Literatura académica sobre el tema "Films nanoporeux"
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Artículos de revistas sobre el tema "Films nanoporeux"
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Abelow, Alexis E., Ryan J. White, Kevin W. Plaxco y Ilya Zharov. "Nanoporous silica colloidal films with molecular transport gated by aptamers responsive to small molecules". Collection of Czechoslovak Chemical Communications 76, n.º 6 (2011): 683–94. http://dx.doi.org/10.1135/cccc2011022.
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We report the preparation of colloidal nanoporous silica films whose function mimics that of protein channels in gating the transport of small molecules across a cell membrane. Specifically, we report a means of controlling the molecular flux through colloidal nanopores that employ aptamer oligonucleotides binding to a specific organic small molecule (cocaine). These biomacromolecules have been introduced onto the nanopore surface by attaching pre-made oligonucleotides to the activated nanopore surface. The aptamers change their conformation in response to the binding events, and thus alter the free volume of the colloidal nanopores available for molecular transport.
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Srisuwan, Y., N. Kotsaeng, Y. Baimark, N. Narkkong y W. Simchuer. "Study on Morphology and Thermal Stability of Nanoporous Silk Fibroin Films". Advanced Materials Research 55-57 (agosto de 2008): 721–24. http://dx.doi.org/10.4028/www.scientific.net/amr.55-57.721.
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Nanoporous silk fibroin (SF) films were prepared as SF film loaded with methoxy poly(ethylene glycol)-b-poly(D,L-lactide) (MPEG-b-PDLL) nanoparticles by film casting of MPEG-b-PDLL nanoparticle suspension-SF solution. Nanoporous structures of the SF films were formed due to self-condensation and nanophase separation of nanoparticles from SF film matrix during drying process. The films with SF/MPEG-b-PDLL ratios of 20/1, 20/2 and 20/3 (w/w) were prepared and investigated. The MPEG-b-PDLL nanoparticles can be observed on film surface and cross-section with 100-300 nm in size. The size of interconnected nanopore was in the range of 20 – 300 nm. The number and size of nanopores increased as increasing the MPEG-b-PDLL ratio. Thermal stability of the films studied from differential thermogravimetric (DTG) thermogram found that the nanoparticles dispersed into the SF films could improve thermal stability of each component. This indicated strong hydrogen bond interactions between SF and MPEG-b-PDLL were existed. Film transparency of the SF nanoporous films decreased when the MPEG-b-PDLL ratio was increased.
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Her, Hyun Jung, Jung Min Kim, Yun Soo Lim, Jae Wan Kim, Y. J. Choi, C. J. Kang y Yong Sang Kim. "Nanoporous Titania by Embossing with PMMA Nanopoles Made from Nanoporous Alumina Template". Materials Science Forum 544-545 (mayo de 2007): 1017–20. http://dx.doi.org/10.4028/www.scientific.net/msf.544-545.1017.
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We produced highly uniform nanoporous thin films of the dense array of titania (TiO2) pores of 70~80 nm in diameter with nanoimprinting method. Titania in HCl and 2-propanol solution was coated on an indium tin oxide (ITO) surface and embossed with an array of PMMA nanopoles which was produced using a nanoporous alumina (Al2O3) template. Two-step anodization was introduced to produce highly uniform and dense nanopores on the aluminum surface. The polymethyl methacrylate (PMMA) was poured onto and infiltrated into the nanoporous alumina surface which was heated at 150 oC. The alumina nanopores and aluminum plate were removed by wet-etching leaving an array of PMMA nanopoles. These highly uniform nanostructured titania films will be very useful for photovoltaic and photocatalytic applications where nanostructuring of surface with controlled dimensions are essential.
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Leenheer, Andrew J., Alexander Miedaner, Calvin J. Curtis, Maikel F. A. M. van Hest y David S. Ginley. "Fabrication of nanoporous titania on glass and transparent conducting oxide substrates by anodization of titanium films". Journal of Materials Research 22, n.º 3 (marzo de 2007): 681–87. http://dx.doi.org/10.1557/jmr.2007.0078.
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Nanoporous titania (TiO2) or titania nanotubes could provide a continuous nanostructured electron-conducting anode for organic photovoltaics. In this work, nanoporous titania was formed by anodizing thin films of titanium on both glass and transparent conducting oxide (TCO) substrates. Titanium thin films (500–700 nm) were deposited by radio frequency (RF) magnetron sputtering. Films were anodized in acidic electrolytes containing small amounts of hydrofluoric acid (HF) at constant voltages ranging from 7 to 15 V. Scanning electron microscope (SEM) analysis revealed a nanoporous structure. Nanoporous titania structures were grown on glass in an electrolyte containing sulfuric acid, trisodium citrate, and potassium fluoride, with pore diameters around 50 nm. Analyzing the films at different anodization times, the stages of nanopore formation were elucidated. Additionally, nanoporous titania was formed on a TCO substrate by anodizing in an electrolyte containing acetic acid and hydrofluoric acid. While not completely transparent, the nanoporous titania is promising for use in organic photovoltaics.
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Chojenka, Juliusz, Arkadiusz Zarzycki, Marcin Perzanowski, Michał Krupiński, Tamás Fodor, Kálmán Vad y Marta Marszałek. "Tuning of the Titanium Oxide Surface to Control Magnetic Properties of Thin Iron Films". Materials 16, n.º 1 (28 de diciembre de 2022): 289. http://dx.doi.org/10.3390/ma16010289.
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We describe the magnetic properties of thin iron films deposited on the nanoporous titanium oxide templates and analyze their dependance on nanopore radius. We then compare the results to a continuous iron film of the same thickness. Additionally, we investigate the evolution of the magnetic properties of these films after annealing. We demonstrate that the M(H) loops consist of two magnetic phases originating from the iron layer and iron oxides formed at the titanium oxide/iron interface. We perform deconvolution of hysteresis loops to extract information for each magnetic phase. Finally, we investigate the magnetic interactions between the phases and verify the presence of exchange coupling between them. We observe the altering of the magnetic properties by the nanopores as a magnetic hardening of the magnetic material. The ZFC-FC (Zero-field cooled/field cooled) measurements indicate the presence of a disordered glass state below 50 K, which can be explained by the formation of iron oxide at the titanium oxide-iron interface with a short-range magnetic order.
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Benetti, Giulio, Francesco Banfi, Emanuele Cavaliere y Luca Gavioli. "Mechanical Properties of Nanoporous Metallic Ultrathin Films: A Paradigmatic Case". Nanomaterials 11, n.º 11 (18 de noviembre de 2021): 3116. http://dx.doi.org/10.3390/nano11113116.
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Nanoporous ultrathin films, constituted by a slab less than 100 nm thick and a certain void volume fraction provided by nanopores, are emerging as a new class of systems with a wide range of possible applications, including electrochemistry, energy storage, gas sensing and supercapacitors. The film porosity and morphology strongly affect nanoporous films mechanical properties, the knowledge of which is fundamental for designing films for specific applications. To unveil the relationships among the morphology, structure and mechanical response, a comprehensive and non-destructive investigation of a model system was sought. In this review, we examined the paradigmatic case of a nanoporous, granular, metallic ultrathin film with comprehensive bottom-up and top-down approaches, both experimentals and theoreticals. The granular film was made of Ag nanoparticles deposited by gas-phase synthesis, thus providing a solvent-free and ultrapure nanoporous system at room temperature. The results, bearing generality beyond the specific model system, are discussed for several applications specific to the morphological and mechanical properties of the investigated films, including bendable electronics, membrane separation and nanofluidic sensing.
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Yu, Yang-Yen y Chang-Chung Yang. "Preparation of Nanoporous Poly(Methyl Silsesquioxanes) Films Using PS-b-P4VP as Template". Journal of Nanoscience and Nanotechnology 8, n.º 3 (1 de marzo de 2008): 1537–44. http://dx.doi.org/10.1166/jnn.2008.073.
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Nanoporous poly(methyl silsesquioxane) (PMSSQ) film was prepared through the templating of an amphiphilic block copolymer, poly(styrene-4-vinyl pyridine) (PS-b-P4VP). The experimental and theoretical studies suggest that the intermolecular hydrogen bonding is existed between the PMSSQ precursor and PS-b-P4VP. The miscible hybrid and the narrow thermal decomposition of the PS-b-P4VP lead to nanopores in the prepared films from the results of TGA, AFM, and TEM. The effects of the loading ratio on the morphology and properties of the prepared nanoporous PMSSQ films were investigated. The TEM and AFM studies show that the uniform pore morphology with pore size 10–15 nm can be prepared from a modest porogen loading level for the optimum intermolecular hydrogen bonding. The refractive index and dielectric constant of the prepared nanoporous films decreases with an increase in PS-b-P4VP loading. On the other hand, the porosity increases with an increasing PS-b-P4VP loading. This study demonstrates a methodology to control pore morphology and properties of the nanoporous PMSSQ films through the templating of PS-b-P4VP.
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Yu, Yang Yen, Wen Chen Chien y Shih Ting Chen. "Preparation of Nanoporous Mondispersed Silica Nanoparticles Films Using Poly(styrene)- Block-Poly( 2-Vinyl Pyridine) as Template". Advanced Materials Research 47-50 (junio de 2008): 646–49. http://dx.doi.org/10.4028/www.scientific.net/amr.47-50.646.
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Nanoporous silica films were prepared through the templating of amphiphilic block copolymer, poly(styrene-2-vinyl pyridine) (PS-b-P2VP), and colloidal silica nanoparticles. The experimental and theoretical studies suggested that the intermolecular hydrogen bonding was existed between the colloidal silica nanoparticles and PS-b-P2VP. The miscible hybrid and the narrow thermal decomposition of the PS-b-P2VP led to nanopores in the prepared films from the results of TGA, AFM, and TEM. The effects of the loading ratio and P2VP chain length on the morphology and properties of the prepared nanoporous silica films were investigated. The TEM and AFM studies showed that the uniform pore morphology with pore size 10-15nm was prepared from a modest porogen loading level for the optimum intermolecular hydrogen bonding. The refractive index and dielectric constant of the prepared nanoporous films decreased with an increase in PS-b-P2VP loading. On the other hand, the porosity increased with an increasing PS-b-P2VP loading. This study demonstrated a methodology to control pore morphology and properties of the nanoporous silica films through the templating of PS-b-P2VP.
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Her, Hyun-Jung, Jung-Min Kim, C. J. Kang y Yong-Sang Kim. "Fabrication of Thin Film Titania with Nanopores, Nanopoles, and Nanopipes by Nanoporous Alumina Template". Journal of Nanoscience and Nanotechnology 8, n.º 9 (1 de septiembre de 2008): 4808–12. http://dx.doi.org/10.1166/jnn.2008.ic84.
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We demonstrate the formation of thin film titania (TiO2) with a dense array of nanopores, nanopoles, and nanopipes. The heights of pores, poles, and pipes were approximately 130 nm, 180 nm, and 200 nm, respectively. The aspect ratios of these three structures were approximated between 2 and 3. In order to obtain titania thin films, a nanoporous alumina (Al2O3) template was fabricated by performing a two-step anodization process. The spin-coated titania films were uniformly patterned by a nanoimprinting lithography technique with a textured poly(methyl methacrylate) (PMMA) mold or nanoporous alumina template. The titania films are very useful for solar cells, photocatalytic and sensing applications, in which nano-structuring of surfaces with controlled dimensions is vital.
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Chou, Chia-Man, Tong-You Wade Wei, Jou-May Maureen Chen, Wei-Ting Chang, Chang-Tze Ricky Yu y Vincent K. S. Hsiao. "Preparation of Nanoporous Polymer Films for Real-Time Viability Monitoring of Cells". Journal of Nanomaterials 2011 (2011): 1–6. http://dx.doi.org/10.1155/2011/436528.
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We have demonstrated an alternative way to monitor the viability of cells adhered on a nanoporous polymer film in real time. The nanoporous polymer films were prepared by laser interference pattering. During exposure of holographic patterning, the dissolved solvents were phase separated with photocured polymer and the nanopores were created as the solvents evaporated. The diffracted spectra from the nanoporous polymer film responded to each activity of the cell cycle, from initial cell seeding, through growth, and eventual cell death. This cell-based biosensor uses a nanoporous polymer film to noninvasively monitor cell viability and may prove useful for biotechnological applications.
Tesis sobre el tema "Films nanoporeux"
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Cojocaru, Ludmila. "Films d’oxydes semi-conducteurs nanoporeux et nanocristallins pour dispositifs photovoltaïques hybrides". Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14630/document.
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Dans le contexte de la mise au point de dispositifs photovoltaïques efficaces, bon marché et respectueux de l’environnement, la synthèse d’oxydes métalliques semi-conducteurs tels que SnO2, Zn2SnO4 et WO3 de morphologies et textures diverses a été développée afin d’élaborer des photoanodes poreuses pour cellules solaires à colorant. D’après les études réalisées par différentes méthodes (MEB, MET, DRX et BET), les matériaux obtenus présentent des caractéristiques texturales, morphologiques et structurales appropriées pour l’application visée. Des cellules solaires à colorant ont donc été réalisées à partir de ces oxydes, puis différents paramètres influençant leurs performances ont été optimisés afin d’améliorer l’efficacité de la conversion photovoltaïque. Notamment l’influence positive de différents traitements des photoanodes (i.e. solution aqueuse de TiCl4 ou traitement à l’eau) sur les rendements de conversion énergétique et la stabilité des dispositifs a été démontrée. Ainsi, des performances comparables ou supérieures à l’état de l’art ont été atteintes pour les systèmes à base de SnO2. Ces performances ont ensuite été interprétées en déterminant les processus électroniques et ioniques ayant lieu dans ces cellules par différentes méthodes physiques (mesures de tension de seuil et de décroissance de circuit-ouvert, spectroscopie d’impédance). Enfin, des électrodes réalisées à partir de WO3 déposé sur substrats flexibles ont démontré des propriétés électrochromes très prometteuses ce qui ouvre de nouvelles perspectives dans le domaine de l’affichageIn the context of the development of efficient, low-cost and environmentally friendly photovoltaic devices, the synthesis of metal-oxide semiconductors such as SnO2, Zn2SnO4 and WO3 with various textures and morphologies have been developed in order to achieve nanoporous photoanodes for dye-sensitized solar cells. According to studies carried out by different characterization methods (SEM, TEM, XRD and BET), the resulting materials show interesting features for the expected application. Dye solar cells were then fabricated from photoanodes processed with these oxides and several parameters influencing their performance were optimized to improve the overall conversion efficiency. In particular, the beneficial effect of different treatments of the photoanodes (ie aqueous TiCl4 or water treatment) on the power conversion efficiency and the stability of the devices has been evidenced. Thus, state-of-the art or, even, record efficiencies were reached in the case of SnO2-based systems. These performances were then rationalized by determining the electronic and ionic processes occurring in these devices by various physical methods (threshold voltage and open-circuit photovoltage decay measurements, electrochemical impedance spectroscopy). Finally, electrodes based on WO3 and deposited on flexible substrates have shown very promising electrochromic properties, which opens up new prospects in the field of smart displays
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Mauroy, Cyprien. "Films multicouches nanocristaux de cellulose/Ge-Imogolite pour l'élaboration de nouveaux matériaux nanoporeux". Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0265/document.
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Lors des dix dernières années, les films multicouches ont suscité l’intérêt de la communauté scientifique pour leurs propriétés innovantes. Principalement issus de l’association de polyélectrolytes et/ou de nanoparticules de différentes morphologies, ils ont ouvert la voie à la fabrication d’une nouvelle catégorie de matériaux nanoporeux, possédant des propriétés optiques attractives telles que la coloration structurale et l’antireflet. Les films multicouches à base de deux nanoparticules de charges opposées sont plus rares et permettent de jumeler les propriétés des deux nanoparticules utilisées et d’en faire émerger de nouvelles. Dans cette étude, nous nous sommes intéressés à deux nanoparticules anisotropes, de facteurs d’aspects contrôlés et respectivement bio/geosourcées : les nanocristaux de cellulose (NCC) et des nanotubes d’imogolite. Le but de cette étude est d’étudier la possibilité de créer un film multicouche bio-géo inspiré à base de ces deux nanoparticules par immersion et d’en étudier les propriétés optiques. Dans un premier temps, nous avons comparé les films multicouches NCC/Ge-imogolites à ceux plus communément décrits dans la littérature, à savoir, des films à base de NCC ou d’imogolite associés à un polyélectrolyte de charge opposée. Les différents paramètres de trempage comme le temps d’immersion et la force ionique de la suspension ont été variés afin d’obtenir une densité de film optimale. Pour finir la porosité des films et leur comportement dans l’eau ont été étudiés par QCM-D, ainsi que leurs propriétés optiques par mesure de transmittanceIn the past decade, multilayer thin films drew the scientific community attention for their unique properties. Indeed, principally made of an association of polyelectrolytes and/or nanoparticles, of various morphologies and chemistries, they allow the design of a range of porous nanomaterials with unique optical properties, such as structural colors or anti-reflectivity. Less commonly described, thin films made of two nanoparticles of opposite charges are gaining interest since they combine the properties of the two nanoparticles used, and generate new ones through their association. In this study, multilayer coatings were formed through the association of two anisotropic oppositely charged nanorods of well-controlled aspect ratio, i.e. bio-based anionic cellulose nanocrystals (CNC) and geo-based cationic Imogolites. This study deals with the feasibility to create a bio-geo-inspired multilayer thin film based on these two nanoparticles by dipping and characterize their optical properties. Firstly, elaboration of multilayered thin films from CNC and Ge-Imogolites nanorods, were studied in comparison with reference films incorporating CNC or Imogolites with polyelectrolytes bearing opposite charges of the nanorods. Multilayered thin films were assembled by the dipping procedure and various parameters (adsorption time, ionic strength, etc.) were varied to investigate the optimal density for the film. To finish, film porosities were investigated using QCM-D, and optical properties were investigated by transmittance measurements
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Pastre, Aymeric. "Élaboration d’électrodes à base de films d’or nanoporeux et conception de micro-supercondensateurs intégrés". Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10187/document.
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Le travail de thèse a pour objectif la conception de micro-supercondensateurs tout-solide à base d’or nanoporeux, intégrés sur substrat de silicium. Dans un premier temps nous avons développé un procédé de formation de films d’or par réduction chimique auto-catalytique. Afin d’augmenter l’adhérence du film d’or sur le substrat de silicium, une couche d’accroche originale a été élaborée par procédé sol-gel. Il s’agit d’un film mince d’oxyde de zirconium (ZrO2) dopé par des nanoparticules d’or. La porosité de ces films d’or a été contrôlée par une méthode de templating à partir de microsphères de polystyrène (Ø ≈ 20 nm). Les films d’or nanoporeux peuvent atteindre 1,2 µm d’épaisseur en l’absence de délamination. La porosité est totalement interconnectée et la taille des pores (20 nm) a été choisie afin d’être compatible avec l’électrolyte utilisé. Le procédé fait uniquement intervenir des méthodes chimiques en solution et est totalement compatible avec les procédés classiques de micro-fabrication. Les films d’or nanoporeux constituant le matériau d’électrodes du micro-supercondensateur, ont été structurés par photolithographie sous la forme de peignes interdigités. L’imprégnation d’un électrolyte polymère gélifié (PVA / KOH) a permis de finaliser la fabrication du micro-supercondensateur tout-solide. Les caractérisations électrochimiques montrent que le micro-dispositif atteint une capacité surfacique de 240 µF/cm² à 20 mV/s, et peut endurer plus de 8000 cycles en ne perdant que 5% de sa capacité initiale. Ces performances sont comparables à celles des micro-supercondensateurs intégrés tout-solide reportées dans la littératureThe thesis work aims at the design of nanoporous gold-based all-solid state micro-supercapacitors, integrated on a silicon substrate. In a first step, we have developed a process for the formation of gold films by auto-catalytic chemical reduction. In order to enhance the adhesion of the gold film to the silicon substrate, an original seed layer was produced by a sol-gel process. It consists in a thin film of zirconium oxide (ZrO2) doped with gold nanoparticles. The porosity of these gold films was controlled by a templating method using polystyrene microspheres (Ø ≈ 20 nm). Nanoporous gold films can reach a 1.2 μm thickness in the absence of delamination. The porosity is completely interconnected and the pore size (20 nm) was chosen in order to be compatible with the used electrolyte. The method only involves wet chemistry processes and is fully compatible with conventional micro-manufacturing processes. The nanoporous gold films constituting the electrode material of the micro-supercapacitor have been structured by photolithography in the form of interdigitated combs. The impregnation of a gelled polymer electrolyte (PVA / KOH) made it possible to finalize the manufacture of the all-solid state micro-supercapacitor. Electrochemical characterizations show that the micro-device reaches a surface capacitance of 240 μF/cm² at 20 mV/s, and can endure more than 8000 cycles, while losing only 5% of its initial capacitance. These performances are comparable to those of the all-solid state integrated micro-supercapacitors reported in the literature
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Wong, Ka Lun. "Incorporation des semi-conducteurs dans des matériaux nanoporeux et mise en forme de films minces". Caen, 2010. http://www.theses.fr/2010CAEN2056.
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Les semi-conducteurs nanométriques (NSCs) sont des matériaux à haut potentiel pour diverses applications tels que l’optoélectronique, le photovoltaïque, et les capteurs chimiques. Dans cette étude, deux types de synthèses ont été développées pour la fabrication des NSCs dans des matériaux zéolitiques: une synthèse en une étape (OSS), et une synthèse par échange d’ion et irradiation (IEI). La méthode OSS permet de synthétiser directement des NSCs dans une zéolithe hydrophobe de silice pure de type MFI par co-condensation de précurseur de silice, de 3-mercaptopropyl-trimethoxysilane (MPTS), de précurseur métallique (Cd2+, Zn2+, Pb2+, Mo5+, Co2+) et de tetrapropylammonium hydroxyde (TPAOH). Pour la méthode IEI, le précurseur métallique est introduit dans les zéolithes des aluminosilicates (zéolithe du type LTL, FAU et MFI) par échange d’ion. La suspension de zéolithe, en présence de 2-mercaptoethanol, est irradiée avec différentes doses de rayon gamma pour favoriser la formation de métaux soufrés nanométriques. Les particules CdS, emprisonnées dans les canaux de la LTL, maintiennent leur taille dans la gamme sous-nanométrique. Tandis que dans les zéolithes du type FAU et MFI, 2 types de CdS sont formés. Les échantillons préparés par les approches OSS et IEI sont stables dans l’air et assemblés en films minces. Ainsi, une nouvelle voie de préparation de NSCs appliquée à la fabrication de capteur chimique, d’optoélectronique et de photovoltaïque est possibleNanosized semiconductors (NSCs) are potential materials for a variety of optoelectronic, solar photovoltaic and sensor devices. In this study, two main approaches for preparation of stable NSCs in zeolitic materials, namely the one-step synthesis (OSS) and the ion-exchange-irradiation (IEI) have been developed. The OSS approach involves direct synthesis of NSCs in hydrophobic pure silica MFI-type zeolite via co-condensation of silica source, 3-mercaptopropyl-trimethoxysilane (MPTS), metal precursor (Cd2+, Zn2+, Pb2+, Mo5+, Co2+) and tetrapropylammonium hydroxide (TPAOH). For IEI approach, metal precursors were first introduced into the as-prepared aluminosilicate zeolites (LTL, FAU and MFI- type zeolites) by ion-exchange process. The ion-exchanged zeolite suspensions in the presence of 2-mercaptoethanol are irradiated with different doses of gamma ray to facilitate the formation of nanosized metal sulfides. The NSCs trapped in the LTL channels maintain their maximum particle size in the sub-nm range, while two different populations of clusters in FAU and MFI zeolites are formed. The NSCs samples prepared by both OSS and IEI approaches are stable in air and assembled into thin films. Thus, alternative routes for preparation of stable NSCs for fabrication of new sensing, optoelectronic and photovoltaic devices are disclosed
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Amyar, Hajar. "Probing the formation and the sorption response of nanoporous films by in situ optical spectroscopies". Electronic Thesis or Diss., Sorbonne université, 2023. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2023SORUS204.pdf.
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Les films nanoporeux présentent un grand intérêt en raison de leurs propriétés uniques et de leurs applications variées dans différents domaines. La caractérisation de ces films est cruciale pour comprendre et contrôler leurs propriétés (telles que la taille et la distribution des pores, l'aire de surface, la porosité et la résistance mécanique) et leur évolution dans des conditions de fonctionnement. A cet égard, parmi les méthodes spectroscopiques optiques, l'ellipsométrie, en particulier l'ellipsométrie in situ, est une technique puissante et non-destructive pour caractériser les films nanoporeux. Cette technique est bien adaptée pour contrôler l'épaisseur et les propriétés optiques du film dans différents environnements. Il s'agit d'un outil important pour les applications dans lesquelles des molécules invitées sont absorbées dans la porosité (détection, capture de gaz, récolte d'eau, refroidisseurs). Malgré ses nombreux avantages, l'ellipsométrie spectroscopique in situ ne parvient toujours pas à fournir certaines informations clés qui restent insaisissables ou n'ont pas été étudiées, telles que (i) l'évolution chimique dans les films, (ii) la réponse cinétique des films dans des conditions hors équilibre et (iii) la cartographie locale de processus d'adsorption. Dans cette thèse, nous avons abordé certaines des questions mentionnées ci-dessus en développant trois méthodologies optiques pour caractériser plus en profondeur les films nanoporeux. Nous avons d'abord introduit l'ellipsométrie IR in situ avec une chambre environnementale/thermique pour suivre l'évolution des propriétés structurelles, optiques et chimiques pendant la formation de films mésoporeux dérivés de sol-gel. A titre d'exemple, nous avons étudié la formation de TiO2 mésoporeux pendant les processus de calcination et de photo-recuit. De plus, nous introduisons une nouvelle approche appelée "ellipsométrie cyclique" pour étudier le comportement cinétique d'adsorption de différents films nanoporeux connus, y compris les films de TiO2, SiO2 et MOFs. Inspirée de la voltampérométrie cyclique (en électrochimie), cette méthode nous permet d'étudier la réponse d'adsorption dans les pores des films dans des conditions hors équilibre. Enfin, nous étudions la possibilité de visualiser les processus d'adsorption locaux en combinant la structure poreuse avec des nanoantennes plasmoniques. Nous avons d'abord développé une boîte à outils de simulation pour décrire les propriétés optiques des films plasmoniques composites. Ensuite, nous introduisons la microscopie hyperspectrale environnementale pour suivre les mécanismes d'adsorption au niveau d'une seule nanoantenne. Enfin, nous avons fabriqué un revêtement poreux plasmonique composite dans lequel un chauffage local est induit par irradiation lumineuse, une première étape vers de futurs dispositifs programmables. Plus largement, nos études soulignent le potentiel des spectroscopies optiques avec des chambres environnementales pour sonder la réponse et l'évolution des films nanoporeux dans diverses conditions (équilibre ou hors équilibre) et à différentes échelles (locale ou d'ensemble) avec des implications importantes au niveau fondamental et appliquéNanoporous films are of great interest due to their unique properties and various applications in different fields. Characterization of these films is crucial to understanding and controlling their properties (such as pore size and distribution, surface area, porosity, and mechanical strength) and their evolution in operating conditions. In this regard, among the optical spectroscopic methods, ellipsometry, especially in situ ellipsometry is a powerful and non-destructive technique for characterizing nanoporous films. This technique is well suited to monitor the film's thickness and optical properties in different environments. This is an important tool for applications in which guest molecules are uptaken into the porosity (sensing, gas capture, water harvesting, chillers). Despite the many advantages, the in situ spectroscopic ellipsometry still fails in providing some key insights that remain elusive or have not been investigated, such as (i) the chemical evolution in the films, (i) the kinetics response of the films under out-of-equilibrium conditions and (iii) the local mapping of sorption events. In this thesis, we addressed some of the abovementioned questions by developing three optical methodologies to characterized nanoporous films more in depth. We first introduce in situ IR ellipsometry with an environmental/thermal chamber to monitor the evolution of structural, optical, and chemical properties during the formation of sol-gel derived mesoporous films. As a case of study, we investigated mesoporous TiO2 formation during the calcination and photo-annealing processe. Furthermore, we introduce a new approach called "cyclic ellipsometry" to study the sorption kinetics behavior of different known nanoporous films, including TiO2, SiO2, and MOFs films. Inspired by cyclic voltammetry (in electrochemistry), this method allows us to investigate sorption response into the pores of the films in out-of-equilibrium conditions. At last, we investigate the possibility of visualizing local sorption events by the combination of porous structure with plasmonic nanoantennas. First, we developed a simulation toolbox to describe the optical properties of the composite plasmonic films. Then, we introduce environmental hyperspectral microscopy to follow sorption behaviors at the single antenna level. At last, a composite plasmonic porous coating was fabricated in which local heating is induced by light irradiation, a first step toward future programmable devices. More broadly, our studies highlight the potential of optical spectroscopies with environmental chambers to probe the response and the evolution of nanoporous films in various conditions (equilibrium vs out-of-equilibrium) and at different scales (local vs ensemble) with important implications at the fundamental and applied levels
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Topoglidis, Emmanuel. "Biosensors based on nanoporous TiO2 films". Thesis, Imperial College London, 2001. http://hdl.handle.net/10044/1/7573.
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Gage, David Maxwell. "Fracture of nanoporous organosilicate thin films /". May be available electronically:, 2008. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
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Ceratti, Davide Raffaele. "Viability of nanoporous films for nanofluidic applications". Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066482/document.
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Ces travaux de thèse ont eu deux objectifs: i) le développent de systèmes nanofluidique en utilisant une méthode non-lithographique, peu chère et facilement transposable à l'échelle industrielle ii) la compréhension des phénomènes nanofluidiques au travers des études expérimentales et de modélisation. Des couches minces mesoporeuses, en particulier des structures planaires avec des nanopiliers, ont été utilisé pour des études sur l'infiltration capillaire des liquides dans espaces confiné au niveau nanométrique. En plus des premiers tests pour des applications plus complexes comme des séparations et réactions nanoconfiné. Des structures mesoporeuses non-organisés ont aussi été étudiées pour déterminer la relation entre la nanostructure et la vitesse de remplissage capillaire. A été aussi démontré que pour des porosités avec des forts rétrécissements le remplissage capillaire se produit par l'intermédiaire d'une phase vapeur. Les échantillons ont été préparés par dip-coating. Une méthode de préparation basé sur une substitution de la plus grande parte de la solution à déposer par un fluide inerte a été développé. La méthode permet de réduire fortement le cout de procédé et, par conséquence, de faire des dépôts sur plus grande surface. Un effort dans la modélisation des phénomènes nanofluidiques a aussi été fait pendant cette thèse. Une méthode de simulation qui permet de décrire adéquatement les interactions hydrodynamiques dans un système nano a été utilisée pour simuler un flux électro-osmotique. La méthode, Stochastic Rotational Dynamics, a été valide par confrontation avec des résultats connus et l'influence des certains paramètres de simulation évaluée dans le détailThis 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
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Ceratti, Davide Raffaele. "Viability of nanoporous films for nanofluidic applications". Electronic Thesis or Diss., Paris 6, 2015. http://www.theses.fr/2015PA066482.
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Ces travaux de thèse ont eu deux objectifs: i) le développent de systèmes nanofluidique en utilisant une méthode non-lithographique, peu chère et facilement transposable à l'échelle industrielle ii) la compréhension des phénomènes nanofluidiques au travers des études expérimentales et de modélisation. Des couches minces mesoporeuses, en particulier des structures planaires avec des nanopiliers, ont été utilisé pour des études sur l'infiltration capillaire des liquides dans espaces confiné au niveau nanométrique. En plus des premiers tests pour des applications plus complexes comme des séparations et réactions nanoconfiné. Des structures mesoporeuses non-organisés ont aussi été étudiées pour déterminer la relation entre la nanostructure et la vitesse de remplissage capillaire. A été aussi démontré que pour des porosités avec des forts rétrécissements le remplissage capillaire se produit par l'intermédiaire d'une phase vapeur. Les échantillons ont été préparés par dip-coating. Une méthode de préparation basé sur une substitution de la plus grande parte de la solution à déposer par un fluide inerte a été développé. La méthode permet de réduire fortement le cout de procédé et, par conséquence, de faire des dépôts sur plus grande surface. Un effort dans la modélisation des phénomènes nanofluidiques a aussi été fait pendant cette thèse. Une méthode de simulation qui permet de décrire adéquatement les interactions hydrodynamiques dans un système nano a été utilisée pour simuler un flux électro-osmotique. La méthode, Stochastic Rotational Dynamics, a été valide par confrontation avec des résultats connus et l'influence des certains paramètres de simulation évaluée dans le détailThis 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
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Kipnusu, Wycliffe Kiprop. "Effects of Nanoscale Confinement on the Structure and Dynamics of Glass-forming Systems". Doctoral thesis, Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-183530.
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Structure and dynamics of nanoconfined glass-forming oligomers and diblock coplymers (BPCs) are investigated by a combination of infrared transition moment orientational analysis (IR-TMOA), positron annihilation lifetime spectroscopy (PALS), grazing incidence small angle X-ray scattering (GISAXS), atomic force microscopy (AFM), scanning electron microscopy (SEM) and broadband dielectric spectroscopy (BDS). The oligomers probed are the van der Waals type, tris(2-ethyhexyl)phosphate (TEHP) and the self-associating molecules of 2-ethyl-1-hexanol (2E1H). Symmetric and asymmetric poly(styrene-b-1,4-isoprene) P(S-b-I) are studied for the case of BCPs. The samples are confined either in one-dimensional (1D) in form of thin films or in 2D (nanopores) geometrical constraints. The molecular order of TEHP in nanopores as studied by IR-TMOA shows that about 7% of the molecules are preferentially oriented perpendicular to the long axis of the pores due to their interaction with the pore walls. PALS results reveal that 2E1H confined in nanopores exhibit larger free volume with respect to the bulk. In thin films (1D), P(S-b-I) having volume fraction of isoprene blocks f(PI)= 0.55 exhibits randomly oriented lamellae and their thicknesses are directly proportional to the film thickness d(film). For f(PI) = 0.73, perpendicular cylinders with respect to the substrate are observed for d(film)>50 nm but they lie along the substrate plane when d(film) < 50 nm. In AAO pores (2D) with average pore diameter d(pore) of 150 nm, straight nanorods are formed which change to helical structures in 18 nm pores. Molecular dynamics of 2E1H and TEHP constrained in nanopores (2D), is influenced by the interplay between confinement and surface effects. Confinement effects show up as an increase in the structural relaxation rate with decreasing pore sizes at the vicinity of the glass transition temperature. This is attributed to the reduced packing density of the molecules in pores as quantified by PALS results for 2E1H. Whereas the orientation and morphologies of the domains in P(S-b-I) and the chain dynamics of isoprene chains are influenced by the finite--size and dimensionality of confinement, the segmental motion, related to the dynamic glass transition (DGT) of both styrene and isoprene blocks remains unaffected-in its relaxation time-within experimental accuracy. Effects of nanoscale confinement on the molecular dynamics therefore depend on a number of factors: the type of molecules (polymers, low molecular liquids), interfacial interactions and the dimensionality of the constraining geometries.
Libros sobre el tema "Films nanoporeux"
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Ree, Moonhor. Low-k nanoporous interdielectrics: Materials, thin film fabrications, structures and properties. Hauppauge, N.Y: Nova Science Publishers, 2010.
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Koblischka, M. R. Growth and Characterization of HTSc Nanowires and Nanoribbons. Editado por A. V. Narlikar. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780198738169.013.11.
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This article describes the fabrication of high-temperature superconducting nanowires and their characterization by magnetic and electric transport measurements. In the literature, nanowires of high-temperature superconductors (HTSc) are obtained by means of lithography, using thin film material as a base. However, there are two main problems with this approach: first, the substrate often influences the HTSc nanowire, and second, only electric transport measurements can be performed. This article explains how nanowires and nanobelts of high-temperature superconducting cuprates can be prepared by the template method and by electrospinning. It also considers the possibilities for employing substrate-free HTSc nanowires as building blocks to realize new, nanoporous bulk superconducting materials for a variety of applications.
Capítulos de libros sobre el tema "Films nanoporeux"
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Dufort y Álvarez, Guillermo, Gadiel Seroussi, Pablo Smircich, José Sotelo, Idoia Ochoa y Álvaro Martín. "Compression of Nanopore FASTQ Files". En Bioinformatics and Biomedical Engineering, 36–47. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-17938-0_4.
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Wu, Shuanghong, Han Zhou, Mengmeng Hao y Zhi Chen. "Nanoporous Palladium Films Based Resistive Hydrogen Sensors". En Outlook and Challenges of Nano Devices, Sensors, and MEMS, 365–93. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-50824-5_13.
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Smith, Joanna J. y Ilya Zharov. "Ion Transport in Sulfonated Nanoporous Opal Films". En ACS Symposium Series, 248–55. Washington, DC: American Chemical Society, 2008. http://dx.doi.org/10.1021/bk-2008-0996.ch018.
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Khabibullin, Amir y Ilya Zharov. "Responsive Nanoporous Silica Colloidal Films and Membranes". En Intelligent Stimuli-Responsive Materials, 265–91. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118680469.ch8.
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Joshi, Ved Prakash, Nitish Kumar y Rahul R. Salunkhe. "Nanoporous Metal Oxides for Supercapacitor Applications". En Chemically Deposited Nanocrystalline Metal Oxide Thin Films, 601–21. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-68462-4_23.
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Del Giudice, Alessandra, Giulio Benetti, Claudio Piazzoni y Francesca Borghi. "Porosity of Nanostructured Carbon Thin Films". En Nanoporous Carbons for Soft and Flexible Energy Devices, 159–79. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-81827-2_8.
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Yadav, Arti, Prashant Pendyala y M. S. Bobji. "On Using Nanoporous Alumina Films as Tribological Coating". En Lecture Notes in Mechanical Engineering, 403–9. New Delhi: Springer India, 2013. http://dx.doi.org/10.1007/978-81-322-1656-8_36.
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Ohgai, Takeshi, Masayuki Mizumoto, Shigeki Nomura y Akio Kagawa. "Electrodeposition of Metallic Nanowires in Nanoporous Polycarbonate Films". En THERMEC 2006, 1253–57. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-428-6.1253.
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Hyeon Lee, Jingyu, Yi Yeol Lyu, Mong Sup Lee, Jin Heong Yim y Sang Youl Kim. "Characterization of Nanoporous Low Dielectric Polysilsesquioxane Thin Films". En Key Engineering Materials, 907–11. Stafa: Trans Tech Publications Ltd., 2005. http://dx.doi.org/10.4028/0-87849-958-x.907.
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Kashefi-Kheyrabadi, Leila, Abolhassan Noori y Masoud Ayatollahi Mehrgardi. "Application of Bioconjugated Nanoporous Gold Films in Electrochemical Biosensors". En Biosensors Nanotechnology, 345–74. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2014. http://dx.doi.org/10.1002/9781118773826.ch11.
Texto completoActas de conferencias sobre el tema "Films nanoporeux"
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Gan, Yong X., Surya V. Pothula y Matthew J. Franchetti. "Plasticity of Nanoporous Ni/YSZ Anode: A Numerical Analysis". En ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33194.
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Thin electrolytes (YSZ) and anode-supported (nanoporous Ni-YSZ ) cells operating in the temperature range of 650–850°C are considered as promising solid oxide fuel cell systems. Understanding the thermal-mechanical deformation behavior of the Ni/YSZ interface is critical for the design and durability assessment of the YSZ high temperature fuel cells. One of the problems still remains to be solved is the microstructure instability of the nanoporous Ni at the elevated temperatures. In this work, modeling the thermal-mechanical deformation in the nanoporous Ni/YSZ interface region was performed. Nanoporous Ni thin film bounded to YSZ was considered to establish a simplified 2-D model. On the Ni/YSZ interface, the nanopores are modeled as spherical or cylindrical pores. Crystal lattice rotation due to dislocation motion was simulated and the numerical solutions to the in-plane lattice rotation for the nanoporous Ni was used to predict the microstructure evolution in the interface area of the Ni/YSZ anode.
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Garahan, Anna, Laurent Pilon, Juan Yin y Indu Saxena. "Optical Properties of Nanocomposite Thin-Films". En ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-13309.
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This paper aims at developing numerically validated models for predicting the through-plane effective index of refraction and absorption index of nanocomposite thin-films. First, models for the effective optical properties are derived from previously reported analysis applying the volume averaging theory (VAT) to the Maxwell's equations. The transmittance and reflectance of nanoporous thin-films are computed by solving the Maxwell's equations and the associated boundary conditions at all interfaces using finite element methods. The effective optical properties of the films are retrieved by minimizing the root mean square of the relative errors between the computed and theoretical transmittance and reflectance. Nanoporous thin-films made of SiO2 and TiO2 consisting of cylindrical nanopores and nanowires are investigated for different diameters and various porosities. Similarly, electromagnetic wave transport through dielectric medium with embedded metallic nanowires are simulated. Numerical results are compared with predictions from widely used effective property models including (1) Maxwell-Garnett Theory, (2) Bruggeman effective medium approximation, (3) parallel, (4) series, (5) Lorentz-Lorenz, and (6) VAT models. Very good agreement is found with the VAT model for both the effective index of refraction and absorption index. Finally, the effect of volume fraction on the effective complex index of refraction predicted by the VAT model is discussed. For certain values of wavelengths and volume fractions, the effective index of refraction or absorption index of the composite material can be smaller than that of both the continuous and dispersed phases. These results indicate guidelines for designing nanocomposite optical materials.
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Yahaya, Hafizal, Yoshifumi Ikoma, Keiji Kuriyama y Teruaki Motooka. "Fabrication of nanopores utilizing SiC/Si(001) heteroepitaxial growth on SOI substrates: nanopore density control". En Seventh International Conference on Thin Film Physics and Applications, editado por Junhao Chu y Zhanshan Wang. SPIE, 2010. http://dx.doi.org/10.1117/12.888388.
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Ghazaryan, Lilit y Adriana Viorica Szeghalmi. "Reproducibility and stability of nanoporous SiO2 thin film coatings". En Advances in Optical Thin Films VI, editado por Michel Lequime, H. Angus Macleod y Detlev Ristau. SPIE, 2018. http://dx.doi.org/10.1117/12.2313847.
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Hu, Lili, Junlan Wang, Zijian Li, Shuang Li y Yushan Yan. "Interfacial Adhesion of Nanoporous Zeolite Thin Films". En ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-62022.
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Nanoporous zeolite thin films are promising candidates as future low-k materials. During the integration with other semiconducting materials, the high stresses resulted from the synthesis process can cause the film to fracture or delaminate from the substrates. Evaluating the interfacial adhesion of zeolite thin films is very important in achieving high performance low-k materials. In this work, laser spallation technique is utilized to investigate the interfacial strength of zeolite thin films from three different synthesis processes. The preliminary results show that the fully crystalline zeolite thin films from hydro-thermal in-situ and seeded growth methods have a stronger interface than that from the spin-on process. Effort is also being made to compare the interfacial strength of the zeolite films between the two hydro-thermal methods. This is the first time that the interfacial strength of zeolite thin films is quantitatively evaluated. The results have great significance in the future applications of low-k zeolite thin films.
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Zolotoukhina, Tatiana y Takeo Fukui. "Identification of Nucleobases of Single Stranded DNA by Nanopore Force Resolution at Different Film Thickness". En ASME/JSME 2011 8th Thermal Engineering Joint Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajtec2011-44260.
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The model of the molecular translocation of all types of DNA base molecules of cytosine, thymine, adenine and guanine through the nanoporous membrane of a solid thin film has been considered from the point of view of improving the resolution of forces by changing parameters of the membrane itself. The results of simulation of translocation process were compared for all four DNA nucleotides. The molecular dynamics (MD) method with the force field potential has been used for the atomic level modeling of the cytosine (C), thymine (T), adenine (A), and guanine (G) molecules and a configuration of the nanoporous Si membrane. With the planar structure of base molecules and cylindrical symmetry of pore, the two-dimensional projection was used in the simulation. The force field between the base molecule and atoms of nanopore has been estimated. Influence of the Si surface hydrogenization and film thickness on the force resolution for each nucleobase was evaluated vs. possible signal resolution. At 5 layer thickness of the film it was possible to cut thermal fluctuations and distinguish four nucleobase types.
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Shafer, Juliet, Jonghyun Lee y Debjyoti Banerjee. "Experimental Investigation of the Nano-Fin Effect (nFE) During Thin Film Evaporation From Nanopores Using Temperature Nano-Sensors". En ASME 2023 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2023. http://dx.doi.org/10.1115/imece2023-117183.
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Abstract Recent advances in micro/nano-fabrication has enabled the deployment of nanostructured surfaces, nanochannels, and nanoporous membranes for development of new generation thermal management devices with remarkable potential for heat transfer enhancement. Anomalous heat transfer has been reported in studies involving heaters with nanostructured surfaces. For example, nanofins with lower thermal conductivity values can cause higher levels of enhancement in heat flux values, especially during phase change (such as for boiling on heaters with nanostructured surfaces). In addition, confinement of fluid in nanopores can also result in anomalous properties. This is manifest in anomalous production curves during hydraulic fracturing operations in oil and gas applications. A transport model that resolves these conundrums is termed as the “nanoFin Effect (nFE)”. nFE is governed by interfacial phenomena, i.e., the formation of thermal impedances in parallel circuit configuration: (a) interfacial thermal resistance (also known as “Kapitza resistance”); (b) thermal capacitor; and (c) thermal diode (that form at the interface between each nanoparticle and the surface adsorbed thin-film of solvent molecules). nFE (i.e., primarily the interfacial thermal diode effect) also leads to preferential trapping of ions on the surface adsorbed thin film of solvent molecules leading to very high concentration gradients causing drastic reduction in corrosion. The motivation of this study was to explore nFE during thin film evaporation from nanopores. The methods used in this study include mounting a nano-thermocouple array (also termed as Thin Film Thermocouples or “TFT”) on a hot plate and observing the transient response recorded by the TFT array when a small liquid droplet (of fixed mass or volume) is dispensed on to an isotropic AAO membrane containing nanopores. In this study, two different pore sizes were explored: 200 nm and 10 nm. The experiments were performed using acetone and isopropyl alcohol droplets for four different temperature settings of the heated membrane (containing the nanopores).
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Shafer, Julie, Jonghyun Lee, Ashok Thyagarajan y Debjyoti Banerjee. "Experimental Study of the Nano-Fin Effect (nFE) During Thin Film Evaporation From Nanopores in Anodic Aluminum Oxide (AAO) Membrane Substrates Integrated With Nano-Thermocouple / Thin Film Thermocouple (TFT) Array". En ASME 2022 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/imece2022-96168.
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Abstract Recent advances in micro/nano-fabrication has enabled the deployment of nanostructured surfaces, nanochannels, and nanoporous membranes for development of new generation thermal management devices with remarkable potential for heat transfer enhancement. Anomalous heat transfer has been reported in studies involving heaters with nanostructured surfaces. For example, nanofins with lower thermal conductivity values can cause higher levels of enhancement in heat flux values, especially during phase change (such as for boiling on heaters with nanostructured surfaces). In addition, confinement of fluid in nanopores can also result in anomalous properties. This is manifest in anomalous production curves during hydraulic fracturing operations in oil and gas applications. A transport model that resolves these conundrums is termed as the “nanoFin Effect (nFE)”. nFE is governed by interfacial phenomena, i.e., the formation of thermal impedances in parallel circuit configuration, consisting of: (a) interfacial thermal resistance (also known as “Kapitza resistance”); (b) thermal capacitor; and (c) thermal diode (that form at the interface between each nanoparticle and the surface adsorbed thin-film of solvent molecules). nFE (i.e., primarily the interfacial thermal diode effect) also leads to preferential trapping of ions on the surface adsorbed thin film of solvent molecules leading to very high concentration gradients causing drastic reduction in corrosion. The motivation of this study was to explore nFE during thin film evaporation from nanopores. The methods used in this study include mounting a nano-thermocouple array (also termed as Thin Film Thermocouples or “TFT”) on a hot plate and observing the transient response recorded by the TFT array when a small liquid droplet (of fixed mass or volume) is dispensed on to an anisotropic AAO membrane containing nanopores. In this study, two different pore sizes were explored: 200 nm and 10 nm. The experiments were performed using isopropyl alcohol (IPA) droplets for four different temperature settings of the heated membrane (containing the nanopores).
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Zou, An, Sajag Poudel y Shalabh C. Maroo. "Confinement Effects on Molecular Mechanics and Structure of the Liquid Layers at Solid-Liquid Interface". En ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-70811.
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Abstract Liquid layer structuring occurs at the solid-liquid interface. Here we present an investigation of the confinement effects on the first layer adjacent to the solid surface in a nanopore. Compared to a thin film on a surface with free liquid-vapor interface, strong confinement effects were observed in relatively small nanopores, where only structured layers exist and the first layer is affected by both surfaces. The confinement effects are weak in relatively large pores, where bulk liquid exists and the first layer is affected by the adjacent surface only.
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Niauzorau, Stanislau, Placid Ferreira y Bruno Azeredo. "Synthesis of Porous Noble Metal Films With Tunable Porosity by Timed Dealloying". En ASME 2018 13th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/msec2018-6665.
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Nanoporous metal foams have an increasing importance in applications such as chemical catalysis, energy storage, and nanomedicine. This paper examines a simple strategy for controlling the pore volume fraction and pore size of nanoporous films synthesized by dealloying thin-films. By means of controlling the temperature and concentration of nitric acid in dealloying of AgAu thin-films, partially dealloyed AgAu nanoporous films are produced with a high degree of control over the pore size and pore volume fraction. Such capability enables the design of nanoporous metal catalysts materials with desired morphology.
Informes sobre el tema "Films nanoporeux"
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Costanzo, Francesco. Model-Based Simulations to Engineer Nanoporous Thin Films. Fort Belvoir, VA: Defense Technical Information Center, diciembre de 2004. http://dx.doi.org/10.21236/ada438559.
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Rowen, Adam M., Daniel David Koleske, Hongyou Fan, C. Jeffrey Brinker, David Bruce Burckel, John Dalton Williams, Christian L. Arrington y William Arthur Steen. Nanoporous films for epitaxial growth of single crystal semiconductor materials : final LDRD report. Office of Scientific and Technical Information (OSTI), octubre de 2007. http://dx.doi.org/10.2172/966925.
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Hattar, Khalid Mikhiel y David Robinson. In-situ 3D characterization of He bubble and displacement damage in dense and nanoporous thin films. Office of Scientific and Technical Information (OSTI), octubre de 2015. http://dx.doi.org/10.2172/1226424.
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