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1
Muraleedharan, Nair Mahesh. "High surface area mesoporous perovskites for catalytic applications." Thesis, Université Laval, 2014. http://www.theses.ulaval.ca/2014/30509/30509.pdf.
Abstract:
Les pérovskites sont des oxydes métalliques mixtes qui peuvent être représentés par la formule générale ABO3. Depuis la première revue mettant en évidence leur activité catalytique, ces matériaux ont attiré l’attention des chercheurs dans le monde entier. Il a été confirmé que les pérovskites peuvent être considérées comme des alternatives rentables et efficaces aux métaux nobles pour plusieurs applications (les réactions de synthèse à titre d’exemple). En outre, ces oxydes métalliques mixtes sont bien connus pour leur stabilité à haute température, leur grande mobilité d'oxygène ainsi que la stabilisation des inhabituels états d'oxydation des cations. Pour ces raisons, plusieurs stratégies ont été développées pour la synthèse de ces matériaux. Cependant, les méthodes conventionnelles de synthèse des pérovskites permettent d’obtenir seulement des matériaux ayant une faible surface spécifique, ce qui constitue un inconvénient majeur du fait que des applications catalytiques sont mis en jeux. La faible surface spécifique est due à un traitement thermique de haute température appliqué au cours de la synthèse de ces matériaux. Le premier objectif de ce présent travail est donc l’obtention d’oxydes métalliques mixtes structurés de type pérovskite avec une grande surface spécifique. Le “Nanocasting”, une méthode de gabarits solides récemment développée, a montré son efficacité pour la synthèse de diverses compositions chimiques ayant des valeurs extrêmement élevées de surface spécifique. En se basant sur cette méthode, plusieurs pérovskites LaBO3 (B = Mn , Ni , Co, Fe) ont été synthétisées. Ces matériaux se caractérisent par leur grande surface spécifique qui peut atteindre 150 m2 g-1. Les premiers essais de l'oxydation totale du méthanol, une molécule sonde, out confirmé que ces nouveaux matériaux sont des catalyseurs très actifs, en particulier les LaMnO3. De plus, d'autres études ont confirmé que l'augmentation de l’activité catalytique est évidemment liée à la plus grande surface spécifique et a la plus grande quantité d’oxygène adsorbée des pérovskites développées. Les résultats ont montré une proportionnalité entre les vitesses des réactions et la surface spécifique du catalyseur. Dans une étude suivante, l’intérêt de la recherche est porté sur reformage du méthane à sec, comme cette réaction est très pertinente pour l’industrie du fait qu’elle consiste en la conversion de deux gaz à effet serre (CH4 et CO2) en gaz de synthèse (CO + H2). Des résultats prometteurs ont été obtenus dans ce cas aussi en utilisant les matériaux développés de type LaNiO3 comme un pré-catalyseur. De meilleures efficacité et stabilité ont été observées pour Ni/La2O3, catalyseurs dérivés des LaNiO3, par rapport à son homologue en vrac.Perovskites are mixed metal oxides that can be represented by the general formula ABO3. Since the initial report regarding their catalytic activity, these materials have received immense research attention worldwide. Perovskites are proven to be cost effective and efficient alternatives to noble metals for various total/partial oxidation as well as synthetic chemical reactions. Additionally these mixed metal oxides are well known for their high temperature stability, high mobility of oxygen and the stabilization of unusual cation oxidation states. For these reasons various strategies were developed for the synthesis of these materials. However perovskites synthesized using conventional methods generally result in low specific surface area materials, which is a major drawback as far as catalytic applications are concerned. This pertinent lower value of surface area is resulting from the high temperature treatment involved in the synthesis of these materials. This issue was taken up and in the present project the first goal was to obtain perovskite structured mixed metal oxides with high specific surface area. Nanocasting is a recently developed solid templating method that is proven to be efficient for the synthesis of various chemical compositions with extremely high values of specific surface area. By applying this method a series of LaBO3 (B = Mn, Ni, Co, Fe) perovskites were synthesized and these materials were found to posses extremely high values of specific surface areas (up to 150 m2g-1). Initial tests for the total oxidation of methanol as a probe molecule confirmed that these novel materials are highly active catalysts, especially LaMnO3. Further studies confirmed that the enhanced activity was obviously related to the higher specific surface areas and higher amount of adsorbed oxygen species obtained for the nanocast perovskites in comparison with the bulk. Our results demonstrated the proportionality of reaction rates to the specific surface area of the catalyst. In a following study, we chose dry reforming of methane, since this reaction involves the conversion of two green house gases (CH4 and CO2) into syngas (CO + H2), which is more industrially relevant. Promising results were obtained in this case also using nanocast LaNiO3 as a pre-catalyst. Enhanced efficiency and stability were observed for Ni/La2O3 catalysts derived from nanocast LaNiO3 in comparison to its bulk counterpart. In particular, these materials were found to be coke resistant for 48 hours under the conditions of dry reforming.
2
Klechikov, Alexey, Guillaume Mercier, Tiva Sharifi, Igor A. Baburin, Gotthard Seifert, and Alexandr V. Talyzin. "Hydrogen storage in high surface area graphene scaffolds." Royal Society of Chemistry, 2015. https://tud.qucosa.de/id/qucosa%3A36058.
Abstract:
Using an optimized KOH activation procedure we prepared highly porous graphene scaffoldmaterials with SSA values up to 3400m² g⁻¹ and a pore volume up to 2.2 cm³ gˉ¹, which are among the highest for carbon materials. Hydrogen uptake of activated graphene samples was evaluated in a broad temperature interval (77–296 K). After additional activation by hydrogen annealing the maximal excess H2 uptake of 7.5 wt% was obtained at 77 K. A hydrogen storage value as high as 4 wt% was observed already at 193 K (120 bar H₂), a temperature of solid CO₂, which can be easily maintained using common industrial refrigeration methods.
3
Krawiec, Piotr. "Nanostructured Porous High Surface Area Ceramics for Catalytic Applications." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2007. http://nbn-resolving.de/urn:nbn:de:swb:14-1170181622265-56905.
Abstract:
In the present work new methods were developed for preparation of novel nanosized and nanostructured ceramic materials. Ordered mesoporous silica SBA-15 was found to be useful as a hard template for the nanocasting of silicon carbide and allowed the preparation of high temperature stable mesoporous silicon carbide ceramics. Chemical vapor infiltration of SBA-15 with dimethyldichlorosilane at elevated temperatures yields SiC/SBA-15 nanocomposites. The subsequent HF treatment of those composites resulted in silica removal and preparation of mesoporous silicon carbide with surface areas between 410 and 830 m2g-1 and high mesopore volume (up to 0.9 cm3g-1). The pore size (between 3 and 7nm in diameter) and surface area of mesoporous silicon carbide were controlled by adjusting the infiltration conditions (time, atmosphere). The mesoporous silicon carbide prepared via this method showed high structural thermal stability at 1300 oC, exceeding that of the SBA-15 template. However, the ordering on the mesoscopic scale was low. Nevertheless, highly ordered mesoporous silicon carbide materials were obtained via polymer melt infiltration in SBA-15. The low molecular weight polycarbosilane used as a preceramic precursor was converted at 1300 oC to silicon carbide inside the SBA-15, and after subsequent silica removal by HF, a highly ordered mesoporous material was obtained. Ordered mesoporous silicon carbide prepared by the methods reported here, may be an interesting material as a support due to its high temperature stability, chemical inertness, high thermal conductivity and semiconductor properties. In contrast to the nanocasting approach, based on the complete pore filling, also a new in-situ procedure for the preparation of finely dispersed metal and metal oxide particles inside ordered mesoporous silica was developed. A swelling agent (toluene) was used to deliver a hydrophobic platinum precursor into the surfactant micelles before addition of silica source. Such an in-situ method resulted in very high platinum incorporation (80-100%), not achieved for any other in-situ preparation procedures. Additionally, the presence of platinum allowed to decrease the template removal temperatures. Moreover, the method was also extended to other metal or metal oxide/ordered mesoporous silica systems. This may be especially interesting for the preparation of ordered mesoporous materials with low melting points, where typically the structure collapses during the high temperature calcinations process. The in-situ synthesized V2O5/MCM-41 materials were used to prepare VN/MCM-41 composites via nitridation in ammonia at 800oC. This method allowed to prepare highly dispersed, X-ray amorphous vanadium nitride species, with high activity in the propane dehydrogenation. Compared to nitridation of supported vanadium oxide prepared via the ex-situ procedure, in-situ synthesized materials showed similar catalytic activity, in spite of having significantly lower vanadium loading. As an alternative for the preparation of supported nitride materials, a novel preparation procedure of bulk not supported nanocrystalline vanadium nitride with high surface area was presented. Instead of pure oxide powder (which was typically used in the preparation of high surface area vanadium nitride catalysts), a macroporous amine intercalated V2O5 was used as the starting material. The obtained nitride consisted of small crystallites and had a surface area up to 198 m2g-1. Moreover, this foam-derived VN showed significantly improved activity as a catalyst in propane dehydrogenation. This novel preparation method could also be extended to other systems such as ternary VMoxNy nitrides.
4
Krawiec, Piotr. "Nanostructured Porous High Surface Area Ceramics for Catalytic Applications." Doctoral thesis, Technische Universität Dresden, 2006. https://tud.qucosa.de/id/qucosa%3A24989.
Abstract:
In the present work new methods were developed for preparation of novel nanosized and nanostructured ceramic materials. Ordered mesoporous silica SBA-15 was found to be useful as a hard template for the nanocasting of silicon carbide and allowed the preparation of high temperature stable mesoporous silicon carbide ceramics. Chemical vapor infiltration of SBA-15 with dimethyldichlorosilane at elevated temperatures yields SiC/SBA-15 nanocomposites. The subsequent HF treatment of those composites resulted in silica removal and preparation of mesoporous silicon carbide with surface areas between 410 and 830 m2g-1 and high mesopore volume (up to 0.9 cm3g-1). The pore size (between 3 and 7nm in diameter) and surface area of mesoporous silicon carbide were controlled by adjusting the infiltration conditions (time, atmosphere). The mesoporous silicon carbide prepared via this method showed high structural thermal stability at 1300 oC, exceeding that of the SBA-15 template. However, the ordering on the mesoscopic scale was low. Nevertheless, highly ordered mesoporous silicon carbide materials were obtained via polymer melt infiltration in SBA-15. The low molecular weight polycarbosilane used as a preceramic precursor was converted at 1300 oC to silicon carbide inside the SBA-15, and after subsequent silica removal by HF, a highly ordered mesoporous material was obtained. Ordered mesoporous silicon carbide prepared by the methods reported here, may be an interesting material as a support due to its high temperature stability, chemical inertness, high thermal conductivity and semiconductor properties. In contrast to the nanocasting approach, based on the complete pore filling, also a new in-situ procedure for the preparation of finely dispersed metal and metal oxide particles inside ordered mesoporous silica was developed. A swelling agent (toluene) was used to deliver a hydrophobic platinum precursor into the surfactant micelles before addition of silica source. Such an in-situ method resulted in very high platinum incorporation (80-100%), not achieved for any other in-situ preparation procedures. Additionally, the presence of platinum allowed to decrease the template removal temperatures. Moreover, the method was also extended to other metal or metal oxide/ordered mesoporous silica systems. This may be especially interesting for the preparation of ordered mesoporous materials with low melting points, where typically the structure collapses during the high temperature calcinations process. The in-situ synthesized V2O5/MCM-41 materials were used to prepare VN/MCM-41 composites via nitridation in ammonia at 800oC. This method allowed to prepare highly dispersed, X-ray amorphous vanadium nitride species, with high activity in the propane dehydrogenation. Compared to nitridation of supported vanadium oxide prepared via the ex-situ procedure, in-situ synthesized materials showed similar catalytic activity, in spite of having significantly lower vanadium loading. As an alternative for the preparation of supported nitride materials, a novel preparation procedure of bulk not supported nanocrystalline vanadium nitride with high surface area was presented. Instead of pure oxide powder (which was typically used in the preparation of high surface area vanadium nitride catalysts), a macroporous amine intercalated V2O5 was used as the starting material. The obtained nitride consisted of small crystallites and had a surface area up to 198 m2g-1. Moreover, this foam-derived VN showed significantly improved activity as a catalyst in propane dehydrogenation. This novel preparation method could also be extended to other systems such as ternary VMoxNy nitrides.
5
Chen, Qihang. "Exploiting High Surface Area Polymer Gels for Dye Adsorption." University of Akron / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=akron1619184015747879.
6
Damle, Madhura S. "Fabrication and Characterization of High Surface Area Gold Electrodes." VCU Scholars Compass, 2014. http://scholarscompass.vcu.edu/etd/3632.
Abstract:
High surface area gold electrodes are very good substrates for biosensors, catalysis and drug delivery. Their performance is characterized by good sensitivity, low detection limit and high signal. As a result, extensive research is being carried out in this field using different approaches of fabrication to generate high surface area porous electrodes of different morphology, pore size and structure. The morphology of the electrodes can be changed based on whether the approach involves a template or not, types of metal deposition, method and time of dealloying etc. The deposition of metal can be carried out using various approaches such as electroless deposition, electrochemical deposition, combination of electroless and electrochemical deposition, pulsed laser deposition, laser deposition etc. These electrodes can then be used in electrochemical measurements and their performance compared with an unmodified flat gold electrode.
We used a template based approach, combined with electrochemical deposition, to fabricate macroporous, macro-nanoporous and nanoporous gold electrodes. To generate nanopores, in case of macro-nanoporous and nanoporous gold electrodes, we used gold-silver alloy electrochemical deposition method, followed by chemical dealloying. The morphology of electrodes was later observed under HITACHI Scanning Electron Microscope (SEM) and their elemental composition studied using HITACHI Energy Dispersion Spectroscopy (EDS). The electrodes were used in electrochemical measurements and their voltammetric data was compared. These measurements involved the determination of surface area, faradaic current using redox molecules with fast and slow electron transfer and charging current in KCl. Surface adsorption of dopamine was studied and detection of dopamine in the presence of ascorbic acid was carried out.
7
Grünker, Ronny, Volodymyr Bon, Philipp Müller, Ulrich Stoeck, Simon Krause, Uwe Mueller, Irena Senkovska, and Stefan Kaskel. "A new metal–organic framework with ultra-high surface area." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-149154.
Abstract:
A new mesoporous MOF, Zn4O(bpdc)(btctb)4/3 (DUT-32), containing linear ditopic (bpdc2−; 4,4′-biphenylenedicarboxylic acid) and tritopic (btctb3−; 4,4′,4′′-[benzene-1,3,5-triyltris(carbonylimino)]tris-benzoate) linkers, was synthesised. The highly porous solid has a total pore volume of 3.16 cm3 g−1 and a specific BET surface area of 6411 m2 g−1, adding this compound to the top ten porous materials with the highest BET surface area.
8
Matthews, Jermey Norman Augustus. "Production of high surface area silica particles by acoustodispersion precipitation." College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/1743.
Abstract:
Thesis (M.S.) -- University of Maryland, College Park, 2004.Thesis research directed by: Dept. of Chemical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
9
Al-Rashed, Rashed (Rashed Ahmed), and Marta Krason. "Fabrication and characterization of high surface area nickel-deposited graphite substrates." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/98824.
Abstract:
Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, June 2015. First author.Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, June 2014. Second author.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 61-63).
In certain electrochemical battery cells, inefficiencies arise due to the formation of hydrogen from corrosion reactions at the anode. One way to reduce these inefficiencies is to operate the cell at high current densities, which is obtainable given a high cathode to anode surface area ratio; however, commercially available metal foams often do not provide sufficient surface area density (cm 2/g). Coating high-surface area materials in the appropriate metal is a premier alternative, but while methods to effectively coat two-dimensional substrates in metal through electrodeposition has been well documented, attempts to scale electrodeposition to three-dimensional coating to achieve high-surface area catalysts has encountered certain challenges. The formation of a pure metal crust on the outer surface area of the catalyst prevents the penetration of metal ions into the inner fibers of the material, resulting in a lower surface area density. This thesis describes simple, repeatable electrodeposition methods to increase the homogeneity of the nickel coating throughout highly porous graphite catalysts and prevent the formation of a metal crust. Parameters such as direct/pulsating current, ultrasonic vibration pretreatment, and varying electrodeposition solution concentrations were tested in order to optimize the electrodeposition procedure. Three techniques were used to characterize the post-synthesis surface condition including scanning electron microscopy, electron dispersive spectroscopy and cyclic voltammetry. The improved electrodeposition method led to nickel-coated graphite felt with a specific surface area of 620 cm2/cm 3 and a surface area density of 7500 cm2/g, achieving a 890% higher surface area and 4650% higher surface area density than commercially available nickel foams. The proposed electrodeposition method provides high-surface area, full-volume coating of highly porous catalysts, applicable not only to electrochemical batteries but to any battery chemistry with an electrolyte that contains fuels, particularly flow batteries. The proposed methods to obtain effective full-coated, high-surface area catalysts have the potential to optimize outputted battery power and thereby revolutionize battery electrode fabrication.
by Rashed Al-Rashed [and] Marta Krason.
S.B.
10
Viggiano, Rocco P. III. "Investigations into High Surface Area and Hierarchical Phase Segregated Network Structures." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1440572438.
11
Wong, Hin-cheong Henry. "Effects of water content, packing density and solid surface area on cement paste rheology." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B39326032.
12
Wong, Hin-cheong Henry, and 黃憲昌. "Effects of water content, packing density and solid surface area on cement paste rheology." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39326032.
13
Paggiaro, Ricardo Gaspar. "Investigation of cryogenic hydrogen storage on high surface area activated carbon : equilibrium and dynamics." München Verl. Dr. Hut, 2009. http://mediatum2.ub.tum.de/node?id=681021.
14
Heimböckel, Ruben [Verfasser], and Michael [Akademischer Betreuer] Fröba. "High Surface Area Nanoporous Carbons for Energy-Related Applications / Ruben Heimböckel ; Betreuer: Michael Fröba." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2019. http://d-nb.info/1200548140/34.
15
Paggiaro, Ricardo Gaspar. "Investigation of cryogenic hydrogen storage on high surface area activated carbon equilibrium and dynamics." München Verl. Dr. Hut, 2008. http://d-nb.info/992644909/04.
16
Olsen, Rebecca Elizabeth. "Synthesis, Characterization, and Application of High Surface Area, Mesoporous, Stabilized Anatase TiO2 Catalyst Supports." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3884.
Abstract:
Nanomaterials have attracted substantial attention in the area of catalysis due to the unique properties they exhibit such as high surface areas, intricate pore networks and unique morphologies. TiO2 has attracted attention as a catalyst since the discovery of its high photocatalytic activity by Fuishima and Honda in 1972. Given its high thermal stability, low cost, low environmental impact, and versatility, TiO2 is a widely used commercial catalyst and catalyst support. TiO2 is used in many applications such as photocatalysis is also an excellent support material for noble metals in a number of oxidative synthesis and pollution-control reactions. Though TiO2 is a widely used catalyst support, currently available commercial titanias often have low surface area and poor thermal and hydrothermal stability. While several methods reported in literature produce materials of higher surface area and more ideal porosity relative to commercially available titanias, these procedures generally involve inherent drawbacks including time-consuming, complicated, and expensive processes that are not industrially viable. Cost-effective, large-scale preparations of stable, high surface area, mesoporous TiO2 need to be developed. The work in this dissertation focuses on (1) producing high surface area stabilized TiO2 supports of controlled pore diameters and (2) the preparation of well dispersed Pt on these supports using industrially viable processes. The effects of dopants Al, La, Si, and Zr on the stability, surface area, and porosity of anatase TiO2 supports were investigated. Results show that dopants increased the surface area and thermal stability of anatase through structural modifications and grain growth inhibition. Stabilized titanias produced by this method demonstrated equivalent or higher thermal stability and surface area compared with pure anatase and previously reported materials after treatment at 400°C and 700°C including 22 mol% Al-TiO2 calcined at 400°C which had a surface area of 479 ± 39 m2/g, a pore volume of 0.46 ± 0.04 cm3/g, and a pore diameter of 2.9 ± 0.2 nm. Ten synthesis variables were examined and optimized using statistically designed experiments (DOEs). Equations were developed to predict the conditions to obtain the highest surface area and pore volume at the desired pore diameter and predict the pore diameter range that may be obtained for aluminum-modified anatase TiO2. Confirmation trials closely matched predicted surface areas, pore volumes, and pore diameters in all but one trial, demonstrating the power of DOEs in identifying and controlling synthesis variables in relatively few experiments. The structure of Al-modified anatase TiO2 was analyzed to determine the mechanism of Al stabilization. Surface Al stabilized TiO2 by lowering anatase surface energy, stabilizing planes of high surface energy which would otherwise join to achieve stabilization. Al in TiO2 lattice vacancies stabilized TiO2 through increasing lattice strain and limiting mass transport necessary for grain growth. Results demonstrate the importance of structure analysis of doped nanomaterials in the development of stabilized catalysts and catalyst supports. An industrially viable, one-pot synthesis of Pt supported on 22 mol% Al-modified anatase is presented. Pt dispersions as high as 54% (one-pot method) and 59% (DI method) have been obtained. Results show that this one-pot method and the DI method using our Al-modified supports are promising syntheses of highly dispersed Pt catalysts and demonstrate that the alumina-stabilized anatase support is superior to other many available anatase supports.
17
Yelamanchili, Ram Sai. "New approaches to the synthesis of porous and, or high surface area transition metal oxides." kostenfrei, 2008. http://opus.ub.uni-bayreuth.de/volltexte/2009/547/.
18
Castanheira, Luis Filipe Rodrigues. "Corrosion of high surface area carbon supports used in proton-exchange membrane fuel cell electrodes." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI084/document.
Abstract:
Cette thèse est consacrée à l’étude des mécanismes de dégradation de noirs de carbone de forte surface spécifique (HSAC) utilisés comme supports d’électrocatalyseurs dans une pile à combustible à membrane échangeuse de protons (PEMFC). Nous avons montré que le mécanisme et les cinétiques de la corrosion électrochimique du carbone (COR) sont influencés par la présence d’ionomère Nafion®, la limite supérieure de potentiel électrochimique, la nature et le nombre de caractérisations intermédiaires présentes dans des tests de dégradation accélérés. En utilisant la spectroscopie Raman,il apparaît que la COR est sensible à la structure cristallographique des HSAC et procède plus rapidement sur les domaines désordonnés (carbone amorphe, cristallites de graphite présentant des défauts). Le taux de recouvrement en espèces oxygénées évalué par spectroscopie de photoélectrons X a été comparé à celui trouvé en intégrant l’intensité du pic quinone/hydroquinone (Q/HQ) envol tampérométrie cyclique. Finalement, une comparaison avec des matériaux carbonés ayant fonctionné pendant 12860 heures en PEMFC confirme nos principaux résultats et permet d’élaborer des stratégies pour atténuer les conséquences de la CORThis thesis investigates the degradation mechanism of high surfacearea carbon (HSAC) supports used in proton-exchange membrane fuel cell (PEMFC) electrodes. The structural and the chemical properties of different HSAC supports were established. The effectof the Nafion® ionomer used as a proton conductor, the gas atmosphere, the upper potential limit and the intermediate electrochemical characterizations used to monitor the changes ofthe electrochemical surface area during accelerated stress tests(ASTs) were investigated. The long-term physical and chemical changes of Pt/HSAC electrocatalysts were investigated insimulated PEMFC operating conditions. Using Raman spectroscopy, we showed that the COR is strongly structure sensitive and proceeds more rapidly on disordered domains of the HSAC (amorphous carbon and defective graphite crystallites) thanon graphitic domains. The coverage with carbon surface oxides was investigated with X-ray photoelectron spectroscopy and bridged tothe intensity of the quinone/hydroquinone (Q/HQ) peak monitored by cyclic voltammetry. Finally, the analyses realized on membrane electrode assemblies operated for 12,860h disclosed a perfect agreement between model and real PEMFC operating conditions, and confirmed the structural dependency of the COR kinetics
19
Chih-Hsiang, Yo. "The Synthesis Of High Surface Area Ti Sponges By Halide Conversion Process For Capacitor Anodes." Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1363107584.
20
Banjade, Dila Ram. "Galvanic Corrosion of Magnesium Coupled to Steel at High Cathode-to-Anode Area Ratios." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/5623.
Abstract:
In this study, the impact of galvanic coupling of magnesium to steel on the corrosion rate, surface morphology, and surface film formation was investigated. In particular, the role of self-corrosion was quantified as previous studies showed discrepancies between model predictions and experimental results that were likely due to significant self-corrosion. This experimental study examined the corrosion of Mg coupled to steel in 5 wt% NaCl at cathode-to-anode area ratios that ranged from 5 to 27. Results showed that self-corrosion was significant and accounted for, on average, one-third of total corrosion. Moreover, self-corrosion varied with time and cathode size, and was accelerated by the high dissolution rate. Film formation was observed on the magnesium surface that inhibited the corrosion rates. This film contained approximately 30% of the Mg lost to corrosion. The morphology of the coupled Mg showed the rapid formation of pits with considerable depth, and was quite distinct from previously studied filiform and disk corrosion for uncoupled Mg. This study demonstrates the important role of self-corrosion during galvanic corrosion of Mg and the need to account for such corrosion when predicting corrosion rates. This study also provides important insight into the processes that control Mg corrosion under several conditions.
21
Kothalawala, Kothalawalage Nuwan. "Nanoporous high surface area silicas with chelating groups for heavy metal ion adsorption from aqueous solution /." View online, 2010. http://repository.eiu.edu/theses/docs/32211131524422.pdf.
22
Mogrovejo, Carrasco Daniel Estuardo. "Enhancing Pavement Surface Macrotexture Characterization." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/51957.
Abstract:
One of the most important objectives for transportation engineers is to understand pavement surface properties and their positive and negative effects on the user. This can improve the design of the infrastructure, adequacy of tools, and consistency of methodologies that are essential for transportation practitioners regarding macrotexture characterization. Important pavement surface characteristics, or tire-pavement interactions, such as friction, tire-pavement noise, splash and spray, and rolling resistance, are significantly influenced by pavement macrotexture.
This dissertation compares static and dynamic macrotexture measurements and proposes and enhanced method to quantify the macrotexture. Dynamic measurements performed with vehicle-mounted lasers have the advantage of measuring macrotexture at traffic speed. One drawback of these laser devices is the presence of 'spikes' in the collected data, which impact the texture measurements. The dissertation proposes two robust and innovative methods to overcome this limitation.
The first method is a data-driven adaptive method that detects and removes the spikes from high-speed laser texture measurements. The method first calculates the discrete wavelet transform of the texture measurements. It then detects (at all levels) and removes the spikes from the obtained wavelet coefficients (or differences). Finally, it calculates the inverse discrete wavelet transform with the processed wavelet coefficients (without outliers) to obtain the Mean Profile Depth (MPD) from the measurements with the spikes removed. The method was validated by comparing the results with MPD measurements obtained with a Circular Texture Meter (CTMeter) that was chosen as the control device.
Although this first method was able to successfully remove the spikes, it has the drawback that it depends on manual modeling of the distribution of the wavelet coefficients to correctly define an appropriate threshold. The next step of this dissertation proposes an enhanced to the spike removal methodology for macrotexture measurements taken with high-speed laser devices. This denoising methodology uses an algorithm that defines the distribution of texture measurements by using the family of Generalized Gaussian Distributions (GGD), along with the False Discovery Rate (FDR) method that controls the proportion of wrongly identified spikes among all identified spikes. The FDR control allows for an adaptive threshold selection that differentiates between valid measurements and spikes. The validation of the method showed that the MPD results obtained with denoised dynamic measurements are comparable to MPD results from the control devices. This second method is included as a crucial step in the last stage of this dissertation as explained following.
The last part of the dissertation presents an enhanced macrotexture characterization index based on the Effective Area for Water Evacuation (EAWE), which: (1) Estimates the potential of the pavement to drain water and (2) Correlates better with two pavement surface properties affected by macrotexture (friction and noise) that the current MPD method. The proposed index is defined by a three-step process that: (1) removes the spikes, assuring the reliability of the texture profile data, (2) finds the enveloping profile that is necessary to delimit the area between the tire and the pavement when contact occurs, and (3) computes the EAWE. Comparisons of current (MPD) and proposed (EAWE) macrotexture characterization indices showed that the MPD overestimates the ability of the pavement for draining the surface water under a tire.Ph. D.
23
Zhou, Xu. "Synthesis and characterization of rigid nanoporous hypercrosslinked copolymers for high surface area materials with potential hydrogen storage capabilities." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/78048.
Abstract:
Hydrogen storage remains a major technological barrier to the widespread adoption of hydrogen as an energy source. Organic polymers offer one potential route to useful hydrogen storage materials. Recently, Frechet and his coworkers described a series of hypercrosslinked polymers with high surface area and studied their surface properties and hydrogen storage capacities. McKeown and his coworkers studied a class of materials termed Polymers of Intrinsic Microporosity (PIMs) which are also based on a "hypercrosslinked" concept. We enchained N-substituted maleimide and functionalized stilbene alternating copolymers into a "hypercrosslinked system" to achieve high rigidity, high surface areas, high aromatic content and good thermal stability.
Hypercrosslinked copolymers of N-(3-methylphenyl)maleimide (3MPMI), 4-methyl stilbene (4MSTBB), vinylbenzyl chloride (VBC) and divinyl benzene (DVB) were synthesized. Scanning electron micrographs (SEM) show the copolymers are porous and some examples have shown surface areas over 1200 m²/g. We have also found the incorporation of 3MPMI and 4MSTBB improves the thermal stability and raises the glass transition temperature of the copolymer. However, the incorporation of 3MPMI and 4MSTBB decreases the hypercrosslinking density and therefore causes a decrease in the copolymer surface area. The systematic study of styrene (STR) – vinylbenzyl chloride (VBC) – divinyl benzene (DVB) networks indicates that a low density of chloromethyl groups leads to a decrease in surface area. Therefore, we are continuing to investigate other monomers, such as N-substituted maleimide and functionalized stilbene containing chloromethyl groups, in order to enhance thermal stability while maintaining surface area.
In order to increase the enthalpy of hydrogen adsorption and thus raise the temperature of hydrogen storage, the monomer N,N-dimethyl-N',N'-diethyl-4,4'-diaminostilbene (4,4'DASTB-3MPMI) which contains electron donating groups was incorporated into hypercrosslinked polymer particles. Hypercrosslinked polymer (4,4'DASTB-3MPMI)1.0(VBC)98.5(DVB).50 exhibits a surface area of 3257 m²/g.Master of Science
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Ye, Deping. "Topics in Convex Geometry and Phenomena in High Dimension." Case Western Reserve University School of Graduate Studies / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=case1244228324.
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Barančíková, Miriama. "Vysoce porézní keramické materiály připravené metodou Spark Plasma Sintering." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-442603.
Abstract:
Porous ceramic materials are an interesting group of materials due to a wide range of physical properties, low density, and good permeability. Production of a monolith with a shape stability that would also have a high specific surface area and high porosity is a common problem with porous ceramics. The goal of this work was to maintain the high specific surface area and to produce a monolith with a shape stability. Two forms of porous silica nanofibers (as prepared and milled) were used and partially sintered using the Spark Plasma Sintering method (SPS). Different sintering times and temperatures for SPS were tested. The findings revealed that the best SPS conditions were as follows: temperature: 600 °C, sintering time: 5 minutes, pressure: 3 MPa, and the heating rate: 144 °C/min. These sintering conditions resulted in a stable silica based machinable monolith made from fibers or milled fibers. The monoliths have the specific surface area of up to 470 m^2/g and porosity of 72 %, or the specific surface area of up to 422 m^2/g and porosity of 69 % for as prepared fibers and milled fibers, respectively.
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Bobb, Julian A. "LASER SYNTHESIS OF NANOMATERIALS INCORPORATED WITHIN HIGH SURFACE AREA MATERIALS: APPLICATIONS FOR HETEROGENEOUS CATALYSIS, WATER TREATMENT, AND PHOTOTHERMAL ENERGY CONVERSION." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5693.
Abstract:
Chemical methods are generally used for the synthesis of active nanoparticles (metals, semi-metals, metal oxides, and etc) supported on high surface area materials. Chemical methods involve using strong solvents, harmful gases (H2 & CO), and high temperature techniques such as high boiling solvents, calcination and pyrolysis. The main drawbacks of using this approach, is the prevalence of chemical agents on nanomaterials which tends to negate its applications. Alternatively, photochemical and photothermal methods are widely being considered for the synthesis and design of nanomaterials.
For these studies, the active nanomaterials incorporated within high surface area materials were prepared by the laser vaporization-controlled condensation (LVCC) technique or by the laser irradiation in solution (LIS) technique. The LVCC technique involves the irradiation of a solid target at the focal point of a laser beam (532 nm, 30 Hz) by the Nd: YAG laser inside a chamber that is sandwiched between two steel plates in the presence of high purity He. Whereas, the LIS technique involves the laser irradiation of chemical precursors in aqueous solvents using an unfocused beam. The LVCC technique was used for the preparation of carbonaceous and N-doped carbonaceous TiO2 support materials from MIL-125(Ti) and NH2-MIL-125(Ti) metal organic frameworks, Ge and GeO2 nanostructures, GeOx/PRGO nanocomposite, and the Fe3O4/PRGO nanocomposite. On the other hand, Pd supported on MIL-125(Ti) and NH2-MIL-125(Ti) nanocatalysts, GeO2/RGO, and the poly(ethylene glycol methacrylate-co-bisacrylamide) hydrogels were all prepared by the LIS technique.
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Lasagni, Andrés F., Tim Kunze, Matthias Bieda, Denise Günther, Anne Gärtner, Valentin Lang, Andreas Rank, and Teja Roch. "Large area micro-/nano-structuring using direct laser interference patterning." SPIE, 2016. https://tud.qucosa.de/id/qucosa%3A34803.
Abstract:
Smart surfaces are a source of innovation in the 21^st Century. Potential applications can be found in a wide range of fields where improved optical, mechanical or biological properties can enhance the functions of products. In the last years, a method called Direct LaserInterference Patterning (DLIP) has demonstrated to be capable of fabricating a wide range of periodic surface patterns even with resolution at the nanometer and sub-micrometer scales. This article describes recent advances of the DLIP method to process 2D and 3D parts. Firstly, the possibility to fabricate periodic arrays on metallic substrates with sub-micrometer resolution is shown. After that, different concepts to process three dimensional parts are shown, including the use of Cartesian translational stages as well as an industrial robot arm. Finally, some application examples aredescribed.
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Jalalpoor, Daniel Dariusch [Verfasser], Ferdi [Gutachter] Schüth, and Karl [Gutachter] Maryhofer. "Morphology controlled high-surface area support materials for electrochemical applications / Daniel Dariusch Jalalpoor ; Gutachter: Ferdi Schüth, Karl Maryhofer ; Fakultät für Chemie und Biochemie." Bochum : Ruhr-Universität Bochum, 2019. http://d-nb.info/1177364085/34.
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McDonald, Shannon Scott. "Characterization and optimization of a high surface area-solid phase microextraction sampler for the collection of trace level volatile organic compounds in the field /." Download the thesis in PDF, 2006. http://www.lrc.usuhs.mil/dissertations/pdf/McDonald2006.pdf.
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Di, Biase Emanuela. "Systematic development of predictive molecular models of high surface area activated carbons for the simulation of multi-component adsorption processes related to carbon capture." Thesis, University of Edinburgh, 2015. http://hdl.handle.net/1842/16155.
Abstract:
Adsorption in porous materials is a promising technology for CO2 capture and storage. Particularly important applications are adsorption separation of streams associated with the fossil fuel power plants operation, as well as natural gas sweetening. High surface area activated carbons are a promising family of materials for these applications, especially in the high pressure regimes. As the streams under consideration are generally multi-component mixtures, development and optimization of adsorption processes for their separation would substantially benefit from predictive simulation models. In this project we combine experimental data and molecular simulations to systematically develop a model for a high surface area carbon material, taking activated carbon Maxsorb MSC-30 as a reference. Our study starts from the application of the well-established slit pore model, and then evolves through the development of a more realistic model, based on a random packing of small graphitic fragments. In the construction of the model, we introduce a number of constraints, such as the value of the accessible surface area, concentration of the surface groups and pore volume, to bring the properties of the model structure close to the reference porous material. Once a plausible model is developed, its properties are further tuned through comparison between simulated and experimental results for carbon dioxide and methane. The model is then validated by predictions for the same species at different conditions and by prediction of other species involved in the carbon capture processes. The model is applied to simulate the separations involved in pre and post combustion capture processes and sweetening of sour natural gas, using realistic conditions and compositions for the multicomponent mixtures. Finally, it is used to explore the effect of water in pre and post combustion separations.
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Wu, Yimin A. "Towards large area single crystalline two dimensional atomic crystals for nanotechnology applications." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:bdb827e5-f3fd-4806-8085-0206e67c7144.
Abstract:
Nanomaterials have attracted great interest due to the unique physical properties and great potential in the applications of nanoscale devices. Two dimensional atomic crystals, which are atomic thickness, especially graphene, have triggered the gold rush recently due to the fascinating high mobility at room temperature for future electronics. The crystal structure of nanomaterials will have great influence on their physical properties. Thus, this thesis is focused on developing the methods to control the crystal structure of nanomaterials, namely quantum dots as semiconductor, boron nitride (BN) as insulator, graphene as semimetal, with low cost for their applications in photonics, structural support and electronics. In this thesis, firstly, Mn doped ZnSe quantum dots have been synthesized using colloidal synthesis. The shape control of Mn doped ZnSe quantum dots has been achieved from branched to spherical by switching the injection temperature from kinetics to thermodynamics region. Injection rates have been found to have effect on controlling the crystal phase from zinc blende to wurtzite. The structural-property relationship has been investigated. It is found that the spherical wurtzite Mn doped ZnSe quantum dots have the highest quantum yield comparing with other shape or crystal phase of the dots. Then, the Mn doped ZnSe quantum dots were deposited onto the BN sheets, which were micron-sized and fabricated by chemical exfoliation, for high resolution imaging. It is the first demonstration of utilizing ultrathin carbon free 2D atomic crystal as support for high resolution imaging. Phase contrast images reveal moiré interference patterns between nanocrystals and BN substrate that are used to determine the relative orientation of the nanocrystals with respect to the BN sheets and interference lattice planes using a newly developed equation method. Double diffraction is observed and has been analyzed using a vector method. As only a few microns sized 2D atomic crystal, like BN, can be fabricated by the chemical exfoliation. Chemical vapour deposition (CVD) is as used as an alternative to fabricate large area graphene. The mechanism and growth dynamics of graphene domains have been investigated using Cu catalyzed atmospheric pressure CVD. Rectangular few layer graphene domains were synthesized for the first time. It only grows on the Cu grains with (111) orientation due to the interplay between atomic structure of Cu lattice and graphene domains. Hexagonal graphene domains can form on nearly all non-(111) Cu surfaces. The few layer hexagonal single crystal graphene domains were aligned in their crystallographic orientation over millimetre scale. In order to improve the alignment and reduce the layer of graphene domains, a novel method is invented to perform the CVD reaction above the melting point of copper (1090 ºC) and using molybdenum or tungsten to prevent the balling of the copper from dewetting. By controlling the amount of hydrogen during the growth, individual single crystal domains of monolayer over 200 µm are produced determined by electron diffraction mapping. Raman mapping shows the monolayer nature of graphene grown by this method. This graphene exhibits a linear dispersion relationship and no sign of doping. The large scale alignment of monolayer hexagonal graphene domains with epitaxial relationship on Cu is the key to get wafer-sized single crystal monolayer graphene films. This paves the way for industry scale production of 2D single crystal graphene.
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André, Bérangère. "Structure et réactivité de poudres d’aluminium nanostructurées." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4301.
Abstract:
Les poudres d'aluminium sont depuis longtemps utilisées comme additifs dans de nombreuses formulations pour la pyrotechnie ou les propergols. Introduites en quantité relativement faible dans les propergols des fusées, elles permettent d'accroître significativement les vitesses de combustion. Cependant, les mécanismes à l'origine de cette meilleure réactivité restent encore mal compris et vont bien au-delà d'une simple explication en terme d'augmentation de l'état de division. Au cours de cette thèse nous avons élaboré des poudres d'aluminium par broyage à haute énergie, technique mécanique peu couteuse qui pourrait être une alternative aux procédés de fabrication actuels. Nous montrons que cette méthode permet l'obtention de particules micrométriques ou nanométriques suivant les conditions de broyage. Les particules sont polycristallines et présentent une morphologie en plaquette. Les poudres nanométriques obtenues présentent une réactivité comparable voire même supérieure aux nanopoudres sphériques actuellement élaborées par électro-explosion de fil ou voie plasma. Nous montrons que cette bonne réactivité est lié à la morphologie des particules ainsi qu'à la microstructure de la couche d'alumine native qui passive l'aluminiumAluminium nanopowders have been using for a long time as additives in many formulations for propergol or in pyrotechnics. Introduced in small quantity in rocket propergol they allow to increase the combustion rate. However, the reactivity of aluminium particles is not really understood and not just linked to the size reduction effect. All along this study, we have elaborated aluminium powders using high energy mechanical milling, a mechanical technique with a low cost which could be an alternative process of powders fabrication. We prove that this method allows elaboration of micro and nano-particles as a function of the mechanical parameters. The particles are polycristallines with flake morphology. The obtained nanopowders have a similar reactivity, or better than spherical nanopowders obtained by wire electrical explosion or plasma. We proove that this good reactivity is linked to the particles morphology, as well as also to the microstructure of the native alumina core shell
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Grant, Stacy M. "Polymer Templating Synthesis, Adsorption and Structural Properties of Alumina-Based Ordered Mesoporous Materials." Kent State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=kent1317593306.
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Abdesselam, Hayat. "Étude du comportement en fatigue et des mécanismes associés dans un acier à très haute résistance pour application aéronautique." Thesis, Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLEM018.
Abstract:
Le comportement en fatigue de l’acier à très haute résistance (THR) X23NiCoCrMoAl13-6-3 étudié est caractérisé par une dispersion dans les performances de tenue en fatigue. Deux modes d’amorçages de fissures sont observés sur sa courbe de Wöhler : le premier mode correspondant à des amorçages de fissures à partir d’inclusions non métalliques en surface des éprouvettes menant aux plus faibles durées de vie. Le second mode correspond à des amorçages de fissures en interne sur inclusions menant à de longues durées de vie et à des fissures en forme d’œil de poisson (« fish-eye »). Le lien entre les conditions d’essai (niveau de sollicitation, température et environnement), la nature et la localisation du site d’amorçage et la durée de vie résultante n’est jusqu’alors pas clairement identifié. L’objectif de ce travail de thèse est donc de mieux appréhender les mécanismes physiques à l’origine des différents types d’amorçage et de propagation en fatigue menant à la dispersion en durée de vie.La première partie de ce document présente la caractérisation microstructurale multi-échelle de l’acier THR avec l’identification des entités microstructurales et de leurs dimensions caractéristiques. Ensuite, l’analyse des faciès de rupture a permis de caractériser de manière approfondie les zones associées aux différents stades de propagation de la fissure de fatigue. Pour l’amorçage en surface, on trouve : 1) la particule rompue 2) la propagation sous air 3) la rupture ductile finale. Pour les amorçages en interne deux stades supplémentaires sont observés : 1.a) formation d’une zone à grains fins (« fine granular area, (FGA) ») autour de la particule si sa taille est inférieure à une taille critique et 1.b) propagation sous vide. La mécanique linéaire de la rupture est utilisée pour estimer le facteur d’intensité des contraintes de la fissure, Kmax, pour chacune de ces zones.Le facteur Kmax associé à la transition entre FGA et fish-eye se révèle être constant à une température donnée. Cette transition se caractérise par une taille de zone plastique en pointe de fissure de l’ordre de trois fois la largeur des lattes de martensite. Lorsque la température augmente, le Kmax en fin de FGA diminue mais la taille de la zone plastique reste constante. Le caractère cristallographique, pseudo stade I, de la propagation dans la FGA est mis en évidence. Il a été de plus confirmé qu’une FGA pouvait se former en cours de propagation de fissures à partir d’éprouvettes entaillées (SENT), sous vide sollicitées à Kmax faible. Le caractère cristallographique a été confirmé par analyse EBSD 3D du faciès de rupture. Un calcul de durée de vie en propagation pure sous air et sous vide a montré que les durées de vie peuvent varier d’un ordre de grandeur en fonction de l’environnementThe fatigue behavior of a very high strength steel X23NiCoCrMoAl13-6-3 shows a large scatter in fatigue life. Two fatigue crack initiation scenarios are found. They are separated by a plateau in the Wöhler curve: the first one corresponds to crack initiation at the specimen surface from non-metallic inclusions leading to short fatigue lives. The second scenario corresponds to internal crack initiation from particles leading to so-called fish-eye cracks. The link between test conditions (load level, temperature and environment), the nature and location of the crack initiation site and the associated fatigue life has yet not been clearly established. The objective of the present PhD project is to better understand the physical mechanisms leading to the different fatigue crack initiation and propagation mechanisms.In the first part of the thesis the microstructure of the very high strength steel was studied at multiple scales and its main constituents and their respective sizes were identified.Further, the analysis of the fatigue tests by fractography has permitted to identify the different characteristic fatigue crack propagation stages. For surface fatigue crack initiation, the following stages were found: 1) a broken particle 2) fatigue crack propagation in air 3) the final ductile fracture. For internal fatigue crack initiation two more fatigue crack propagation stages are observed: 1.a) formation of a fine granular area (FGA) for small particles and 1.b) propagation in vacuum. Linear elastic fracture mechanics are used to evaluate the stress intensity factor, Kmax for each of these zones.Kmax revealed to be constant at the end of the FGA. The size of the plastic zone at the end of the FGA was calculated and corresponded to three times the width of the martensite laths. Tests at different temperatures (20°C, 200°C and 400°C) revealed a decreasing FGA size with increasing temperature at constant applied stress amplitude. As a consequence, the critical stress intensity factor varied as the FGA decreased with temperature. In contrast, the critical plastic zone size remained constant and equal to the sizes of microstructural features. This represents a strong similarity between crystallographic, stage I-like, crack propagation and FGA formation in a vacuum. This was further confirmed as an FGA was formed during crack propagation using SENT samples in vacuum and for low Kmax levels. The crystallographic character was verified by an SEM/FIB analysis of the fracture surface. A fatigue life prediction, assuming propagation only, showed that the fatigue life can vary by an order of magnitude as a function of the test environment corresponding to surface and internal crack initiation
35
Stoeck, Ulrich, Simon Krause, Volodymyr Bon, Irena Senkovska, and Stefan Kaskel. "A highly porous metal–organic framework, constructed from a cuboctahedral super-molecular building block, with exceptionally high methane uptake." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-138864.
Abstract:
A highly porous metal–organic framework Cu2(BBCDC) (BBCDC = 9,9′-([1,1′-[b with combining low line]iphenyl]-4,4′-diyl)[b with combining low line]is(9H-[c with combining low line]arbazole-3,6-[d with combining low line]i[c with combining low line]arboxylate) (DUT-49) with a specific surface area of 5476 m2 g−1, a pore volume of 2.91 cm3 g−1, a H2 excess uptake of 80 mg g−1 (77 K, 50 bar), a CO2 excess uptake of 2.01 g g−1 (298 K, 50 bar) and an exceptionally high excess methane storage capacity of 308 mg g−1 (298 K, 110 bar) was obtained using an extended tetratopic linkerDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
36
Bogatu, Bettina Ulrike. "Die Adsorption von Lipoproteinen an der Oberfläche fibrogener und inerter Mineralstäube." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2004. http://dx.doi.org/10.18452/15079.
Abstract:
Sieben fibrogene und fünf nicht fibrogene (inerte) Mineralstäube wurden auf ihr Adsorptionsvermögen gegenüber Lipoproteinen untersucht. Die Adsorption erfolgte aus menschlichem Serum bzw. bovinem Lipoproteinkonzentrat. Die spezifischen Oberflächen der Stäube wurden mit Hilfe einer neuen Methode ermittelt, die auf der Adsorption von Nonadecansäure beruht. Sie vernachlässigt Oberflächenporen mit ÖffnungsdurchmessernSeven fibrogenic and five nonfibogenic (inert) mineral dusts were examined for their adsorption capacity for lipoproteins. Lipoproteins came from human serum and bovine lipoprotein- concentrate. The specific surface areas of the dusts were determined with the help of a new method, which is based on the adsorption of nonadecanoic acid. It neglects surface pores with opening diameters less than 2,5nm. The most important result is that fibrogenic dusts adsorb significantly more high density lipoproteins (HDL), than the inert dusts. The adsorption of HDL on quartz can be reduced up to 96% by addition of Polyvinylpyridine-N-oxide (PVPNO), an inhibitor of quartz- induced fibrosis. The HDL- adsorption might play a role during the developing process of mineral-dust-induced fibrosis.
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Stoeck, Ulrich, Simon Krause, Volodymyr Bon, Irena Senkovska, and Stefan Kaskel. "A highly porous metal–organic framework, constructed from a cuboctahedral super-molecular building block, with exceptionally high methane uptake." Royal Society of Chemistry, 2012. https://tud.qucosa.de/id/qucosa%3A27787.
Abstract:
A highly porous metal–organic framework Cu2(BBCDC) (BBCDC = 9,9′-([1,1′-[b with combining low line]iphenyl]-4,4′-diyl)[b with combining low line]is(9H-[c with combining low line]arbazole-3,6-[d with combining low line]i[c with combining low line]arboxylate) (DUT-49) with a specific surface area of 5476 m2 g−1, a pore volume of 2.91 cm3 g−1, a H2 excess uptake of 80 mg g−1 (77 K, 50 bar), a CO2 excess uptake of 2.01 g g−1 (298 K, 50 bar) and an exceptionally high excess methane storage capacity of 308 mg g−1 (298 K, 110 bar) was obtained using an extended tetratopic linker.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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Darpentigny, Clémentine. "Fonctionnalisation de structures de nanocellulose en fluide supercritique pour des applications de pansements antimicrobiens Ice-templated freeze-dried cryogels from tunicate cellulose nanocrystals with high specific surface area and anisotropic morphological and mechanical properties Highly Absorbent Cellulose Nanofibrils Aerogels Prepared by Supercritical Drying." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAV052.
Abstract:
Dans un contexte où la demande en matériaux médicaux innovants augmente et où la question environnementale devient une préoccupation majeure, l’objectif du projet a été de préparer des pansements antimicrobiens par la voie la plus verte possible. Pour cela, les nanocelluloses ont été retenues comme briques de base biosourcées et biocompatibles pour le design d’architectures poreuses et leur fonctionnalisation par des agents antimicrobiens a été ensuite entreprise en milieu CO2 supercritique (CO2sc) utilisé comme alternative aux solvants organiques en tirant profit de ses spécificités telles qu’une diffusivité élevée, une élimination aisée du solvant et des réactifs résiduels et une compatibilité avec les matériaux fragiles. Ainsi, des structures 2D et 3D, nanopapiers, cryogels et aérogels, ont été préparées à partir de nanofibrilles (NFC) et de nanocristaux (NCC) de cellulose et présentent des propriétés variées en termes de porosité, morphologie et surface spécifique. Dans le but d’introduire une fonction antibactérienne, les cryogels préparés à partir de nanocelluloses de chimie de surface variées ont été dans un premier temps imprégnés en CO2sc d’un antibiotique synthétique, la ciprofloxacine. Les cryogels imprégnés présentent une activité antibactérienne contre les bactéries Gram-positive et Gram-négative. Ensuite, quatre matériaux de surface spécifique croissante tous préparés à partir de NFC ont été imprégnés avec une molécule issue d’huiles essentielles, le thymol. Les résultats montrent un contrôle direct de la quantité imprégnée avec la surface spécifique qui conduit dans le cas des cryo- et aérogels à de bonnes propriétés antimicrobiennes contre deux types de bactéries et une levure. La seconde stratégie de fonctionnalisation a porté sur le greffage covalent d’un silane aminé antimicrobien en CO2sc. Des méthodes d’analyse de surface (spectrométrie photoélectronique X, angle de contact et potentiel zêta de surface) ont permis de confirmer le succès du greffage sur les nanopapiers. Les propriétés antibactériennes par contact des nanopapiers et cryogels greffés ont été confirmées. Ces résultats sont prometteurs pour l’élaboration en conditions supercritiques de dispositifs médicaux antimicrobiens bio-sourcés et biocompatiblesIn a context where the need for innovative medical devices is increasing and the environmental issue is becoming a major concern, the objective of the project the aim of the project was to prepare antimicrobial wound dressings using the greenest possible way. For this purpose, nanocelluloses have been chosen as bio-based and biocompatible building blocks for the design of porous architectures and their functionalization with antimicrobial agents was then undertaken in supercritical CO2 medium (CO2sc) used as an alternative to organic solvents and by taking advantage of its specificities such as high diffusivity, easy removal of solvent and residual reagents and compatibility with fragile materials. Thus, 2D and 3D structures, nanopapers, cryogels and aerogels, were prepared from cellulose nanofibrils (CNFs) and nanocrystals (CNCs), and exhibited various properties in terms of morphology, porosity and specific surface area. In order to introduce antibacterial functionality, cryogels prepared from nanocellulose with varied surface chemistries were impregnated in scCO2 with a synthetic antibiotic, ciprofloxacin. Impregnated cryogels exhibited antibacterial activity against both gram-negative and gram-positive bacterial strains. Then, four materials of increasing specific surface area, all prepared from CNFs, were impregnated with an essential oil molecule, thymol. Results show a direct relationship between of the amount of impregnated molecules and the specific surface that leads in the case of cryo- and aerogels to good antimicrobial properties against two types of bacteria and yeast. In a second strategy, covalent grafting of CNFs structures in supercritical CO2 was investigated with a novel antibacterial aminosilane. Surface analysis characterizations methods (X-ray photoelectron spectroscopy, contact angle and surface zeta potential analysis) confirmed the successful grafting on nanopapers. The contact active properties of grafted nanopapers and cryogels were assessed. These results are very promising for the design of antimicrobial bio-based and biocompatible medical devices using supercritical conditions
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Yoshikawa, Naruo. "The chemical and photochemical reactivity of modified and unmodified high area titania surfaces." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343010.
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Vincent, Dominick A. "Aerosol optical depth retrievals from high-resolution commercial satellite imagery over areas of high surface reflectance." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Jun%5FVincent_Phd.pdf.
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Augustine, Robin. "Electromagnetic modelling of human tissues and its application on the interaction between antenna and human body in the BAN context." Phd thesis, Université Paris-Est, 2009. http://tel.archives-ouvertes.fr/tel-00499255.
Abstract:
Les réseaux BAN (Body Area Network) révolutionnent le concept de la surveillance et de la prise en charge à distance de la santé du patient. Le BAN fournit des informations sur l'état de santé du patient en temps réel quelque soit l'endroit où il se trouve. Dans le « télé monitoring », des capteurs de mouvement, de respiration ou du rythme cardiaque placés à l'intérieur ou sur le corps humain transmettent des données via le réseau sans fil constituant le BAN, une antenne étant associée à chaque nœud du réseau. La communication peut être in/on, on/on ou on/off selon que les antennes sont placées à l'intérieur, sur ou à l'extérieur du corps. Le développement des BAN nécessite la réalisation de modèles (ou fantômes) simulant au mieux les propriétés électromagnétiques du corps humain. Des antennes portables, miniaturisées doivent être réalisées avec des contraintes d'intégration d'une part (aux vêtements, à des objets type montre ou badge), des contraintes de résistance ou de prise en compte de l'influence du corps d'autre part. La réduction de l'impact des antennes sur les tissus en terme de SAR (Specific Absorption Rate) doit également être considérée. Dans ce travail, l'objectif est de développer des fantômes valables pour les communications dans et sur le corps. Les matériaux de base sélectionnés sont d'origine biologique (biocéramiques et biopolymères) avec des propriétés proches de celles des tissus humains. Ces fantômes étant biocompatibles, ils sont essentiellement non toxiques alors que les fantômes usuels le sont en général. D'autre part, différents types d'antennes conformables, fonctionnant dans la bande ISM 2.4 GHz ont été développées et étudiées dans la perspective du BAN. Les antennes voient leur adaptation et leur efficacité chuter au contact ou à proximité du corps, ce qui constitue un écueil majeur pour établir une bonne communication. Différentes méthodes permettant de réduire l'influence du corps (plan de masse à l'arrière, surface haute impédance, feuille de ferrite polymère) sont testés et leurs avantages et inconvénients développés. Des mesures de SAR permettent aussi de démontrer l'efficacité de ces méthodes sur la réduction de la puissance absorbée par les tissus. Au final, ce travail apporte une contribution à l'étude théorique et expérimentale de l'interaction entre corps humain et antenne dans le cadre des réseaux BAN appliqués à la télésurveillance de la santé
42
Porfiri, Martina. "Digital surface model generation over urban areas using high resolution satellite SAR imagery : tomographic techniques and their application to 3-Dchange monitoring." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S035/document.
Abstract:
L'urbanisation et la gestion de l'environnement urbain et sa périphérie deviennent l'un des problèmes les plus cruciaux dans les pays développés et en développement. Dans ces circonstances, les données de télédétection sont une source importante d'information qui reflète les interactions entre les êtres humains et leur environnement. Compte tenu de leur indépendance totale des contraintes logistiques sur le terrain, l'éclairage (lumière du jour) et météorologiques (nuages) conditions, Synthetic Aperture Radar (SAR) les systèmes de satellites peuvent fournir des contributions importantes dans des environnements complexes de reconstruction 3-D. La nouvelle génération de haute résolution SAR capteurs comme COSMOSkyMed, TerraSAR-X RADARSAT-2 a permis d'acquérir des images SAR à haute résolution. Ici, l'attention est mis sur la technique pour l'imagerie 3-D nominée tomographie SAR: à partir d'une pile d'images ont été recueillies en utilisant les données multibaseline effectuées dans la configuration interférométrique, une telle technique permet d'extraire les informations de hauteur formant une ouverture synthétique dans la direction d'élévation afin d'obtenir une résolution sensiblement améliorée. Cette thèse de doctorat se concentre sur les potentialités élevées de techniques tomographiques en 3-D surveillance des changements et la caractérisation des zones complexes et denses bâties en utilisant des estimateurs mono-dimensionnelle de base comme Beamforming, Capon et MUSIC combinée au satellite très haute résolution des images SAR. 2-D et de l'analyse 3-D ont été présentés sur la zone urbaine de Paris en utilisant les données TerraSAR-X à haute résolution et de polarisation unique. Être porté principalement sur les techniques tomographiques 3-D, dans les méthodes de travail 4-D présentés, tels que le Compressive Sensing, ne sont pas pris en compte. Dans un premier temps, l'analyse de la qualité interférométrique de l'ensemble de données transformées a montré de bonnes valeurs de cohérence moyenne et ont permis de détecter des images considérées comme des valeurs aberrantes. L'extraction des tomographies 2-D sur l'azimut différent de profil a montré la capacité de distinguer plus d'un diffuseur à l'intérieur de la même cellule de résolution et de reconstituer les profilés de construction verticaux. Successivement, une caractérisation 3-D globale en terme de bâtiments hauteurs et réflectivité verticale a été réalisée dans le but de développer un outil de suivi des changements des structures simples. En outre, la possibilité de corriger les distorsions géométriques en raison de l'escale (qui affecte fortement ce genre de scénarios) et de déterminer les informations sur le nombre de diffuseurs (jusqu'à trois) et la réflectivité correspondant à l'intérieur d'une cellule de résolution ont été évaluésThe urbanization and the management of urban environment and its periphery become one of the most crucial issues in developed and developing countries. In these circumstances, remote sensing data are an important source of information that reflects interactions between human beings and their environment. Given their complete independence from logistic constraints on the ground, illumination (daylight), and weather (clouds) conditions, Synthetic Aperture Radar (SAR) satellite systems may provide important contributions in complex environments 3-D reconstruction. The new generation of high resolution SAR sensors as COSMO-SkyMed, TerraSAR-X and RADARSAT-2 allowed to acquire high resolution SAR imagery. Here the attention is put on the 3-D imaging technique called SAR Tomography: starting from a stack of images collected using multibaseline data performed in interferometric configuration, such a technique allows to retrieve height information forming a synthetic aperture in the elevation direction in order to achieve a substantially improved resolution. The present PhD thesis is focused on the high potentialities of tomographic techniques in 3-D change monitoring and characterization for complex and dense built-up areas using basic mono-dimensional estimators as Beamforming, Capon and MUSIC combined to very high satellite SAR resolution imagery. 2-D and 3-D analysis have been presented over the urban area of Paris using TerraSAR-X data at high resolution and single polarisation. Being mainly focused on the 3-D tomographic techniques, in the presented work 4-D methods, such as compressive sensing (CS), have not been taken into account. At first, the analysis of the interferometric quality of the processed data set has been performed and results showed good mean coherence values within the entire stack. The extraction of 2-D tomograms over different azimuth-profile has showed the capabilities to distinguish more than one scatterer within the same resolution cell and to reconstruct the vertical building profiles. Successively, a global 3-D characterization both in term of buildings heights and vertical reflectivity has been performed in order to develop a monitoring tool for the changes of single structures. Moreover, the possibility to correct the geometric distortions due to the layover (that strongly affects such kind of scenarios) and to determine the information about the number of scatterers (up to three) and the corresponding reflectivity within one resolution cell have been evaluated. Moreover an innovative time stability analysis of the observed scene have been carried out in order to detect the stable and unstable scatterers. Globally, the investigations showed noisier and sparser point clouds for the Capon method, whereas better capabilities for the Beamforming and MUSIC ones. Indeed, it was possible to detect different scatterers located within the same resolution cell and to resolve pixels affected by the layover. This has lead to perform a good reconstruction of building shape and location and a good estimation of their elevation. The 3-D time stability analysis demonstrated the possibility to monitor the 3-D change depending on the time. Eventually, it is possible to assert that processing high resolution SAR data allows to achieve a strong improvement in 3-D imaging capabilities. It has been demonstrated the potentialities of TomoSAR technique in distortions correction and in 3-D change monitoring using basic mono-dimensional estimators
43
Hsu, Shu-Fan, and 許書凡. "High-Temperature Sulfation of High-Surface-Area Calcium Carbonate." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/09241700407983355049.
Abstract:
碩士國立臺灣大學
化學工程學研究所
99
High surface area CaCO3 particles were produced by absorption of CO2 in aqueous suspensions of Ca(OH)2 in a bubble column. In the absence of any additive, CaCO3 with a surface area of 15.6 m2/g was obtained at 2.4 wt% Ca(OH)2 and 2.5 L/min CO2. CaCO3 with a surface area of 35.3 m2/g was obtained by adding 0.1 wt% Dispex A40 at pH 6.5 – 6.2, and with a surface area of 70.7 m2/g by adding 0.2 wt% PAAS at pH 11.4 –11.1. The primary CaCO3 particles agglomerated to form large particles, the average particle diameters of which were 10.4, 17.5, and 4.6 µm for the three CaCO3 samples prepared, respectively. The initial rate and 1 min conversion for the sulfation of CaCO3 increased with increasing specific surface area, temperature, and SO2 concentration, but decreased with increasing CO2 concentration, and were independent of H2O concentration. A conversion of 0.88 was achieved when CaCO3 with a surface area of 70.7 m2/g was sulfated at 950ºC and 4400 ppm SO2 in a simulated flue gas for 1 min. The kinetics of the sulfation of CaCO3 particles can be described by the changing grain size model. Under the conditions that CaCO3 can decompose, the sulfation rate was controlled by grain product layer diffusion and particle pore diffusion. Under the conditions that CaCO3 cannot decompose, the sulfation rate was controlled by grain chemical reaction, grain product layer diffusion, and particle pore diffusion.
44
Wu, Yao-Min, and 吳耀閔. "Preparation of high-surface-area mesoporous activated carbon." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/59318245564822744294.
Abstract:
碩士崑山科技大學
環境工程研究所
99
This research used Urea-Resorcinol-Formaldehyde as carbon precursor and tri-polymer interface activator, and home-made equipment to manufacture activated carbon in medium-size cavities for studying the effect of manufacturing process on dynamic adsorption power of methyl blue, methylene blue, benzene and acetone. The study results showed that before being activated by KOH, the surface area of carbon material was about 500 m2/g; cavity volume was about 0.8 cm3/g; cavity size was about 12 nm; after being activated by KOH, the surface area of the activated carbon became about 1300~1600 m2/g; cavity volume was about 0.4~0.9 cm3/g; cavity size was about 8~12 nm. After being activated with KOH, URF-AC ratio at 4:1 had the highest specific surface area 1672.8 m2/g, the adsorption amount of methyl blue liquid reaches 3232.0 mg/g of adsorbent; methylene blue liquid was 3068.8 mg/g of adsorbent; benzene was 306 mg/g; acetone was 133 mg/g. This research discovered that the adsorption is determined by the amount of cavities; and is proportional to specific surface area, and adsorption efficiency is affected by the cavity volume and size.
45
Yang, Jung-Hsin, and 楊榮欣. "Preparation and High-Temperature Sulfation of High- Surface-Area Calcium Carbonate." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/03975967720733585281.
Abstract:
博士臺灣大學
化學工程學研究所
98
High surface area and porous CaCO3 particles were produced by absorption of CO2 in aqueous suspensions of Ca(OH)2 with the addition of a suitable additive in a bubble column. In the absence of any additive, the CaCO3 surface area varied with the initial Ca(OH)2 concentration and reached a highest value ( 19.6 m2/g ) at 2.4 wt% Ca(OH)2. The CaCO3 surface area was affected little by the CO2 flow rate ( 1.0-3.5 L/min ) and decreased with increasing solution temperature ( 27-45 oC ). The CaCO3 surface area was affected markedly by the kind of additive, the amount of additive, and the solution pH when adding the additive. An effective additive in raising the CaCO3 surface area was to enhance the formation of fine CaCO3 primary particles and the loose aggregation of them; the additive should be added only after bubbling CO2 into the Ca(OH)2 suspension except EDTA. Among all the additives tested, CaCO3 samples prepared with PAAS, EDTA, (NaPO3)6, and Na5P3O10 could have surface areas above 70 m2/g. The CaCO3 with the highest surface area ( 87.7 m2/g ) was obtained by adding 0.2 wt% PAAS to a suspension of 2.4 wt% Ca(OH)2 in the pH range of 11.4-11.1. The reactivity of CaCO3 increased with increasing surface area in general. A conversion of 0.95 was achieved when CaCO3 with highest surface area was sulfated at 950 oC and 4000 ppm SO2 in air for 1 min. Prior calcination reduced markedly the reactivity of CaCO3. The initial rate and 1 h conversion for the sulfation of CaCO3 increased with increasing temperature and SO2 concentration, decreased with increasing CO2 concentration, and were independent of the O2 and H2O concentrations. The kinetic of the sulfation of CaCO3 was well described by the model assuming product layer diffusion control.
46
Teixeira, Sandra Maria da Silva. "Bioactive ceramics with high specific surface area for osteoconduction." Tese, 2008. http://hdl.handle.net/10216/12336.
47
Chou, Chebg Chang, and 周承璋. "Development of high-surface-area structures for TiO2photoelectrocatalytic films." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/68239800642250045135.
Abstract:
碩士南台科技大學
奈米科技研究所
96
In this study , high-surface-area structures were developed to improve the photocurrents of coated TiO2 films .Two kinds of structures were prepared: one by the photo-lithography and wet etch technique；the other by AAO and glancing angle deposition technique. The effects of prepared structures on the photocurrents of coated TiO2 films were investigated. The morphologies of prepared structures were observed by a scanning electron microscopy. The photocurrents were measured by a potentiostat system. The experimental results show that the photocurrent increases with increasing the aspect ratio of patterns generated by photo-lithography and wet etch technique. The photocurrent increased from 59.2 to 147.5 μA/cm2 with increasing the surface area from 0.25 to 0.51 cm2 . For the structures prepared by AAO and glancing angle deposition, the photocurrents of TiO2 films were increased from 61 to、85 μA/cm2 and from 59 to 111 μA/cm2 by using stainless steel and titanium as the deposited materials , respectively.
48
Teixeira, Sandra Maria da Silva. "Bioactive ceramics with high specific surface area for osteoconduction." Doctoral thesis, 2008. http://hdl.handle.net/10216/12336.
49
Shih, Ming-Hsun, and 施名訓. "Synthesis and application of high surface area alumina and silica." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/08898160612540077689.
Abstract:
碩士南台科技大學
化學工程與材枓工程系
95
In this study, the high surface area powders were synthesized by aluminium sec- butylate (ASB), boehmite and silica as the raw materials, respectively. When used ASB as the raw maerial, the various amount of different acids was added to synthesized the products. The shorter fiber (30-40nm in length) and spherical particle (10nm in diameter) were formed in the case by using actectic acid as the catalysis. If phosphoric acid was adopted, the formed powder was a 50-60nm in length fiber. Increasing the calcination temperature to 1200℃, the powder grow rapidly as it phase- transfered to α-alumina. But if adding phosphoric acid as the catalysis, the phase transformation of α-alumina was retarded to 1400℃.The retardation of phase transformation of alumina may is not important as the ratio of P/Al below than 0.01. IF P/Al ratio is higher than 0.057, the specific area of the powder was reduced. In the case that boehmite was the raw material, increasing the phosphoric acid concentration would induce the increase of the amount of fiber. The product can be maintain at the high surface area after the long aging time(100 h) at 1000 ℃. In the study of the high surface area silica, sodium silicate was adopted to form form silica xerogel with the different amount butanol in ambient drying. According to the experimental results, the product has a small surface area and small pore size diameter as it dried directly. Increasing the amount of buatanol, the surface area is increased and then decreased. The pore size was in 4.5～6 nm as the volume ratio of butanol to silicate <1. However, the pore diameter was in 12~17 nm as the volume ratio of butanol to silicate >1. The pore volume of the product was increased by increasing the volume ratio of butanol to silicate until to reach a maximum value and then was not increased by increasing the volume ratio of butanol to silicate. The result shows butanol can control the pore size and pore volume of the xerogel in the ambient pressure.
50
AGUSTIN, YUANA ELLY, and 吳愛麗. "A BIOMOLECULE-BASED METHOD FOR HIGH THROUGHPUT SURFACE AREA MEASUREMENT." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/42395429118211992869.
Abstract:
碩士國立臺灣科技大學
化學工程系
102
The increasing utilization of metallic nanoparticles in many areas of human activity has raised some concern to develop an effective and efficient method to understand the nature and characteristic of metallic nanoparticles, especially the surface area of metallic nanoparticles. In this study, an alternative approach for measuring the surface area of nanoparticles in suspension was studied with the aid of genetic engineering. A selective metal binding peptide that immobilized on a cellulose matrix was used to capture the metal nanoparticles from the solution and the Green Fluorescence Protein (GFP) that fused with metal binding peptide was used to investigate the correlation between fluorescence intensity with the total surface area of the nanoparticles. This newly method provides a fast and selective approach to detect the surface area of target metallic nanoparticles in a mixed solution. The recombinant modular protein quite stabile and can be used until 6 days in the 4oC storage temperature.