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  • 1.
    Abtahi, Farhad
    et al.
    KTH-School of Technology and Health.
    Ji, Guangchao
    KTH-School of Technology and Health.
    Lu, Ke
    KTH-School of Technology and Health.
    Rödby, Kristian
    University of Borås, Faculty of Textiles, Engineering and Business.
    Björlin, Anders
    Kiwok AB.
    Östlund, Anders
    Kiwok AB.
    Seoane, Fernando
    University of Borås, Faculty of Caring Science, Work Life and Social Welfare. KTH-School of Technology and Health.
    Lindecrantz, Kaj
    KTH-School of Technology and Health.
    Textile-Electronic Integration in Wearable Measurement Garments for Pervasive Healthcare Monitoring2015Conference paper (Other academic)
  • 2.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Ji, Guangchao
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Lu, Ke
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Rödby, Kristian
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Björlin, Anders
    Kiwok AB.
    Östlund, Anders
    Kiwok AB.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. Högskolan i Borås, Akademin för vård, arbetsliv och välfärd.
    Lindecrantz, Kaj
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Textile-Electronic Integration in Wearable Measurement Garments for Pervasive Healthcare Monitoring2015Conference paper (Other academic)
  • 3.
    Abtahi, Farhad
    et al.
    KTH-School of Technology and Health.
    Lu, Ke
    KTH-School of Technology and Health.
    Guangchao, Li
    KTH-School of Technology and Health.
    Rödby, Kristian
    University of Borås, Faculty of Textiles, Engineering and Business.
    Seoane, Fernando
    University of Borås, Faculty of Caring Science, Work Life and Social Welfare. KTH-School of Technology and Health.
    A Knitted Garment using Intarsia Technique for Heart Rate Variability Biofeedback: Evaluation of Initial Prototype.2015Conference paper (Other academic)
  • 4.
    Abtahi, Farhad
    et al.
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Lu, Ke
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Guangchao, Li
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems.
    Rödby, Kristian
    Högskolan i Borås, Akademin för textil, teknik och ekonomi.
    Seoane, Fernando
    KTH, School of Technology and Health (STH), Medical Engineering, Medical sensors, signals and systems. Högskolan i Borås.
    A Knitted Garment using Intarsia Technique for Heart Rate Variability Biofeedback: Evaluation of Initial Prototype.2015Conference paper (Other academic)
  • 5.
    Adawi, Rahim
    University of Skövde, School of Engineering Science.
    Preventing fatal effects of overworking: Product design solution2018Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    “Overworking to death” is a phenomenon that has been noticeable in developing countries. The cause of death is mainly through ischemic strokes. While the victims’ occupations differed, they all shared a common characteristic, being positioned in a sedentary work, ranging from IT workers to doctors. This project’s aim was to develop a product that prevented or decreased the strokes that derived from sedentary overwork. This was mainly tackled by preventing one of the three causes of developing blood props, slowed blood flow. In order to gather rich data of the phenomenon, a qualitative study was conducted in China, during two months. By doing an extensive structured sampling, information rich data could be gathered during a short period of time. Data were derived from observations, questionnaires and an interview, which then was interpreted to customer needs and the final product specification. The final product became a trouser with an in built dynamic compression mechanic, that can compress the veins mostly during sitting activities, in order to prevent blood stasis. The compression mechanic works like the Chinese finger trap; compressing the calves while sitting and stretching the legs forward. It is made only out of polysaccharides fibres; cotton and corn.

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    PREVENTING FATAL EFFECTS OF OVERWORKING – PRODUCT DESIGN SOLUTION / Rahim_Adawi
  • 6.
    Agnhage, Tove
    University of Borås, Faculty of Textiles, Engineering and Business. University Lille 1, France; Soochow University, China.
    Eco-designed functionalization of polyester fabric2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    There is an increased awareness of the textile dyeing and finishing sector’s high impact on the environment due to high water consumption, polluted wastewater, and inefficient use of energy. To reduce environmental impacts, researchers propose the use of dyes from natural sources. The purpose of using these is to impart new attributes to textiles without compromising on environmental sustainability. The attributes given to the textile can be color and/or other characteristics. A drawback however, is that the use of bio-sourced dyes is not free from environmental concerns. Thus, it becomes paramount to assess the environmental impacts from using them and improve the environmental profile, but studies on this topic are generally absent.

    The research presented in this thesis has included environmental impact assessment, using the life cycle assessment (LCA) tool, in the design process of a multifunctional polyester (PET) fabric using natural anthraquinones. By doing so an eco-design approach has been applied, with the intention to pave the way towards eco-sustainable bio-functionalization of textiles.

    The anthraquinones were obtained from the root extracts of the madder plant (Rubia tinctorum L.), referred to as madder dye. The research questions were therefore formulated related to the use of madder dye. Three research questions have been answered: (I) Can madder dye serve as a multifunctional species onto a PET woven fabric? (II) How does the environmental profile of the dyeing process of PET with madder dye look like, and how can it be improved? (III) What are the main challenges in using LCA to assess the environmental impacts of textile dyeing with plant-based dyes?

    It is concluded that there is a potential for the madder dye to serve as a multifunctional species onto PET. Based on the encouraging result, a recommendation for future work would be to focus on the durability of the functionalities presented and their improvement potential, both in exhaustion dyeing and pad-dyeing. LCA driven process optimization of the exhaustion dyeing enabled improvement in every impact category studied. However, several challenges have been identified which need to be overcome for the LCA to contribute to the sustainable use of multifunctional plant-based species in textile dyeing. The main challenges are the lack of available data at the research stage and the interdisciplinary nature of the research arena. It is envisaged that if these challenges are addressed, LCA can contribute towards sustainable bio-functionalization of textiles. 

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  • 7.
    Alexander Deen, Fusi
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Synthetic Functionalization of Colloidal Lignin Particles for Wood Adhesive Applications2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Functionalizable spherical colloidal lignin particles (CLPs) represent a valuable asset for the valorization of lignin side-streams from the pulp industry. The spherical structure allows for the circumvention of the heterogeneous and poorly dispersible structure of the biopolymer. However, organic solvents and alkaline media degrade the particle structure and dissolve the polymers due to their chemical nature and solubility. The solvents will alter the aggregated polymers into irregular shapes that would correspond to inconsistent physicochemical properties. Then, the material will become unusable for advanced material applications, namely wood adhesives. In this study, a replicable process to yield pH ca. 12 stable CLPs for wood adhesives or further functionalization for other advanced material applications was developed and optimized. Lignin was functionalized with cross-linkers, glyoxal or formaldehyde, and selfassembled into spherical structures in the micro emulsification of the organic solution. The formed colloids were partially rotary evaporated to retain organic solvents within the colloidal structures, and then be cured at 73-76 °C until pH stable and further functionalized for advanced material applications. The functionalization with glyoxal was pursued further for its possibly increased reactivity and the health concerns associated with formaldehyde. The process requires the addition of glyoxal to lignin in an acidic organi cmedia at ambient temperature, and the solution to react at 64 °C. Glyoxal is likely added to the polymer structure in its hydrated and dimerized form, and its attachment to lignin should be analyzed through the behavior of glyoxal in different media. The formed colloids were rotary evaporated to an organic solvent content of 60 wt. % of the spheres to allow the occurrence of the curing reaction. These materials were finally cured by thermosetting them at 73-76 °C until pH stable. The particles can be cured with base-catalysis through the controlled addition of the base NaOH(aq). However, the mode and rate of addition of the catalyst are critically important for a nondegradative infusion of a base into solvent present ot removed particles without morphological changes. Further procedural improvement and larger batches are necessary to conduct CLP adhesive experiments.

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  • 8.
    Alici, Gursel
    et al.
    School of Mechanical, Materials, and Mechatronic Engineering, ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, Australia.
    Mutlu, Rahim
    School of Mechanical, Materials, and Mechatronic Engineering, ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, Australia.
    Melling, Daniel
    Institute for Medical Science and Technology, University of Dundee, Dundee, UK.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Kaneto, Keiichi
    Kyushu Institute of Technology, Eamex Co. Ltd, Chuoku, Fukuoka, Japan.
    Conducting Polymers as EAPs: Device Configurations2016In: Electromechanically Active Polymers: A Concise Reference / [ed] Federico Carpi, Cham: Springer, 2016, p. 257-292Chapter in book (Other academic)
    Abstract [en]

    This chapter focuses on device configurations based on conjugated polymer transducers. After the actuation and sensing configurations in the literature are presented, some successful device configurations are reviewed, and a detailed account of their operation principles is described. The chapter is concluded with critical research issues. With reference to the significant progress made in the field of EAP transducers in the last two decades, there is an increasing need to change our approach to the establishment of new device configurations, novel device concepts, and cutting-edge applications. To this aim, we should start from the performance specifications and end up with the material synthesis conditions and properties which will meet the performance specifications (top-to-down approach). The question should be “what electroactive material or materials can be used for a specific purpose or application,” rather than looking for an application or a device concept suitable to the unique properties of the EAPs and transducers already made of these materials. The field is mature enough to undertake this paradigm change.

  • 9.
    Almgren, Anna
    Halmstad University, School of Business and Engineering (SET).
    Material- och tillverkningsteknikval för en stol åt Källemo2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta projekt har pågått under sista terminen på maskiningenjörsprogrammet vid högskolan i Halmstad. Projektet har utförts av en student och tillsammans med företaget Källemo. Syftet med projektet har varit att studenten ska hitta och utvärdera ett lämpligt material åt en ny stol. Materialvalet skulle också kompletteras med en lämplig tillverkningsmetod. Stolen är designad av Pierre Sindre, SandellSandberg, och kommer att produceras och säljas av Källemo. Pierre Sindres ritningar och renderingar var underlaget som var utgångspunkt för projektet. Arbetet har inneburit att olika material har utvärderats och framförallt formpressad filt. Lämpligheten har testat genom liknande referensmöbler och fysiska tester. Bland annat har provbitar testat med enkla handtester. En dialog har också förts med leverantörer av material som haft mycket erfarenhet och kunnat bidra med tips och idéer.  Då projektet inte har varit ett typiskt konstruktionsprojekt har metoden utvecklats efterhand som olika resultat uppkommit. Detta har varit ett arbetssätt som har varit väldigt lärorikt för studenten och också väldigt tidseffektivt då ingen onödig tid har lagt på irrelevanta processer. Varje steg i arbetets gång har diskuterats med både uppdragsgivaren på företaget och två handledare som högskolan tillhandahållit. Veckomöten varje vecka har också bidragit till ett mycket tidseffektivt arbete där snedsteg tidigt kunnat upptäckas av de med mer erfarenhet. Dessa möten har varit avgörande för det goda resultatet som erhållits. Resultatet består av fem lösningsförslag som tagits fram och vid diskussion med företaget och leverantörer utmynnat i ett slutligt resultat som nu är färdigt för produktion. När projektet avslutades var den första delen i produktion och således målet med projektet uppfyllt.

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    Examensarbete, Anna Almgren
  • 10.
    Altgen, Michael
    et al.
    Aalto Univ, Finland.
    Willems, Wim
    FirmoLin Technol BV, Netherlands.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Rautkari, Lauri
    Aalto Univ, Finland.
    Hydroxyl accessibility and dimensional changes of Scots pine sapwood affected by alterations in the cell wall ultrastructure during heattreatment2018In: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 152, p. 244-252Article in journal (Refereed)
    Abstract [en]

    There is a complex link between the water sorption behavior and the presence of accessible hydroxyl groups in the wood cell wall, which can be altered by heat-treatment (HT). This study analyses the effect of changes in the cell wall ultrastructure caused by two HT techniques on the hydroxyl accessibility, water vapor sorption and dimensional changes of Scots pine (Pinus sylvestris L.) sapwood. HT of wood in pressurized hot water at 120-170 °C was applied to cause the preferential bond cleavage, whereas HT of wood in oven-dry state in superheated steam at 180-240 °C was performed to create additional covalent cross-links within the cell wall matrix. Removal of cell wall polymers by HT and water leaching reduced the oven-dry dimensions of wood and enhanced the cellulose aggregation during drying. Cellulose aggregation restricted the cell wall shrinkage in circumferential direction, resulting in inhomogeneous shrinkage of the cell wall with only little changes in lumen volume by HT. Cellulose aggregation also reduced the water-saturated dimensions, but a decrease in swelling was only achieved when additional cross-links were formed by HT in dry state. Additional cross-links in the cell wall matrix also resulted in an additional reduction in water sorption at 25 °C and 93% RH. However, this was not caused by a further reduction in the hydroxyl accessibility. Instead, cross-linking was shown to reduce the amount of accessible OH groups that are simultaneously active in sorption, which was explained based on the concept of sorption of water dimers at hydroxyl group pairs at high RH levels.

  • 11.
    Amaia Beatriz, Ortega-Santos
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Martinez, Jose Gabriel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Enzymatic biofuel cells embedded polymer-based soft actuators2022Conference paper (Other academic)
    Abstract [en]

    Enzymatic biofuel cells are presented as an untethered alternative energy source that could power small implantable or wearable medical devices. However, most of these catalytic processes do not provide with enough energy to power common small electronic-mechanical devices. On the other hand, conducting polymer-based actuators are of great interest for their biocompatibility, flexibility, processability, possibility to be miniaturized and low power consumption. So far, these artificial muscles have been driven by external power sources that prevent them for being completely autonomous. There is a need for a novel power source to elaborate actuators that could use physiological processes as a driving force. These soft actuators’ low power consumption matches the electrical power generated by the biocatalysis of some enzymes, such as glucose oxidase and laccase in presence of glucose and oxygen in aqueous media. Here, we present the latest results in the development of polypyrrole-based soft actuators powered by enzymatic biofuel cells. The actuator consists of a tri-layer conductive substrate on which the polypyrrole is electrodeposited in both sides. The polypyrrole layers act as the active part, expanding and contracting upon a redox reaction, resulting in a bending movement. Tetrathiofulvlene-7,7,8,8-tetracyanoquinodimethane (TTF-TCNQ) and 2,2′-azino-di-(3-ethylbenzthiazoline sulfonic acid) (ABTS) electron transfer mediators are cast on the surface of the polypyrrole to help the electron transmission. The glucose oxidase and laccase enzymes are immobilized in the modified-conducting polymer surface, integrating the electrode to the actuator. The bio-catalysis of enzymes in presence of glucose and oxygen in aqueous solution provides the actuator with the electrons needed for the redox reaction, converting the chemical energy into mechanical energy, i.e., movement. The glucose-self-powered soft actuator may contribute to the development of more complex implantable, ingestible, or wearable biomedical devices such as cardio-stimulators, insulin pumps, or muscle implants.

  • 12.
    Amaia Beatriz, Ortega-Santos
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Martinez, Jose Gabriel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    The effect of enzyme immobilization methods in polypyrrole-based soft actuators driven by glucose and O22023Conference paper (Other academic)
  • 13.
    Andersson Ersman, Peter
    et al.
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Eriksson, Jerry
    RISE Research Institutes of Sweden, Built Environment, Building and Real Estate. Elitfönster AB, Sweden.
    Jakonis, Darius
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Pantzare, Sandra
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Åhlin, Jessica
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Strandberg, Jan
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Sundin, Stefan
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Toss, Henrik
    RISE Research Institutes of Sweden, Digital Systems, Mobility and Systems.
    Ahrentorp, Fredrik
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Daoud, Kaies
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Jonasson, Christian
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Svensson, Henrik
    Elitfönster AB, Sweden.
    Gregard, Greger
    ChromoGenics AB, Sweden.
    Näslund, Ulf
    Vasakronan AB, Sweden.
    Johansson, Christer
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Integration of Screen Printed Piezoelectric Sensors for Force Impact Sensing in Smart Multifunctional Glass Applications2022In: Advanced Engineering Materials, ISSN 1438-1656, E-ISSN 1527-2648, Vol. 24, no 11, article id 2200399Article in journal (Refereed)
    Abstract [en]

    Screen printed piezoelectric polyvinylidene fluoride?trifluoro ethylene (PVDF?TrFE)-based sensors laminated between glass panes in the temperature range 80?110?°C are presented. No degradation of the piezoelectric signals is observed for the sensors laminated at 110?°C, despite approaching the Curie temperature of the piezoelectric material. The piezoelectric sensors, here monitoring force impact in smart glass applications, are characterized by using a calibrated impact hammer system and standardized impact situations. Stand-alone piezoelectric sensors and piezoelectric sensors integrated on poly(methyl methacrylate) are also evaluated. The piezoelectric constants obtained from the measurements of the nonintegrated piezoelectric sensors are in good agreement with the literature. The piezoelectric sensor response is measured by using either physical electrical contacts between the piezoelectric sensors and the readout electronics, or wirelessly via both noncontact capacitive coupling and Bluetooth low-energy radio link. The developed sensor concept is finally demonstrated in smart window prototypes, in which integrated piezoelectric sensors are used to detect break-in attempts. Additionally, each prototype includes an electrochromic film to control the light transmittance of the window, a screen printed electrochromic display for status indications and wireless communication with an external server, and a holistic approach of hybrid printed electronic systems targeting smart multifunctional glass applications.

  • 14.
    Andersson, Mattias
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Oxfall, Henrik
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Nilsson, Camilla
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Mapping and Evaluation of some Restricted Chemical Substances in Recycled Plastics Originating from ELV and WEEE Collected in Europe2019Report (Other academic)
    Abstract [en]

    Recycling of plastics is a critical step toward the realisation of a sustainable society. Plastic is a fitting material to recycle, as it often can easily be melted and formed into new products. Plastic recycling is therefore an easy process with pure plastics, however, most of the plastics that are recycled today are not pure and contain additives and/or impurities. Some of these additives can be hazardous substances that could be harmful for both humans and the environment. It is therefore important that these hazardous substances are not recycled and transferred into new products. To ensure a safe use of plastics, these substances are today regulated in new products, but old products could still contain these substances (legacy chemicals). To comply with legislation it is therefore critical that these substances are removed during the recycling process. There are however many hazardous substances that are yet not regulated, which may also be present in products and therefore recycled material. 

    Waste Electronic and Electrical Equipment (WEEE) and End-of-Life Vehicles (ELV) are two of the materials streams that contains a high amount of legacy chemicals. These streams have been associated with spreading legacy chemicals after recycling. In several reports WEEE plastics have been identified as the source of brominated flame retardants (BRF) found in toys and everyday items. According to the EU regulation the use of certain BFRs is not permitted in new products or articles above a certain value. Recyclers and resellers of the recycled plastic often specified that the products should not be used in toys, medical equipment of food contact application, yet BFRs from WEEE can still be found in these products. This could mean that either producers that use recycled material in new products do not follow the recommendations from the recyclers, or that the recycled material does not fulfil the regulations. Another possibility for the findings of legacy chemicals in these items could be a meagre follow-up on imported plastics.

    In this study the Research Institutes of Sweden (RISE) has, on behalf of the Swedish Environmental Protection Agency (Naturvårdsverket), investigated the content of legacy chemicals in recycled plastics that have been processed in a recycling facility. The plastics originated from WEEE and ELV and have been gathered from recyclers across Europe. A number of different legacy chemicals were investigated, both inorganic (Cd, Pb, Hg) and organic substances (flame retardants and plasticisers). To simulate a real case scenario and to get better measurement accuracy, all samples were injection moulded. The analysis of the samples was performed using X-ray fluorescence spectrometry (XRF), Inductively coupled plasma (ICP) and Gas chromatography with a Mass spectrometer (GC-MS). All the processing and analysis (except for SCCP/MCCP)) were done by RISE which gives good control over the analysis process, which are important when interpreting the results. In total 54 samples of PE, PP, ABS and PS, were gathered and tested. It was found that all but two samples contained legacy chemicals below the regulated values. The two samples that did not meet the legal limit had a HBCDD content above 100 ppm. All the tested materials contained detectable amounts of bromine, and 15 samples contained detectable amounts of regulated BFRs. None of the detected regulated BRFs were above 186 ppm.  Most of the materials also contained detectable amounts of cadmium and lead.

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  • 15.
    Andersson, Oscar
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mechanical Engineering.
    Wiklund, Alexander
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mechanical Engineering.
    Strain rate-dependent mechanical properties of high-density polyethylene(HDPE)2022Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In today’s packaging industry HDPE is widely used and correct understanding of itsproperties and how to model them is of vital importance. HDPE is a semi-crystallinepolymer with a known strain rate dependence, that is a higher yield and lower strainto failure at higher strain rates. HDPE does also exhibit the phenomena of cold-drawing, together with other polymers. Cold-drawing is where after the specimenhas necked, the necking stabilizes and starts to pull material above and below intothe neck, effectively elongating the neck while maintaining its width.

    The objective of the study is to look at the local strain rates as the specimen necksand if a simple Abaqus model can capture those effects. The effect of strain rate onthe shape of the neck was also studied.

    The work was to test HDPE in uniaxial tension with different strain rates (∼10-3 s-1to ∼10-1 s-1) and measure the local strain rates with 2D-DIC. A decent amount oftime was used to make sure the camera setup gave the best quality possible for theequipment available. The videos produced was used for the DIC analysis as well asfor the image analysis to measure the width of the neck. After the tests a calibrationscheme was used to create a material model that matched the force-displacementfrom the physical 100 mm/min test data.

    Studying the force displacement the strain rate effects noted in previous researchare present. The results from the DIC show a very high local strain rate as the spec-imen necks, between 11-65 times higher than the global (grip-to-grip) strain rate.From the measurement of the width there are some rate effects as well. The slowerspeeds (5 and 10 mm/min) shows a continually reducing width while the 50 and 100mm/min shows a more stable neck and the 500 mm/min test does not have any sig-nificant neck propagation. The simple elastic-plastic model show similar local strainrates as the experiment however does show a noticeable thinner neck.

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  • 16.
    Andersson Trojer, Markus
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF. Max Planck Institute of Colloids and Interfaces, Germany.
    Ananievskaia, Anna
    University of Gothenburg, Sweden.
    Gabul-Zada, Asvad A.
    University of Gothenburg, Sweden.
    Nordstierna, Lars
    Chalmers University of Technology, Sweden.
    Blanck, Hans
    University of Gothenburg, Sweden.
    Polymer Core-Polymer Shell Particle Formation Enabled by Ultralow Interfacial Tension Via Internal Phase Separation: Morphology Prediction Using the Van Oss Formalism2018In: Colloid and Interface Science Communications, ISSN 2215-0382, Vol. 25, p. 36-40Article in journal (Refereed)
    Abstract [en]

    The internal phase separation technique is a versatile method for liquid core-polymer shell formation, yet limited to very hydrophobic core materials and actives. The use of polymeric cores instead circumvents this restriction due to the absent mixing entropy for binary polymer mixtures which allows the polymeric core (and the active) to approach the polarity of the shell. Polystyrene core-shell and janus particles were formulated using polymethylmethacrylate, poly(lactic acid), poly(lactic acid-co-glycolic acid), poly(ε-caprolactone) or cellulose triacetate as shell-forming polymers. The morphology and the partitioning was experimentally determined by selectively staining the core and the shell with β-carotene and methylene blue respectively. In addition, the van Oss formalism was introduced to theoretically predict the thermodynamic equilibrium morphology. As elucidated using the theoretical predictions as well as experimental optical tensiometry, it was found that the driving force for core-shell morphology is, in contrast to liquid core-polymer shell particles, a low core-shell interfacial tension.

  • 17.
    Anselmo, Ana Sofia
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Dzwilewski, Andrzej
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Rysz, Jakub
    M. Smoluchowski Insitute of Physics, Jagiellonian University, Reymonta 4, Krakow 30–059, Poland.
    Budkowski, Andrzej
    M. Smoluchowski Insitute of Physics, Jagiellonian University, Reymonta 4, Krakow 30–059, Poland.
    Svensson, Krister
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    van Stam, Jan
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Moons, Ellen
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering. Karlstad University, Faculty of Technology and Science, Materials Science.
    Polymer solar cells: Visualizing vertical phase separation in solution-processed films of polymer fullerene blends2012In: Proceedings of the 5th International Symposium Technologies for Polymer Electronics - TPE 12 / [ed] Hans-Klaus Roth, Klaus Heinemann, Ilmenau, Germany: Universitätsverlag Ilmenau , 2012, p. 125-128Conference paper (Refereed)
  • 18.
    Anuar Bahari, Shahril
    et al.
    Universiti Teknologi MARA (UiTM), Malaysia.
    Nazarudin Zakaria, Mohd
    Universiti Teknologi MARA (UiTM), Malaysia.
    Osman, Syaiful
    Universiti Teknologi MARA (UiTM), Malaysia.
    Abu, Falah
    Universiti Teknologi MARA (UiTM), Malaysia.
    Jani Saad, Mohamad
    Malaysian Agricultural Research and Development Institute (MARDI), Malaysia.
    Hosseinpourpia, Reza
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials. Linnaeus University, Linnaeus Knowledge Environments, Green Sustainable Development.
    Strength Performance and Microstructure Characteristic of Naturally-Bonded Fiberboard Composite from Malaysian Bamboo (Bambusa vulgaris)2022In: Journal of Renewable Materials, ISSN 2164-6325, E-ISSN 2164-6341, Vol. 10, no 10, p. 2581-2591Article in journal (Refereed)
    Abstract [en]

    This study investigated the mechanical properties and microstructural characteristics of fiberboard composite produced by naturally-bonded Malaysian bamboo fiber (Bambusa vulgaris). The components that obtained through soda pulping of bamboo culms such as fiber and black liquor, were used for the preparation of high-density fibreboard composite at two target densities of 850 and 950 kg/m3. The bamboo fiberboard composite (BFC) were then produced at 200°C and two pressing parameters of 125 and 175 s/mm. The mechanical properties, e.g., flexural strength and internal bonding (IB) of BFC samples were evaluated according to BS EN 310: 1993 and BS EN 319: 1993, respectively. It was found that the mechanical performance of the composite with 850 kg/m3 density was significantly higher than 950 kg/m3 ones, especially for the samples with 125 s/mm pressing parameter. Microstructure characteristic of the BFC samples illustrated that the fiber linkages were cracked in the composites with higher density, e.g., the composite with the density of 950 kg/m3 and also black liquor were slightly degraded at longer pressing time, which led to the reduction in mechanical properties, especially in IB strength.

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  • 19. Aronsson, Julia
    et al.
    Persson, Anders
    University of Borås, Faculty of Textiles, Engineering and Business. The Swedish School of Textiles.
    Tearing of post-consumer cotton T-shirts and jeans of varying degree of wear2020In: Journal of Engineered Fibers and Fabrics, E-ISSN 1558-9250, Vol. 15, p. 1-9Article in journal (Refereed)
    Abstract [en]

    The demand for textile fibres is growing quickly. However, global cotton production has stabilized around 25 Mton/year. This is a sound development since cotton cultivation causes major sustainable development issues. Even if regenerated cellulose fibre production steadily grows, it is still only from a sixth to a fifth of cotton volumes. Hence, it is essential to find resource-efficient routes to generate alternatives to virgin cotton. There are many promising research initiatives that discover the possibility to utilize waste streams of neat cotton and cotton in fibre blends as raw materials for dissolving pulp for regeneration into, for example, viscose or Lyocell. However, there is a much simpler and energy-efficient route at hand. If fabrics are disintegrated mechanically, the separated fibres can be turned into yarn again. However, since fibre length is a key parameter to accomplish strong and durable textiles, fibre length loss upon tearing should be minimized. This study evaluates how fibre length distribution alters upon tearing of post-consumer cotton waste of two different constructions: denim and single jersey; and different degrees of wear, rendering four different fractions: (1) barely worn denim, (2) rather worn denim, (3) barely worn single-jersey and (4) rather worn single-jersey. Before tearing, the garments were dissembled, their yarns were characterized, fibre length distributions were manually determined for (1)–(4). Length analysis of the recovered fibres after tearing revealed that the length drop was most severe for (a) the finer single-jersey and (b) the barely worn fractions. The findings suggest that significant wear does not exclude from mechanical recycling.

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  • 20.
    Artur, Cavaco-Paulo
    et al.
    University of Minho, Braga, Portugal.
    Nierstrasz, VincentUniversity of Borås, Faculty of Textiles, Engineering and Business.Wang, QiangJiangnan University, Wuxi, China.
    Advances in Textile Biotechnology 2nd Edition2019Collection (editor) (Refereed)
    Abstract [en]

    Description

    Advances in Textile Biotechnology, Second Edition examines the latest in biotechnology for the fiber and textile industry. This new edition has been fully revised to include the current essential areas of development in the field, covering both natural and synthetic fibers. Chapters cover the latest technology in bioprocessing for bast fiber, PVA, polyester, wool and silk before exploring issues of enzyme stability. Essential areas of application and development are then considered, including biomedical textiles, silk materials for biotechnological applications, bacterial cellulose, the ink jetting of enzymes, and the role of enzymes, wool and silk fibers.

    Containing groundbreaking research, this book will be essential reading for manufacturers, designers and engineers in the textiles industry, textile and fiber scientists, and academic researchers and postgraduate students working in the area of textile technology.

    Key Features

    • Provides a thorough overview of current and future focuses of biotechnology in the fiber and textile industry
    • Presents fully revised content, with a new focus on biosynthesis and bioprocessing for novel textile fibers, both synthetic and natural
    • Enables readers to understand and utilize the benefits of biotechnology for the manufacture and production of textiles

    Readership

    Textile manufacturers, designers and engineers in the textile industry; textile and fibre scientists; academic researchers and postgraduate students in textile technology; experts in the biology, chemical and environmental engineering industries

  • 21.
    Arwin, Hans
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Schoeche, Stefan
    JA Woollam Co Inc, NE 68508 USA.
    Hilfiker, James
    JA Woollam Co Inc, NE 68508 USA.
    Hartveit, Mattias
    Univ Rochester, NY 14627 USA.
    Järrendahl, Kenneth
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Juarez-Rivera, Olga Rubi
    Cinvestav Queretaro, Mexico.
    Mendoza-Galvan, Arturo
    Cinvestav Queretaro, Mexico.
    Magnusson, Roger
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Optical Chirality Determined from Mueller Matrices2021In: Applied Sciences, E-ISSN 2076-3417, Vol. 11, no 15, article id 6742Article in journal (Refereed)
    Abstract [en]

    Featured Application The analysis of the transmission of Mueller matrices facilitates studies of optical activity in samples that also exhibit linear anisotropy and depolarization and may have a multilayered structure. Such studies are important for the development of applications in chiroptics. Optical chirality, in terms of circular birefringence and circular dichroism, is described by its electromagnetic and magnetoelectric material tensors, and the corresponding optical activity contributes to the Mueller matrix. Here, spectroscopic ellipsometry in the spectral range 210-1690 nm is used to address chiral phenomena by measuring Mueller matrices in transmission. Three approaches to determine chirality parameters are discussed. In the first approach, applicable in the absence of linear polarization effects, circular birefringence and circular dichroism are evaluated directly from elements of a Mueller matrix. In the second method, differential decomposition is employed, which allows for the unique separation of chirality parameters from linear anisotropic parameters as well as from depolarization provided that the sample is homogeneous along the optical path. Finally, electromagnetic modeling using the Tellegen constitutive relations is presented. The last method also allows structural effects to be included. The three methods to quantify optical chirality are demonstrated for selected materials, including sugar solutions, alpha-quartz, liquid crystals, beetle cuticle, and films of cellulose nanocrystals.

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  • 22.
    Asadi, Milad
    University of Borås, Faculty of Textiles, Engineering and Business.
    Graphene: a vision to the future of smart E-Textile application2022Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Smart textile is a term referring to the textiles that could interact with their environment, receiving input and giving output based on their applications. Among smart textiles, electrically driven smart textiles (E-textiles) are being produced by various methods and materials integrated with textile substances. Graphene is one of these compounds that could be integrated into the polymer or integrated into the textile materials such as fibres. Therefore, other elements could be doped or immobilised on the graphene nanosheets for a wider range of applications, such as catalytic and electrocatalytic systems.  

    However, finding the most applicable and efficient method to integrate graphene into the textile fibres and further establishing a method for catalyst immobilisation are challenging and require focused research.  

    Therefore, this doctoral thesis focused on the innovative concept of integration of graphene and immobilisation of iron nanoparticles on it. Evidence from the systematic experiments was gathered for the case of dip-coating of polyester textiles with graphene oxide dispersion and enhancing the electrostatic bonding between fibres and graphene oxide nanosheets. In the second step, systematic experiments were gathered for the case of immobilisation of an inorganic catalyst (zerovalent iron) on textile supports. The goal of this thesis is to establish the feasibility of a mild and applicable method for textile material supports, which requires low temperature and mild pH, and further fabrication of heterogeneous catalytic and electrocatalytic systems for wastewater treatment. Polyester was chosen as the textile support material for graphene oxide coating and catalyst immobilisation due to its availability and cost-effectiveness.  

    The thesis has four distinct parts related to (a) Pre-surface-charge modification of the polyester for strong electrostatic bonding between polyester and graphene, (b) Design a continuous yarn coating system for mass production of graphene-coated conductive yarns, (c) Immobilisation of Fe0 on graphene-coated polyester textiles and optimising their feasibility in catalytic systems and (d) Design and prove the feasibility of knitting a fully textile-based reactor having two anodic and cathodic sections by using rGO-Fe0 yarns and stainless-steel multifilament yarns, respectively as a concept of electro-Fenton wastewater treatment.  

    Diverse analytical and instrumental techniques were used to monitor the surface modification of the polyester textiles and conductivity of the resulting textiles; moreover, the electromechanical and electrothermal properties of the graphene-modified textiles were examined. Further, the efficiency of catalyst immobilisation, physio-chemical properties of the immobilised catalyst, and their catalytical activities in dye removal from the water was studied. Results showed that surface charge modification of polyester fabric with both chitosan and hexadecylpyridinium chloride (HDPC) gives the most homogeneous graphene coating, resulting in high conductivity and very good fastness. Furthermore, results from scanning electron microscope (SEM), Differential scanning calorimetry (DSC), and UV/Visible spectrophotometry prove the success of immobilisation of zerovalent iron on the graphene-modified textiles. 

    The novelty of the research presented in this doctoral thesis is primarily attributed to the novelty of a hybrid graphene-catalyst immobilisation-grafting on polyester textile supports for wastewater treatment applications. The final concept of the thesis is to introduce the potential for assembling a fully textile-based reactor for Electro-Fenton wastewater treatments.

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  • 23.
    Asadi, Milad
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Bashir, Tariq
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Development of eco-friendly flame retardant polypropylene fibers2017Conference paper (Refereed)
  • 24.
    Asare, Richard
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering.
    Dynamic Mechanical Thermal Analysis of Polyoxymethylene2024Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis, conducted in collaboration with IKEA Components, explores the rate-temperature dependence of polyoxymethylene (POM) thermoplastic using dynamic mechanical thermal analysis (DMTA). A force-controlled DMTA study was carried out, and the experimental data were processed to derive the complex, storage, and loss modulus.

    Master curves were constructed using the time-temperature superposition (TTS) method, comparing the Arrhenius and William-Landel-Ferry (WLF) equations. Additionally, a master curve was manually created by shifting isothermal material properties. This manual curve was then compared to those generated using standard equations.

    The study found that the storage modulus was the dominant phenomenon in POM, with the loss modulus showing distortion likely due to measurement noise. Results indicated a slight softening of the storage modulus with increased cyclic loading. The manually constructed master curve was more coherent compared to those derived from the Arrhenius and WLF equations.

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  • 25.
    Asp, Kenneth
    Swedish National Road and Transport Research Institute.
    Proceedings of Strategic Highway Research Program and Traffic Safety on Two Continents. Conference in Gothenburg, Sweden, September 18-20, 1991: Part 5. Asphalt. Highway operations and concrete and structures1991Conference proceedings (editor) (Other academic)
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  • 26.
    Asp, Kenneth
    Swedish National Road and Transport Research Institute.
    Proceedings of Strategic Highway Research Program and Traffic Safety on Two Continents. Conference in Gothenburg, Sweden, September 18-20, 1991: Part 6. Long-term pavement performance1991Conference proceedings (editor) (Other academic)
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  • 27.
    Asres, Bersabeh Zemedagegnehu
    University of Borås, Faculty of Textiles, Engineering and Business.
    Viskostygs inverkan på plagg efter tvätt.: Hur krympning av viskos påverkar plaggets passform, mått och konstruktion för en klänning2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study is developed in collaboration with a small company that works with women's clothing. The company has had recurring problems with the fit of their viscose dress. The purpose of the study is to analyze the effect of the viscose material shrinkage after laundering on the fit of the garment such as balance, ease, length and the garment dimension. Viscose is one of the finest textile materials for dresses sewing because of its properties such as it’s fine shine, drapes well and it have high absorbent. In contrast, viscose material tends to lose strength when wet, which affects garment fit due to viscoses shrinkage after laundering. The study is performed through comparing of three production processes of a dress to get the best fit and dimensions. For sample A and B, the same pattern construction is used, except for sample B, the viscose fabric was pre-washed in advance. While for sample C fabric samples was washed and the number of shrinkage is calculated . Pattern construction was adjusted by adding the results of shrinkage . The three sample dresses were sewn with the same viscose fabric, and the fit were tasted by one person in size Medium .The dress samples were measured both before and after laundering. The result of prototype C showed that the dress has shrunk to the best fit and meets the desired garment sizes in comparison with prototypes A and B. The study showed that garments that are sewn in viscose material change both in fit and size after washing. Washing viscose material before cutting will not ensure that the sewn garment will not shrink or that the garments will retain its dimension after washing. The change in pattern design gives better results.

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  • 28.
    Atarijabarzadeh, Sevil
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Biofilm adhesion on silicone materials2011Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Silicone composite high voltage insulators are sometimes contaminated by microorganisms in outdoor applications, which results in the insulator becoming conductive and thereafter failure of the insulators. In this work, it has been tried to develop silicone materials with antimicrobial properties. Silicone was blended with various antimicrobial agents. Affectivity and appropriate concentration of the biocides were decided through a fast test prior to the manufacturing of the samples.

    Samples were aged according to an international biodegradation test. To study the extent of the growth on the samples’ surface visual analysis and scanning electron microscopy (SEM) were performed. Samples were studied for changes in surface properties and surface chemical composition with carrying out dynamic contact angle measurements and Fourier transform infrared spectroscopy respectively. Results from the biodegradation test showed some biocides could inhibit the fungal growth comparing the results for the reference samples. Biofilm formation resulted in changes in surface hydrophobicity and surface chemical composition.

    Further, silicone materials were compounded with clay nanoparticles, which were modified with different organic compounds. Reference samples were manufactured with clay nanoparticles modified with a siloxane surfactant to make the dispersion of the particles into the silicone matrix easier. Clay nanoparticles were also grafted with two organic compounds with antimicrobial effect in order to synthesis organoclays, which have antimicrobial properties. Furthermore, grafting clay with these two compounds was also aimed to make the easy dispersion of the particles into silicone possible.

    Nanocomposites compounded with antimicrobial clay nanoparticles as well as reference nanocomposites were tested with quick test for microbial growth. Changes in the clay particles morphology were examined with x-ray diffraction as well as SEM. Manufactured nanocomposites were also examined with x-ray and SEM to study the dispersion of nanoparticles into the silicone matrix. Changes in clay morphology were observed due to modification with organic compounds. Microbial growth was inhibited on some samples due to presence of antimicrobial organoclays.

  • 29.
    Atarijabarzadeh, Sevil
    et al.
    KTH Royal Inst Technol, Sch Chem Sci & Engn, Fibre & Polymer Technol, Stockholm, Sweden.
    Nilsson, Fritjof
    KTH Royal Inst Technol, Sch Chem Sci & Engn, Fibre & Polymer Technol, Stockholm, Sweden / ABB, Corp Res, Västerås, Sweden.
    Hillborg, Henrik
    KTH Royal Inst Technol, Sch Chem Sci & Engn, Fibre & Polymer Technol, Stockholm, Sweden / ABB, Corp Res, Västerås, Sweden.
    Karlsson, Sigbritt
    University of Skövde. KTH Royal Inst Technol, Sch Chem Sci & Engn, Fibre & Polymer Technol, Stockholm, Sweden.
    Strömberg, Emma
    KTH Royal Inst Technol, Sch Chem Sci & Engn, Fibre & Polymer Technol, Stockholm, Sweden.
    Image Analysis Determination of the Influence of Surface Structure of Silicone Rubbers on Biofouling2015In: International Journal of Polymer Science, ISSN 1687-9422, E-ISSN 1687-9430, article id 390292Article in journal (Refereed)
    Abstract [en]

    This study focuses on how the texture of the silicone rubber material affects the distribution of microbial growth on the surface of materials used for high voltage insulation. The analysis of surface wetting properties showed that the textured surfaces provide higher receding contact angles and therefore lower contact angle hysteresis. The textured surfaces decrease the risk for dry band formation and thus preserve the electrical properties of the material due to a more homogeneous distribution of water on the surface, which, however, promotes the formation of more extensive biofilms. The samples were inoculated with fungal suspension and incubated in a microenvironment chamber simulating authentic conditions in the field. The extent and distribution of microbial growth on the textured and plane surface samples representing the different parts of the insulator housing that is shank and shed were determined by visual inspection and image analysis methods. The results showed that the microbial growth was evenly distributed on the surface of the textured samples but restricted to limited areas on the plane samples. More intensive microbial growth was determined on the textured samples representing sheds. It would therefore be preferable to use the textured surface silicone rubber for the shank of the insulator.

  • 30.
    Austrell, Per-Erik
    et al.
    Division of Structural Mechanics, Lund Institute of Technology.
    Kari, LeifKTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, MWL Structural and vibroacoustics.
    Constitutive Models for Rubber IV: proceedings of the 4th European Conference for Constitutive Models for Rubber, ECCMR 2005, Stockholm, Sweden, 27-29 June 20052005Collection (editor) (Refereed)
    Abstract [en]

    The unique properties of elastomeric materials are taken advantage of in many engineering applications. Elastomeric units are used as couplings or mountings between stiff parts. Examples are shock absorbers, vibration insulators, flexible joints, seals and suspensions etc.

     

    However, the complicated nature of the material behavior makes it difficult to accurately predict the performance of these units, using for example finite element modelling. It is therefore necessary that the constitutive model accurately capture relevant aspects of the mechanical behavior.

     

    The latest development concerning constitutive modelling of rubber is collected in these proceedings. It is the fourth ECCMR-European Conference on Constitutive Modelling in a series on this subject.

     

    Topics included in this volume are, Hyperelastic models, Strength, fracture & fatigue, Dynamic properties & the Fletcher-Gent effect, Micro-mechanical & statistical approaches, Stress softening, Viscoelasticity, Filler reinforcement, and Tyres, fiber & cord reinforced rubber.

  • 31.
    Aziz, Shazed
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Martinez, Jose Gabriel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Salahuddin, Bidita
    Australian Institute For Innovative Materials University Of Wollongong Innovation Campus, Squires Way, North Wollongong, NSW 2522, Australia.
    Persson, Nils-Krister
    Smart Textiles Technology Lab Swedish School Of Textiles University Of Borås Borås SE-501 90, Sweden.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    PEDOT:PSS coated twisted and coiled yarn actuators2021In: EuroEAP 2021: International conference on Electromechanically Active Polymer (EAP) transducers & artificial muscles, 2021Conference paper (Other academic)
    Abstract [en]

    Commercial yarns can be functionalized with conducting polymers (CPs) todevelop yarn and textile actuators. Here we show a method of functionalizationof commercial polyamide yarns by poly-3,4-ethylenedioxythiophene:polystyrenesulfonate (PEDOT:PSS) coating. Aftercoating, while PEDOT:PSS is drying, it is possible to twist and coil the yarns,resulting in a major improvement of their linear strain and speed of movement.By using a potential window between +0.6 V and -1.2 V vs Ag/AgCl it waspossible to obtain a fully reversible actuation of a coiled yarn providing up to1.62% strain. A strain higher than 1% was achieved in less than 1 second.Compared to the untwisted, regular yarns, the twisted and coiled yarns produce>9× and >20× higher strain, respectively. These results are a step forward towardsthe development of soft, silent and compliant smart textile exoskeletons.

  • 32.
    Babu, NB Karthik
    et al.
    Department of Mechanical Engineering, Assam Energy Institute, A Centre of Rajiv Gandhi Institute of Petroleum Technology, Sivasagar, India.
    Mensah, Rhoda Afriyie
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Shanmugam, Vigneshwaran
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Rashedi, Ahmad
    School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore, Singapore.
    Athimoolam, Pugazhenthi
    Department of Mechanical Engineering, University College of Engineering Dindigul, Dindigul, India.
    Aseer, J. Ronald
    Department of Mechanical Engineering, National Institute of Technology Puducherry, Karaikal, India.
    Das, Oisik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Self‐reinforced polymer composites: An opportunity to recycle plastic wastes and their future trends2022In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 139, no 46, article id e53143Article, review/survey (Refereed)
    Abstract [en]

    Polymers and their composites have played an important role in industrial development. Polymer composites are becoming much stronger and more competitive than other materials as a result of ongoing research and development. This was made possible by newly developed techniques that could alter the physical and chemical properties of constituents. One of them is the self-reinforcement technique, which allows for the fabrication of high-strength thermoplastic polymer composites with reserved degradability, which is not possible with glass fiber/carbon fiber reinforcement. A self-reinforced polymer composite is made of a single polymeric material, which serves as both the matrix and the reinforcement. This review article discusses the use of self-reinforcement in various polymers and its impact on mechanical, thermal, and fire properties. Furthermore, the effects of process parameters (such as temperature and time, an), reinforcement structure, and mechanical property variation on the structure of self-reinforced composites are reviewed and presented in detail. In addition, the effect of foreign filler addition (such as flame retardants, inorganic particles, natural fibers, etc.) on self-reinforced composites is highlighted. In the end, the need for future research and its scope is presented.

  • 33.
    Bachinger, Angelika
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites.
    Sandinge, Anna
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Lindqvist, Karin
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites.
    Strid, Anna
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites.
    Gong, Guan
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites.
    Systematic evaluation of bromine-free flame-retardant systems in acrylonitrile-butadiene-styrene2022In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 139, no 13, article id 51861Article in journal (Refereed)
    Abstract [en]

    A systematic investigation of phosphorus-based flame-retardant (PFR) systems in acrylonitrile-butadiene-styrene (ABS) is presented. The effect of various PFRs, combinations thereof and influence of different synergists is studied in terms of fire and mechanical performance, as well as toxicity of resulting ABS. Sustainable flame-retardant systems with a promising effect on the fire-retardant properties of ABS are identified: A combination of aluminum diethylphosphinate and ammonium polyphosphate is shown to exhibit superior flame-retardant properties in ABS compared to other studied PFRs and PFR combinations. Among a variety of studied potential synergists for this system, a grade of expandable graphite with a high-initiation temperature and a molybdenum-based smoke suppressant show the most promising effect, leading to a significant reduction of the peak heat release rate as well as the smoke production rate. Compared to current state-of-the-art brominated flame-retardant for ABS, the identified flame-retardant systems reduce the maximum smoke production rate by 70% and the peak heat release rate by 40%. However, a significant reduction of the impact performance of the resulting ABS is identified, which requires further investigation.

  • 34.
    Backe, Carin
    et al.
    University of Borås.
    Guo, Li
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Persson, Nils-Krister
    University of Borås.
    Towards responding fabrics – textile processing of thin threadlike pneumatic actuators2019Conference paper (Other academic)
    Abstract [en]

    With few exceptions (such as 1) textiles have not been considered as means for obtaining actuation. This is surprising as textiles have many advantageous characteristics such as the D=M property, which stands for Doing Devices while Making the Material. This means that functions are introduced simultaneously as the material, such as in a weave, is built up tread by tread. Traditionally a tread could have a certain colour so in total an aesthetical pattern is formed. Now we take a step beyond this working with threads having more advanced functions. Included are fiber formed structures showing actuation behavior. 

    This we employ here. We make fiber formed actuating structures (FAS) following the McKibben principle (2) with braided mesh sleeves surrounding a prolonged inflatable tube. Here we worked with relatively large diameters in the relaxed state but show that there is prospect for obtaining relaxed diameters of less than 1 mm approaching the range of large scale weaving manufacturing.

    We study the behavior of these fibre formed actuating structures individually. Length changes obtained are -20%. We then make textile constructions by integrating several of these FASes with textile processing. By this, we build simple models of fabrics showing actuating behavior.  

     

    This study shows how textile constructions can support or hinder overall movement. It is a first logical step in order to get an understanding of actuating fabrics based also on other actuating mechanisms (3).

  • 35.
    Backe, Carin
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Martinez, Jose G
    Guo, Li
    University of Borås, Faculty of Textiles, Engineering and Business.
    Jager, Edwin W. H.
    Persson, Nils-Krister
    University of Borås, Faculty of Textiles, Engineering and Business.
    Serially connected EAP based tape yarns for in-air actuation using textile structures2023Conference paper (Other academic)
    Abstract [en]

    Smart textiles that have the capability for actuation are of great interest for creating wearables and haptic devices. Through the use of textile fabric production processes electroactive polymeric materials in the form of film-based yarns can be integrated and combined with passive yarns to create soft, actuating fabrics. This way single EAP materials can be transformed into segments consisting of multiple EAP yarns working together. Furthermore, these segments can be positioned within a fabric to work individually or simultaneously in different patterns by use of incorporated conductive yarn paths. While the chase for additivity in force is a long-standing part of developing new actuator structures, so is the need for additivity in displacement motion. Here we construct an actuating textile fabric through the process of weaving that is able to operate in-air using polypyrrole-based tape yarns with choline acetate ionic liquid. Finding the balance between the weaving parameters turned out to be key. We found that in a vertically suspended arrangement, a three-segment serially connected fabric assembly demonstrated an accumulative effect in displacement and a joint-like motion behaviour. This opens up for more complicated motion patterns to be created through textile processing of EAP materials. 

  • 36. Backe, Carin
    et al.
    Martinez, Jose Gabriel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Guo, Li
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Persson, Nils-Krister
    Multi-Assembly of Soft Electroactive Polymeric Yarn Actuators by Using Textile Processes2021Conference paper (Other academic)
  • 37. Backe, Carin
    et al.
    Martinez, Jose Gabriel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Guo, Li
    Persson, Nils-Krister
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Serially connected EAP based tape yarns for in-air actuation using textile structures2023Conference paper (Other academic)
  • 38.
    Backe, Carin
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skelte, Gabrielle
    University of Borås, Faculty of Textiles, Engineering and Business.
    Piezoelektriska filament: från garn till textil applikation2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Piezoelectric materials are frequently used in different sensors as they can generate a measurable electrical signal during applied pressure or when subjected to extension. This project examines how a piezoelectric yarn containing Polyvinylidene fluoride (PVDF) is affected when exposed to moisture, heat and long-term mechanical deformation. Focus has been directed towards investigating the properties of the piezoelectric yarn as well as how it can be applied in textile fabrics and textile applications. The piezoelectric yarn has been subjected to a series of tests. Most of the samples have undergone cyclic deformation in an extensometer during tests. The piezoelectric yarn has been examined by experiments in laboratory environment, practical tests in textile applications as well as by statistical analysis. It can be stated that factors such as moisture and temperature have influence on the piezoelectric effect of the yarn. Long-term tests reveal how the yarn displays a change in length while undergoing deformation, which contributes to the diminished signal strength of the yarn. The piezoelectric yarn can successfully be integrated in a piece of fabric by the means of sewing when using correct stitch- length, where higher stitch-length gives a higher signal output. The same method can be applied to construct a piezoelectric sensor used in a training sock. This project can conclude that parameters such as moisture, creep-behaviour and structural variation within the PVDF-filaments have a significant effect on the signal created by the piezoelectric yarn. The potential of the yarn as a sensor can be seen by successfully applying it to a textile structure as well as in a training sock that can monitor the fore and rear foot while running. It can be stated that much remains to be studied in this particular research area regarding piezoelectric filaments and yarns. Further research in the subject will lead to new innovative applications that can be of use in different parts of society, not to say the least in the area of medicine.

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  • 39.
    Backe, Carin
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skelte, Gabrielle
    Rundqvist, Karin
    University of Borås, Faculty of Textiles, Engineering and Business.
    Sandsjö, Leif
    University of Borås, Faculty of Caring Science, Work Life and Social Welfare.
    Persson, Nils-Krister
    University of Borås, Faculty of Textiles, Engineering and Business.
    Piezoelektriska strumpor för rörelsemonitorering - En känslighetsanalys2015In: Abstracts - Medicinteknikdagarna 2015, Svensk förening för medicinsk teknik och fysik , 2015, p. 60-Conference paper (Other academic)
  • 40.
    Baghaei, Behnaz
    University of Borås, Faculty of Textiles, Engineering and Business.
    Development of thermoplastic biocomposites based on aligned hybrid yarns for fast composite manufacturing2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The interest in natural fibres as reinforcement for composite materials has been steadily increasing due to their attractive mechanical properties and the possibility of making more eco-friendly materials. Currently, various alternatives are being introduced for commercial applications, as fibres such as hemp, jute and flax exhibit properties, which make them appropriate for structural composite components. Biocomposites offer reductions in weight and cost and have less reliance on foreign oil resources, making them attractive. Several investigations have revealed that the full utilisation of fibre mechanical properties in the final composites can be exploited, provided an aligned fibre orientation is chosen. In fact, a major challenge for natural fibre reinforced composites is to achieve high mechanical performance at competitive prices. The use of commingled/hybrid yarns is one of the more promising methods for manufacturing structural thermoplastic composites.

    Commingled yarns of thermoplastic and reinforcing fibres offer a potential for cost-effective production of composite parts, thanks to reduced applied pressures and impregnation times during processing. Besides economic advantages, there is also direct control over fibre placements and ease of handling of fibres in yarn process. The yarn technologies provide homogenous distribution of reinforcing fibre and matrix. Variation in natural fibre properties has been a major problem facing composite manufacturers, compared to carbon and glass fibres that have well-defined production processes. This issue can be addressed by regenerated cellulose fibres. These fibres can be reproduced easily with high surface evenness and even quality, making it possible to get consistent results, which is not possible with natural fibres. Combination of natural and regenerated cellulose fibre brings together the best of both materials. The end result is a product with superior properties, which could not be obtained by the individual components.

    This thesis describes the development of aligned hybrid yarns with low fibre twist, for high performance natural (hemp) and man-made (Lyocell) cellulose fibre-reinforced biocomposites, suitable for use in structural or semi-structural applications. The properties of composites in terms of fibre orientation, off-axis angle and alkali treatment were investigated, focusing on determining void%, water absorption, mechanical and thermo-mechanical properties. The results show that combining hemp and Lyocell in PLA composite leads to the reduction of moisture absorption and can improve the mechanical properties. The mechanical properties of the composites were highly affected by the fibre direction. The alkali treatment on hemp fibre improved the mechanical properties of the composites.

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  • 41.
    Baghaei, Behnaz
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Johansson, Belinda
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Kadi, Nawar
    University of Borås, Faculty of Textiles, Engineering and Business.
    All-Cellulose Composites Properties from Pre- and Post-Consumer Denim Wastes: Comparative Study2022In: Journal of Composites Science, E-ISSN 2504-477X, Vol. 6, no 5, article id 130Article in journal (Other (popular science, discussion, etc.))
    Abstract [en]

    This study reports the recycling of discarded denim textiles by the production of all-cellulose composites (ACCs). Discarded denim fabrics were shredded into fibers and then made into nonwoven fabrics by carding and needle punching. The produced nonwoven fabrics were converted to ACCs by one-step and two-step methods using an ionic liquid (IL), 1-butyl-3-methyl imidazolium acetate ([BMIM][Ac]). In this study, the effect of different ACC manufacturing methods, denim fabrics with different contents (a 100% cotton denim (CO) and a blend material (cotton, poly-ester and elastane (BCO)) and reusing of IL as a recycled cellulose solvent on the mechanical pro-perties of the formed ACCs were investigated. The ACCs were characterized according to their tensile and impact properties, as well as their void content. Microscopic analysis was carried out to study the morphology of a cross-section of the formed composites. The choice of the one-step method with recycled IL, pure IL or with a blend material (BCO) had no influence on the tensile properties. Instead, the result showed that the two-step method, with and without DMSO, will influence the E-modulus but not the tensile strength. Regarding the impact properties of the samples, the only factor likely to influence the impact energy was the one-step method with CO and BCO.

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  • 42.
    Bakoglidis, Konstantinos
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering. Univ Manchester, England.
    Palisaitis, Justinas
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    dos Santos, Renato B.
    Univ Fed Bahia, Brazil.
    Rivelino, Roberto
    Univ Fed Bahia, Brazil.
    Persson, Per O A
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Gueorguiev, Gueorgui Kostov
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Self-Healing in Carbon Nitride Evidenced As Material Inflation and Superlubric Behavior2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 19, p. 16238-16243Article in journal (Refereed)
    Abstract [en]

    All known materials wear under extended mechanical contacting. Superlubricity may present solutions, but is an expressed mystery in C-based materials. We report negative wear of carbon nitride films; a wear-less condition with mechanically induced material inflation at the nanoscale and friction coefficient approaching ultralow values (0.06). Superlubricity in carbon nitride is expressed as C-N bond breaking for reduced coupling between graphitic-like sheets and eventual N-2 desorption. The transforming surface layer acts as a solid lubricant, whereas the film bulk retains its high elasticity. The present findings offer new means for materials design at the atomic level, and for property optimization in wear-critical applications like magnetic reading devices or nanomachines.

  • 43.
    Barick, Prasenjit
    et al.
    International Advanced Research Centre for Powder Metallurgy and New Materials, Balapur Post, Hyderabad-500005, Telangana, India.
    Saha, Bhaskar Prasad
    International Advanced Research Centre for Powder Metallurgy and New Materials, Balapur Post, Hyderabad-500005, Telangana, India.
    Joshi, Shrikant
    University West, Department of Engineering Science, Research Enviroment Production Technology West. International Advanced Research Centre for Powder Metallurgy and New Materials, Balapur Post, Hyderabad-500005, Telangana, India.
    Mitra, Rahul
    Department of Metallurgical and Materials Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, 721302, India.
    Spray-freeze-dried nanosized silicon carbide containing granules: Properties, compaction behaviour and sintering2016In: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 36, no 16, p. 3863-3877Article in journal (Refereed)
    Abstract [en]

    Spherical granules comprising silicon carbide nanoparticles have been produced with the help of sprayfreeze-drying (SFD) technique. The effect of solid loading of slurries on rheological properties, flowability and morphology of the resulting SFD granules has been studied. Further, a systematic study has been performed to investigate the effect of applied pressures and granule density on the relative densities and microstructures of the green compacts. A marginal increase in viscosity is noted as the solid content of slurries increases from 5 to 15 vol% with significant increase in viscosity being observed in case of 18 vol% slurry. The granules prepared from SiC slurries are spherical in shape with their mean size, density, gravimetric flow rate, and yield strength increasing with the increase in solid content. The mechanical properties of sintered SiC produced from SFD granules are found relatively superior to that made from commercially available spray-dried (SD) granules.

  • 44.
    Barth, Hampus
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Strategies for Carbon Dioxide Reduction in Scaffolding Sheets: A Case Study of Xervon Sweden AB2024Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This bachelor thesis investigates strategies for enhancing sustainability in material usage within Xervon Sweden AB, a leading provider of scaffolding and weather protection solutions. The research integrates life cycle analysis (LCA) with the exploration of alternative materials and recycling methods to identify environmentally friendly approaches to managing plastic waste in facade work.

    The study employs a comprehensive LCA to assess the environmental impact of current scaffolding materials, including High-Density Polyethylene (HDPE) and Low-Density Polyethylene (LDPE). It explores new materials such as Polyhydroxyalkanoates (PHA), evaluates their feasibility through data collection and analysis, and investigates innovative recycling and reuse methods in collaboration with industry partners.

    The results from this bachelor thesis revealed from the LCA that material extrusion contributes significantly to CO2 emissions and energy consumption. PHA emerged as a promising alternative due to its renewable sourcing and biodegradability, despite its higher cost. The study also identified a circular system for recycling scaffolding sheets into granules for manufacturing new sheets as the most efficient strategy for CO2 reduction. Additionally, opportunities for external reuse of plastic materials with painting companies and agricultural associations were explored.

    The conclusions drawn in this bachelor thesis is that Xervon is currently using the most sustainable material within its price range. While PHA shows potential for future adoption, creating a circular system for scaffolding sheets offers immediate benefits. Collaborations with external partners can further extend the lifespan of materials, contributing to overall sustainability efforts. Future research should include broader sustainability indicators and in-house laboratory tests to validate findings. By focusing on these strategies, Xervon can significantly reduce its environmental footprint while maintaining operational efficiency and economic viability.

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  • 45.
    Bashir, Tariq
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Persson, Nils-Krister
    University of Borås, Faculty of Textiles, Engineering and Business.
    High-strength electrically conductive fibers: functionalization of polyamide, aramid and polyester fibers with PEDOT polymer2017In: Polymers for Advanced Technologies, ISSN 1042-7147, E-ISSN 1099-1581, Vol. 29, no 1, p. 310-318, article id 10.1002/pat.4116Article in journal (Refereed)
    Abstract [en]

    In this work, high-performance fibers such as aramid (Twaron), polyamide (PA6), polyester (PET), and hybrid Twaron/PA6 fibers were transformed into electroactive fibers by coating them with conjugated polymer, poly(3,4-ethylenedioxythiophene) (PEDOT) through vapor phase polymerization (VPP) method. The VPP is considered as an efficient technique for depositing CPs on different substrates regardless of their lower solubility in various solvents. In this paper, PEDOT-coated high-performance fibers were prepared under already optimized reaction conditions, and then a comparison between electrical, thermal, and mechanical properties of different fibers, before and after coating, was made. The obtained coated fibers were characterized through scanning electron microscope (SEM), thermogravimetric analysis (TGA), 2-probe electrical resistance measurement method, and tensile testing. It was revealed that at particular reaction conditions, all high performance textile substrates were successfully converted into electroactive fibers. The voltage-current (V-I) characteristics showed that PEDOT-coated polyester fibers exhibited highest conductivity value among all other substrate fibers. The active PEDOT layers on high performance fibers could behave as an antistatic coating to minimize the risks associated with static charges at work places. Also, the obtained fibers have potential to be used as smart materials for various medical, sports, and military applications.

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  • 46.
    Bashir, Tariq
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business.
    Skrifvars, Mikael
    University of Borås, Faculty of Textiles, Engineering and Business.
    Persson, Nils-Krister
    University of Borås, Faculty of Textiles, Engineering and Business.
    High-strengthelectrically conductive fibers: Functionalization of polyamide, aramid andpolyester fibers with PEDOT polymer2017In: Polymers for Advanced Technologies, ISSN 1042-7147, E-ISSN 1099-1581Article in journal (Refereed)
    Abstract [en]

    In this work, high-performance fibers such as aramid (Twaron), polyamide (PA6), polyester (PET), and hybrid Twaron/PA6 fibers were transformed into electroactive fibers by coating them with conjugated polymer, poly(3,4-ethylenedioxythiophene) (PEDOT) through vapor phase polymerization (VPP) method. The VPP is considered as an efficient technique for depositing CPs on different substrates regardless of their lower solubility in various solvents. In this paper, PEDOT-coated high-performance fibers were prepared under already optimized reaction conditions, and then a comparison between electrical, thermal, and mechanical properties of different fibers, before and after coating, was made. The obtained coated fibers were characterized through scanning electron microscope (SEM), thermogravimetric analysis (TGA), 2-probe electrical resistance measurement method, and tensile testing. It was revealed that at particular reaction conditions, all high performance textile substrates were successfully converted into electroactive fibers. The voltage-current (V-I) characteristics showed that PEDOT-coated polyester fibers exhibited highest conductivity value among all other substrate fibers. The active PEDOT layers on high performance fibers could behave as an antistatic coating to minimize the risks associated with static charges at work places. Also, the obtained fibers have potential to be used as smart materials for various medical, sports, and military applications.

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  • 47.
    Bayrak Pehlivan, İlknur
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Functionalization of polymer electrolytes for electrochromic windows2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Saving energy in buildings is of great importance because about 30 to 40 % of the energy in the world is used in buildings. An electrochromic window (ECW), which makes it possible to regulate the inflow of visible light and solar energy into buildings, is a promising technology providing a reduction in energy consumption in buildings along with indoor comfort. A polymer electrolyte is positioned at the center of multi-layer structure of an ECW and plays a significant role in the working of the ECW.

    In this study, polyethyleneimine: lithium (bis(trifluoromethane)sulfonimide (PEI:LiTFSI)-based polymer electrolytes were characterized by using dielectric/impedance spectroscopy, differential scanning calorimetry, viscosity recording, optical spectroscopy, and electrochromic measurements.

    In the first part of the study, PEI:LiTFSI electrolytes were characterized at various salt concentrations and temperatures. Temperature dependence of viscosity and ionic conductivity of the electrolytes followed Arrhenius behavior. The viscosity was modeled by the Bingham plastic equation. Molar conductivity, glass transition temperature, viscosity, Walden product, and iso-viscosity conductivity analysis showed effects of segmental flexibility, ion pairs, and mobility on the conductivity. A connection between ionic conductivity and ion-pair relaxation was seen by means of (i) the Barton-Nakajima-Namikawa relation, (ii) activation energies of the bulk relaxation, and ionic conduction and (iii) comparing two equivalent circuit models, containing different types of Havriliak-Negami elements, for the bulk response.

    In the second part, nanocomposite PEI:LiTFSI electrolytes with SiO2, In2O3, and In2O3:Sn (ITO) were examined. Adding SiO2 to the PEI:LiTFSI enhanced the ionic conductivity by an order of magnitude without any degradation of the optical properties. The effect of segmental flexibility and free ion concentration on the conduction in the presence of SiO2 is discussed. The PEI:LiTFSI:ITO electrolytes had high haze-free luminous transmittance and strong near-infrared absorption without diminished ionic conductivity. Ionic conductivity and optical clarity did not deteriorate for the PEI:LiTFSI:In2O3 and the PEI:LiTFSI:SiO2:ITO electrolytes.

    Finally, propylene carbonate (PC) and ethylene carbonate (EC) were added to PEI:LiTFSI in order to perform electrochromic measurements. ITO and SiO2 were added to the PEI:LiTFSI:PC:EC and to a proprietary electrolyte. The nanocomposite electrolytes were tested for ECWs with the configuration of the ECWs being plastic/ITO/WO3/polymer electrolyte/NiO (or IrO2)/ITO/plastic. It was seen that adding nanoparticles to polymer electrolytes can improve the coloring/bleaching dynamics of the ECWs.

    From this study, we show that nanocomposite polymer electrolytes can add new functionalities as well as enhancement in ECW applications.

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  • 48.
    Becerra, Marley
    et al.
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Friberg, Andreas
    ABB Corporate Research, Västerås.
    Arc jets blown by outgassing polymers in air2014In: Proceedings of the 20th International Conference on Gas Discharges and Their Applications GD2014, GD2014 , 2014, p. 1-4Conference paper (Refereed)
    Abstract [en]

    This paper describes experimental results about the behaviour of arc jets transversely blown in the presence of outgassing polymers (POM –CH2O– or PMMA –C5H8O2–). The arc jets are ignited in air between copper electrodes under a 2 kA, 50 Hz AC current. High speed photography and optical emission spectroscopy are used to study the mechanism leading to the increase of the arc voltage when polymers are used instead of non-ablating materials (e.g. quartz). It is found that the transversal blowing flow caused by the injection of ablation vapours have a weak effect on the arc voltage build-up. Instead, the chemical changes in the plasma environment appear to better explain the observed increase in the arc voltage when polymers are used. 

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  • 49.
    Belov, Ilja
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing - Surface technology. Jönköping University, School of Engineering, JTH. Research area Robust Embedded Systems.
    Chedid, Michel
    Leisner, Peter
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing - Surface technology. Jönköping University, School of Engineering, JTH. Research area Robust Embedded Systems.
    Investigation of Snap-on Feeding Arrangements for a Wearable UHF Textile Patch Antenna2008In: Ambience 08 International Scientific Conference: proceedings 2008 : smart textiles - technology and design : Borås, Sweden / [ed] Lars Hallnäs, Pernilla Walkenström, Lennart Wasling, Borås: Centrum för textilforskning (CTF), The Swedish School of Textiles, University College of Borås , 2008, p. 84-88Conference paper (Refereed)
  • 50.
    Bengtsson, Jenny
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Jedvert, Kerstin
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Theliander, T
    Coagulation of dry-jet wet-spun lignin-based carbon fibre precursors2018In: Proceedings of the 15th European workshop on lignocellulosics and pulp, 2018, p. 123-126Conference paper (Refereed)
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