Dissertations / Theses on the topic 'Nanoporous'
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Pugh, Dylan Vicente. "Nanoporous Platinum." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/27256.
Full textPh. D.
Nguyen, Thanh Xuan. "Characterization of nanoporous carbons /." [St. Lucia, Qld.], 2006. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19108.pdf.
Full textWilke, Kyle (Kyle L. ). "Evaporation from nanoporous membranes." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/104571.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (pages 56-58).
Cooling demands of advanced electronics are increasing rapidly, often exceeding capabilities of conventional thermal management techniques. Thin film evaporation has emerged as one of the most promising thermal management solutions. High heat transfer rates can be achieved in thin films of liquids due to a small conduction resistance through the film to the evaporating interface. In this thesis, we investigated evaporation from nanoporous membranes. The capillary wicking of the nanopores supplies liquid to the evaporating interface, passively maintaining the thin film. Different evaporation regimes were predicted through modeling and were demonstrated experimentally. Good agreement was shown between the predicted and observed transitions between regimes. Improved heat transfer performance was demonstrated in the pore level evaporation regime over other regimes, with heat transfer rates up to one order of magnitude larger for a given superheat in comparison to the flooding regime. An improved experimental setup for investigating thin film evaporation from nanopores was developed, where a biphilic membrane, i.e., a membrane with two wetting behaviors, was used for enhanced experimental control to allow characterization of the importance of different design parameters. This improved setup was then used to demonstrate the dependence of thin film evaporation on the location of the meniscus within the nanopores. This dependence on meniscus location within the pore was also shown to increase with increasing superheat. We observed a 46% reduction in heat transfer rates at a superheat of 15 °C for an L* of 14.67 compared to an L* of 2, where L* is the ratio of the depth of the meniscus within the pore to the pore radius. This work provides practical insights for the design of devices based on nanoporous evaporation. Heat transfer regimes can be predicted based on fluid supply conditions, evaporative heat flux, and membrane geometry. Furthermore, the biphilic membrane serves as a valuable experimental platform for testing the role of membrane geometry on heat transfer performance in the pore level evaporation regime. Future work will focus on demonstrating the importance of different parameters and using experimental results to either validate existing models for evaporation from nanopores or develop more suitable ones.
by Kyle Wilke.
S.M.
Crowson, Douglas A. "Stability of Nanoporous Metals." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/28111.
Full textPh. D.
Cooney, D. T. P. "Nanoporous materials from block copolymers." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597952.
Full textPreuss, Frida, Julia Asp, Sofia Larsson, and Stephanie Kylington. "Separation of Nanoporous Silica Particles." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-277106.
Full textOdunsi, Oluwatoni Yewande. "Hydrogen storage on nanoporous carbons." Thesis, University of Bath, 2007. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437723.
Full textMorgado, Lopes André. "Reactive transport through nanoporous materials." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0560/document.
Full textThis work aims to study the complex behaviors of asphaltenes within the hydrotreatment catalytic porous system including transport properties and adsorption. Inverse size-exclusion chromatography (ISEC) and impedance spectroscopy are used to determine the topological characteristics of different alumina porous solids (porosity, pore size, tortuosity). The effective diffusion coefficient of polystyrenes of different sizes was studied via chromatography in non-adsorbing conditions. Elution peaks are used to determine the effect of molecule size on the accessible pore volume and the transport properties therein: molecules of relatively small sizes penetrate further into the porous medium, thus taking more time to navigate the chromatographic setup, while larger molecules traverse much faster, through the macroporosity. The liquid chromatography technique is divided in two different methods. Both methods yield diffusion coefficient values which are modelled, predicting the behavior of molecules of any size. Columns were assembled manually from alumina powders or monoliths. A synthesized asphaltene model molecule was used and its adsorption behavior was determined and compared to an asphaltene fraction recovered from crude oil. The asphaltene model molecule shows a dimerization behavior as well as extremely strong interactions with the alumina surface. Dynamic method was attempted in short alumina columns at saturation conditions and an apparent influence of the flow rate on the extent and mechanics of adsorption was observed
Freeman, Christopher J. "Biosensing and Catalysis Applications of Nanoporous Gold (NPG) and Platinum-Speckled Nanoporous Gold (NPG-Pt) Electrodes." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5473.
Full textBera, Chandan. "Thermo electric properties of nanocomposite materials." Phd thesis, Ecole Centrale Paris, 2010. http://tel.archives-ouvertes.fr/tel-00576360.
Full textQuintana, Puebla Alberto. "Enhanced magnetoelectric effects in electrolyte-gated nanoporous metallic alloy and dense metal oxide films." Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/663838.
Full textThis Thesis covers the study of the magnetoelectric response in nanoporous metallic alloy and transition metal oxide dense films. The interfacial nature of magnetoelectric processes, independently of its origin, has limited its study to ultrathin film configurations (usually 1-2 nm). Here we propose a novel approach to overcome this thickness limitation, thus achieving magnetoelectric response in materials whose overall thickness is larger than 100 nm. To accomplish this, we have employed nanoporous materials, with pore walls and ligands of very few nanometers, which are characterized by a large surface to volume ratio. These materials have been synthesized by micelle assisted electrodeposition. Micelles get trapped during the electrodeposition process thus acting as a soft templating agent, allowing us to synthesize nanoporous copper-nickel alloy films with tunable composition and morphology. Voltage application has been performed through electrolyte-gating, taking advantage of the generation of an electrical double layer in aprotic organic electrolytes which helps to avoid spurious oxidation processes. This method allows for the application of electric fields as high as hundreds of MV/cm. Thanks to the high electric field achieved, together with the ultrahigh surface area of nanoporous materials, a 32 % reduction in the coercivity of a Cu25Ni75 nanoporous film has been achieved. Ab-initio simulations attribute this large effect to changes in the magnetic anisotropy energy due to charge accumulation in the sample|electrolyte interface. In a second approach, the voltage control of redox processes has been studied in aqueous electrolytes (1M NaOH). After positive bias application up to a 33 % reduction in the magnetization has been achieved in a Cu20Ni80 nanoporous sample thanks to the selective Cu oxidation. The controlled oxidation process resulted in an enriched Ni alloy which possesses a larger magnetic moment. Moreover, we have demonstrated the suitability of atomic layer deposition to conformally coat the nanoporous alloys, preserving the morphology and structure, thus setting the basis for future solid state applications. In the last part of this Thesis, it has been demonstrated that, upon electric field application, a ferromagnetic response arises in a paramagnetic single Co3O4 layer, at room temperature. The applied voltage promotes the ionic diffusion, resulting in oxygen rich and cobalt rich regions, being the latter the responsible of the induced magnetic signal. This experiment is one of the first evidences of ionic motion at room temperature without the assistance of oxygen buffer layers such as Gd2O3 or HfO2.
Topoglidis, Emmanuel. "Biosensors based on nanoporous TiO2 films." Thesis, Imperial College London, 2001. http://hdl.handle.net/10044/1/7573.
Full textSchofield, Eleanor Josephine. "Formation and characterisation of nanoporous materials." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429052.
Full textRoche, Iain. "Nanoporous polymeric adsorbents for blood purification." Thesis, Loughborough University, 2009. https://dspace.lboro.ac.uk/2134/8143.
Full textGage, David Maxwell. "Fracture of nanoporous organosilicate thin films /." May be available electronically:, 2008. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
Full textBrown, Jacob Leslie. "Vapour-liquid equilibria within nanoporous media." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/277690.
Full textHu, Yan. "Quantitative confocal imaging of nanoporous silica." Diss., University of Iowa, 2016. https://ir.uiowa.edu/etd/3106.
Full textSvensson, Anna. "Nanocomposites made from nanoporous cellulose fibre." Licentiate thesis, KTH, Fiberteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-103342.
Full textQC 20121011
Gomis, Berenguer Alicia. "Photochemical response of nanoporous carbons. Role as catalysts, photoelectrodes and additives to semiconductors." Doctoral thesis, Universidad de Alicante, 2016. http://hdl.handle.net/10045/63668.
Full textBrach, Stella. "Strength properties of nanoporous materials : theoretical analyses and molecular dynamics computations." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066618.
Full textThe main objectif of the thesis consisted in investigating strength properties of nanoporous materials by means of theoretical and numerical approaches. In the framework of homogenization methods, novel macroscopic strength criteria have been established via a non-linear homogenization procedure and a kinematic limit-analysis approach. Resulting yield functions allowed to take into account void-size effects on nanoporous materials strength properties, thereby resulting in a strong enhancement of available estimates. Furthermore, aiming to funish effective benchmarking evidence for the calibration and/or the assessment of theoretical models, molecular-dynamics based computations have been carried out on in-silico single crystals embedding spherical nanovoids, simulation domains undergoing multiaxial strain-rate boundary conditions. With respect to available numerical studies, proposed results clearly showed the influence of all the three isotropic stress invariants on computed material strength surfaces. Finally, with the aim to account for physical indications coming from numerical simulations, a ductile nanoporous material with a general isotropic plastic matrix has been investigated via a limit analysis approach, by referring to a modified version of the bigoni strength criterion. The limit state of a hollow-sphere model undergoing isotropic loadings has been exactly determined. Correspondigly, a novel strength criterion has been analytically established in the case of axysimmetric boundary conditions
O'Brien, Matthew Graham. "Investigations into the formation of nanoporous materials." Thesis, University College London (University of London), 2007. http://discovery.ucl.ac.uk/1445764/.
Full textDavid, Allan E. "Immobilization of enzymes on nanoporous, silica composites." College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/2055.
Full textThesis research directed by: Chemical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
Lee, Kah Peng. "Fabrication and applications of nanoporous alumina membranes." Thesis, University of Bath, 2013. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.589649.
Full textCohen-Tanugi, David. "Nanoporous graphene as a water desalination membrane." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98743.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (pages 147-162).
Desalination is one of the most promising approaches to supply new fresh water in the face of growing water issues. However, commercial reverse osmosis (RO) techniques still suffer from important drawbacks. In order for desalination to live up to the water challenges of this century, a step-change is needed in RO membrane technology. Thanks to significant advances in the field of computational materials science in the past decade, it is becoming possible to develop a new generation of RO membranes. In this thesis, we explore how computational approaches can be employed to understand, predict and ultimately design a future generation of RO membranes based on graphene. We show that graphene, an atom-thick layer of carbon with exceptional physical and mechanical properties, could allow for water passage while rejecting salt ions if it possessed nanometer-sized pores. Using computer simulations from the atomic scale to the engineering scale, we begin by investigating the relationship between the atomic structure of nanoporous graphene and its membrane properties in RO applications. We then investigate the thermodynamics, chemistry and mechanics of graphene and the water and salt surrounding it. Finally, we establish the system-level implications of graphene's promising membrane properties for desalination plants. Overall, this thesis reveals that graphene can act as an RO membrane with two orders of magnitude higher water permeability than commercial polymer membranes as long as the nanopores have diameters around 0.6nm, that graphene is strong enough to withstand RO pressures as long as it is supported by a substrate material with adequate porosity, and that a nanoporous graphene membrane could ultimately reduce either the energy footprint or the capital requirements of RO desalination. Ultimately, this thesis highlights a path for the development of next-generation membranes for clean water production in the 21st century.
by David Cohen-Tanugi.
Ph. D.
Rosario, Ryan (Ryan A. ). "Topological characterization of nanoporous gold during coarsening." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/76173.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (p. 34-35).
Previous studies of nanoporous gold have found that, during the coarsening process, the genus per characteristic volume of nanoporous gold has remained constant. Using a rolling-ball type algorithm, in which a test probe rolls over the surface to identify atoms, several test structures and a small-scale nanoporous structure were meshed. The genus was then calculated for each of these meshed structures. It was found that an algorithm that accounts for periodic boundary conditions is required for an accurate genus calculation.
by Ryan Rosario.
S.B.
Kadhim, Mohammed Salman. "Characterisation of nanoporous polymers for water treatment." Thesis, University of Newcastle upon Tyne, 2017. http://hdl.handle.net/10443/4011.
Full textSneddon, Gregor. "Nanoporous carbon capture materials from sustainable sources." Thesis, Heriot-Watt University, 2017. http://hdl.handle.net/10399/3364.
Full textChung-Fu, Cheng. "NANOPOROUS MATERIALS FOR ENERGY STORAGE AND ELECTROCATALYSIS." University of Akron / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=akron16188502947935.
Full textKong, Xinguo. "APPLICATION OF NANOPOROUS MATERIALS IN MECHANICAL SYSTEMS." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1150255954.
Full textSmith, Ross Andrew. "Biomedical Applications Employing Microfabricated Silicon Nanoporous Membranes." Case Western Reserve University School of Graduate Studies / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1278705155.
Full textUppalapati, Badharinadh. "Fabrication of Nanoporous Gold and Biological Applications." VCU Scholars Compass, 2014. http://scholarscompass.vcu.edu/etd/3552.
Full textKim, Seongjun [Verfasser]. "Nanoporous materials for optical applications / Seongjun Kim." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2020. http://d-nb.info/1224883616/34.
Full textVanella, Andrea. "Nanoparticle formation in nanoporous structures and applications." Doctoral thesis, Università di Siena, 2022. http://hdl.handle.net/11365/1210313.
Full textPINNA, ANDREA. "Nanoporous Metals: Fabrication and Structure-Properties Relationship." Doctoral thesis, Università degli Studi di Cagliari, 2022. http://hdl.handle.net/11584/332684.
Full textCeratti, Davide Raffaele. "Viability of nanoporous films for nanofluidic applications." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066482/document.
Full textThis thesis had a dual purpose: i) the development of nanofluidic devices through not lithographic, cheap and scalable bottom-up approach ii) the understanding of nanofluidic phenomena both through experiments and simulations. Mesoporous thin films, in particular Pillared Planar Nanochannels (PPNs), were prepared and utilized to study the capillary infiltration of liquids in nanostructures and have been tested for future nanofluidic applications like separations and nanoconfined reactions. Non organized mesoporous films have also been studied to determine the relationship between nanostructure characteristics and infiltration speed. It has been also demonstrated that in the case of porosities with reduced bottle-necks capillary penetration is performed through a vapor mediated mechanism The samples were prepared by dip-coating. A novel method of preparation based on the substitution of a large part of the deposing solution in dip-coating with an inert fluid has been developed in order to strongly reduce the fabrication costs and allow the preparation of larger samples. Moreover advancement in control of the dip-coating technique in “acceleration-mode” to produce thickness gradients has been developed and some potential application linked to fluidics shown. Finally a part of the effort of this thesis has been placed in the modeling of the electro-osmotic phenomenon in nanostructures through a rather novel simulation method, Stochastic Rotational Dynamics, which takes into account the hydrodynamics and the other interactions inside a nanofluidic system. Validations of the method and further investigations in particular nanofluidic conditions have been performed
Ceratti, Davide Raffaele. "Viability of nanoporous films for nanofluidic applications." Electronic Thesis or Diss., Paris 6, 2015. http://www.theses.fr/2015PA066482.
Full textThis thesis had a dual purpose: i) the development of nanofluidic devices through not lithographic, cheap and scalable bottom-up approach ii) the understanding of nanofluidic phenomena both through experiments and simulations. Mesoporous thin films, in particular Pillared Planar Nanochannels (PPNs), were prepared and utilized to study the capillary infiltration of liquids in nanostructures and have been tested for future nanofluidic applications like separations and nanoconfined reactions. Non organized mesoporous films have also been studied to determine the relationship between nanostructure characteristics and infiltration speed. It has been also demonstrated that in the case of porosities with reduced bottle-necks capillary penetration is performed through a vapor mediated mechanism The samples were prepared by dip-coating. A novel method of preparation based on the substitution of a large part of the deposing solution in dip-coating with an inert fluid has been developed in order to strongly reduce the fabrication costs and allow the preparation of larger samples. Moreover advancement in control of the dip-coating technique in “acceleration-mode” to produce thickness gradients has been developed and some potential application linked to fluidics shown. Finally a part of the effort of this thesis has been placed in the modeling of the electro-osmotic phenomenon in nanostructures through a rather novel simulation method, Stochastic Rotational Dynamics, which takes into account the hydrodynamics and the other interactions inside a nanofluidic system. Validations of the method and further investigations in particular nanofluidic conditions have been performed
Porta, Batalla Maria. "Development of Nanoporous Anodic Alumina Technologies for Drug Delivery." Doctoral thesis, Universitat Rovira i Virgili, 2017. http://hdl.handle.net/10803/460761.
Full textLa liberación de fármaco es un procedimiento en el que un compuesto o un dispositivo libera una molécula de una manera controlada. Posteriormente, este fármaco podrà someterse a absorción, distribución, metabolismo y excreción. Se utilizan semiconductores nanoporosos como la alúmina o el silicio para fabricar vehículos de fármacos debido a sus características distintivas tales como: fabricación de bajo costo, estructura de poros/tamaño controlable de los nanotubos, química de superficie adaptable, área superficial grande, alta capacidad de carga, resistividad química y rigidez mecánica. Estos materiales pueden tener papel especial en la tecnología de liberación controlada de fármacos. Aunque se ha estudiado la liberación de fármacos a partir de materiales nanoporosos y mesoporosos, existe una falta de comprensión de la cinética de liberación de estas plataformas y de la dinámica que las gobierna. En este sentido, nuestro objetivo es explicar la cinética de liberación de superficies nanoporosas y mesoporosas y modelarlas. Este modelo será elucidado mediante un estudio sistemático de los perfiles de liberación. En conjunto, la tecnología, la caracterización y las aplicaciones presentadas en esta tesis son bastante alentadoras y proporcionan un punto de partida para el desarrollo de estructuras inteligentes e innovadoras que encontrarán aplicaciones en los sistemas de administración de fármacos.
Drug release is a procedure in which a composite or a device releases a molecule in a controlled way. Subsequently the drug would be subjected to absorption, distribution, metabolism and excretion. Nanoporous semiconductors like alumina or silicon are used to fabricate carriers because of their distinctive features such as: low-cost fabrication, controllable pore/nanotube structure, tailored surface chemistry, high surface area, high loading capability, chemical resistivity and mechanical rigidity, have affianced a special role in drug delivery technology. Although drug release from nanoporous and mesoporous materials has been studied, there is a lack of understanding of the release kinetics from these platforms and the dynamics governing them. For this reason, our aim is to explain the release kinetics from nanoporous and mesoporous surfaces and model them. This model will be elucidated by means of a systematic study of release profiles. Altogether, technology, characterization and applications presented in this thesis are rather encouraging and are providing a starting point for developing innovative smart structures that will find applications in drug delivery systems.
Barsuk, Daria. "Conception Métallurgique de Nouvelles Structures Nanoporeuses." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAI051/document.
Full textNew nanoporous metallic materials based on non-Pt group metals have been synthesized via dealloying of rapidly solidified alloys and aimed to demonstrate competitive catalytic performance in the field of direct alkaline fuel cells and SERS-active substrates. Nanostructured copper surface and nanoporous copper matrix with very fine morphology and specific surface area were obtained by chemical dealloying of bulk Cu90(HfZr)10 and melt-spun amorphous CuxCa100-x (x ranging from 35 to 80 at.%) family of alloys accordingly. Nanoporous silver and cobalt substrates were produced by dealloying of M38.75Cu38.75Si22.5 crystalline ribbons (M = Co and Ag) as a result of the removal of Cu and Si-rich phases. In addition to conventional characterization methods, all nanoporous structures have been reconstructed by FIB-nanotomography, clearly exposing the morphological diversity of the three systems with transversal porosity when visualized and color-mapped in 3D by a special numerical tomography tool. It is for the first time that a practical significance of these materials has been explored in the scope of self-supported anodic catalysts, suggested throughout this study as an alternative to the unstable Pt-based carbon-supported commercial composites. Half-cell electrochemical tests demonstrated an excellent catalytic activity towards the oxidation of a borane fuel and superior stability of functioning in the alkaline environment compared to Pt/C catalyst. In similar conditions, nanoporous Co showed higher efficiency but lower stability, attributed to the complex chemical composition of its porous scaffold. Nanoporous Cu has not been exploited for the mentioned applications due to its high brittleness and is suggested to go through improvements on the step of precursor synthesis. Lastly, while exploring the mechanical behavior of the NPMs by instrumented nanoindentation of different nanoporous Ag substrates, a load-displacement dependence phenomenological model has been suggested for this class of metallic materials
Wang, Jian. "The nanoporous morphology of photopolymerized crosslinked polyacrylamide hydrogels." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2687.
Full textChennapragada, Pavani. "Fabrication of palladium nanoparticles and nanoporous alumina templates." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001027.
Full textSantos, Alejandro Abel. "Structural engineering of nanoporous anodic alumina and applications." Doctoral thesis, Universitat Rovira i Virgili, 2010. http://hdl.handle.net/10803/8480.
Full textEn primer lugar, se fabrican cuatro tipos tradicionales de alúmina porosa autoordenada utilizando la anodización blanda en dos pasos. Los ácidos utilizados para fabricar dichos tipos de alúmina porosa son sulfúrico, oxálico y fosfórico. Los voltajes de anodización aplicados son 20, 40 y 160-195 V, respectivamente. El diámetro del poro varia entre 20 y 250 nm, siendo la distancia entre poros 55, 100 y 400-500 nm, respectivamente. Posteriormente, se fabrica alúmina porosa autoordenada utilizando la anodización dura en un paso utilizando ácido oxálico. También se emplea la anodización dura en dos pasos para fabricar moldes de alúmina porosa ordenada sin capa protectiva, la cuál es característica de un proceso de anodización dura en un paso.
Además, siguiendo una técnica de re-anodización, se elimina la capa barrera de óxido de la parte posterior de los moldes de alúmina sin eliminar el sustrato de aluminio ni desprender el molde de alúmina del sustrato. Después, por medio de un proceso de anodización asimétrico en el cuál se modifican las condiciones de anodización (voltaje de anodinado, tipo y concentración de ácido), se fabrican moldes de alúmina jerarquizados con múltiples configuraciones. También se producen moldes de alúmina porosa bicapa combinando anodizado duro y blando. Posteriormente, se emplea un molde de nitruro de silicio para fabricar moldes de alúmina porosa perfectamente ordenados mediante la técnica de nanoimpresión. Además, utilizando esta misma técnica y seleccionando las condiciones de anodización adecuadas, es posible fabricar moldes de alúmina porosa perfectamente ordenados con un ordenamiento de poros extraordinario. Finalmente, se fabrican nanoembudos basados en alúmina porosa intercalando consecutivamente pasos de anodizado y ampliación de diámetro de poro. Dichas nanoestructuras son diseñadas con un alto grado de precisión mediante dos procesos de calibración sistemáticos. Además, se desarrolla un modelo teórico que predice el crecimiento del poro durante el proceso de anodización. Este modelo es experimentalmente validado.
A partir de dichas nanoestructuras basadas en moldes de alúmina porosa se estudian varias aplicaciones. En primer lugar, se sinterizan nanopilares magnéticos ordenados sobre sustratos de aluminio mediante deposición electroquímica. Estos se caracterizan por varias técnicas (ESEM, EDXS y XRD). Por sus propiedades magnéticas, dichos nanopilares podrían ser empleados como nanoelectrodos para deposición directa de nanopartículas desde una corriente de gas o como precipitadores electrostáticos. En segundo lugar, se fabrican estructuras poliméricas compuestas de nanopilares sobre un sustrato nanoestructurado basado en el mismo polímero. Para ello, se emplean moldes de alúmina porosa jerarquizados. Además, nanopilares del mismo polímero son transferidos sobre sustratos de ITO/vidrio. La nanoestructura resultante es caracterizada por ESEM, TEM, XRD, CS-AFM y se demuestra que ésta puede ser óptima para integrarse en celdas solares orgánicas con heterouniones volumétricas de alto rendimiento. En tercer lugar, se presenta la primera etapa en la fabricación de mosaicos de nanohilos y nanotubos de níquel. Además, dichas nanoestructuras se utilizan para llevar a cabo un estudio sistemático sobre cómo la re-organización de los poros durante el cambio de régimen de anodización de blando a duro en moldes de alúmina porosa bicapa. Estos mosaicos de nanoestructuras magnéticas podrían ser empleados para desarrollar nuevas plataformas de almacenamiento de datos. Finalmente, se fabrican cadenas de nanoesferas de silicio por infiltración bajo vacío a través de nanoembudos basados en alúmina porosa. Dichas nanoestructuras podrían ser integradas en dispositivos ópticos de tamaño nanométrico.
In this PhD thesis, several structural engineering strategies are applied to develop innovative templates based on nanoporous anodic alumina. These templates are subsequently used to develop other nanostructures based on certain materials with multiple applications such as polymers, magnetic metals and semiconductors. These replicated nanostructures could be integrated in various types of nanodevices (e.g. nanoelectrodes for direct deposition of nanoparticles from a gas draught, bulk-heterojunction solar cells, one-dimensional optoelectronic devices, nanofilters and so on). It is expected that the results presented will become a starting point to develop new nanodevices and applications in a wide range of research fields.
Kirstein, Johanna. "Diffusion of single molecules in nanoporous mesostructured materials." Diss., lmu, 2007. http://nbn-resolving.de/urn:nbn:de:bvb:19-79478.
Full textWoodford, Julia Jane. "Hierarchical nanoporous solid base catalysts for biodiesel synthesis." Thesis, Cardiff University, 2013. http://orca.cf.ac.uk/51927/.
Full textNguyen, Khanh Dieu Hong. "Framework redox sites in nanoporous molecular sieve catalyst." Thesis, University College London (University of London), 2008. http://discovery.ucl.ac.uk/17226/.
Full textSchmidt, Iver. "Design of nanoporous materials for light alkane transformation." Thesis, University of Liverpool, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369114.
Full textBorchardt, Lars, Claudia Hoffmann, Martin Oschatz, Lars Mammitzsch, Uwe Petasch, Mathias Herrmann, and Stefan Kaskel. "Preparation and application of cellular and nanoporous carbides." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-138910.
Full textDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
Kulkarni, Ambarish R. "Multiscale modeling of nanoporous materials for adsorptive separations." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53053.
Full textMarkham, Matthew L. "An investigation into the properties of nanoporous semiconductors." Thesis, University of Southampton, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432628.
Full textFung, Alex Weng Pui. "Localization transport in granular and nanoporous carbon systems." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/34088.
Full textNazarudin, N. "Catalytic cracking of plastic waste using nanoporous materials." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1380400/.
Full text