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  • 51. Souza, J. F.
    et al.
    Moreira, Milena
    Doi, I.
    Diniz, J. A.
    Tatsch, P. J.
    Gonçalves, J. L.
    Preparation and characterization of high-k aluminium nitride (AlN) thin film for sensor and integrated circuits applications2012In: Physica Status Solidi. C, Current topics in solid state physics, ISSN 1610-1634, E-ISSN 1610-1642, Vol. 9, no 6, p. 1454-1457Article in journal (Refereed)
  • 52.
    Storvall, Linda
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Bergstrand, David
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Crack Propagation in Fiber-Reinforced Composites: A semi-analytical method for determining cohesive laws2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 53.
    Ström, Petter
    et al.
    KTH Royal Inst Technol, Sch Elect Engn, Dept Fus Plasma Phys, SE-10044 Stockholm, Sweden..
    Primetzhofer, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Applied Nuclear Physics.
    Schwarz-Selinger, Thomas
    Max Planck Inst Plasma Phys, D-85748 Garching, Germany..
    Sugiyama, Kazuyoshi
    Max Planck Inst Plasma Phys, D-85748 Garching, Germany..
    Compositional and morphological analysis of FeW films modified by sputtering and heating2017In: NUCLEAR MATERIALS AND ENERGY, ISSN 2352-1791, Vol. 12, p. 472-477Article in journal (Refereed)
    Abstract [en]

    Surface compositional changes of iron- tungsten films by deuterium (D) ion bombardment were studied by means of medium energy ion scattering, elastic recoil detection analysis and Rutherford backscattering spectrometry. The energy of the bombarding ions was 200 eV/D and the fluence was varied from 10(21) D/m(2) to 10 24 D/m(2). A significant increase of the tungsten concentration within the 20 nm closest to the sample surface, caused by preferential sputtering of iron, was seen for the films exposed 10(23) D/m(2) or more. In the sample exposed to the highest fluence, 10(24) D/m(2), the concentration of tungsten was increased from an initial 1.7 at. % up to approximately 24 at. % averaged over the 5 nm closest to the surface. The analysis was complicated by the presence of oxygen on the sample surfaces. In order to study the thermal stability of the tungsten enriched layer, the sample initially exposed to 10(23) D/m(2) at room temperature was heated to 400 degrees C in the measurement chamber for medium energy ion scattering and several spectra were recorded at intermediate temperatures. The obtained data showed that the layer was relatively stable below 200 degrees C whereas a drastic change in the film composition occurred between 200 degrees C and 250 degrees C due to interdiffusion of iron and silicon, the latter of which was the substrate material. The surface morphologies of the films were probed with atomic force microscopy showing that protrusions of 10-100 nm width appeared after deuterium bombardment at fluences higher than 10(22) D/m(2).

  • 54.
    Sun, Fengzhen
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Wiklund, Urban
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Aviles, F.
    Ctr Invest Cient Yucatan AC, Unidad Mat, Calle 43 130 X 32 Y 34,Col Chuburna Hidalgo, Merida 97205, Yucatan, Mexico..
    Gamstedt, E. Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Assessing local yield stress and fracture toughness of carbon nanotube poly(methyl methacrylate) composite by nanosectioning2017In: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 153, p. 95-102Article in journal (Refereed)
    Abstract [en]

    A nanosectioning (cutting) method was used to test the local shear yield stress and fracture toughness (specific work of surface formation) of multiwall carbon nanotube (MWCNT) poly(methyl methacrylate) (PMMA) composites, and the effects of MWCNT content on the yield stress and toughness were investigated. The composites were prepared by a solution casting method, with MWCNT content varying from 0.05 to 1.0 wt%. Above 0.1 wt% MWCNT content, the yield stress reduced by the addition of MWCNTs. The fracture toughness of the composite was effectively enhanced by the addition of MWCNTs, ranging from 17 J/m2 for the neat PMMA to 25 J/m2 for the 1.0 wt% composite. The shear yield stresses obtained by nanosectioning were correlated to nanoindentation measurement, and possible contributions from the MWCNTs to the fracture toughness of the composite were analysed.

  • 55.
    Tavares da Costa, Marcus Vinicius
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Bolinsson, Jessica
    Tetra Pak AB, DSO Packaging Materials, Lund, Sweden.
    Fayet, Pierre
    Adhemon Sarl, Thin Technology, Lausanne, Switzerland.
    Gamstedt, E. Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Experimental and numerical investigations to assess the interfacial strength of the ultrathin coatings on polymers substrates2018Conference paper (Refereed)
    Abstract [en]

    Metal coating with a nanometer scale thickness on flexible polymer substrates is an interesting combination for food packaging applications. This combination provides an enhancement of the barrier performance in the carton package [1, 2]. A concern is the cracking of the brittle coating when subjected to tension and bending in the manufacturing process. Such cracks can affect the permeability. In this study, the coatings were produced by atomic layer deposition of metal oxides, with thickness values between 4 and 20 nanometers on poly(ethylene terephthalate) substrate films.

    The interfacial strength between coating and substrate is known to affect the crack formation. We have used an experimental technique known as the Fragmentation test (see e.g. Ref. [3]) and an analytical model to quantify the interfacial strength. The fragmentation test was performed by in situ tensile loading in a scanning electron microscope stage to track the crack accumulation and subsequently to calculate interfacial shear strength. As the scanning electron and atomic force microscopy is becoming easier to use and more cost efficient, increased local information on crack geometry can be obtained. In this work, we explore a mixed numerical-experimental method to quantify the interfacial strength based on observed delamination emanating from coating cracks, as schematically outlined in the figure. The results from this alternative method are compared with those from the more established fragmentation test. The advantages and disadvantages of the two methods are discusses, as well as the accuracy of the assumptions in their underlying models.

  • 56.
    Tran, Sofia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Microstructure investigations of WC-Co cemented carbide containing Eta-phase and Cr2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Cemented carbide containing sub carbide phases, M6C and M12C, known as eta-phase, increases the lifetime milling cutters due to increased resistance to comb cracks. When milling, the inserts much sustain high temperatures, meaning edgeline toughness and thermal fatigue resistance are needed. To obtain this, finer grains and higher binder content are needed.

    In this study, WC-Co cemented carbides with eta-phase and Cr as well as a higher binder content are investigated. The microstructure is the focus, with parameters such as eta-phase particle size and volume fraction, WC grain size being evaluated. Another part of the study is the investigate the effect of Cr on heat treatment.

    The addition of Cr in a WC-Co cemented carbide with eta-phase has shown to give rise to smaller eta-phase particle sizes and WC grain size as compared to without Cr. Also, increasing the volume fraction of eta-phase has less influence on WC and eta-phase particle size.

    Heat treated samples without Cr is shown to increase the coercivity of the samples at 700 degrees Celsius, without change in WC grain size. The effect is also leading to an increase in hardness. But with addition of Cr, the effect seems to diminish.

  • 57.
    Wen, Rui-Tao
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Electrochromism in Metal Oxide Thin Films: Towards long-term durability and materials rejuvenation2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Electrochromic thin films can effectively regulate the visible and infrared light passing through a window, demonstrating great potential to save energy and offer a comfortable indoor environment in buildings. However, long-term durability is a big issue and the physics behind this is far from clear. This dissertation work concerns two important parts of an electrochromic window: the anodic and cathodic layers. In particular, work focusing on the anodic side develop a new Ni oxide based layers and uncover degradation dynamics in Ni oxide thin films; and work focusing on the cathodic side addresses materials rejuvenation with the aim to eliminate degradation.

    In the first part of this dissertation work, iridium oxide is found to be compatible with acids, bases and Li+-containing electrolytes, and an anodic layer with very superior long-term durability was developed by incorporating of small amount (7.6 at. %) of Ir into Ni oxide. This film demonstrated sustained cycle-dependent growth of charge density and electrochromic modulation even after 10,000 CV cycles. The (111) and (100) crystal facets in Ni oxide are found to possess different abilities to absorb cation and/or anion, which yields different degrees of coloration and this is very significant for the electrochromic properties. The degradation of charge capacity in Ni oxide has an inevitable rapid decay in the first hundreds of cycles, subsequently combined with a more gradual decay, which is independent of applied potential and film composition. The consistent phenomenon can be very well modeled by power-law or stretched exponential decay; however the two models are indistinguishable in the current stage. Interestingly, in both models, the power-law exponent is 0.2 ≤ p ≤ 0.8, with most of the values around 0.5, in line with normal or anomalous diffusion models.

    The second part of dissertation work deals with cathodic WO3 and TiO2. WO3 suffers from ion trapping induced degradation of charge capacity and optical modulation upon electrochemical cycling. This speculation is strongly supported by direct evidence from Time-of-Flight Elastic Recoil Detection Analysis (ToF-ERDA). Most importantly, this ion trapping induced degradation can be eliminated by a galvanostatic de-trapping process. Significant ion-trapping takes place when x exceeds ~0.65 in LixWO3. The trapped ions are stable in the host structure, meaning that the ions cannot de-trap without external stimuli. The similar work done on TiO2 significantly complements and extends the work on the recuperation of WO3; the difference is that the trapped ions in host TiO2 seem to be less stable compared with the trapped ions in WO3.

        Overall, this dissertation presents a refined conceptual framework for developing superior electrochromic windows in energy efficient buildings.

    List of papers
    1. Electrochromic iridium oxide films: Compatibility with propionic acid, potassium hydroxide, and lithium perchlorate in propylene carbonate
    Open this publication in new window or tab >>Electrochromic iridium oxide films: Compatibility with propionic acid, potassium hydroxide, and lithium perchlorate in propylene carbonate
    2014 (English)In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 120, no Part A, p. 151-156Article in journal (Refereed) Published
    Abstract [en]

    Porous thin films of It oxide were prepared by reactive dc magnetron sputtering onto unheated substrates. The crystallite size was similar to 5 nm, and a small amount of unoxidized Ir was present. The electrochromic performance was studied by optical transmittance measurements and cyclic voltammetry applied to films in aqueous and non-aqueous electrolytes, specifically being 1 M propionic acid, 1 M potassium hydroxide (KOH), and 1 M lithium perchlorate in propylene carbonate (Li-PC). Cyclic voltammetry measurements indicated that the films had a fractal surface structure. Good electrochromism, with mid-luminous transmittance modulation between similar to 55 and similar to 90% in similar to 100-nm-thick films, was documented in all of the electrolytes.

    Keywords
    Ir oxide, Porous thin films, Electrochromism, Transmittance, Durability
    National Category
    Engineering and Technology
    Research subject
    Engineering Science with specialization in Solid State Physics
    Identifiers
    urn:nbn:se:uu:diva-218594 (URN)10.1016/j.solmat.2013.08.035 (DOI)000329595400018 ()
    Projects
    EU GRINDOOR
    Funder
    EU, FP7, Seventh Framework Programme, 267234
    Available from: 2014-02-13 Created: 2014-02-13 Last updated: 2017-12-06Bibliographically approved
    2. Anodic Electrochromism for Energy-Efficient Windows: Cation/Anion-Based Surface Processes and Effects of Crystal Facets in Nickel Oxide Thin Films
    Open this publication in new window or tab >>Anodic Electrochromism for Energy-Efficient Windows: Cation/Anion-Based Surface Processes and Effects of Crystal Facets in Nickel Oxide Thin Films
    2015 (English)In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 25, no 22, p. 3359-3370Article in journal (Refereed) Published
    Abstract [en]

    Anodic electrochromic (EC) oxides are of major interest as counter electrodes for smart window applications owing to their unique optical properties upon charge insertion and extraction. However, performance optimization of such oxides has been hampered by limited understanding of their EC mechanism, particularly in Li+-conducting electrolytes. This paper reports on NiOx films with 1.16 x 1.32, prepared by sputter deposition. These films are immersed in an electrolyte of lithium perchlorate in propylene carbonate, and EC properties are studied by cyclic voltammetry and in situ optical transmittance measurements. The electrochromism is significantly enhanced at large values of x. It has been found that charge exchange in Ni oxide is mainly due to surface processes and involves both cations and anions from the electrolyte, which is different from the case of cathodic EC materials such as WO3. Whereas previous studies of Ni oxide have focused on cation intercalation, the cation/anion-based mechanism presented here offers a new paradigm for designing and developing EC devices such as smart windows for energy efficient buildings.

    Keywords
    cation, anion adsorption, electrochromism, nickel oxides, surface process
    National Category
    Condensed Matter Physics Engineering and Technology
    Research subject
    Engineering Science with specialization in Solid State Physics
    Identifiers
    urn:nbn:se:uu:diva-256995 (URN)10.1002/adfm.201500676 (DOI)000355992600012 ()
    Funder
    EU, European Research Council, 267234
    Available from: 2015-06-30 Created: 2015-06-29 Last updated: 2018-08-30Bibliographically approved
    3. Cyclic voltammetry on sputter-deposited films of electrochromic Ni oxide: Power-law decay of the charge density exchange
    Open this publication in new window or tab >>Cyclic voltammetry on sputter-deposited films of electrochromic Ni oxide: Power-law decay of the charge density exchange
    2014 (English)In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 105, no 16, p. 163502-Article in journal (Refereed) Published
    Abstract [en]

    Ni-oxide-based thin films were produced by reactive direct-current magnetron sputtering and were characterized by X-ray diffraction and Rutherford backscattering spectroscopy. Intercalation of Li+ ions was accomplished by cyclic voltammetry (CV) in an electrolyte of LiClO4 in propylene carbonate, and electrochromism was documented by spectrophotometry. The charge density exchange, and hence the optical modulation span, decayed gradually upon repeated cycling. This phenomenon was accurately described by an empirical power law, which was valid for at least 10(4) cycles when the applied voltage was limited to 4.1V vs Li/Li+. Our results allow lifetime assessments for one of the essential components in an electrochromic device such as a "smart window" for energy-efficient buildings.

    National Category
    Engineering and Technology Physical Sciences
    Research subject
    Engineering Science with specialization in Solid State Physics
    Identifiers
    urn:nbn:se:uu:diva-234931 (URN)10.1063/1.4899069 (DOI)000344363000084 ()
    Projects
    EU GRINDOOR
    Funder
    EU, FP7, Seventh Framework Programme, 267234
    Available from: 2014-10-27 Created: 2014-10-27 Last updated: 2017-12-05Bibliographically approved
    4. Anodic Electrochromism for Energy-Efficient Windows: Decay of Charge Density upon Extensive Electrochemical Cycling of Nickel Oxide Thin Films
    Open this publication in new window or tab >>Anodic Electrochromism for Energy-Efficient Windows: Decay of Charge Density upon Extensive Electrochemical Cycling of Nickel Oxide Thin Films
    (English)Article, review/survey (Refereed) Submitted
    National Category
    Energy Systems Manufacturing, Surface and Joining Technology Composite Science and Engineering
    Identifiers
    urn:nbn:se:uu:diva-267132 (URN)
    Available from: 2015-11-18 Created: 2015-11-18 Last updated: 2016-01-13
    5. Strongly Improved Electrochemical Cycling Durability by Adding Iridium to Electrochromic Nickel Oxide Films
    Open this publication in new window or tab >>Strongly Improved Electrochemical Cycling Durability by Adding Iridium to Electrochromic Nickel Oxide Films
    2015 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 7, no 18, p. 9319-9322Article in journal (Refereed) Published
    Abstract [en]

    Anodically colored nickel oxide (NiO) thin films :are of much interest as counter electrodes in tungsten oxide based electrochromic devices such as "smart windows" for energy-efficient buildings. However, NiO films are prone to Suffering severe charge density degradation upon prolonged electrochemical cycling, which can lead to insufficient device lifetime. Therefore, a means to improve the durability of NiO-based films is an important challenge at present. Here we report that the incorporation of a modest amount of iridium into NiO films [Ir/(Ir + Ni) = 7.6 atom %] leads to remarkable durability, exceeding 10000 cycles in a lithium-conducting, electrolyte, along with significantly improved optical modulation during extended cycling. Structure characterization showed that the face-centered-cubic-type NiO structure remained after iridium addition. Moreover, the crystallinity of these films was enhanced upon electrochemical cycling.

    Keywords
    electrochromic, iridium-nickel oxide, improved durability, charge density, optical modulation
    National Category
    Nano Technology Engineering and Technology
    Research subject
    Engineering Science with specialization in Solid State Physics
    Identifiers
    urn:nbn:se:uu:diva-256240 (URN)10.1021/acsami.5b01715 (DOI)000354906500002 ()25919917 (PubMedID)
    Funder
    EU, European Research Council, 267234
    Available from: 2015-06-24 Created: 2015-06-22 Last updated: 2017-12-04Bibliographically approved
    6. Electrochromic Iridium-Containing Nickel Oxide Films with Excellent Electrochemical Cycling Performance
    Open this publication in new window or tab >>Electrochromic Iridium-Containing Nickel Oxide Films with Excellent Electrochemical Cycling Performance
    2016 (English)In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 163, no 2, p. E7-E13Article in journal (Refereed) Published
    Abstract [en]

    Electrochromic Ni oxide thin films attract much interest because of their large potential for applications as optically active layers in energy-saving and comfort enhancing smart windows in buildings. However Ni oxide, typically being the anodic counter electrode in a W-oxide-based device, may suffer severe charge capacity degradation upon extended electrochemical cycling. It is therefore important to identify improved Ni-oxide-based thin films for electrochromics. Here we describe a new class of such films wherein an addition of a small amount of Ir to Ni oxide is found to provide strongly improved electrochemical cycling durability. Best properties were achieved with Ir/(Ir + Ni) = 7.6%, and such films displayed charge capacity and optical modulation that, remarkably, were still increasing after 10,000 cycles.

    Keywords
    Electrochromic, Ir -Ni oxide, thin films, durability
    National Category
    Chemical Sciences Physical Sciences Engineering and Technology Materials Chemistry
    Research subject
    Engineering Science with specialization in Solid State Physics
    Identifiers
    urn:nbn:se:uu:diva-267706 (URN)10.1149/2.0591602jes (DOI)000367324400057 ()
    Funder
    EU, European Research Council, 267234
    Available from: 2015-11-25 Created: 2015-11-25 Last updated: 2018-08-30Bibliographically approved
    7. Eliminating degradation and uncovering ion-trapping dynamics in electrochromic WO3 thin films
    Open this publication in new window or tab >>Eliminating degradation and uncovering ion-trapping dynamics in electrochromic WO3 thin films
    2015 (English)In: Nature Materials, ISSN 1476-1122, E-ISSN 1476-4660, Vol. 14, p. 996-1001Article in journal (Refereed) Published
    Abstract [en]

    There is keen interest in the use of amorphous WO3 thin films as cathodic electrodes in transmittance-modulating electrochromic devices1–4. However, these films suer from ion-trapping-induced degradation of optical modulation and reversibility on extended LiC-ion exchange. Here,we demonstrate that ion-trapping-induced degradation, which is commonly believed to be irreversible, can be successfully eliminatedby constant-current-driven de-trapping; that is, WO3 films can be rejuvenated and regain their initial highly reversible electrochromic performance. Pronounced ion trapping occurs when x exceeds 0.65 in LixWO3 during ion insertion. We find two main kinds of Li+-ion-trapping site (intermediate and deep) in WO3, where the intermediate ones are most prevalent. Li+ ions can be completely removed from intermediate traps but are irreversibly bound in deep traps. Our results provide a general framework for developing and designing superior electrochromic materials and devices.

    Keywords
    WO3 films, electrochromic, variable-transmittance windows, ion-trapping
    National Category
    Materials Engineering
    Identifiers
    urn:nbn:se:uu:diva-264725 (URN)10.1038/nmat4368 (DOI)000361771800018 ()
    Funder
    EU, European Research Council, 267234
    Available from: 2015-10-15 Created: 2015-10-15 Last updated: 2018-08-30Bibliographically approved
    8. Sustainable rejuvenation of electrochromic WO3 films
    Open this publication in new window or tab >>Sustainable rejuvenation of electrochromic WO3 films
    2015 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 7, no 51, p. 28100-28104Article, review/survey (Refereed) Published
    Abstract [en]

    Devices relying on ion transport normally suffer from a decline of their long-term performance due to irreversible ion accumulation in the host material, and this effect may severely curtail the operational lifetime of the device. In this work, we demonstrate that degraded electrochromic WO3 films can sustainably regain their initial performance through galvanostatic de-trapping of Li+ ions. The rejuvenated films displayed degradation features similar to those of the as-prepared films, thus indicating that the de-trapping process is effectively reversible so that long-term performance degradation can be successfully avoided. De-trapping did not occur in the absence of an electric current.

    Keywords
    electrochromic, WO3, optical, sustainable rejuvenation, de-trapping
    National Category
    Manufacturing, Surface and Joining Technology Engineering and Technology
    Research subject
    Engineering Science with specialization in Solid State Physics
    Identifiers
    urn:nbn:se:uu:diva-266808 (URN)10.1021/acsami.5b09035 (DOI)000369448200013 ()26562589 (PubMedID)
    Funder
    EU, European Research Council, 267234
    Available from: 2015-11-18 Created: 2015-11-11 Last updated: 2018-08-30Bibliographically approved
    9. Galvanostatic ion de-trapping rejuvenates oxide thin films
    Open this publication in new window or tab >>Galvanostatic ion de-trapping rejuvenates oxide thin films
    Show others...
    2015 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 7, no 48, p. 26387-26390Article in journal (Refereed) Published
    Abstract [en]

    Ion trapping under charge insertion-extraction is well-known to degrade the electrochemical performance of oxides. Galvano-static treatment was recently shown capable to rejuvenate the oxide, but the detailed mechanism remained uncertain. Here we report on amorphous electrochromic (EC) WO3 thin films prepared by sputtering and electrochemically cycled in a lithium-containing electrolyte under conditions leading to severe loss of charge exchange capacity and optical modulation span. Time-of-flight elastic recoil detection analysis (ToF-ERDA) documented pronounced Li+ trapping associated with the degradation of the EC properties and, importantly, that Li+ detrapping, caused by a weak constant current drawn through the film for some time, could recover the original EC performance. Thus, ToF-ERDA provided direct and unambiguous evidence for Li+ detrapping.

    National Category
    Other Materials Engineering Atom and Molecular Physics and Optics Engineering and Technology
    Research subject
    Engineering Science with specialization in Solid State Physics
    Identifiers
    urn:nbn:se:uu:diva-267134 (URN)10.1021/acsami.5b09430 (DOI)000366339100006 ()26599729 (PubMedID)
    Funder
    EU, FP7, Seventh Framework Programme, 267234
    Available from: 2015-11-18 Created: 2015-11-18 Last updated: 2018-08-30Bibliographically approved
    10. Electrochromism for energy conservation: Eliminating degradation in amorphous TiO2 thin films
    Open this publication in new window or tab >>Electrochromism for energy conservation: Eliminating degradation in amorphous TiO2 thin films
    (English)Article, review/survey (Refereed) Submitted
    Keywords
    Smart windows, TiO2, electrochromism, ion-trapping, rejuvenating
    National Category
    Nano Technology Energy Systems Materials Engineering
    Identifiers
    urn:nbn:se:uu:diva-267127 (URN)
    Available from: 2015-11-18 Created: 2015-11-18 Last updated: 2016-01-13
  • 58.
    Wen, Rui-Tao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Granqvist, Gunnar
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Niklasson, Gunnar
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Anodic Electrochromism for Energy-Efficient Windows: Decay of Charge Density upon Extensive Electrochemical Cycling of Nickel Oxide Thin FilmsArticle, review/survey (Refereed)
  • 59.
    Wu, Zhigang
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology. Huazhong Univ Sci & Technol, State Key Lab Digital Mfg Equipment & Technol, Luoyu Rd 1037, Wuhan 430074, Hubei, Peoples R China.
    Zhang, Shuo
    Huazhong Univ Sci & Technol, State Key Lab Digital Mfg Equipment & Technol, Luoyu Rd 1037, Wuhan 430074, Hubei, Peoples R China.
    Vorobyev, Alexey
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Gamstedt, E. Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Wu, Kang
    Huazhong Univ Sci & Technol, State Key Lab Digital Mfg Equipment & Technol, Luoyu Rd 1037, Wuhan 430074, Hubei, Peoples R China.
    Guo, Chuanfei
    Southern Univ Sci & Technol, Dept Mat Sci & Engn, Shenzhen 518055, Peoples R China.
    Jeong, Seung Hee
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Seamless modulus gradient structures for highly resilient, stretchable system integration2018In: MATERIALS TODAY PHYSICS, ISSN 2542-5293, Vol. 4, p. 28-35Article in journal (Refereed)
    Abstract [en]

    Hybrid system integration of rigid components into stretchable systems is often necessary when targeting for valuable functions in various scenarios. Among them, (Young's) modulus gradient structures for system integration demonstrate excellent mechanical performance when stretched. However, the mechanical reliability is still limited under large deformation due to the inherent interface between materials of different modulus. Here, a seamless transition between heterogeneous moduli parts made with polydimethylsiloxane (PDMS)-based elastomers is presented for stretchable system integration by simply tuning their modulus via introducing a small amount of an additive into some parts of the substrate. These gradient structures not only provide a high stretchability (similar to 250%) for the overall system, but also improve the resilience of the system (can be stretched up to 50,000 cycles from 0 to 150% global strain) at the same time. The seamless modulus gradient structures provide a simple and effective way of allowing highly resilient and stretchable system integration for various soft intelligent systems.

  • 60.
    Zhao, Jie
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics. Northwest Univ Xian, Key Lab Synthet & Nat Funct Mol Chem, Minist Educ, Coll Chem & Mat Sci, Xian 710069, Shaanxi, Peoples R China.
    Zeng, Shuangshuang
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Wu, Biao
    Northwest Univ Xian, Key Lab Synthet & Nat Funct Mol Chem, Minist Educ, Coll Chem & Mat Sci, Xian 710069, Shaanxi, Peoples R China.
    Zhang, Shi-Li
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Zhang, Zhi-Bin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Re-organized graphene nanoplatelet thin films achieved by a two-step hydraulic method2018In: Diamond and related materials, ISSN 0925-9635, E-ISSN 1879-0062, Vol. 84, p. 141-145Article in journal (Refereed)
    Abstract [en]

    Film deposition of graphene nanoplatelets (GNPs) from dispersion via casting and printing approaches features cost- and material-efficiency, however, it usually suffers from poor uniformity, rough surface and loose flake stacking due to adverse effect of hydraulic force. Here, a simple two-step method exploiting hydraulic force is presented to readily deliver GNP films of improved quality from an aqueous dispersion. While as-deposited GNP films exhibit the aforementioned film defects, the hydraulic force in the subsequent step constituting soaking in water and drying leads to an efficient re-organization of the individual GNPs in the films, The majority of GNPs thus are oriented horizontally and closely stacked. As a result, densified, smoothened and homogenized GNP thin films can be readily achieved. The GNP re-organization reduces resistivity from > 1 Omega cm to 10(-2) Omega cm. The method developed is universally applicable to solution-phase film deposition of 2D materials.

  • 61.
    Zoma, Fati
    et al.
    Univ Ouaga 01 Pr Joseph KI ZERBO, Lab Phys & Chem Environm, 03 BP 7021, Ouagadougou, Burkina Faso.
    Toguyeni, David Y. K.
    Univ Ouaga 01 Pr Joseph KI ZERBO, Lab Phys & Chem Environm, 03 BP 7021, Ouagadougou, Burkina Faso.
    Coulibaly, Ousmane
    Univ Ouaga 01 Pr Joseph KI ZERBO, Lab Phys & Chem Environm, 03 BP 7021, Ouagadougou, Burkina Faso.
    Hassel, Ivón
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Ouedraogo, Abdoulaye
    Univ Ouaga 01 Pr Joseph KI ZERBO, Lab Thermal & Renewable Energies, 03 BP 7021, Ouagadougou, Burkina Faso.
    Potentials of an Eco-Friendly Composite in Hot-Dry Climate2018In: Journal of Renewable Materials, ISSN 2164-6325, E-ISSN 2164-6341, Vol. 6, no 1, p. 47-54Article in journal (Refereed)
    Abstract [en]

    This study aims to show the aptitude of a locally made composite for providing thermal comfort and mechanical resistance in buildings in hot-dry climates. The thermal characterization reveals that the thermal diffusivity of the studied material is lower than that of commonly used materials such as agglomerated and full cinderblocks and laterite blocks and therefore is a better insulating material. In addition, its thermal inertia is the highest compared to commonly used materials of agglomerated and full cinderblocks, laterite blocks and compressed earth blocks, which implies a longer time lag. On the basis of mechanical resistance, with a compression resistance of 3.61 MPa, the studied material meets the requirement of CRATerre and NBF 02-003 (2009) as a material for construction of single-storey buildings. Therefore, this material, containing 1% Hibiscus sabdariffa fibers and compacted by vibration, is a suitable material for the walls of standing buildings and for thermal comfort in hot dry climates.

  • 62.
    Åkerlund, Elin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Development of polymer based composite filaments for 3D printing2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The relatively new and still growing field of 3D-printing has opened up the possibilities to manufacture patient-specific medical devices with high geometrical accuracy in a precise and quick manner. Additionally, biocompatible materials are a demand for all medical applications while biodegradability is of importance when developing scaffolds for tissue growth for instance. With respect to this, this project consisted of developing biocompatible and bioresorbable polymer blend and composite filaments, for fused deposition modeling (FDM) printing. Poly(lactic acid) (PLA) and polycaprolactone (PCL) were used as supporting polymer matrix while hydroxyapatite (HA), a calcium phosphate with similar chemical composition to the mineral phase of human bone, was added to the composites to enhance the biological activity. PLA and PCL content was varied between 90–70 wt% and 10-30 wt%, respectively, while the HA content was 15 wt% in all composites. All materials were characterized in terms of mechanical properties, thermal stability, chemical composition and morphology. An accelerated degradation study of the materials was also executed in order to investigate the degradation behavior as well as the impact of the degradation on the above mentioned properties. The results showed that all processed materials exhibited higher mechanical properties compared to the human trabecular bone, even after degradation with a mass loss of around 30% for the polymer blends and 60% for the composites. It was also apparent that the mineral accelerated the polymer degradation significantly, which can be advantageous for injuries with faster healing time, requiring only support for a shorter time period.

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