with mixtures of H-2 and air. The deployment of H-2 technologies is rapidlyaccelerating in emerging energy, transport, and green steel-makingsectors, where not only safety but also process monitoring sensorsare in high demand. To meet this demand, cost-effective and scalableroutes for mass production of sensing materials are required. Here,the state-of-the-art often resorts to processes derived from the microelectronicsindustry where surface-based micro- and nanofabrication are the methodsof choice and where (H-2) sensor manufacturing is no exception. In this Account, we discuss how our recent efforts to develop sensorsbased on plasmonic plastics may complement the current state-of-the-art.We explore a new H-2 sensor paradigm, established througha series of recent publications, that combines (i) the plasmonic opticalH(2) detection principle and (ii) bulk-processed nanocompositematerials. In particular, plasmonic plastic nanocomposite sensingmaterials are described that comprise plasmonic H-2-sensitivecolloidally synthesized nanoparticles dispersed in a polymer matrixand enable the additive manufacturing of H-2 sensors ina cost-effective and scalable way. We first discuss the concept ofplasmonic plastic nanocomposite materials for the additive manufacturingof an active plasmonic sensing material on the basis of the threekey components that require individual and concerted optimization:(i) the plasmonic sensing metal nanoparticles, (ii) the surfactant/stabilizermolecules on the nanoparticle surface from colloidal synthesis, and(iii) the polymer matrix. We then introduce the working principleof plasmonic H-2 detection, which relies on the selectiveabsorption of H species into hydride-forming metal nanoparticles that,in turn, induces distinct changes in their optical plasmonic signaturein proportion to the H-2 concentration in the local atmosphere.Subsequently, we assess the roles of the key components of a plasmonicplastic for H-2 sensing, where we have established that(i) alloying Pd with Au and Cu eliminates hysteresis and introducesintrinsic deactivation resistance at ambient conditions, (ii) surfactant/stabilizermolecules can significantly accelerate and decelerate H-2 sorption and thus sensor response, and (iii) polymer coatings acceleratesensor response, reduce the limit of detection (LoD), and enable molecularfiltering for sensor operation in chemically challenging environments.Based on these insights, we discuss the rational development and detailedcharacterization of bulk-processed plasmonic plastics based on glassyand fluorinated matrix polymers and on tailored flow-chemistry-basedsynthesis of Pd and PdAu alloy colloidal nanoparticles with optimizedstabilizer molecules. In their champion implementation, they enablehighly stable H-2 sensors with response times in the 2 srange and an LoD of few 10 ppm of H-2. To put plasmonicplastics in a wider perspective, we also report their implementationusing different polymer matrix materials that can be used for 3D printingand (an)isotropic Au nanoparticles that enable the manufacturing ofmacroscopic plasmonic objects with, if required, dichroic opticalproperties and in amounts that can be readily upscaled. We advertisethat melt processing of plasmonic plastic nanocomposites is a viableroute toward the realization of plasmonic objects and sensors, producedby scalable colloidal synthesis and additive manufacturing techniques.
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| 6. |
- Deralia, Parveen Kumar, 1985, et al.
(författare)
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Hydrophobization of arabinoxylan with n-butyl glycidyl ether yields stretchable thermoplastic materials
- 2021
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Ingår i: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 188, s. 491-500
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Tidskriftsartikel (refereegranskat)abstract
- Hemicelluloses are regarded as one of the first candidates for the development of value-added materials due to their renewability, abundance, and functionality. However, because most hemicelluloses are brittle, they can only be processed as a solution and cannot be processed using industrial melt-based polymer processing techniques. In this study, arabinoxylan (AX) was hydrophobized by incorporating butyl glycidyl ether (BuGE) into the hydroxyl groups through the opening of the BuGE epoxide ring, yielding alkoxy alcohols with terminal ethers. The formed BuGE derivatives were melt processable and can be manufactured into stretchable thermoplastic films through compression molding, which has never been done before with hemicellulose modified in a single step. The structural and thermomechanical properties of the one-step synthesis approach were compared to those of a two-step synthesis with a pre-activation step to demonstrate its robustness. The strain at break for the one-step synthesized AX thermoplastic with 3 mol of BuGE is ≈200%. These findings suggest that thermoplastic polymers can be composited with hemicelluloses or that thermoplastic polymers made entirely of hemicelluloses can be designed as packaging and stretchable electronics supports.
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| 7. |
- Deralia, Parveen Kumar, 1985, et al.
(författare)
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Oxidation Level and Glycidyl Ether Structure Determine Thermal Processability and Thermomechanical Properties of Arabinoxylan-Derived Thermoplastics
- 2021
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Ingår i: ACS Applied Bio Materials. - : American Chemical Society (ACS). - 2576-6422. ; 4:4, s. 3133-3144
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Tidskriftsartikel (refereegranskat)abstract
- Developing flexible, stretchable, and thermally processable materials for packaging and stretchable electronic applications from polysaccharide-based polymers contributes to the smooth transition of the fossil-based economy to the circular bioeconomy. We present arabinoxylan (AX)-based thermoplastics obtained by ring-opening oxidation and subsequent reduction (dA-AX) combined with hydrophobization with three different glycidyl ethers [n-butyl (BuGE), isopropyl (iPrGE), and 2-ethyl hexyl (EtHGE) glycidyl ether]. We also investigate the relationship between structural composition, thermal processing, and thermomechanical properties. BuGE- A nd iPrGE-etherified dA-AXs showed glass-transition temperatures (Tg) far below their degradation temperatures and gave thermoplastic materials when compression-molded at 140 °C. The BuGE (3 mol)-etherified dA-AX films at 19 and 31% oxidation levels show 244% (±42) and 267% (±72) elongation, respectively. In contrast, iPrGE-dA-AX samples with shorter and branched terminals in the side chains had a maximum of 60% (±19) elongation. No studies have reported such superior elongation of AX thermoplastic films and its relationship with molar substitution and Tg. These findings have implications on the strategic development of chemical modification routes using commercial polymer processing technologies and on fine-tuning structures and properties when specific polysaccharide-based polymers are used to engineer bio-based products for film, packaging, and substrates for stretchable electronic applications.
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| 8. |
- Deralia, Parveen Kumar, 1985, et al.
(författare)
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Side chains affect the melt processing and stretchability of arabinoxylan biomass-based thermoplastic films
- 2022
-
Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 294
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Tidskriftsartikel (refereegranskat)abstract
- Hydrophobization of hemicellulose causes melt processing and makes them stretchable thermoplastics. Understanding how native and/or appended side chains in various hemicelluloses after chemical modification affect melt processing and material properties can help in the development of products for film packaging and substrates for stretchable electronics applications. Herein, we describe a one-step and two-step strategy for the fabrication of flexible and stretchable thermoplastics prepared by compression molding of two structurally different arabinoxylans (AX). For one-step synthesis, the n-butyl glycidyl ether epoxide ring was opened to the hydroxyl group, resulting in the introduction of alkoxide side chains. The first step in the two-step synthesis was periodate oxidation. Because the melt processability for AXs having low arabinose to xylose ratio (araf/xylp<0.5) have been limited, two structurally distinct AXs extracted from wheat bran (AXWB, araf/xylp = 3/4) and barley husk (AXBH, araf/xylp = 1/4) were used to investigate the effect of araf/xylp and hydrophobization on the melt processability and properties of the final material. Melt compression processability was achieved in AXBH derived samples. DSC and DMA confirmed that the thermoplastics derived from AXWB and AXBH had dual and single glass transition (Tg) characteristics, respectively, but the thermoplastics derived from AXBH had lower stretchability (maximum 160%) compared to the AXWB samples (maximum 300%). Higher araf/xylp values, and thus longer alkoxide side chains in AXWB-derived thermoplastics, explain the stretchability differences.
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| 9. |
- Hofmann, Anna, 1987, et al.
(författare)
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All-Polymer Conducting Fibers and 3D Prints via Melt Processing and Templated Polymerization
- 2020
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Ingår i: ACS Applied Materials & Interfaces. - : American Chemical Society (ACS). - 1944-8252 .- 1944-8244. ; 12:7, s. 8713-8721
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Tidskriftsartikel (refereegranskat)abstract
- Because of their attractive mechanical properties, conducting polymers are widely perceived as materials of choice for wearable electronics and electronic textiles. However, most state-of-the-art conducting polymers contain harmful dopants and are only processable from solution but not in bulk, restricting the design possibilities for applications that require conducting micro-to-millimeter scale structures, such as textile fibers or thermoelectric modules. In this work, we present a strategy based on melt processing that enables the fabrication of nonhazardous, all-polymer conducting bulk structures composed of poly(3,4-ethylenedioxythiophene) (PEDOT) polymerized within a Nafion template. Importantly, we employ classical polymer processing techniques including melt extrusion followed by fiber spinning or fused filament 3D printing, which cannot be implemented with the majority of doped polymers. To demonstrate the versatility of our approach, we fabricated melt-spun PEDOT:Nafion fibers, which are highly flexible, retain their conductivity of about 3 S cm(-1) upon stretching to 100% elongation, and can be used to construct organic electrochemical transistors (OECTs). Furthermore, we demonstrate the precise 3D printing of complex conducting structures from OECTs to centimeter-sized PEDOT:Nafion figurines and millimeter-thick 100-leg thermoelectric modules on textile substrates. Thus, our strategy opens up new possibilities for the design of conducting, all-polymer bulk structures and the development of wearable electronics and electronic textiles.
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| 10. |
- Hwang, Byungil, et al.
(författare)
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Machine-Washable Conductive Silk Yarns with a Composite Coating of Ag Nanowires and PEDOT:PSS
- 2020
-
Ingår i: ACS Applied Materials & Interfaces. - : American Chemical Society (ACS). - 1944-8252 .- 1944-8244. ; 12:24, s. 27537-27544
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Tidskriftsartikel (refereegranskat)abstract
- Electrically conducting fibers and yarns are critical components of future wearable electronic textile (e-textile) devices such as sensors, antennae, information processors, and energy harvesters. To achieve reliable wearable devices, the development of robust yarns with a high conductivity and excellent washability is urgently needed. In the present study, highly conductive and machine-washable silk yarns were developed utilizing a Ag nanowire and PEDOT:PSS composite coating. Ag nanowires were coated on the silk yarn via a dip-coating process followed by coating with the conjugated polymer:polyelectrolyte complex PEDOT:PSS. The PEDOT:PSS covered the Ag nanowire layers while electrostatically binding to the silk, which significantly improved the robustness of the yarn as compared with the Ag nanowire-coated reference yarns. The fabricated conductive silk yarns had an excellent bulk conductivity of up to ∼320 S/cm, which is largely retained even after several cycles of machine washing. To demonstrate that these yarns can be incorporated into e-textiles, the conductive yarns were used to construct an all-textile out-of-plane thermoelectric device and a Joule heating element in a woven heating fabric.
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| 11. |
- Hynynen, Jonna, 1987, et al.
(författare)
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Enhanced Thermoelectric Power Factor of Tensile Drawn Poly(3-hexylthiophene)
- 2019
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Ingår i: ACS Macro Letters. - : American Chemical Society (ACS). - 2161-1653. ; 8:1, s. 70-76
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Tidskriftsartikel (refereegranskat)abstract
- © 2018 American Chemical Society. The thermoelectric power factor of a broad range of organic semiconductors scales with their electrical conductivity according to a widely obeyed power law, and therefore, strategies that permit this empirical trend to be surpassed are highly sought after. Here, tensile drawing of the conjugated polymer poly(3-hexylthiophene) (P3HT) is employed to create free-standing films with a high degree of uniaxial alignment. Along the direction of orientation, sequential doping with a molybdenum tris(dithiolene) complex leads to a 5-fold enhancement of the power factor beyond the predicted value, reaching up to 16 μW m-1 K-2 for a conductivity of about 13 S cm-1. Neither stretching nor doping affect the glass transition temperature of P3HT, giving rise to robust free-standing materials that are of interest for the design of flexible thermoelectric devices.
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| 12. |
- Kim, Youngseok, et al.
(författare)
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Robust PEDOT:PSS Wet‐Spun Fibers for Thermoelectric Textiles
- 2020
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Ingår i: Macromolecular Materials and Engineering. - : Wiley. - 1439-2054 .- 1438-7492. ; 305:3, s. 1900749-
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Tidskriftsartikel (refereegranskat)abstract
- To realize thermoelectric textiles that can convert body heat to electricity, fibers with excellent mechanical and thermoelectric properties are needed. Although poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is among the most promising organic thermoelectric materials, reports that explore its use for thermoelectric fibers are all but absent. Herein, the mechanical and thermoelectric properties of wet‐spun PEDOT:PSS fibers are reported, and their use in energy‐harvesting textiles is discussed. Wet‐spinning into sulfuric acid results in water‐stable semicrystalline fibers with a Young's modulus of up to 1.9 GPa, an electrical conductivity of 830 S cm−1, and a thermoelectric power factor of 30 μV m−1 K−2. Stretching beyond the yield point as well as repeated tensile deformation and bending leave the electrical properties of these fibers almost unaffected. The mechanical robustness/durability and excellent underwater stability of semicrystalline PEDOT:PSS fibers, combined with a promising thermoelectric performance, opens up their use in practical energy‐harvesting textiles, as illustrated by an embroidered thermoelectric fabric module.
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| 13. |
- Kroon, Renee, 1982, et al.
(författare)
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Thermally Activated in Situ Doping Enables Solid-State Processing of Conducting Polymers
- 2019
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 1520-5002 .- 0897-4756. ; 31:8, s. 2770-2777
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Tidskriftsartikel (refereegranskat)abstract
- Free-standing bulk structures encompassing highly doped conjugated polymers are currently heavily explored for wearable electronics as thermoelectric elements, conducting fibers, and a plethora of sensory devices. One-step manufacturing of such bulk structures is challenging because the interaction of dopants with conjugated polymers results in poor solution and solid-state processability, whereas doping of thick conjugated polymer structures after processing suffers from diffusion-limited transport of the dopant. Here, we introduce the concept of thermally activated latent dopants for in situ bulk doping of conjugated polymers. Latent dopants allow for noninteractive coprocessing of dopants and polymers, while thermal activation eliminates any thickness-dependent diffusion and activation limitations. Two latent acid dopants were synthesized in the form of thermal acid generators based on aryl sulfonic acids and an o-nitrobenzyl capping moiety. First, we show that these acid dopant precursors can be coprocessed noninteractively with three different polythiophenes. Second, the polymer films were doped in situ through thermal activation of the dopants. Ultimately, we demonstrate that solid-state processing with a latent acid dopant can be readily carried out and that it is possible to dope more than 100 μm-thick polymer films through thermal activation of the latent dopant.
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| 14. |
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| 15. |
- Licea Jimenez, Liliana, 1977, et al.
(författare)
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MWNT reinforced melamine-formaldehyde containing alpha-cellulose
- 2007
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Ingår i: Composites Science and Technology. - : Elsevier BV. - 0266-3538 .- 1879-1050. ; 67, s. 844-854
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Tidskriftsartikel (refereegranskat)abstract
- Multi-wall carbon nanotubes (MWNT) were used as reinforcement for melamine-formaldehyde (MF). They were oxidised in HNO3/ H2SO4 mixture and analyzed by means of X-ray Photoelectron Spectroscopy (XPS). Two anionic surfactants: sodium dodecyl sulphate (SDS) and sodium dodecylbenzenesulfonate (NaDDBS) were used to assist the dispersion of nanotubes. The MWNT content was varied from 0 to 1.0 wt%, and the influence of nanotubes on viscosity (flow curves) was measured. The viscosity of SDS-assisted aqueous solution of MF containing a small amount (0.1 wt%) of MWNT is low, and thus promising towards manufacturing processes. A film stacking-like manufacturing route was adapted to prepare ternary MWNT/cellulose/MF thin composite layers. Transmission electron microscopy (TEM) and Light microscopy (LM) were used to observe dispersion. The addition of 0.1 wt% MWNT assisted with SDS increased the storage modulus and tensile strength by 50%. Conventional calculations of the Young's modulus were made. Values underestimating the modulus were found. The observed discrepancy was attributed to polymer chain immobilisation as a result of crosslinking.
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| 16. |
- Lund, Anja, 1971, et al.
(författare)
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A polymer-based textile thermoelectric generator for wearable energy harvesting
- 2020
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 480
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Tidskriftsartikel (refereegranskat)abstract
- Conducting polymers offer new opportunities to design soft, conformable and light-weight thermoelectric textile generators that can be unobtrusively integrated into garments or upholstery. Using the widely available conducting polymer:polyelectrolyte complex poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as the p-type material, we have prepared an electrically conducting sewing thread, which we then embroidered into thick wool fabrics to form out-of-plane thermoelectric textile generators. The influence of device design is discussed in detail, and we show that the performance of e-textile devices can be accurately predicted and optimized using modeling developed for conventional thermoelectric systems, provided that the electrical and thermal contact resistances are included in the model. Finally, we demonstrate a thermoelectric textile device that can generate a, for polymer-based devices, unprecedented power of 1.2 μW at a temperature gradient ΔT of 65 K, and over 0.2 μW at a more modest ΔT of 30 K.
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| 17. |
- Lund, Anja, 1971, et al.
(författare)
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A study on melt spinning of potentially electroactive textile fibres, and the influence of melt spinning parameters on molecular structure development
- 2009
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Ingår i: Poster186-P, PPS-2009, Europe /Africa Regional Meeting, Larnaca, Cyprus, October 18-21, 2009.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 18. |
- Lund, Anja, 1971, et al.
(författare)
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Conducting materials as building blocks for electronic textiles
- 2021
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Ingår i: MRS Bulletin. - : Springer Science and Business Media LLC. - 0883-7694 .- 1938-1425. ; 46:6, s. 491-501
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Forskningsöversikt (refereegranskat)abstract
- To realize the full gamut of functions that are envisaged for electronic textiles (e-textiles) a range of semiconducting, conducting and electrochemically active materials are needed. This article will discuss how metals, conducting polymers, carbon nanotubes, and two-dimensional (2D) materials, including graphene and MXenes, can be used in concert to create e-textile materials, from fibers and yarns to patterned fabrics. Many of the most promising architectures utilize several classes of materials (e.g., elastic fibers composed of a conducting material and a stretchable polymer, or textile devices constructed with conducting polymers or 2D materials and metal electrodes). While an increasing number of materials and devices display a promising degree of wash and wear resistance, sustainability aspects of e-textiles will require greater attention.
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| 19. |
- Lund, Anja, 1971, et al.
(författare)
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Electrically conducting fibres for e-textiles: An open playground for conjugated polymers and carbon nanomaterials
- 2018
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Ingår i: Materials Science and Engineering: R: Reports. - : Elsevier BV. - 0927-796X .- 1879-212X. ; 126, s. 1-29
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Forskningsöversikt (refereegranskat)abstract
- Conducting fibres and yams promise to become an essential part of the next generation of wearable electronics that seamlessly integrate electronic function into one of the most versatile and most widely used form of materials: textiles. This review explores the many types of conducting fibres and yarns that can be realised with conjugated polymers and carbon materials, including carbon black, carbon nanotubes and graphene. We discuss how the interplay of materials properties and the chosen processing technique lead to fibres with a wide range of electrical and mechanical properties. Depending on the choice of conjugated polymer, carbon nanotube, graphene, polymer blend, or nanocomposite the electrical conductivity can vary from less than 10(-3) to more than 10(3) S cm(-1), accompanied by an increase in Young's modulus from 10 s of MPa to 100 s of GPa. Further, we discuss how conducting fibres can be integrated into electronic textiles (e-textiles) through e.g. weaving and knitting. Then, we provide an overview of some of the envisaged functionalities, such as sensing, data processing and storage, as well as energy harvesting e.g. by using the piezoelectric, thermoelectric, triboelectric or photovoltaic effect. Finally, we critically discuss sustainability aspects such as the supply of materials, their toxicity, the embodied energy of fibre and textile production and recyclability, which currently are not adequately considered but must be taken into account to ready carbon based conducting fibres for truly practical e-textile applications.
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| 20. |
- Lund, Anja, 1971-, et al.
(författare)
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Energy harvesting textiles for a rainy day : woven piezoelectrics based on melt-spun PVDF microfibres with a conducting core
- 2018
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Ingår i: npj Flexible Electronics. - : Springer Science and Business Media LLC. - 2397-4621. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- Recent advances in ubiquitous low-power electronics call for the development of light-weight and flexible energy sources. The textile format is highly attractive for unobtrusive harvesting of energy from e.g., biomechanical movements. Here, we report the manufacture and characterisation of fully textile piezoelectric generators that can operate under wet conditions. We use a weaving loom to realise textile bands with yarns of melt-spun piezoelectric microfibres, that consist of a conducting core surrounded by β-phase poly(vinylidene fluoride) (PVDF), in the warp direction. The core-sheath constitution of the piezoelectric microfibres results in a—for electronic textiles—unique architecture. The inner electrode is fully shielded from the outer electrode (made up of conducting yarns that are integrated in the weft direction) which prevents shorting under wet conditions. As a result, and in contrast to other energy harvesting textiles, we are able to demonstrate piezoelectric fabrics that do not only continue to function when in contact with water, but show enhanced performance. The piezoelectric bands generate an output of several volts at strains below one percent. We show that integration into the shoulder strap of a laptop case permits the continuous generation of four microwatts of power during a brisk walk. This promising performance, combined with the fact that our solution uses scalable materials and well-established industrial manufacturing methods, opens up the possibility to develop wearable electronics that are powered by piezoelectric textiles.
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| 21. |
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| 22. |
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| 23. |
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| 24. |
- Lund, Anja, 1971-, et al.
(författare)
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Melt Spun PVDF Actuator Fibres : The Effect of Spin-Line Orientation and MW on Actuation
- 2015
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Ingår i: Regional Conference Polymer Processing Society Graz 2015. ; , s. 306-
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents the melt spinning and characterisation of polymer actuator fibres; fibres that reversibly contract along the fibre axis in response to heat. Recently, Haines et al (1) showed that low-cost filaments, e.g. fishing lines, can be relevant precursors for artificial muscles. They demonstrated a reversible fibre-direction thermal contraction, which was significantly amplified when the fibres were twisted and coiled. The effect was explained to result from an increase in the conformational entropy of the amorphous phase. In earlier studies on negative thermal expansion in anisotropic polymer structures, it has been shown that the negative thermal expansion in oriented highly crystalline polymers approaches values typical of polymer crystals (2). To further investigate the mechanisms behind these seemingly simple artificial muscles, we have melt spun fibres from poly(vinylidene fluoride) (PVDF) – Solef 1006 and 1008 kindly provided by Solvay (Milan, Italy) – and compared their properties to a commercially available PVDF-fishing line. The fibres were characterised with respect to their thermal actuation properties, crystal morphology and degree of orientation along the spin-line axis. We have further done modelling on the molecular and macroscopic levels examining the possible mechanisms of negative thermal expansion in semi-crystalline PVDF. We believe that tie molecules (a polymer chain linking two crystalline regions) are the predominant factor influencing actuation. Two mechanisms are considered: an entropic effect and a conformational change effect. The entropic effect causes an increase in the elastic stiffness with an increase in temperature, effectively resulting in a contraction of a strained fibre. The conformational change effect is also expected to contribute to contraction as tie molecules, under strain, revert to their unloaded preferred conformation when heated.C. S. Haines et al., Artificial Muscles from Fishing Line and Sewing Thread. Science 343, 868-872 (2014).C. L. Choy et al., Negative Thermal Expansion in Oriented Crystalline Polymers. Journal of Polymer Science: Polymer Physics Edition 19, 335-352 (1981).
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| 25. |
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| 26. |
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| 27. |
- Lund, Anja, 1971, et al.
(författare)
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Roll-to-Roll Dyed Conducting Silk Yarns: A Versatile Material for E-Textile Devices
- 2018
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Ingår i: Advanced Materials Technologies. - : Wiley. - 2365-709X. ; 3:12
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Tidskriftsartikel (refereegranskat)abstract
- KGaA, Weinheim Textiles are a promising base material for flexible and wearable electronic applications such as sensors, actuators, and energy harvesters. An essential component in such electronic textiles (e-textiles) is electrically conducting yarns. Here, a continuous dyeing process is presented to convert an off-the-shelf silk sewing thread into a wash and wear resistant functional thread with a conductivity of about 70 S cm−1; a record high value for coated yarns. An aqueous ink based on the conducting polymer:polyelectrolyte complex poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is modified, to produce more than 100 m of dyed conducting threads, which are subsequently converted into e-textiles by both hand weaving and machine embroidery. The yarns are resistant to abrasion and wear, and can be machine washed at least 15 times with retained electronic properties. The woven fabric is used to design a capacitive touch sensor which functions as an e-textile keyboard.
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| 28. |
- Müller, Christian, 1980, et al.
(författare)
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From Single Molecules to Thin Film Electronics, Nanofibers, e-Textiles and Power Cables : Bridging Length Scales with Organic Semiconductors
- 2019
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Ingår i: Advanced Materials. - : Wiley-VCH Verlag. - 0935-9648 .- 1521-4095.
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Tidskriftsartikel (refereegranskat)abstract
- Organic semiconductors are the centerpiece of several vibrant research fields from single-molecule to organic electronics, and they are finding increasing use in bioelectronics and even classical polymer technology. The versatile chemistry and broad range of electronic functionalities of conjugated materials enable the bridging of length scales 15 orders of magnitude apart, ranging from a single nanometer (10 −9 m) to the size of continents (10 6 m). This work provides a taste of the diverse applications that can be realized with organic semiconductors. The reader will embark on a journey from single molecular junctions to thin film organic electronics, supramolecular assemblies, biomaterials such as amyloid fibrils and nanofibrillated cellulose, conducting fibers and yarns for e-textiles, and finally to power cables that shuffle power across thousands of kilometers.
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| 29. |
- Ouyang, Yingwei, 1995, et al.
(författare)
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High-temperature creep resistant ternary blends based on polyethylene and polypropylene for thermoplastic power cable insulation
- 2021
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Ingår i: Journal of Polymer Science. - : Wiley. - 2642-4150 .- 2642-4169. ; 59:11, s. 1084-1094
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Tidskriftsartikel (refereegranskat)abstract
- The impact of a small amount of polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS) on the thermomechanical and electrical properties of blends comprising low-density polyethylene (LDPE) and isotactic polypropylene (PP) is investigated. SEBS is found to assemble at the PP:LDPE interface as well as within isolated PP domains. The addition of 10 wt% SEBS significantly increases the storage modulus between the melting temperatures of the two polyolefins, 110 and 160°C, and results in improved resistance to creep during both tensile deformation as well as compression. Furthermore, the ternary blends display a very low direct-current (DC) conductivity as low as 3.4 × 10 S m at 70°C and 30 kV mm , which is considerably lower than values measured for neat LDPE. The here presented type of ternary blend shows potential as an insulation material for high-voltage direct current power cables.
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| 30. |
- Ouyang, Yingwei, 1995, et al.
(författare)
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Highly insulating thermoplastic blends comprising a styrenic copolymer for direct-current power cable insulation
- 2022
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Ingår i: High Voltage. - : Institution of Engineering and Technology (IET). - 2397-7264. ; 7:2, s. 251-259
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Tidskriftsartikel (refereegranskat)abstract
- The impact of the composition of blends comprising low-density polyethylene (LDPE), isotactic polypropylene (PP) and a styrenic copolymer additive on the thermomechanical properties as well as the direct-current (DC) electrical and thermal conductivity is investigated. The presence of 5 weight percent (wt%) of the styrenic copolymer strongly reduces the amount of PP that is needed to enhance the storage modulus above the melting temperature of LDPE from 40 to 24 wt%. At the same time, the copolymer improves the consistency of the thermomechanical properties of the resulting ternary blends. While both the DC electrical and thermal conductivity strongly decrease with PP content, the addition of the styrenic copolymer appears to have little influence on either property. Evidently, PP in combination with small amounts of a styrenic copolymer not only allows to reinforce LDPE at elevated temperatures but also functions as an electrical conductivity-reducing additive, which makes such thermoplastic ternary formulations possible candidates for the insulation of high-voltage power cables.
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| 31. |
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| 32. |
- Pourrahimi, Amir Masoud, 1985, et al.
(författare)
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Repurposing Poly(3-hexylthiophene) as a Conductivity-Reducing Additive for Polyethylene-Based High-Voltage Insulation
- 2021
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 33:27
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Tidskriftsartikel (refereegranskat)abstract
- Poly(3-hexylthiophene) (P3HT) is found to be a highly effective conductivity-reducing additive for low-density polyethylene (LDPE), which introduces a new application area to the field of conjugated polymers. Additives that reduce the direct-current (DC) electrical conductivity of an insulation material at high electric fields have gained a lot of research interest because they may facilitate the design of more efficient high-voltage direct-current power cables. An ultralow concentration of regio-regular P3HT of 0.0005 wt% is found to reduce the DC conductivity of LDPE threefold, which translates into the highest efficiency reported for any conductivity-reducing additive to date. The here-established approach, i.e., the use of a conjugated polymer as a mere additive, may boost demand in absolute terms beyond the quantities needed for thin-film electronics, which would turn organic semiconductors from a niche product into commodity chemicals.
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| 33. |
- Raudaschl, M., et al.
(författare)
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Piezoelectric Textile Facade for the energy supply of active sensor technology with regard to data management for circular economy in building construction
- 2022
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Ingår i: <em>IOP Conference Series: Earth and Environmental Science, </em>Volume 1078, Issue 12022, Article number 012037. - : Institute of Physics.
-
Konferensbidrag (refereegranskat)abstract
- The high GWP potential of construction requires a holistic approach such as circular economy. Currently, common joining, construction and planning practices result in heterogeneous assemblies of different components that are difficult to deconstruct. Furthermore, there is currently little information and data on building components used and the climatic impacts on them. In this context and with the intention of recording long-term (circular) processes in construction, the Piezo-Klett basic research project (FFG no. 879459) funded by the Austrian Research Promotion Agency (FFG) deals with the energy supply of active sensor technology in construction by combining the hook and loop fastener with piezoelectric components. The aim is to open new perspectives on sustainable energy production systems by transforming buildings into energy carriers and generators, analogous to a "battery". To this purpose, the result presented in this conference paper is a description of the constructive structure (climatic impacts, construction, piezo technology) of a "Piezoelectric Textile Facade" as well as test results on piezo tapes. This opens new possibilities in the context of the application of hook- and-loop fasteners, the energy supply of active sensor technologies as well as in the field of data acquisition and data management.
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| 34. |
- Ryan, Jason, 1988, et al.
(författare)
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All-Organic Textile Thermoelectrics with Carbon-Nanotube-Coated n-Type Yarns
- 2018
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Ingår i: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 1:6, s. 2934-2941
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Tidskriftsartikel (refereegranskat)abstract
- Thermoelectric textiles that are able to generate electricity from heat gradients may find use as power sources for a wide range of miniature wearable electronics. To realize such thermoelectric textiles, both p- and n-type yarns are needed. The realization of air-stable and flexible n-type yarns, i.e., conducting yarns where electrons are the majority charge carriers, presents a considerable challenge due to the scarcity of air-stable n-doped organic materials. Here, we realize such n-type yarns by coating commercial sewing threads with a nanocomposite of multiwalled carbon nanotubes (MWNTs) and poly(N-vinylpyrrolidone) (PVP). Our n-type yarns have a bulk conductivity of 1 S cm -1 and a Seebeck coefficient of -14 μV K -1 , which is stable for several months at ambient conditions. We combine our coated n-type yarns with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) dyed silk yarns, constituting the p-type component, to realize a textile thermoelectric module with 38 n/p elements, which are capable of producing an open-circuit voltage of 143 mV when exposed to a temperature gradient of 116 °C and a maximum power output of 7.1 nW at a temperature gradient of 80 °C.
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| 35. |
- Ryan, Jason, 1988, et al.
(författare)
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Machine-Washable PEDOT:PSS Dyed Silk Yarns for Electronic Textiles
- 2017
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Ingår i: ACS Applied Materials & Interfaces. - : American Chemical Society (ACS). - 1944-8252 .- 1944-8244. ; 9:10, s. 9045-9050
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Tidskriftsartikel (refereegranskat)abstract
- Durable, electrically conducting yarns are a critical component of electronic textiles (e-textiles). Here, such yarns with exceptional wear and wash resistance are realized through dyeing silk from the silkworm Bombyx mori with the conjugated polymer:polyelectrolyte complex PEDOT:PSS. A high Young's modulus of approximately 2 GPa combined with a robust and scalable dyeing process results in up to 40 m long yarns that maintain their bulk electrical conductivity of approximately 14 S cm(-1) when experiencing repeated bending stress as well as mechanical wear during sewing. Moreover, a high degree of ambient stability is paired with the ability to withstand both machine washing and dry cleaning. For the potential use for e-textile applications to be illustrated, an in-plane thermoelectric module that comprises 26 p-type legs is demonstrated by embroidery of dyed silk yarns onto a piece of felted wool fabric.
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| 36. |
- Rychwalski, Rodney, 1945, et al.
(författare)
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DWNT/PVDF melt-spun piezoelectric fibres
- 2011
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Ingår i: NT11 International Conference on Science and Applications of Nanotubes, University of Cambridge, July 11-16, Cambridge (UK), 2011.
-
Konferensbidrag (refereegranskat)abstract
- Crystalline morphology in poly(vinylidene fluoride)(PVDF), in particular the presence of polar β phase crystals, is of utmost importance towards the material´s piezoelectricity. Nanoparticles have been in focus recently as means of enhancing β phase crystals formation in PVDF. Dominantly, the so-far work has been carried out on films/thin sheets. The influence of CNT on PVDF crystalline structure has been less investigated, however some results indicating an enhancing role of multi-wall carbon nanotubes (MWNT) in solution compounded PVDF films are available. Published results for MWNT/PVDF films are not in good agreement. The only study into single-wall carbon nanotube (SWNT)/PVDF has been made on electrospun nanofibres. An overview of results for PVDF films/sheets and fibres using various nanoparticles published and in the literature is given in [1]. In the present work we focus on melt-spun double-wall carbon nanotubes (DWNT)/PVDF fibres. We present new results for melt-spun PVDF fibres containing non-functionalized and amino-functionalized DWNT. The key finding is that amino-DWNT can favourably influence the β to α polymorphic balance. [1][1] A. Lund, C. Gustafsson, H. Bertilsson, R.W. Rychwalski, Compos. Sci. Tech., Vol. 71, 222-229 (2011)Acknowledgement: The Swedish Foundation for Strategic Research (SSF) is acknowledged (AL, RWR).
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| 37. |
- Rychwalski, Rodney, 1945, et al.
(författare)
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Towards piezoelectric nanocarbon/PVDF fibres
- 2011
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Ingår i: A Nano Connect Scandinavia event NanoUpdate 2011, May 23-24, Helsingborg (Sweden), 2011.
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Konferensbidrag (refereegranskat)
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| 38. |
- Satyanarayana, K. C., et al.
(författare)
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Analysis of the torsion angle distribution of poly(vinylidene fluoride) in the melt
- 2012
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Ingår i: Polymer. - : Elsevier BV. - 0032-3861 .- 1873-2291. ; 53:5, s. 1109-1114
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Tidskriftsartikel (refereegranskat)abstract
- Analysis of the torsion angle distribution of poly(vinylidene fluoride) (PVDF) structures at temperatures above its melting point is addressed by combining first principles methods, atomistic simulations and laboratory experiments. Amorphous, alpha- and beta-conformations of PVDF structures have been considered. The results from the atomistic simulations as well as the experiments show that there is a larger probability of the PVDF torsions to be near +/- 180 degrees at temperatures above the melting point, which is associated more with the beta-conformation than the alpha-conformation.
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| 39. |
- Yu, Liyang, 1986, et al.
(författare)
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Sequential doping of solid chunks of a conjugated polymer for body-heat-powered thermoelectric modules
- 2021
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 119:18
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Tidskriftsartikel (refereegranskat)abstract
- Sequential doping of 1 mm3 sized cubes of regio-regular poly(3-hexylthiophene) (P3HT) with 2,3,5,6-tetrafluoro-tetracyanoquinodimethane is found to result in a doping gradient. The dopant ingresses into the solid material and after two weeks of sequential doping yields a 250 μm thick doped surface layer, while the interior of the cubes remains undoped. The doping gradient is mapped with energy dispersive x-ray spectroscopy (EDX), which is used to estimate a diffusion coefficient of 1 × 10-10 cm2 s-1 at room temperature. The cubes, prepared by pressing at 150 °C, feature alignment of polymer chains along the flow direction, which yields an electrical conductivity of 2.2 S cm-1 in the same direction. A 4-leg thermoelectric module was fabricated with slabs of pressed and doped P3HT, which generated a power of 0.22 μW for a temperature gradient of 10.2 °C generated by body heat.
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| 40. |
- Zokaei, Sepideh, 1991, et al.
(författare)
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Electrically Conducting Elastomeric Fibers with High Stretchability and Stability
- 2022
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 18:5
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Tidskriftsartikel (refereegranskat)abstract
- Stretchable conducting materials are appealing for the design of unobtrusive wearable electronic devices. Conjugated polymers with oligoethylene glycol side chains are excellent candidate materials owing to their low elastic modulus and good compatibility with polar stretchable polymers. Here, electrically conducting elastomeric blend fibers with high stretchability, wet spun from a blend of a doped polar polythiophene with tetraethylene glycol side chains and a polyurethane are reported. The wet-spinning process is versatile, reproducible, scalable, and produces continuous filaments with a diameter ranging from 30 to 70 µm. The fibers are stretchable up to 480% even after chemical doping with iron(III) p-toluenesulfonate hexahydrate and exhibit an electrical conductivity of up to 7.4 S cm−1, which represents a record combination of properties for conjugated polymer-based fibers. The fibers remain conductive during elongation until fiber fracture and display excellent long-term stability at ambient conditions. Cyclic stretching up to 50% strain for at least 400 strain cycles reveals that the doped fibers exhibit high cyclic stability and retain their electrical conductivity. Finally, a directional strain sensing device, which makes use of the linear increase in resistance of the fibers up to 120% strain is demonstrated.
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| 41. |
- Zokaei, Sepideh, 1991, et al.
(författare)
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Toughening of a Soft Polar Polythiophene through Copolymerization with Hard Urethane Segments
- 2021
-
Ingår i: Advanced Science. - : Wiley. - 2198-3844. ; 8:2
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Tidskriftsartikel (refereegranskat)abstract
- Polar polythiophenes with oligoethylene glycol side chains are exceedingly soft materials. A low glass transition temperature and low degree of crystallinity prevents their use as a bulk material. The synthesis of a copolymer comprising 1) soft polythiophene blocks with tetraethylene glycol side chains, and 2) hard urethane segments is reported. The molecular design is contrary to that of other semiconductor-insulator copolymers, which typically combine a soft nonconjugated spacer with hard conjugated segments. Copolymerization of polar polythiophenes and urethane segments results in a ductile material that can be used as a free-standing solid. The copolymer displays a storage modulus of 25 MPa at room temperature, elongation at break of 95%, and a reduced degree of swelling due to hydrogen bonding. Both chemical doping and electrochemical oxidation reveal that the introduction of urethane segments does not unduly reduce the hole charge-carrier mobility and ability to take up charge. Further, stable operation is observed when the copolymer is used as the active layer of organic electrochemical transistors.
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| 42. |
- Zokaei, Sepideh, 1991, et al.
(författare)
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Tuning of the elastic modulus of a soft polythiophene through molecular doping
- 2022
-
Ingår i: Materials Horizons. - : Royal Society of Chemistry (RSC). - 2051-6355 .- 2051-6347. ; 9:1, s. 433-443
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Tidskriftsartikel (refereegranskat)abstract
- Molecular doping of a polythiophene with oligoethylene glycol side chains is found to strongly modulate not only the electrical but also the mechanical properties of the polymer. An oxidation level of up to 18% results in an electrical conductivity of more than 52 S cm(-1) and at the same time significantly enhances the elastic modulus from 8 to more than 200 MPa and toughness from 0.5 to 5.1 MJ m(-3). These changes arise because molecular doping strongly influences the glass transition temperature T-g and the degree of pi-stacking of the polymer, as indicated by both X-ray diffraction and molecular dynamics simulations. Surprisingly, a comparison of doped materials containing mono- or dianions reveals that - for a comparable oxidation level - the presence of multivalent counterions has little effect on the stiffness. Evidently, molecular doping is a powerful tool that can be used for the design of mechanically robust conducting materials, which may find use within the field of flexible and stretchable electronics.
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| 43. |
- Åkerfeldt, Maria, 1982, et al.
(författare)
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Textile sensing glove with piezoelectric PVDF fibers and printed electrodes of PEDOT:PSS
- 2015
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Ingår i: Textile Research Journal. - : SAGE Publications. - 0040-5175 .- 1746-7748. ; 85:17, s. 1789-1799
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Tidskriftsartikel (refereegranskat)abstract
- The development of an entirely polymer-based motion sensing glove with possible applications, for example, in physical rehabilitation is described. The importance of comfort for the wearer and the possibility to clean the glove in normal laundering processes were important aspects in the development. The glove is all textile and manufactured using materials and methods suitable for standard textile industry processes. For the first time, melt-spun piezoelectric poly(vinylidene fluoride) (PVDF) fibers with conductive cores were machine embroidered onto a textile glove to function as a sensor element. Electrodes and electrical interconnections were constituted by a screen printed conductive poly(3,4- ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) formulation. The screen printing of the interconnections was shown to be a reliable method for reproducible material deposition, resulting in an average surface resistivity value of 57/square. A repeated strain of 10% only influenced the resistance of the interconnections initially and to a very limited extent. The influence of washing on the electrical resistance of the printed interconnections was also studied; after 15 wash cycles the average surface resistivity was still below 500/square, which was deemed sufficient for the polymeric sensor system to remain functional during long-term use. Sensor data from the glove was also successfully used as input to a microcontroller running a robot gripper, in order to demonstrate its potential applications.
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