To see the other types of publications on this topic, follow the link: Nanostructured composite.
Dissertations / Theses on the topic 'Nanostructured composite'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Nanostructured composite.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Prozorova, M. S., M. Y. Arseenko, M. G. Kovaleva, and Yu N. Tyurin. "Properties of nanostructured composite powder coating." Thesis, Видавництво СумДУ, 2011. http://essuir.sumdu.edu.ua/handle/123456789/20595.
Full text
2
Kurban, Z. "Electrospun nanostructured composite fibres for hydrogen storage applications." Thesis, University College London (University of London), 2011. http://discovery.ucl.ac.uk/1333231/.
Full textAbstract:
The urgent realisation of the low carbon economy requires the development of cheap, safe and lightweight hydrogen storage, both for commercialisation of hydrogen fuel cell vehicles, and for the use of hydrogen as a reservoir of energy from intermittent renewable energy sources. The primary motivation of this PhD project was to investigate (co)electrospinning, a cheap and scalable fibre production technique, for nanostructuring potential solid state hydrogen storage materials. Solid state storage of hydrogen is being extensively investigated worldwide. However, many of the candidate materials are still not able to meet the practical requirements for mobile applications. The principal drawbacks are that these materials either have low capacity for hydrogen storage (physisorption systems), even at cryogenic temperatures, or high release temperatures with slow release rates (chemisorption systems). Because kinetic and thermodynamic properties can be improved by nanoscale processing, nanoengineering of selected materials has emerged as one of the most effective ways of overcoming their associated performance barriers. In this thesis I present two successful approaches to nanostructuring using electrospinning: firstly, by encapsulating chemical hydrides in polymeric nanofibres, as demonstrated by the development of co-axial ammonia borane-encapsulated polystyrene (AB-PS) fibres, and secondly, by post-processing of single-phase electrospun PAN fibres, resulting in the synthesis of potassium-intercalated graphitic nanofibres (K-GNFs). The results show that the micro and nano-structure imparted through electrospinning, can have the effect of reducing dehydrogenation temperatures in AB-PS fibres (from 110 to ~85 °C) and improving the (de)hydrogenation rates by an order of magnitude in both composite fibres (from ~50 to <5 mins in K-GNFs and from ~150 minutes to as low as 15 minutes in AB-PS fibres). The details of co-axial electrospinning as a novel approach to nanoengineering chemical hydrogen storage materials and as a way of possibly overcoming issues regarding reversibility, stability and clean hydrogen release from many of these materials is discussed. The solution selection method I have developed for use in the synthesis of co-axial composite fibres can be applied as an efficient solution selection formula for multi-phase electrospinning in general.
3
Amooali, Khosroabadi Akram. "Optical and Electrical Properties of Composite Nanostructured Materials." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/333480.
Full textAbstract:
A novel lithographic fabrication method is used to fabricate nanopillars arrays of anisotropic Ag and TCO electrodes. Optical and electrical properties of the electrodes including bandgap, free carrier concentration, resistivity and surface plasmon frequency of different electrodes can be tuned by adjusting the dimensions and geometry of the pillars. Given the ability to tune the nonlocal responses of the plasmonic field enhancements, we attempt to determine the nature of the effective refractive index profile within the visible wavelength region for multi-layer hybrid nanostructures. Knowledge of the effective optical constants of the obtained structure is critical for various applications. nanopillars of TCO\Ag core shell structures have been successfully fabricated. The Maxwell-Garnett mixing law has been used to determine the optical constants of the nanostructure based on spectroscopic ellipsometry measurements. Simulated reflection spectra indicate a down shift in the Brewster angle of the pillars resulting from the reduction in the effective refractive index of the nanostructure. Two plasmonic resonances were observed, with one in the visible region and the other in the IR region. Plasmon hybridization model is used to describe the behavior of metal and metal oxide core shell nanostructured electrodes. Different charge density distributions around the pillars determine the plasma frequency which depends on the core and surrounding media dielectric constants. Finite Difference Time Domain (FDTD) simulation of different structures agree well with experiment and help us to understand electric field behavior at different structures with different geometries and dielectric constants. Plasmonic Ag nanopillar arrays are effective substrates for surface enhanced Raman spectroscopy (SERS). An enhancement factor up to 6 orders of magnitude is obtained. Monolayers of C60 is deposited on the Ag nanopillars and the interface of C60/Ag is studied which is important in optoelectronic devices. Electron delocalization between C60 and Ag is confirmed.
4
Xie, Zhibin. "Nanostructured titania films in inorganic/organic composite pholtovoltaic devices." Thesis, University of Oxford, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.555324.
Full textAbstract:
Composite solar cells (CSCs) composed of a titania layer 'and a conjugated polymer thin film sandwiched between anode and cathode have attracted considerable interest as cost- effective alternatives to silicon-based photovoltaic (PV) devices. The titania layer not only affects the dissociation of excitons photogenerated in the conjugated polymer but also plays a crucial role in collecting injected electrons at the anode. As a result, the morphology and electron transport properties of the titania thin films have a great impact on the PV performance of the CSCs. In this project, I first investigated the microstructure of titania thin films fabricated . by doctor blading a colloidal paste (DB-HT), spin coating sol-gel solutions (SC-SG or SC-PP) and glancing angle deposition (GLAD). Random nanocrystalline Ti02 thin film were obtained by the DB-HT, SC-SG and SC-PP techniques while the pore size, porosity and surface roughness all decrease in this order. The power efficiencies of CSCs based on DB- HT Ti02 were reproducibly greater than 0.5% at 80mW/cm2, outperforming similar devices by other groups. Under the same illumination conditions, CSCs based on SC-SG and SC-PP Ti02 gave efficiencies of only 0.10% and 0.007%. These studies suggested that the titania surface roughness was a critical factor controlling Jsc in bi-Iayer CSCs. For the SC-PP titania layer, observations include that anatase nanocrystals with size 5~ 1 Onm exist in as-deposited layers, and that these can work as a blocking layer and have no detrimental effect on their PV performance. Titania layers with controllable columnar structures were fabricated also by glancing angle deposition. The effects of post-deposition annealing and deposition parameters on the microstructures and optical properties of these textured titania thin films were investigated. After preliminary optimization of annealing conditions and deposition angle, CSCs based on GLAD titania achieved an efficiency of 0.13%. A limiting factor for the inferior performance could be limited polymer penetration into the GLAD titania layer. In the second part of the project, photoconductivity (PC) in nanocrystalline Ti02 thin films was studied to understand the electron transport. It was found that PC evolution is heavily influenced by ambient atmosphere, sample temperature, and illumination conditions. These phenomena were interpreted in terms of electron generation, electron trapping and detrapping, hole trapping and detrapping and electron scavenging. I discovered that the 1 initial normalized decay rate increased with reduced light intensity. The experimental data was fitted using a model developed by a colleague to estimate electron mobility and concentration. Finally, it was found that electron transport in the Ti02 thin films at least in the initial stage of illumination controls the performance of Ti02-based CSCs, and that the quasi steady-state PC in Ti02 film appears to be a good indicator of Jsc value in the devices. !.
5
Tyurin, Yu, O. Ivanov, O. Kolisnichenko, M. Kovaleva, I. Duda, O. Maradudina, and Y. Trusova. "Properties of nanostructured composite titanium coating on aluminium surface." Thesis, Видавництво СумДУ, 2011. http://essuir.sumdu.edu.ua/handle/123456789/20488.
Full text
6
Zhang, Xiefei. "Studies on Single Wall Carbon Nanotube and Polymer Composite Films and Fibers." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/7610.
Full textAbstract:
Single wall carbon nanotubes (SWNT) have been extensively studied over the last decade due to their excellent comprehensive properties for a variety of applications. This study is focused on the applications of SWNTs as reinforcement for polymer matrices. Due to van der Waal interactions, SWNTs form bundles of about 30 nm diameters. In order to take full advantage of the SWNT mechanical properties, SWNT must exfoliate or at least disperse in small diameter bundle size. Optical microscopy and SEM only give qualitative information of dispersion. Quantitative characterization through TEM or AFM can be time consuming in order to get statistical result. In this study, simple method is developed to quantitatively estimate the size of SWNT bundle in dispersion based on the geometry controlled electrical percolation behavior. The SWNTs can be dispersed /exfoliated via PVP wrapped SWNT aqueous dispersion assisted by surfactants such as sodium dodycel sulfate. PVA / SWNT composite films prepared through PVP wrapped SWNTs exhibit improved mechanical properties as well as the evidence of load transfer from the polymer matrix to the SWNT as monitored by the Raman spectroscopy. SWNT can also be well dispersed into PVA/DMSO/H2O solution. Gel spinning of PVA/SWNT composite fiber has been successfully carried out with improved mechanical properties. Functionalized tubes can be used to enhance SWNT dispersion and exfoliation. Oxidation in strong acids is one method used for functionalizing nanotubes. SWNTs have been functionalized in nitric acid. The structure and properties of films (buckypaper) processed from nitric acid functionalized tubes have been studied exhibiting high tensile strength and high electrical conductivity. Nitric acid treatment results in selective degradation of the small diameter tubes.
7
Kuryak, Chris A. (Chris Adam). "Nanostructured thin film thermoelectric composite materials using conductive polymer PEDOT:PSS." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/79270.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 65).
Thermoelectric materials have the ability to convert heat directly into electricity. This clean energy technology has advantages over other renewable technologies in that it requires no sunlight, has no moving parts, and is easily scalable. With the majority of the unused energy in the United States being wasted in the form of heat and the recent mandates to reduce greenhouse gas emissions, thermoelectric devices could play an important role in our energy future by recovering this wasted heat and increasing the efficiency of energy production. However, low conversion efficiencies and the high cost of crystalline thermoelectric materials have restricted their implementation into modem society. To combat these issues, composite materials that use conductive polymers have been under investigation due to their low cost, manufacturability, and malleability. These new composite materials could lead to cheaper thermoelectric devices and even introduce the technology to new application areas. Unfortunately, polymer composites have been plagued by low operating efficiencies due to their low Seebeck coefficient. In this research, we show an enhanced Seebeck coefficient at the interface of poly(3,4- ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) spin coated onto silicon substrates. The maximum Seebeck coefficient achieved was 473 uV/K with a PEDOT:PSS thickness of 7.75 nm. Furthermore, the power factor of this interface was optimized with a 15.25 nm PEDOT:PSS thickness to a value of 1.24 uV/K2-cm, which is an order of magnitude larger than PEDOT:PSS itself. The effect of PEDOT:PSS thickness and silicon thickness on the thermoelectric properties is also discussed. Continuing research into this area will attempt to enhance the power factor even further by investigating better sample preparation techniques that avoid silicon surface oxidation, as well as creating a flexible composite material of PEDOT:PSS with silicon nanowires..
by Chris A. Kuryak.
S.M.
8
Al-Hajjaj, A. A. "A nanostructured composite material for hydrogen storage : design & analysis." Thesis, University of Southampton, 2012. https://eprints.soton.ac.uk/348877/.
Full textAbstract:
Hydrogen has long been considered an ideal energy carrier for a sustainable energy economy, for both direct combustion and as a fuel for polymer-electrolyte fuel cells. One of the main challenges associated with the use of hydrogen is to find efficient methods of storage. Any method must be safe, reversible, cost-effective and practical. In this thesis, a general introduction to hydrogen energy and the hydrogen economy is provided, together with descriptions of incumbent and emerging storage methods. A mathematical framework for simulating sorption isotherms in microporous materials is developed. This framework provides explicit expressions for the excess, condensed, compressed and absolute hydrogen masses. Furthermore, key parameters such as the surface area and adsorption volume can be estimated (for the first time) using a single-step nonlinear regression analysis, with the use of any isotherm model. Values are derived for three classes of porous materials, showing consistency with experimental data. A novel composite consisting of titanate nanotubes decorated with nanostructured metal cyanide frameworks, e.g., cadmium ferricyanide (Cd3[Fe(CN)6]2), are synthesised. The equilibrium and kinetic hydrogen sorption properties of the titanate-nanotube/Cd3[Fe(CN)6]2 composite are studied at low, intermediate and high pressure (up to 150 bar), revealing uptake values of ca. 14 weight %, which compare favourably with known materials for hydrogen storage. The role of mass transport in the sorption process is investigated, including the effects of boundary-layer diffusion and intraparticle diffusion. The results suggest that the composite possesses good hydrogen mass transfer characteristics. The effects of the reaction environment during synthesis are explored and the samples are thoroughly characterised. Significant differences in the loading of Cd3[Fe(CN)6]2 on the titanate nanotubes are seen. Hydrogen and nitrogen sorption analyses reveal the role of the pore size distribution on the effective surface area for adsorption and, therefore, the hydrogen uptake.
9
Harris, Kurt E. "Characterization of Carbon Nanostructured Composite Film Using Photothermal Measurement Technique." DigitalCommons@USU, 2018. https://digitalcommons.usu.edu/etd/6931.
Full textAbstract:
Graphene is a form of carbon with unique thermal and structural properties, giving it high potential in many applications, from electronics to driveway heating. Advanced fabrication techniques putting small, graphene-like structures in a polymer matrix could allow for incorporation of some of the benefits of graphene into very lightweight materials, and allow for broader commercialization. Measuring the thermal properties of these thin-film samples is a technical capability in need of development for use with the specific specimens used in this study. Relating those thermal properties to the microstructural composition was the focus of this work.
Several conclusions could be drawn from this study which will help guide future development efforts. Among these findings, it was found that increasing carbon content only improves thermal and electrical conductivity if the samples were of low porosity. Samples of approximately identical overall carbon content and void content had higher thermal conductivity if some carbon nanotubes were added in place of graphite. Nanotubes also appeared to reduce variability in thermal conductivity between pressed and unpressed samples, allowing for more predictable properties in fabrication.
10
Cibrev, Dejan. "Photoelectrocatalytic and photoelectrochromic properties of composite nanostructured metal oxide films." Doctoral thesis, Universidad de Alicante, 2019. http://hdl.handle.net/10045/99689.
Full textAbstract:
Los materiales llamados semiconductores (muchos de ellos óxidos metálicos) son capaces de generar portadores de carga (huecos y electrones) cuando se iluminan con luz suficientemente energética. Estos portadores son capaces de sostener reacciones redox. Los electrones de la banda de conducción (BC) y los huecos de la banda de valencia (BV) pueden reducir y oxidar, respectivamente, especies que estén en contacto directo con el semiconductor. Además, los electrones y huecos fotogenerados pueden eliminarse en el proceso que se conoce como recombinación. El grado en que se producen estas reacciones redox depende de la eficiencia en la separación de las cargas fotogeneradas. Una separación de los portadores efectiva da lugar a aplicaciones. En esta tesis se abordan detalladamente los procesos de foto(electro)cromismo y foto(electro)catálisis. La separación de los portadores de carga en un material puede verse favorecida por: - La creación de heterouniones entre dos semiconductores (óxidos) distintos. - El diseño adecuado de la nanoestructura de los óxidos: estructuras ordenadas y/o estructuras con mucha superficie interfacial. - La modificación de la superficie o del seno de los óxidos semiconductores (dopado). En las aplicaciones prácticas se pretende que haya una transferencia de carga capaz de impulsar el proceso de interés. Por lo tanto, el control de los procesos de transferencia de carga del semiconductor a través de sus interfases es fundamental en el diseño de materiales para una determinada aplicación. Teniendo todo esto en cuenta, los objetivos establecidos para esta tesis han sido: I. Preparar estructuras ordenadas de nanobarras de α-Fe2O3 (hematita) sobre vidrio conductor e investigar sus propiedades catalíticas para fotooxidar agua. Optimizar el proceso de fotooxidación del agua sobre electrodos de hematita aplicando un pretratamiento electroquímico. Estudiar el efecto del pretratamiento sobre la composición, morfología y estructura electrónica de la hematita. II. Modificar los electrodos de hematita con Ti de dos maneras distintas, una que afecte principalmente a todo el material y otra que afecte a la superficie de la hematita, con el fin de mejorar sus propiedades catalíticas para fotooxidar agua. Aplicar y estudiar el pretratamiento reductivo para los electrodos de hematita tras ser modificados con Ti. III. Modificar la superficie de las nanobarras de hematita con trimetilaluminio (TMA) mediante depósito de capa atómica (Atomic layer deposition - ALD) desde fase gas o por adsorción en fase líquida, con el fin de mejorar sus propiedades fotoelectroquímicas para oxidar agua. Investigar los cambios en las propiedades electrónicas y electroquímicas de los electrodos de hematita tras ser modificados. IV. Preparar electrodos nanoporosos de Ni(OH)2 sobre vidrio conductor (SnO2:F - FTO) e investigar sus propiedades catalíticas para oxidar agua en medio alcalino en función de la cantidad depositada y de la morfología del hidróxido. V. Preparar electrodos nanoporosos basados en capas mixtas TiO2/Ni(OH)2 sobre vidrio conductor e investigar la separación de carga en los mismos con el fin de estudiar su posible utilización en dispositivos fotoelectrocrómicos. Estudiar las cinéticas de los procesos de la coloración y decoloración a través de medidas (foto)(espectro)electroquímicas. Las siguientes cinco conclusiones generales resumen los resultados más importantes en relación con los cinco objetivos previamente mencionados. I. En este estudio se ha conseguido sintetizar barras de hematita nanoestructuradas y con orientación (110) depositadas sobre vidrio conductor a través de un método de baño químico. Estas capas se han utilizado para estudiar el proceso de fotoxidación del agua. Para mejorar las propiedades fotocatalíticas de estas capas se ha empleado un pretratamiento electroquímico simple y altamente controlable que consiste en la aplicación de potenciales negativos por un tiempo muy corto (en el rango de segundos). Este pretratamiento da lugar a una mejora de la fotocorriente de hasta ocho veces asociada a la oxidación del agua, junto con un desplazamiento negativo de 20 mV del potencial de inicio de la fotocorriente. Este pretratamiento también induce cambios en la morfología de los electrodos, capacidad electrocatalítica y en su estructura electrónica. Por lo tanto, el dopado electroquímico no puede considerarse simplemente como un dopado tipo-n capaz de aumentar la fotoactividad de las capas debido a una mejora en el transporte de electrones. En realidad, los resultados obtenidos muestran claramente que se producen cambios mucho más profundos en la estructura electrónica y la composición de las capas que mejoran significativamente las propiedades tanto electro- como foto-electrocatalíticas. De hecho, ambas propiedades siguen una tendencia general similar con el potencial del pretratamiento empleado. Dentro de un marco más general, el pretratamiento reductivo puede ser utilizado también para la mejora de estructuras de hematita previamente modificadas o dopadas. Desde una perspectiva práctica, el dopaje electroquímico tiene la limitación de no ser permanente, lo que significa que debe aplicarse periódicamente. Esto no es un inconveniente serio en un dispositivo práctico, siempre y cuando la mejora inducida por el pretratamiento compense claramente esta limitación. II. Se han diseñado dos estrategias de modificación de hematita económicas utilizando una disolución con un mismo precursor de Ti. En un procedimiento el Ti se introduce en la estructura de hematita, mientras que en la otra, se forma una capa de TiO2 ultra-delgada que cubre por completo la superficie de hematita. Ambas modificaciones inducen un aumento significativo en la fotocorriente para la oxidación de agua (4 - 6 veces). La razón principal de la mejora en las capas modificadas con Ti es la disminución significativa del proceso de recombinación. El freno de la recombinación en las muestras modificadas con una sobre-capa de TiO2 se atribuye principalmente al bloqueo de estados superficiales, mientras que en el caso de las muestras modificadas con Ti intercalado en la estructura se relaciona principalmente con el aumento del área interfacial junto con un aumento de la conductividad electrónica. III. Se han preparado electrodos basados en nanobarras de hematita modificadas con TMA empleando una estrategia simple de impregnación a partir de una disolución de hexano. Los resultados se han comparado con los obtenidos modificando los electrodos de hematita con TMA por ALD. Los electrodos modificados muestran una importante mejora, aumentando tres veces la fotocorriente de oxidación de agua. Por un lado, el TMA bloquea los estados superficiales de hematita y por otro, induce un enriquecimiento electrónico. Tal conclusión fue confirmada cualitativamente en el caso de muestras modificadas con TMA utilizando la técnica de ALD. A pesar de que la modificación en fase líquida ha dado una foto-actividad menor en términos de la magnitud de la fotocorriente que la de ALD, representa una alternativa mucho más económica. Además, el método de impregnación a partir de una disolución es industrialmente escalable. Dentro de un marco más general, la modificación con TMA es potencialmente aplicable a otros semiconductores tipo n. Por lo tanto, podría constituir una estrategia relevante para mejorar la eficiencia de la fotooxidación de agua utilizando otros materiales tales como TiO2, BiVO4, WO3, entre otros. IV. Este estudio muestra que, a través de un procedimiento simple y potencialmente escalable como el baño químico, se pueden producir capas nanoestructuradas ultra-finas de Ni(OH)2 sobre FTO. Estas películas se caracterizan por una gran actividad electrocatalítica. Son capaces de oxidar el agua desarrollando corrientes iguales o superiores a las de películas mucho más gruesas. Esto último está relacionado con el hecho de que la reacción de generación de oxígeno depende de la formación de níquel (IV) que puede verse limitada por la baja conductividad eléctrica de Ni(OH)2. Por tanto, el proceso se favorece en capas finas donde la distancia al substrato conductor es menor. Esta noción es muy importante de cara a su aplicación. No solo se minimiza la cantidad de Ni(OH)2 necesaria sino se producen también ánodos altamente eficientes transparentes y prácticamente incoloros. V. Este trabajo ha mostrado que una capa nanoporosa mixta y delgada de TiO2/Ni(OH)2 depositada sobre vidrio conductor y sometida a un potencial catódico constante puede colorearse al ser iluminada con luz ultravioleta, mientras que se decolora completamente cuando se interrumpe la iluminación. Este fenómeno se ha denominado “fotoelectrocromismo reversible potenciostatico”. El valor del potencial empleado permite seleccionar tanto el contraste en la coloración como la cinética de la decoloración. Este fenómeno es posible debido a la existencia de un área interfacial extendida de contacto TiO2/Ni(OH)2 debido a la estructura nanoporosa que permite un contacto íntimo entre ambos componentes. Desde un punto de vista práctico, estos resultados podrían facilitar el desarrollo de ventanas inteligentes con una nueva funcionalidad porque, además del convencional efecto electrocrómico, trabajarían en un segundo modo, en el que, la coloración respondería a la intensidad de la luz incidente (a un potencial constante).
11
Peters, Sarah June. "Fracture Toughness Investigations of Micro and Nano Cellulose Fiber Reinforced Ultra High Performance Concrete." Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/PetersSJ2009.pdf.
Full text
12
Basnayaka, Punya A. "Development of Nanostructured Graphene/Conducting Polymer Composite Materials for Supercapacitor Applications." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4864.
Full textAbstract:
The developments in mobile/portable electronics and alternative energy vehicles prompted engineers and researchers to develop electrochemical energy storage devices called supercapacitors, as the third generation type capacitors. Most of the research and development on supercapacitors focus on electrode materials, electrolytes and hybridization. Some attempts have been directed towards increasing the energy density by employing electroactive materials, such as metal oxides and conducting polymers (CPs). However, the high cost and toxicity of applicable metal oxides and poor long term stability of CPs paved the way to alternative electrode materials. The electroactive materials with carbon particles in composites have been used substantially to improve the stability of supercapacitors. Furthermore, the use of carbon particles and CPs could significantly reduce the cost of supercapacitor electrodes compared to metal oxides. Recent developments in carbon allotropes, such as carbon nanotubes (CNTs) and especially graphene (G), have found applications in supercapacitors because of their enhanced double layer capacitance due to the large surface area, electrochemical stability, and excellent mechanical and thermal properties.
The main objective of the research presented in this dissertation is to increase the energy density of supercapacitors by the development of nanocomposite materials composed of graphene and different CPs, such as: (a) polyaniline derivatives (polyaniline (PANI), methoxy (-OCH3) aniline (POA) and methyl (-CH3) aniline (POT), (b) poly(3-4 ethylenedioxythiophene) (PEDOT) and (c) polypyrrole (PPy). The research was carried out in two phases, namely, (i) the development and performance evaluation of G-CP (graphene in conducting polymers) electrodes for supercapacitors, and (ii) the fabrication and testing of the coin cell supercapacitors with G-CP electrodes.
In the first phase, the synthesis of different morphological structures of CPs as well as their composites with graphene was carried out, and the synthesized nanostructures were characterized by different physical, chemical and thermal characterization techniques, such as Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), UV-visible spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, BET surface area pore size distribution analysis and Thermogravimetric Analysis (TGA). The electrochemical properties of G-CP nanocomposite-based supercapacitors were investigated using Cyclic Voltammetry (CV), galvanostatic charge-discharge and Electrochemical Impedance Spectroscopy (EIS) techniques in different electrolytes, such as acidic (2M H2SO4 and HCl), organic ( 0.2 M LiClO4) and ionic liquid (1M BMIM-PF6) electrolytes.
A comparative study was carried out to investigate the capacitive properties of G-PANI derivatives for supercapacitor applications. The methyl substituted polyaniline with graphene as a nanocomposite (G-POT) exhibited a better capacitance (425 F/g) than the G-PANI or the G-POA nanocomposite due to the electron donating group of G-POT. The relaxation time constants of 0.6, 2.5, and 5s for the G-POT, G-PANI and G-POA nanocomposite-based supercapacitors were calculated from the complex model by using the experimental EIS data.
The specific capacitances of two-electrode system supercapacitor cells were estimated as 425, 400, 380, 305 and 267 F/g for G-POT, G-PANI, G-POA, G-PEDOT and G-PPy, respectively. The improvements in specific capacitance were observed due to the increased surface area with mesoporous nanocomposite structures (5~10 nm pore size distribution) and the pseudocapacitance effect due to the redox properties of the CPs. Further, the operating voltage of G-CP supercapacitors was increased to 3.5 V by employing an ionic liquid electrolyte, compared to 1.5 V operating voltage when aqueous electrolytes were used. On top of the gain in the operating voltage, the graphene nano-filler of the nanocomposite prevented the degradation of the CPs in the long term charging and discharging processes.
In the second phase, after studying the material's chemistry and capacitive properties in three-electrode and two-electrode configuration-based basic electrochemical test cells, coin cell type supercapacitors were fabricated using G-CP nanocomposite electrodes to validate the tested G-CPs as devices. The fabrication process was optimized for the applied force and the number of spacers in crimping the two electrodes together. The pseudocapacitance and double layer capacitance values were extracted by fitting experimental EIS data to a proposed equivalent circuit, and the pseudocapacitive effect was found to be higher with G-PANI derivative nanocomposites than with the other studied G-CP nanocomposites due to the multiple redox states of G-PANI derivatives. The increased specific capacitance, voltage and small relaxation time constants of the G-CPs paved the way for the fabrication of safe, stable and high energy density supercapacitors.
13
Noorbehesht, Nikan. "Enhanced Energy Storage and Conversion through Carbon Nanostructured Composites." Thesis, The University of Sydney, 2016. http://hdl.handle.net/2123/15675.
Full textAbstract:
Experts rank climate change and energy shortage as the most important issues that we confront over the next 50 years. These problems are connected, since non-regenerative fossil fuels are responsible for greenhouse gas emission thanks to the CO2 they produce during combustion. From all the observations, it is evident that these two major global problems concerning energy and the environment must be faced together. Hence, this doctoral work aims to tackle sustainable energy production, conversion, and storage challenges. Graphene and carbon nanotubes (CNTs) have been considered as promising electrode materials for energy conversion and storage due to their unique physical and electrical properties. Considering this fact, a novel nanostructured composite synthesised consisting of graphene and carbon nanotubes (CNTs), each pre-doped with nitrogen (N). This unique composite demonstrated remarkable electrocatalytic activity toward the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and Hydrogen evolution reaction (HER) compared to commercial platinum on supported carbon (Pt/C) catalyst. Therfore, replacing the expensive noble metal catalysts, which offer relatively short service life, with this composite produced from cheap and readily available materials, opens up a new avenue to target sustainable energy production and conversion issues. Employing of this composite to impregnate sulfur into its structure to be used as a cathode in Li-S batteries, and as a support to grow iron and cobalt Oxide (Fe3O4, Co3O4) nanoparticles on its body to be applied in anode for Li-ion batteries, exhibited superior electrochemical performances, including relatively low irreversible capacity loss, high specific capacity, and satisfactory cyclability. This carbon nanostructured composite proved to have a promising potential in sustainable energy storage applications.
14
Tang, Youhong. "Microrheological study on polyethylene/thermotropic liquid crystalline polymer/layered silicates nanocomposites /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?CENG%202007%20TANG.
Full text
15
Zhu, Honggang. "Development of epoxy-organoclay nanocomposite as high performance coating and as matrix material of durable GFRP composite for civil engineering applications /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202009%20ZHU.
Full text
16
Amouroux-Berthe, Solange Claire. "Pressure driven transport of non-wetting fluids in membranes used in composite processing." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 254 p, 2009. http://proquest.umi.com/pqdweb?did=1885755801&sid=5&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Full text
17
Hsieh, Feng-Hsu. "Nanofiber reinforced epoxy composite." Ohio : Ohio University, 2006. http://www.ohiolink.edu/etd/view.cgi?ohiou1146149557.
Full text
18
Yao, Yanli. "Development of amperometric biosensors with carbon nanotube composite materials." HKBU Institutional Repository, 2008. http://repository.hkbu.edu.hk/etd_ra/895.
Full text
19
Thaury, Claire. "Optimisation de matériaux composites Si/Intermétallique/Al/C utilisés comme électrode négative dans des accumulateurs Li-ion." Thesis, Paris Est, 2015. http://www.theses.fr/2015PEST1068/document.
Full textAbstract:
Ce mémoire est consacré à l'étude de matériaux composites innovants du type Si/Intermétallique/Al/C utilisés comme matériaux d'électrodes négatives pour les batteries lithium ion. L'objectif de ces travaux est d'optimiser un matériau de composition 20Ni-48Sn-20Si-3Al-9C ayant été développé auparavant pour obtenir les meilleures performances électrochimiques. Ce matériau se présente sous la forme de nanoparticules de silicium enrobées par une matrice submicrométrique. Plusieurs stratégies ont été mises en œuvre : optimisation des teneurs en carbone et en silicium, influence de l'état de surface du silicium sur les propriétés électrochimiques et remplacement de l'intermétallique Ni3+xSn4 par d'autres alliages : un composé zinc-aluminium Al0, 23Zn0,77 et deux intermétalliques Cu6Sn5 et CoSn. Les composés intermétalliques ont été synthétisés par métallurgie des poudres et les matériaux composites par mécanosynthèse. Les propriétés chimiques et structurales de ces matériaux ont été déterminées par microsonde de Castaing, diffraction des rayons X et microscopies électroniques. Les caractérisations électrochimiques ont été réalisées en demi-cellules (Swagelok et bouton) par cyclage galvanostatique et par voltamétrie cyclique. Ce mémoire détaille l'influence des paramètres étudiés sur les propriétés structurales. Une large étude a notamment été menée sur l'influence des teneurs en carbone et en silicium sur l'obtention d'une matrice homogène, une condition nécessaire pour atteindre de bonnes performances électrochimiques. Le même type d'étude a été mené sur l'influence de l'effet de surface du Si et la nature de l'alliage utilisé. Il a par exemple été montré de meilleurs résultats électrochimiques pour les intermétalliques présentant une réactivité modérée avec le silicium lors du broyage mécanique. Les meilleures performances ont été obtenues pour la composition Ni0.13Sn0.15Si0.26Al0.04C0.42. Ce composite présente une capacité de 650 mAh.g-1 pendant 1000 cycles. L'utilisation d'un silicium carboné en surface améliore la stabilité en cyclage de la SEI même si son utilisation reste à optimiserThis study focuses on the optimization of innovative composite materials Si/Intermetallic/Al/C used as negative electrode in lithium-ion batteries. The aim of this work is optimization of the composition for the material (20Ni-48Sn-20Si-3Al-9C) to improve its electrochemical performances. All materials are made up of silicon nanoparticles embedded in a sub micrometrical matrix. Several issues have been studied in this essay: optimization of the silicon and carbon contents, influence of the silicon surface composition, and substitution of the former intermetallic Ni3+xSn4 by other ones: zinc aluminium compound Al0,23Zn0,77 and two intermetallics Cu6Sn5 et CoSn. Metallic compounds and composites have been synthesised by powder metallurgy and mechanical alloying, respectively. Their chemical and structural properties have been determined by electron probe microanalysis, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Electrochemical characterisations have been carried out by galvanostatic cycling and cyclic voltammetry in coin and Swagelok half cells. This report details the influence of the studied parameters on the structural properties of the composite materials. A large study was devoted to the influence of carbon and silicon contents on the achievement of a homogeneous matrix, which is mandatory to get good electrochemical performances. Influence of the composition of silicon surface and intermetallic on the microstructure and electrochemical properties of the composites was also studied. Thus, we have shown that intermetallics reacting moderately with Si during mechanical alloying have better electrochemical properties. The best electrochemical properties have been obtained for the nominal composition Ni0.13Sn0.15Si0.26Al0.04C0.42. This material provides a reversible capacity of 650 mAh.g-1 during 1000 cycles. The use of carbon coated silicon improves the stability of the SEI during cycling even if this composite still has to be optimized
20
Ekiert, Thomas F. Jr. "Structural and magnetic characterization of nanostructured iron composites formed in the presence of citrate." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 202 p, 2009. http://proquest.umi.com/pqdweb?did=1818417551&sid=4&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Full text
21
Bawane, Kaustubh Krishna. "Silicon Carbide - Nanostructured Ferritic Alloy Composites for Nuclear Applications." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/96403.
Full textAbstract:
Silicon carbide and nanostructured ferritic alloy (SiC-NFA) composites have the potential to maintain the outstanding high temperature corrosion and irradiation resistance and enhance the mechanical integrity for nuclear cladding. However, the formation of detrimental silicide phases due to reaction between SiC and NFA remains a major challenge. By introducing a carbon interfacial barrier on NFA (C@NFA), SiC-C@NFA composites are investigated to reduce the reaction between SiC and NFA. In a similar way, the effect of chromium carbide (Cr3C2) interfacial barrier on SiC (Cr3C2@SiC) is also presented for Cr3C2@SiC-NFA composites. Both the coatings were successful in suppressing silicide formation. However, despite the presence of coatings, SiC was fully consumed during spark plasma sintering process. TEM and EBSD investigations revealed that spark plasma sintered SiC-C@NFA and Cr3C2@SiC-NFA formed varying amounts of different carbides such as (Fe,Cr)7C3, (Ti,W)C and graphite phases in their microstructure. Detailed microstructural examinations after long term thermal treatment at 1000oC on the microstructure of Cr3C2@SiC-NFA showed precipitation of new (Fe,Cr)7C3, (Ti,W)C carbides and also the growth of existing and new carbides. The results were successfully explained using ThermoCalc precipitation and coarsening simulations respectively.
The oxidation resistance of 5, 15 and 25 vol% SiC@NFA and Cr3C2@SiC-NFA composites at 500-1000oC temperature under air+45%water vapor containing atmosphere is investigated. Oxidation temperature effects on surface morphologies, scale characteristics, and cross-sectional microstructures were investigated and analyzed using XRD and SEM. SiC-C@NFA showed reduced weight gain but also showed considerable internal oxidation. Cr3C2@SiC-NFA composites showed a reduction in weight gain with the increasing volume fraction of Cr3C2@SiC (5, 15 and 25) without any indication of internal oxidation in the microstructure. 25 vol% SiC-C@NFA and 25 vol% Cr3C2@SiC-NFA showed over 90% and 97% increase in oxidation resistance (in terms of weight gain) as compared to NFA. The results were explained using the fundamental understanding of the oxidation process and ThermoCalc/DICTRA simulations.
Finally, the irradiation performance of SiC-C@NFA and Cr3C2@SiC-NFA composites was assessed in comparison with NFA using state-of-the-art TEM equipped with in-situ ion irradiation capability. Kr++ ions with 1 MeV energy was used for irradiation experiments. The effect of ion irradiation was recorded after particular dose levels (0-10 dpa) at 300oC and 450oC temperatures. NFA sample showed heavy dislocation damage at both 300oC and 450oC increasing gradually with dose levels (0-10 dpa). Cr3C2@SiC-NFA showed similar behavior as NFA at 300oC. However, at 450oC, Cr3C2@SiC-NFA showed remarkably low dislocation loop density and loop size as compared to NFA. At 300oC, microstructures of NFA and Cr3C2@SiC-NFA show predominantly 1/2<111> type dislocation loops. At 450oC, NFA showed predominantly <100> type loops, however, Cr3C2@SiC-NFA composite was still predominant in ½<111> loops. The possible reasons for this interesting behavior were discussed based on the large surface sink effects and enhanced interstitial-vacancy recombination at higher temperatures. The molecular dynamics simulations did not show considerable difference in formation energies of ½<111> and <100> loops for NFA and Cr3C2@SiC-NFA composites. The additional Si element in the SiC-NFA sample could have been an important factor in determining the dominant loop types. SiC-C@NFA composites showed heavy dislocation damage during irradiation at 300oC. At 450oC, SiC-C@NFA showed high dislocation damage in thicker regions. Thinner regions near the edge of TEM samples were largely free from dislocation loops. The precipitation and growth of new (Ti,W)C carbides were observed at 450oC with increasing irradiation dose. (Fe,Cr)7C3 precipitates were largely free from any dislocation damage. Some Kr bubbles were observed inside (Fe,Cr)7C3 precipitates and at the interface between α-ferrite matrix and carbides ((Fe,Cr)7C3, (Ti,W)C). The results were discussed using the fundamental understanding of irradiation and ThermoCalc simulations.Doctor of Philosophy
With the United Nations describing climate change as 'the most systematic threat to humankind', there is a serious need to control the world's carbon emissions. The ever increasing global energy needs can be fulfilled by the development of clean energy technologies. Nuclear power is an attractive option as it can produce low cost electricity on a large scale with greenhouse gas emissions per kilowatt-hour equivalent to wind, hydropower and solar. The problem with nuclear power is its vulnerability to potentially disastrous accidents. Traditionally, fuel claddings, rods which encase nuclear fuel (e.g. UO2), are made using zirconium based alloys. Under 'loss of coolant accident (LOCA) scenarios' zirconium reacts with high temperature steam to produce large amounts of hydrogen which can explode. The risks associated with accidents can be greatly reduced by the development of new accident tolerant materials. Nanostructured ferritic alloys (NFA) and silicon carbide (SiC) are long considered are leading candidates for replacing zirconium alloys for fuel cladding applications. In this dissertation, a novel composite of SiC and NFA was fabricated using spark plasma sintering (SPS) technology. Chromium carbide (Cr3C2) and carbon (C) coatings were employed on SiC and NFA powder particles respectively to act as reaction barrier between SiC and NFA. Microstructural evolution after spark plasma sintering was studied using advanced characterization tools such as scanning electron microscopy (SEM), electron backscattered diffraction (EBSD), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) techniques. The results revealed that the Cr3C2 and C coatings successfully suppressed the formation of detrimental reaction products such as iron silicide. However, some reaction products such as (Fe,Cr)7C3 and (Ti,W)C carbides and graphite retained in the microstructure. This novel composite material was subjected to high temperature oxidation under a water vapor environment to study its performance under the simulated reactor environment. The degradation of the material due to high temperature irradiation was studied using state-of-the-art TEM equipped with in-situ ion irradiation capabilities. The results revealed excellent oxidation and irradiation resistance in SiC-NFA composites as compared to NFA. The results were discussed based on fundamental theories and thermodynamic simulations using ThermoCalc software. The findings of this dissertation imply a great potential for SiC-NFA based composites for future reactor material designs.
22
Dong, Bowen. "DEVELOPMENT OF NANOSTRUCTURED SOFT MAGNETIC COMPOSITE MATERIALS USING THE FIELD ASSISTED SINTERING TECHNIQUE." Case Western Reserve University School of Graduate Studies / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case1607606832691028.
Full text
23
Liu, Liyu. "Design and fabrication of microfluidic/microelectronic devices from nano particle based composites /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?NSNT%202008%20LIU.
Full text
24
Clark, Andrew Plater-Zyberk. "Self assembly of amphiphilic conjugated polyelectrolytes and nanostructured composite materials for optoelectronic applications." Diss., Restricted to subscribing institutions, 2009. http://proquest.umi.com/pqdweb?did=1790348821&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Full text
25
Hsieh, Chien-Wen. "Formation of composite organic thin film transistors with one-dimensional nanomaterials." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609276.
Full text
26
Tong, Zhaohui. "Water-based suspension of polymer nanoclay composite prepared via miniemulsion polymerization." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19763.
Full textAbstract:
Thesis (Ph.D)--Chemical Engineering, Georgia Institute of Technology, 2008.Committee Chair: Yulin Deng; Committee Member: Howard (Jeff) L. Empie; Committee Member: J. Carson Meredith; Committee Member: Jeffery S. Hsieh; Committee Member: Timothy Patterson.
27
Xu, Jianwen. "Dielectric Nanocomposites for High Performance Embedded Capacitors in Organic Printed Circuit Boards." Diss., Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/11525.
Full textAbstract:
Conventionally discrete passive components like capacitors, resistors, and inductors are surface-mounted on top of the printed circuit boards (PCBs). To match the ever increasing demands of miniaturization, cost reduction, and high performance in microelectronic industry, a promising approach is to integrate passive components into the board during PCB manufacture. Because they are embedded inside multilayer PCBs, such components are called embedded passives.
This work focuses on the materials design, development and processing of polymer-based dielectric nanocomposites for embedded capacitor applications. The methodology of this approach is to combine the advantages of the polymer and the filler to satisfy the electric, dielectric, mechanical, fabrication, and reliability requirements for embedded capacitors. Restrained by poor adhesion and poor thermal stress reliability at high filler loadings, currently polymer-ceramic composites can only achieve a dielectric constant of less than 50. In order to increase the dielectric constant to above 50, effects of high-k polymer matrix, bimodal fillers, and dispersing agent are systematically investigated. Surface functionalization of nanofiller particles and modification of epoxy matrix with a secondary rubberized epoxy to form sea-island structure are proposed to enhance the dielectric constant, adhesion and high-temperature thermal stress reliability of high-k composites. To obtain photodefinable high-k composites, fundamental understanding of the photopolymerization of the novel epoxy-ceramic composite photoresist is addressed. While the properties of high-k composites largely depend on the polymer matrix, the fillers can also drastically affect the material properties. Carbon black- and carbon nanotubes-filled ultrahigh-k polymer composites are investigated as the candidate materials for embedded capacitors. Dielectric composites based on percolation typically show a high dielectric constant, and a high dielectric loss which is not desirable for high frequency applications. To achieve a reproducible low-loss percolative composite, a novel low-cost core-shell particle filled high-k percolative composite is developed. The nanoscale insulating shells allow the electrons in the metallic core to tunnel through it, and thereby the composites exhibit a high dielectric constant as a percolation system; on the other hand, the insulating oxide layer restricts the electron transfer between filler particles, thus leading to a low loss as in a polymer-ceramic system.
28
Zhang, Yan. "Relationship between morphology, crystallization behavior and mechanical properties of polypropylene micro- and nanocomposites /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?CENG%202004%20ZHANG.
Full text
29
Song, Yicheng. "The behavior and properties of ferroelectric single crystals and ferroelectric nano-composites." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/HKUTO/record/B3955806X.
Full text
30
Song, Yicheng, and 宋亦誠. "The behavior and properties of ferroelectric single crystals and ferroelectric nano-composites." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B3955806X.
Full text
31
Foston, Marcus Bernard. "Cyclic, tethered and nanoparticulate silicones for material modification." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24762.
Full textAbstract:
Thesis (Ph.D.)--Polymer, Textile and Fiber Engineering, Georgia Institute of Technology, 2009.Committee Chair: Dr. Haskell W. Beckham; Committee Member: Dr. Anselm Griffin; Committee Member: Dr. Johannes Leisen; Committee Member: Dr. Sankar Nair; Committee Member: Dr. Uwe Bunz.
32
Zhang, Qilei. "Preparation of high-strength and high-modulus HA/UHMWPE nanocomposites for cortical bone replacement /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?CBME%202008%20ZHANG.
Full text
33
Johns, Phillip A. "Investigations of rate limitation in nanostructured composite electrodes and experiments towards a 3D Li-ion microbattery." Thesis, University of Southampton, 2011. https://eprints.soton.ac.uk/206161/.
Full textAbstract:
The factors effecting discharge rate limitation within LiFePO4 composite electrode structures have been investigated. It was found that for composite electrodes containing ‘small particles’ of active material solid state processes are not necessarily rate limiting. A simple model has been developed to describe the rate limitation that occurs in the composite electrode structure due to electrolyte concentration, electrode thickness and lithium ion transference number. The conformal electrodeposition of cathode materials onto 3D current collectors has been achieved with good control of film thickness. The advantage of the 3D current collector configuration over a conventional thin film arrangement has been realised by a 250 times capacity increase for a given footprint area. It was suggested the observed rate performance of half-cell 3D microbatteries, based on a manganese dioxide cathode and a lithium foil anode, was limited by the lithium ion transport distance through the porous 3D structure. The electrodeposition of conformal polymers layers onto 3D substrates was investigated. The use of electrodeposited, electrolyte swollen, poly(acrylonitrile) and poly(aniline) films as polymer electrolytes was demonstrated. A novel method for the determination and differentiation of electronic and ionic resistance in electrodeposited polymer layers has been developed. A ‘working’ cell based on consecutively electrodeposited cathode and polymer electrolyte layers and a ‘soft contact’ liquid anode was presented
34
Lu, Jiongxin. "High dielectric constant polymer nanocomposites for embedded capacitor applications." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26666.
Full textAbstract:
Thesis (Ph.D)--Materials Science and Engineering, Georgia Institute of Technology, 2009.Committee Chair: Wong, C. P.; Committee Member: Jacob, Karl; Committee Member: Liu, M. L.; Committee Member: Tannenbaum, Rina; Committee Member: Wang, Z. L.. Part of the SMARTech Electronic Thesis and Dissertation Collection.
35
El-Chiti, Fadi. "Experimental Variability of E-Glass Reinforced Vinyl Ester Composites Fabricated by VARTM/Scrimp." Fogler Library, University of Maine, 2005. http://www.library.umaine.edu/theses/pdf/El-ChitiF2005.pdf.
Full text
36
Kovaleva, M. G., M. Y. Arseenko, M. S. Prozorova, Y. N. Tyurin, and O. V. Kolisnichenko. "Structure and Properties of Nanocomposite Coatings Based on Titanium, Oxygen, Carbon and Hydrogen Obtained by the Cumulative-Detonation Device." Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/34889.
Full textAbstract:
Nanocomposite coatings based on Ti, O, C and H thickness of 70 – 200 microns with hardness of
1015 250 HV0.05 and porosity 2 – 5% were deposited on aluminium samples by using the cumulativedetonation
equipment. The nanocomposite coatings were examined by scanning electron microscopy
(SEM), transmission electron microscopy (TEM) with diffraction, X-ray phase analysis, hardness measurements.
It is shown that the area of the coating that adjoins to the substrate contains a transition layer
of intermetallic TiAl and the nanocomposite coatings based on Ti, O, C and H are characterized by the
presence of titanium nanocrystalline grains with face-centered close-packed lattice, amorphous phases and
nanoamorphous oxide of titanium. It was found that the main phases of the composite coatings are Ti, TiO,
rutile, anatase, Ti2O3. In the composite coatings formed from the hydrogenated powder was recorded the
presence of -TiH phase and TiH2.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/34889
37
Edfouf, Zineb. "Étude de nouveaux matériaux composites de type Si/Sn Ni/Al/C pour électrode négative de batteries lithium ion." Phd thesis, Université Paris-Est, 2011. http://tel.archives-ouvertes.fr/tel-00673220.
Full textAbstract:
Ce mémoire est consacré à l'étude de nouveaux matériaux composites de type Si/Sn-Ni/Al/C pour former des électrodes négatives de batteries lithium ion. La microstructure de ces matériaux se présente sous la forme de nanoparticules de Si enrobées dans une matrice conductrice constituée de carbone et d'un composé intermétallique Ni3,4Sn4. La nanostructure et la composition du matériau composite lui confèrent de très bonnes performances en termes de capacité réversible, de stabilité électrochimique, et de cinétique de réaction. La mécanosynthèse a été choisie comme méthode d'élaboration. Les propriétés structurales et chimiques du composite ont été déterminées par analyses DRX, par microscopies électroniques MET et MEB, par analyses EDX et EFTEM et par spectroscopie Mössbauer de 119Sn. La caractérisation électrochimique a été réalisée par cyclage galvanostatique et par voltamétrie cyclique. La réactivité de ces matériaux envers le lithium a été étudiée par analyses DRX et spectroscopie Mössbauer de 119Sn in-situ. Ce mémoire détaille les résultats structuraux et électrochimiques obtenus pour différents matériaux composites basés sur Ni3,4Sn4 en ajoutant les éléments C, Al et Si. Une étude des mécanismes réactionnels lors du broyage mécanique ainsi que pendant le cyclage électrochimique a été effectuée et le rôle des différents éléments a été mis en évidence. Enfin, une discussion sur l'influence de la microstructure sur les performances électrochimiques des matériaux composites est donnée. Les meilleures performances électrochimiques sont obtenues pour le composite de composition nominale Ni0,14Sn0,17Si0,32Al0,04C0,35. Il présente une capacité réversible de 920 mAh/g avec une très bonne stabilité sur 280 cycles. Le matériau possède une excellente cinétique de délithiation : 90% de la capacité peut être délivrée en moins de 5 minutes. La capacité irréversible (20%) reste toutefois élevée et doit être encore améliorée en stabilisant l'interface solide/électrolyte (SEI)
38
Gunawidjaja, Ray. "Organic/inorganic nanostructured materials towards synergistic mechanical and optical properties /." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29733.
Full textAbstract:
Thesis (Ph.D)--Industrial and Systems Engineering, Georgia Institute of Technology, 2010.Committee Chair: Tsukruk, Vladimir; Committee Member: Bucknall, David; Committee Member: Kalaitzidou, Kyriaki; Committee Member: Shofner, Meisha; Committee Member: Tannenbaum, Rina. Part of the SMARTech Electronic Thesis and Dissertation Collection.
39
Selleri, Giacomo <1992>. "Nanostructured piezoelectric materials for the design and development of self-sensing composite materials and energy harvesting devices." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amsdottorato.unibo.it/10352/1/PhD%20Thesis_%20Giacomo%20Selleri.pdf.
Full textAbstract:
The work activities reported in this PhD thesis regard the functionalization of composite materials and the realization of energy harvesting devices by using nanostructured piezoelectric materials, which can be integrated in the composite without affecting its mechanical properties.
The self-sensing composite materials were fabricated by interleaving between the plies of the laminate the piezoelectric elements. The problem of negatively impacting on the mechanical properties of the hosting structure was addressed by shaping the piezoelectric materials in appropriate ways. In the case of polymeric piezoelectric materials, the electrospinning technique allowed to produce highly-porous nanofibrous membranes which can be immerged in the hosting matrix without inducing delamination risk. The flexibility of the polymers was exploited also for the production of flexible tactile sensors. The sensing performances of the specimens were evaluated also in terms of lifetime with fatigue tests. In the case of ceramic piezo-materials, the production and the interleaving of nanometric piezoelectric powder limitedly affected the impact resistance of the laminate, which showed enhanced sensing properties.
In addition to this, a model was proposed to predict the piezoelectric response of the self-sensing composite materials as function of the amount of the piezo-phase within the laminate and to adapt its sensing functionalities also for quasi-static loads. Indeed, one final application of the work was to integrate the piezoelectric nanofibers in the sole of a prosthetic foot in order to detect the walking cycle, which has a period in the order of 1 second.
In the end, the energy harvesting capabilities of the piezoelectric materials were investigated, with the aim to design wearable devices able to collect energy from the environment and from the body movements. The research activities focused both on the power transfer capability to an external load and the charging of an energy storage unit, like, e.g., a supercapacitor.
40
Songa, Everlyne Apiyo. "Composite Poly(dimethoxyaniline) Electrochemical Nanobiosensor For Glufosinate And Glyphosate Herbicides." Thesis, University of the Western Cape, 2008. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_5055_1273696186.
Full textAbstract:
In this thesis, I present a simple, sensitive and low cost electrochemical nanobiosensor for quantitative determination of the herbicides glufosinate, glyphosate and its metabolite aminomethylphosphonic acid (AMPA). Firstly, the nanostructured poly(2,5-dimethoxyaniline) (PDMA) materials were synthesized on gold electrode by the electrochemical &ldquo
soft template&rdquo
method using poly(4-styrenesulfonic acid) (PSS) as the dopant and structure-directing molecule. Fourier transform infrared (FTIR) spectroscopy, UV-Vis Spectroscopy, Transmission electron microscopy (TEM) and Scanning electron microscopy (SEM) studies inferred successful doping of the nanostructured PDMA film by PSS and that the template PSS directed the synthesis of both nanotubes and nanoparticles of PDMA with diameters less than 100 nm.
41
Ford, Ericka N. J. "Carbon nanotubes as structural templates within poly(vinyl alcohol) composite fibers." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45921.
Full textAbstract:
Because the gel-spinning process has the potential to yield fibers of high strength and high modulus, this technique was employed to process continuous filaments of PVA/CNT, having CNTs at ¡Ü1 weight percent of polymer. A gel aging technique was employed with the goal of increasing the draw ratio for composite fibers and for promoting the development of crystalline PVA. Since residual solvent can lower the mechanical properties of drawn fibers, solvent phases of water and dimethyl sulfoxide (DMSO) within the drawn fibers were also characterized. As embedded SWNTs were uniaxially aligned along the drawn fiber axis, they were found to induce preferential alignment in the PVA side groups as well as for the residual solvent. This was attributed to charge transfer between SWNT and the respective functional groups. This orientation behavior has been characterized using Raman spectroscopy and infra-red dichroism. The behaviors of gel crystallization and solvent freezing within PVA/CNT dispersions were studied using thermal analysis and rheology. Carbon nanotubes were found to nucleate PVA crystallization in the gel state. PVA/CNT gel aging behavior was characterized by structural, thermal, and mechanical, and dynamic mechanical means. Gel aging was shown to increase the draw ratio of PVA/CNT fibers, and the development of the higher temperature melting peak was attributed to the draw induced ordering of PVA along CNTs. The scanning electron micrographs of fractured PVA/CNT fibers showed fibrils having an average diameter of about 22 nm. The storage modulus of aged gel was a function of solvent diffusion, which changed with aging time. CNTs were shown to have stabilized the gel network, as characterized by the dynamic mechanical properties, and to provide nucleation sites for the ordering of PVA chains, as characterized by WAXD.
42
Shuai, Guo. "Tool life improvement using a shim with nanostructured composite damping coating synthesized by high power impulse magnetron sputtering." Thesis, KTH, Industriell produktion, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-246084.
Full textAbstract:
The thesis made an investigation of the damping treatment on cutting inserts for reducing the high frequency vibrations and improving the tool life. The damping coating of Cr:CuCNx has a multiple layer structure, and was synthesized by high power impulse magnetron sputtering (HIPIMS) method. Comparisons between coated and uncoated shims were carried out under stable turning conditions. The measured acceleration signals showed that the vibration amplitude on high frequency range between 3000 Hz and 22000 Hz on the tool holder was reduced by 30%-50% by using a shim coated with the nanostructured composite material. The flank wear was 193 μm after 32 minutes tuning process for the insert having the damping coating shim, versus 264 μm flank wear of a conventional shim under the same condition. However, the surface roughness of workpiece showed the only marginal difference between the damping coated shim and the conventional shim.En undersökning genomfördes, som en del av avhandlingsarbetet, av hur skärplattor kan behandlas genom dämpande beläggning för att minska högfrekventa vibrationer och förbättra verktygets livslängd. Den dämpande beläggningen av Cr: CuCNx har en flerskiktsstruktur, och syntetiserades medelst högeffektimpulsmagnetronsputtering (HIPIMS) -metod. Jämförelser mellan belagda och obelagda underläggsplattor utfördes under stabila bearbetningsförhållanden (svarvning). De uppmätta accelerationssignalerna visade att vibrationsamplituden inom högfrekvensområdet, mellan 3000 Hz och 22000 Hz på verktygshållaren, reducerades med 30 % -50 % genom att använda en underläggsplatta belagd med det nanostrukturerade kompositmaterialet. Fasförslitningen var 193 μm efter 32 minuters svarvning för skärplattan med dämpningsbelagd underläggsplatta, mot 264 μm fasförslitning av ett konventionellt skär under samma villkor. Emellertid visade ytjämnheten hos arbetsstycket endast marginella skillnaden mellan den dämpade belagda plattan och den konventionella plattan.
43
Tyurin, Yu N., M. Yu Arseenko, M. S. Prozorova, O. V. Kolisnishenko, and M. G. Kovaleva. "The Wear Resistance of the Nanocomposite Coatings Obtained by the Cumulative- Detonation Device." Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/35152.
Full textAbstract:
Nanocomposite coatings based on Ti, O, C and H were deposited on aluminium samples by using the
cumulative-detonation equipment. The nanocomposite coatings were examined by scanning electron microscopy
(SEM), transmission electron microscopy (TEM) with diffraction, X-ray phase analysis, hardness
measurements and tribotests. It was established that the wear of nanocomposite coatings based on Ti, O, C
and H less than to the wear of material of the substrate. For the nanocomposite coating which were formed
from the hydrogenated titanium powder was recorded the lowest wear and coefficient of friction.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35152
44
Jalani, Nikhil H. "Development of nanocomposite polymer electrolyte membranes for higher temperature PEM fuel cells." Link to electronic dissertation, 2006. https://www.wpi.edu/ETD-db/ETD-catalog/view%5Fetd?URN=etd-032706-165027.
Full text
45
Mohseni, Hamidreza. "Tribological Improvements of Carbon-Carbon Composites by Infiltration of Atomic Layer Deposited Lubricious Nanostructured Ceramic Oxides." Thesis, University of North Texas, 2011. https://digital.library.unt.edu/ark:/67531/metadc84254/.
Full textAbstract:
A number of investigators have reported enhancement in oxidation and wear resistant of carbon-carbon composites (CCC) in the presence of protective coating layers. However, application of a surface and subsurface coating system that can preserve its oxidation and wear resistance along with maintaining lubricity at high temperature remains unsolved. To this end, thermodynamically stable protective oxides (ZnO/Al2O3/ZrO2) have been deposited by atomic layer deposition (ALD) to infiltrate porous CCC and graphite foams in order to improve the thermal stability and wear resistance in low and high speed sliding contacts. Characterization of microstructural evolution was achieved by using energy dispersive x-ray spectroscopy (EDS) mapping in scanning electron microscope (SEM) coupled with focused ion beam (FIB), x-ray tomography, high resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy (STEM) and X-ray diffraction (XRD). Evaluation of the tribological properties of CCC coated with abovementioned ALD thin films were performed by employing low speed pure sliding tribometer and a high speed/frequency reciprocating rig to simulate the fretting wear behavior at ambient temperature and elevated temperatures of 400°C.It was determined with x-ray tomography imaging and EDS mapping that ALD ZnO/Al2O3/ZrO2 nanolaminates and baseline ZrO2 coatings exhibited excellent conformality and pore-filling capabilities down to ~100 μm and 1.5 mm in the porous CCC and graphite foam, respectively, which were dependent on the exposure time of the ALD precursors. XRD and HRTEM determined the crystalline phases of {0002} textured ZnO (wurtzite), amorphous Al2O3, and {101}-tetragonal ZrO2. Significant improvements up to ~65% in the sliding and fretting wear factors were determined for the nanolaminates in comparison to the uncoated CCC. A tribochemical sliding-induced mechanically mixed layer (MML) was found to be responsible for these improvements. HRTEM confirmed the presence of a high density of ZnO shear-induced basal stacking faults inside the wear tracks responsible for intrafilm shear velocity accommodation that mitigated friction and wear.
46
Averett, Rodney Dewayne. "Experimental aspects and mechanical modeling paradigms for the prediction of degradation and failure in nanocomposite materials subjected to fatigue loading conditions." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24807.
Full textAbstract:
Thesis (Ph.D.)--Polymer, Textile and Fiber Engineering, Georgia Institute of Technology, 2009.Committee Chair: Realff, Mary L.; Committee Member: Graham, Samuel; Committee Member: Jacob, Karl I.; Committee Member: May, Gary; Committee Member: Shofner, Meisha.
47
Liang, Qizhen. "Preparation and properties of thermally/electrically conductive material architecture based on graphene and other nanomaterials." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/44846.
Full textAbstract:
With excellent electrical, thermal and mechanical properties as well as large specific surface area, graphene has been applied in next-generation nano-electronics, gas sensors, transparent electrical conductors, thermally conductive materials, and superior energy capacitors etc. Convenient and productive preparation of graphene is thereby especially important and strongly desired for its manifold applications.
Chemically developed functionalized graphene from graphene oxide (GO) has significantly high productivity and low cost, however, toxic chemical reduction agents (e.g. hydrazine hydrate) and raised temperature (400-1100°C) are usually necessary in GO reduction yet not preferred in current technologies. Here, microwaves (MW) are applied to reduce the amount of graphene oxide (GO) at a relatively low temperature (~165°C). Experimental results indicate that resurgence of interconnected graphene-like domains contributes to a low sheet resistance with a high optical transparency after MW reduction, indicating the very high efficiency of MW in GO's reduction.
Moreover, graphene is usually recumbent on solid substrates, while vertically aligned graphene architecture on solid substrate is rarely available and less studied. For TIMs, electrodes of ultracapacitors, etc, efficient heat dissipation and electrical conductance in normal direction of solid surfaces is strongly desired. In addition, large-volume heat dissipation requires a joint contribution of a large number of graphene sheets. Graphene sheets must be aligned in a large scale array in order to meet the requirements for TIM application. Here, thermally conductive fuctionalized multilayer graphene sheets (fMGs) are efficiently aligned in a large scale by vacuum filtration method at room temperature, as evidenced by SEM images and polarized Raman spectroscopy. A remarkably strong anisotropy in properties of aligned fMGs is observed. Moreover, VA-fMG TIMs are prepared by constructing a three-dimensional vertically aligned functionalized multilayer graphene architecture between contact Silicon/Silicon surfaces with pure Indium as a metallic medium. Compared with their counterpart from recumbent A-fMGs, VA-fMG TIMs have significantly higher equivalent thermal conductivity and lower contact thermal resistance.
Electrical and thermal conductivities of polymer composite are also greatly interested here. Previous researches indicated that filler loading, morphology of fillers, and chemical bonding across filler/polymer interfaces have significant influence on electrical/thermal conductivity of polymer composite. Therefore, the research also pays substantial attention to these issues. First, electrical resistivity of CPCs is highly sensitive on volume or weight ratio (filler loading) of conductive fillers in polymer matrix, especially when filler loading is close to percolation threshold (pc). Thermal oxidation aging usually can cause a significant weight loss of polymer matrix in a CPC system, resulting in a filler loading change which can be exhibited by a prompt alteration in electrical resistivity of CPCs. Here, the phenomena are applied as approach for in-situ monitoring thermal oxidation status of polymeric materials is developed based on an electrical sensors based on conductive polymeric composites (CPCs). The study developed a model for electrical resistivity of sensors from the CPCs as a function of aging time at constant aging temperature, which is in a good agreement with a Boltzmann-Sigmoidal equation. Based on the finding, the sensors show their capability of in-situ in-situ monitor and estimate aging status of polymeric components by a fast and convenient electrical resistance measurement.
Second, interfacial issues related to these thermal conductive fillers are systemically studied. On the one hand, the study focuses on relationship between morphology of h-BN particles and thermal conductivity of their epoxy composites. It is found that spherical-agglomeration of h-BN particles can significantly enhance thermal conductivity of epoxy resin, compared with dispersed h-BN plates, by substantially reducing specific interfacial area between h-BN and epoxy resin. On the other hand, surface of high thermal conductive fillers such as SiC particles and MWNTs are successfully functionalized, which makes their surface reactive with bisphenol A diglycidyl ether and able to form chemical bonding between fillers and epoxy resin. By this means, thermal conductivity of polymer composites is found to be significantly enhanced compared with control samples, indicating the interfacial chemical bonding across interface between thermal conductive fillers and polymer matrix can promote heat dissipation in polymeric composites. The finding can benefit a development of high thermal conductive polymer composites by interfacial chemical bonding enhancement to meet the demanding requirements in current fine pitch and Cu/low k technology.
48
Al-Aqeeli, Naser. "Development of Al- and Mg-based nanocomposites via solid-state synthesis." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=102948.
Full textAbstract:
Mechanical milling (alloying) is one of the non-equilibrium techniques used to prepare alloys with exceptional properties. This technique was employed in this research to develop a new class of Al- and Mg-based nanocomposite alloys using SPEX high energy milling. These nanocomposites are characterized by the dispersion of nanocrystals in an amorphous matrix. Zirconium was added to the Al-Mg alloys for the purpose of promoting glass formability. As-milled samples were annealed at 400°C for 1 hour to investigate the thermal stability of the nanostructure. The phase evolution of the resulting alloys was studied using XRD and TEM/EDS, which showed a strong dependence of the resulting metastable phases on the starting alloys compositions.The nanocomposite structure was developed at Zr concentrations of 20 and 35 at.% regardless of the Al/Mg ratio and with some traces of oxidation. However, the amount of amorphous phase was varied in each case depending on the Al concentration into the alloy, since in low Al-containing alloys the amount of amorphous phase was less pronounced. It was found that higher Zr concentrations will lead to greater refinement of the nanostructure. These nanocomposites showed improved mechanical properties, in terms of higher hardness values, in addition to improved thermal stability. The improvement in thermal stability was attributed to the presence of Al3Zr which proved to contribute significantly to retarding grain growth via grain boundary pinning.
Additionally, the employment of mechanical alloying was beneficial in producing Al3Zr in the cubic L12 ordered structure which improves the ductility of the alloy. Moreover, the homogeneity ranges of gamma-Al 12Mg17 and Al3Zr were extended significantly due to the nature of the non-equilibrium processing. In this research, the alloy with the maximum hardness was Al40Mg25Zr35, which has an average hardness value close to 780 HV and average crystallite size of about 10 nm. A common observation in the alloys that showed a higher hardness values combined with improved thermal stability, is that they contain higher Al and Zr concentrations.
Le broyage mécanique est une technique hors équilibre qui permet la fabricationde nouveaux alliages avec des propriétés exceptionnelles. Lors de cette recherche, unbroyeur SPEX 8000 a été utilisé pour développer une nouvelle classe denanocomposites à base d'aluminium et de magnésium. Ces nanocomposites tirent leurspécificité de leur dispersion de nanocrystaux dans une matrice amorphe. Duzirconium a été ajouté aux alliages d'aluminium et de magnésium pour promouvoirl'amorphisation. Les échantillons de poudres broyées ont été recuits à 400°C pour 1heure pour évaluer la stabilité thermique des différentes phases. Leur évolution a étécaractérisée par diffraction par rayon-X et par MEBIEDS. TI fut démontré que lesphases métastables obtenues dépendent fortement de la composition des alliages dedépart.
49
Ahmed, Mohammad Shoeb. "Effect of thermal annealing and carbon implantation on the functional properties of nanocomposite TiSiN coatings on steel." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2013. https://ro.ecu.edu.au/theses/536.
Full textAbstract:
This PhD research contributes to the part of advanced materials technology. The machining industry currently faces tremendous pressures with the need for durable cutting tools suitable for eco-friendly high speed machining operations becoming acute. In this thesis innovative design and synthesis strategies are explored to tailor the properties of nanocomposite coatings. Advanced characterisation techniques are applied to identify the mechanisms that control the mechanical, tribological, and corrosion behaviours of these coatings. Cutting tools protected by these coatings are anticipated to exhibit a unique combination of superior toughness and greater resistance to wear and corrosion, providing significant economic and environmental benefits. The thin ceramic coatings are commonly applied to various kinds of steel cutting and machining tools to enhance their mechanical and tribological properties. The most common ceramic coating is TiN. But the major issues that hamper the application of TiN are high friction co-efficient (typically~0.5), lower hardness, lower thermal stability (~5000 C) and lower corrosion resistance. To address some of these problems, TiSiN nanocomposite coatings are developed, which have super-hardness, better thermal stability (~10000C) and better corrosion resistance. But the as-deposited TiSiN coating still has high co-efficient of friction (~0.4) and high residual stress (~7-9 GPa) which consequently affect the adhesion and toughness of the coating. This project aims to address these problems by (a) the application of carbon implantation to modify the structure and chemistry of the surface layer of the nanocomposite coatings with reduced friction and residual stress; and (b) thermal annealing of the nanocomposite coating to reduce the residual stress with enhanced fracture toughness, better corrosion resistance and more thermal stability. In addition, the role of microstructure, residual stress and defects of these hard coating in corrosive environment will be studied. For this research, a combination of microstructural and mechanical properties characterization, corrosion analysis, tribological test and finite element modelling facilities will be used. The study includes focused ion beam (FIB) milling and transmission electron microscopy (TEM), Synchrotron X-Ray Diffraction (XRD), X-ray Photo Spectroscopy (XPS), Energy dispersive X-Ray (EDX), nanoindentation, nano-scratching, potentio-dynamic polarization cell and Atomic force microscopy(AFM).
50
Zoromba, Mohamed Shafick Taha [Verfasser]. "Preparation and characterization of new nanostructured organic, inorganic composite coatings for anti-fog applications / submitted by Mohamed Shafick Taha Zoromba." [Clausthal-Zellerfeld] : [Univ.-Bibliothek], 2009. http://d-nb.info/998434140/34.
Full text