Дисертації з теми "Composite metal nanoparticles"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Composite metal nanoparticles".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
Strossi, Pedrolo Débora Regina. "Synthesis of metal-zeolite composite materials for bifunctional catalytic reactions." Thesis, Université de Lille (2018-2021), 2021. https://pepite-depot.univ-lille.fr/LIBRE/EDSMRE/2021/2021LILUR065.pdf.
Повний текст джерелаZeolite-based catalysts have been widely used in the conversion of biomass. The catalytic yields of the desired products are strongly limited due to the relatively small size of the pores in zeolites and the catalyst preparation by impregnation usually leads to relatively large metal nanoparticles and low contact between metal and acid sites. The purpose of this work is the design of metal-zeolite nanocomposite catalysts containing ruthenium nanoparticles uniformly distributed in the hierarchical BEA and ZSM-5 zeolites. Use of ruthenium avoids formation of inert hardly reducible inert metal silicates and metal aluminates, while carbon nanotubes with supported metal oxide nanoparticles play a role of sacrificial template, which allows creating mesoporosity and bringing metallic functionality inside the zeolite matrix. Compared to the conventional zeolite supported metal catalysts the synthesized hierarchical ruthenium-zeolites exhibited much higher activity and lower methane selectivity in Fischer-Tropsch synthesis. Characterization of the prepared catalysts has indicated initiation of crystallization of zeolites over metal nanoparticles. This effect has been further used to increase the dispersion of metal nanoparticles by secondary crystallization of Ru supported over ZSM-5. Our results show significant re-dispersion of embedded metal oxide nanoparticles and increase in the activity of model reactions. In addition, a synthetic strategy was developed for the preparation of hierarchical metal and zeolite nanocomposite catalysts for direct synthesis of iso-paraffins from syngas. The nanocomposites are synthesized in three steps. In the first step, the parent (core) zeolite is etched with an ammonium fluoride solution. The etching creates small mesopores inside the zeolite crystals. In the second step, the Ru nanoparticles prepared using water-in-oil microemulsion are deposited in the mesopores of the zeolite. In the third step, a zeolite shell of MFI-type zeolites (silicalite-1 or ZSM-5) is grown on the parent zeolite crystals coating both the etched surface and metallic nanoparticles. Thus, the metal nanoparticles become entirely encapsulated inside the zeolite matrix. Most important parameters such as ruthenium content, zeolite mesoporosity, and more particularly, the acidity of the catalyst shell, which affect the catalytic performance of the synthesized nanocomposite materials in low-temperature Fischer−Tropsch synthesis were identified in this work. The higher relative amount of iso-paraffins was observed on the catalysts containing a shell of ZSM-5. The proximity between metal and acid sites in the zeolite shell of the nanocomposite catalysts is a crucial parameter for the design of efficient metal zeolite bifunctional catalysts for selective synthesis of gasoline-type fuels via Fischer−Tropsch synthesis, while the acidity of the catalyst core has only a limited impact on the catalytic performance
Jonke, Alex P. "Atomic metal/polyaniline composites." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49070.
Повний текст джерелаAnyaogu, Kelechi C. "Stabilized metal nanoparticle-polymer composites preparation, characterization and potential applications /." Bowling Green, Ohio : Bowling Green State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=bgsu1222126708.
Повний текст джерелаNavas, M. P. "Pulsed laser ablation of composite metal nanoparticles: studies on growth, plasmonic sensing and catalysis." Thesis, IIT Delhi, 2017. http://localhost:8080/iit/handle/2074/7229.
Повний текст джерелаHardian, Rifan. "Interplay between structure, texture, and reactivity in MOFs in the case of amorphous, defective, and composite materials." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0419/document.
Повний текст джерелаMetal-organic frameworks (MOFs) are a class of porous materials that constructed from metal clusters connected with organic linkers. The main objective of my PhD was to characterize the texture, structure, and reactivity of MOFs materials with a particular focus on defective, amorphous and composite materials. The first study is centered on the properties of the Fe-BTC family and this work was realized in collaboration with Utrecht University and the University of Oxford. A comparative study between crystalline MIL-100(Fe) and its commercial counterpart amorphous Basolite F300 (BASF) were studied by using methanol adsorption to predict the reactivity. Other characterization methods are introduced to investigate both materials which were further tested to be used as supports for metal-impregnation. In the next study, ball-milling was employed as a post-synthesis strategy for MOF modification. This ZIF-8 material was selected since it is commercially available (Basolite Z1200) and is becoming one of the reference materials in this area. Extensive studies including flexibility, textural, structural, as well as reactivity of different milling products is presented. Zirconium-based MOFs (UiO-66 and MOF-808) were also examined in this thesis. These studies were performed in collaboration with TU Munich. UiO-66 series containing engineered defects are first examined. We demonstrated that vapor adsorption measurement is a valuable tool to access the chemistry of the defects. The second studied system is MOF-808 series, where a comprehensive study is presented starting from synthesis strategies of defective and composite MOFs up to adsorption properties and reactivity
Samer, Nassim. "Synthèse réactive de Composites à Matrice Métallique." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1057/document.
Повний текст джерелаMetal Matrix Composites (MMCs) have attracted research and industrial attentions as materials for high technological applications in the aeronautic and aerospace industry. The MMCs differ by their high specific mechanical properties compared to light weight alloys. The most commonly used are the Particulate Reinforcement Metal Matrix Composites (PRMMCs), especially the Al based matrices because of their low density.This thesis deals with the reactive synthesis of PRMMCs reinforced by nanoparticles. Because of the standards governing the use of nanomaterials to limit the exposure of users and environment, handling nanoscaled powders is very problematic and expensive in industry. Furthermore, the cost of this kind of processes is very high. This new synthesis route, developed during this thesis, shows the feasibility of PRMMCs reinforced by nanosized particles, with a mean size of 30 nm, without using any starting nanoparticles.The process consists in a chemical reaction at high temperature between precursor materials which leads to form both of the matrix and the reinforcement phase. Compared to conventional synthesis techniques as stir casting, this route allows to synthesis nanoparticles in-situ and to control their size. In addition, the matrix and the reinforcement, which are formed by a reaction at high temperature, have an interface free of oxide layers which assures a good adhesion.In the NanoTiCAl project, the feasibility of this new method is illustrated in the case of an aluminium based composite reinforced by titanium carbide (TiC). The synthesis were realized between 900°C and 1000°C from a couple of precursors including graphite and titanium aluminide (Al3Ti). The resulting composite, characterized by a high reinforcement ratio (34 wt.%), presents a Young’s modulus of 106 GPa, a maximum elongation of 6 % and a high toughness, about 28 J.cm-3. These values represent an uncommon compromise between strength and toughness never seen in the literature regarding to the high content of reinforcement.The characterization of the composite microstructure and of the reinforcement phase, after extraction of the solid composite, allowed a better understanding of the reaction mechanism during the reactive synthesis. Finally, based on our understanding of the Al-TiC composite, criteria have been identified to generalize this synthesis process. This generalization was demonstrated with success in other systems
Walden, Sarah L. "Nonlinear optical properties of ZnO and ZnO-Au composite nanostructures for nanoscale UV emission." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/114126/9/Sarah_Walden_Thesis.pdf.
Повний текст джерелаMa, Yu. "Effects of TiB2 nanoparticles on the interfacial precipitation and mechanical properties of Al-Zn-Mg-Cu matrix composites." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS252.
Повний текст джерелаThe influences of TiB2 reinforcement nanoparticles (6 wt.%) on the interfacial precipitation of (Zn1.5Cu0.5)Mg phase, the associated tensile and fatigue crack growth (FCG) properties of the Al-Zn-Mg-Cu matrix composites have been studied. The composite samples were produced by in-situ reaction during casting followed by friction stir processing (FSP) and hot extrusion, while only casted and extruded samples were used for evaluating FCG due to size limit of the nugget zone after FSP. Scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and high-resolution scanning transmission electron microscopy (HRSTEM) were employed for the microstructure characterization.The as-processed composite samples contain the fine equiaxed-grain structure, where TiB2 nanoparticles are homogenously distributed. At solid-solution state, the TiB2/Al interfaces are featured by the clean and semi-coherent nature. At the peak-aged and overaged states, the interface precipitate determined as (Zn1.5Cu0.5)Mg phase was formed, and the underlying heterogeneous interfacial precipitation kinetics was discussed. The Al/(Zn1.5Cu0.5)Mg/TiB2 multi-interfaces were revealed to be almost coherent, and the TiB2/Al interfaces were thus strengthened due to the greatly reduced coherency strains. This mechanism was proposed as precipitation assisted interface strengthening, which has contributed to the simultaneously enhanced tensile strength and uniform elongation of the as-processed composite.The majority of TiB2 nanoparticles tend to aggregate along grain boundaries (GBs) in the composite samples without FSP. The FCG rate is increased inside grains at intermediate and high stress intensity factor (ΔK) ranges due to the refined grain size. However, the FCG rate at the GBs is decreased at the low and intermediate ΔK ranges by fatigue crack deflection and trapping due to the presence of TiB2 clusters, while it increases at the high ΔK range due to microvoid coalescence
D'britto, V. "Synthesis of metal nanoparticles and polymer/metal nanoparticle composites: investigation towards biological applications." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2010. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3716.
Повний текст джерелаLee, Tung Chun. "Cucurbit[n]uril-metal nanoparticle composites." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610335.
Повний текст джерелаFlügel, Clemens. "Anorganisch-organische Kompositmaterialien auf Basis von Metallfluoriden." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2016. http://dx.doi.org/10.18452/17549.
Повний текст джерелаThe development of new transparent materials by combination of organic polymers and inorganic fillers was investigated. The fluorolytic sol-gel process was used to prepare fluorine containing nanoscopic inorganic fillers with magnesium, zirconium and titanium as metal components. The preparation and drying methods for the synthesis of xerogels was varied and optimized. Characterization of the metal fluoride sols and the nanoparticles obtained from the sols was executed by NMR and IR spectroscopy as well as SAXS and TEM measurements and elemental analysis. To achieve homogeneous miscibility for the inorganic fillers with the organic polymer matrix modification of the particles’ surface is crucial. This was achieved by covalent attachment of carbon acids; in case of fluorine polymers perfluorinated carbon acids were used. The progress of surface modification and the properties of the modified nanoparticles were monitored by NMR and IR spectroscopy. Based on thermal analysis, thermal stability of the modified nanoparticles was investigated. The modified metal fluoride nanoparticles were introduced into transparent and for industrial applications relevant polymer matrices. A homogeneous distribution to transparent nano composite materials was observed. The alteration of mechanical and thermal properties of the new materials was investigated by DSC, tension tests and nanoindentation and compared with the unmodified pure polymers. Another field of application of these nanoparticles is their application on electrode materials with the aim to improve electrode lifetime and to achieve a better performance of rechargeable batteries.
Martens, Sladana [Verfasser]. "Ultrasound supported electrodeposition of metals and preparation of metal/ceramic composites, colloidal nanoparticles and oxide materials / Sladana Martens." Clausthal-Zellerfeld : Universitätsbibliothek Clausthal, 2012. http://d-nb.info/102166779X/34.
Повний текст джерелаMirza, Nasiri Nooshin Mirza. "Novel Metal-Containing Nanoparticle Composites for Cancer Therapy and Imaging." Thesis, University of North Texas, 2020. https://digital.library.unt.edu/ark:/67531/metadc1707253/.
Повний текст джерелаAnyaogu, Kelechi Chigboo. "Stabilized Metal Nanoparticle-Polymer Composites: Preparation, Characterization and Potential Applications." Bowling Green State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1222126708.
Повний текст джерелаLiang, Wenfeng. "Metal Organic Composites Derived Tin Dioxide/C Nanoparticles For Sodium-Ion Battery." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1460304081.
Повний текст джерелаGlatzel, Stefan. "Cellulose based transition metal nano-composites : structuring and development." Phd thesis, Universität Potsdam, 2013. http://opus.kobv.de/ubp/volltexte/2013/6467/.
Повний текст джерелаDie vorliegende Arbeit beschäftigt sich mit der Synthese und Strukturierung von Nanokompositen, d.h. mit ausgedehnten Strukturen, welche Nanopartikel enthalten. Im Zuge der Arbeit wurde der Mechanismus der katalytischen Graphitisierung, ein Prozess, bei dem ungeordneter Kohlenstoff durch metallische Nanopartikel in geordneten (graphitischen) Kohlenstoff überführt wird, aufgeklärt. Dies wurde exemplarisch am Beispiel von Zellulose und Eisen durchgeführt. Die untersuchte Synthese erfolgte durch das Lösen eines Eisensalzes in Wasser und die anschließende Zugabe von so viel Zellulose, dass das die gesamte Eisensalzlösung aufgenommen wurde. Die so erhaltene Mischung wurde anschließend unter Schutzgas innerhalb kürzester Zeit auf 800 °C erhitzt. Hierbei zeigte sich, dass zu Beginn der Reaktion Eisenoxidnanopartikel (Rost) auf der Oberfläche der Zellulose entstehen. Beim weiteren Erhöhen der Temperatur werden diese Partikel zu Eisenpartikeln umgewandelt. Diese lösen dann kleine Bereiche der Zellulose auf, wandeln sich in Eisenkarbid um und scheiden graphitischen Kohlenstoff ab. Nach der Reaktion sind die Zellulosefasern porös, jedoch bleibt ihre Faserstruktur vollkommen erhalten. Dies konnte am Beispiel eines Origamikranichs gezeigt werden, welcher nach dem Erhitzen zwar seine Farbe von Weiß zu Schwarz verändert hatte, ansonsten aber seine Form vollkommen beibehält. Aufgrund der eingebetteten Eisenkarbid Nanopartikel war der Kranich außerdem hochgradig magnetisch. Basierend auf dieser Technik wurden außerdem winzige metallische Nanopartikel aus Nickel, Nickel-Palladium, Nickel-Eisen, Kobalt, Kobalt-Eisen und Kupfer, sowie Partikel aus den Verbundkarbiden Eisen-Mangan-Karbid und Eisen-Wolfram-Karbid, jeweils in verschiedenen Mischungsverhältnissen, hergestellt und analysiert. Da die Vorstufe der Reaktion flüssig ist, konnte diese mit Hilfe eines einfachen kommerziellen Tintenstrahldruckers strukturiert auf Zellulosepapier aufgebracht werden. Dies ermöglicht gezielt Leiterbahnen, bestehend aus graphitisiertem Kohlenstoff, in ansonsten ungeordnetem (amorphen) Kohlenstoff zu erzeugen. Diese Methode wurde anschließend auf Systeme mit mehreren Metallen übertragen. Hierbei wurde die Tatsache, dass moderne Drucker vier Tintenpatronen beherbergen, ausgenutzt um Nanopartikel mit beliebigen Mischungsverhältnisse von Metallen zu erzeugen. Dieser Ansatz hat potentiell weitreichende Auswirkungen im Feld der Katalyse, da hiermit hunderte oder gar tausende Mischungen simultan erzeugt und getestet werden können. Daraus würden sich große Zeiteinsparungen (Tage anstelle von Monaten) bei der Entwicklung neuer Katalysatoren ergeben. Der letzte Teil der Arbeit beschäftigt sich mit der umweltfreundlichen Synthese der obengenannten Komposite. Hierbei wurden erfolgreich Altmetall und Holzstücke als Ausgangstoffe verwandt. Zusätzlich wurde gezeigt, dass die gesamte Synthese ohne Verwendung von hochentwickeltem Equipment durchgeführt werden kann. Dazu wurde eine sogenannte Fresnel-Linse genutzt um Sonnenlicht zu bündeln und damit direkt die Reaktionsmischung auf die benötigten 800 °C zu erhitzen. Weiterhin wurde ein selbst gebauter Glasreaktor eingesetzt und gezeigt, wie das entstehende Produkt als Abwasserfilter genutzt werden kann. Die Kombination dieser Ergebnisse bedeutet, dass dieses System sich beispielsweise zum Einsatz in Katastrophenregionen eignen würde, um ohne Strom und besondere Ausrüstung vor Ort Wasserfilter herzustellen.
Das, Gupta Tapajyoti. "Study of electrical and optical properties of metal dielectric nano-composite near percolation threshold." Palaiseau, Ecole polytechnique, 2015. http://www.theses.fr/2015EPXX0085.
Повний текст джерелаYazdi, Amirali. "Nanoengineering composites made of metal- and covalent- organic frameworks and inorganic nanoparticles using encapsulation techniques." Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/666772.
Повний текст джерелаThe present PhD Thesis has been dedicated to the design and synthesis of a new type of composites of metal-organic frameworks (MOFs) or covalent-organic frameworks (COFs) with inorganic nanoparticles (iNPs) and the use of these composites for heterogeneous catalysis. In the first chapter, we introduce the family of composites made by supporting iNPs on/in different materials, focusing on those constructed with MOFs and COFs. Then, the general objectives of the Thesis are described in Chapter 2. Chapter 3 shows the results in “The influence of the MOF shell thickness on the catalytic performance of composites made of inorganic (hollow) nanoparticles encapsulated into MOFs”, Catalysis Science & Technology (2016). Herein, we report the encapsulation of hollow Pt or Pd nanoparticles (NPs) into ZIF-8, making a series of composites in which the ZIF-8 shell thickness has been systematically varied. By using these composites as catalysts for the reduction of 4-nitrophenol and Eosin Y, we show that the MOF shell thickness plays a key role in the catalytic performance of this class of composites. In Chapter 4, hybrid core-shell Au/CeO2 NPs dispersed in UiO-66 shaped into microspherical beads are created using the spray-drying continuous-flow method. The combined catalytic properties of nanocrystalline CeO2 and Au in a single particle and the support and protective function of porous UiO-66 beads make the resulting composites show good performances as catalysts for CO oxidation (T50 = 72 °C; T100 = 100 °C) and recyclability. The results are included in the manuscript entitled “Core-shell Au/CeO2 nanoparticles supported in UiO-66 beads exhibiting full CO conversion at 100 °C”, Journal of Materials Chemistry A (2017). Finally, in Chapter 5, we demonstrated a two-step method that enables imparting new functionalities to COFs by nanoparticle confinement. The direct reaction between 1,3,5-tris(4-aminophenyl)benzene and 1,3,5-benzenetricarbaldehyde in the presence of a variety of metallic/metal-oxide nanoparticles resulted in the embedding of the nanoparticles in amorphous and nonporous imine-linked polymer organic spheres. Post-treatment reactions of these polymers with acetic acid under reflux led to crystalline and porous imine-based COF- hybrid spheres. Interestingly, porous imine-based COF-hybrids with Au and Pd NPs were found to be catalytically active. These results have been reported in the publication entitled “Confining Functional Nanoparticles into Colloidal Imine-Based COF Spheres by a Sequential Encapsulation-Crystallization Method”. Chemistry a European Journal (2017).
VU, YEN THI. "SYNTHESIS AND CHARACTERIZATION OF ELASTOMER-BASED COMPOSITES AND POLYMER-IMMOBILIZED COLLOIDAL TRANSITION METAL NANOPARTICLES: CATALYTIC SELECTIVITY AND MORPHOLOGY." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1004541836.
Повний текст джерелаLee, Jung-Hyun. "Interface engineering in zeolite-polymer and metal-polymer hybrid materials." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37120.
Повний текст джерелаGentile, Antonella. "Structural and optical properties of complex-morphology materials based on metal nanostructures." Doctoral thesis, Università di Catania, 2015. http://hdl.handle.net/10761/3886.
Повний текст джерелаNegroni, Matteo. "Studio e sviluppo di tecniche per la produzione di nanocompositi a matrice di alluminio." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/4949/.
Повний текст джерелаUpadhyay, Prabhat Kumar. "Design, Synthesis, and Characterization of Aqueous Polymeric Hybrid Composites and Nanomaterials of Platinum(II) and Gold(I) Phosphorescent Complexes for Sensing and Biomedical Applications." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc822788/.
Повний текст джерелаRoosz, Nicolas. "Elaboration de particules composites silice-polyaniline en vue d'applications environnementales." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCD083/document.
Повний текст джерелаOrganic/inorganic hybrid materials have received much attention in recent years such as in the field of nano-materials. Indeed, these materials possess unique physical and chemical properties due to the synergistic effect of both components. In particular, silica nanoparticles (SiO2) present interesting properties, such as good chemical and thermal stabilities. They can be prepared in different size and can be easily chemically modified. Intrinsically conducting polymers such as polythiophene and polyaniline (PANI) can exist in different oxidation states and respond to external stimuli by changing one of their characteristics (color, conductivity, …). PANI is a non-toxic, thermally stable and low cost polymer with relatively high conductivity that has been used as antistatic coating, electrode materials, corrosion inhibitor and active layer of sensors. Since the discovery of conducting polymer in 1977, several works have been carried out on the preparation, characterization and applications of polymeric films build on various surfaces like silica. Among the different kinds of composites that exist, inorganic-polymer core-shell nanoparticles are more promising candidates. In this study, we decided to work on the synthesis of core@shell hybrid compounds based on PANI shells and silica nanoparticles cores.In the literature, using similar experimental protocols, two morphologies have been obtained after chemical polymerization of aniline in the presence of silica particles: core@shell and raspberry (inverted structure with PANI as core). We thus decided to reinvestigate the synthesis of PANI in the presence of silica particles. For this, we first synthesized silica particles with different sizes by Stöber process. We then performed the chemical polymerization of aniline in the presence of these naked silica particles under different conditions: temperature, concentration of reactive. However, in all cases, we never managed to obtain core@shell structures. Finally, we succeed in developing a method to prepare these core@shell particles which relies on the functionalization of the SiO2 by alkoxysilanes followed by the polymerization of aniline at room temperature. A series of core-shell particles with tunable PANI thickness has been prepared by this method. The last part of this work deals with the first tests that have been carried out in order to use these composites SiO2@PANi for environmental applications. Two applications have been considered, the adsorption of metals for the particle appearance and the detection of gas for the conductive capacities of the PANI
M'Nasri, Najib. "Elaboration de nanomatériaux composites métal@nanoparticules de silice mésoporeuses (MSN) : étude des performances catalytiques en phase aqueuse et des propriétés d'adsorption sélective du diiode en phase gaz." Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20199.
Повний текст джерелаThe objective of this thesis was to develop efficient synthesis routes to prepare mesoporous silica-based nano-sized particles, designated as MSN, with controllable morphology and derivatised with selected transition metals. One-pot preparation and surface functionalisation procedures based on the insertion of the metal-phase precursor into the porogen aggregates were thoroughly optimised leading to silica particles containing such single metals as copper, palladium, platinum, silver or gold, as well as a two-metal phase of copper and palladium or that of palladium and platinum. It was demonstrated that the highly dispersed metal phase was localised on the pore surface and therefore it was readily accessible to the target chemicals on which to base the catalytic performance of the resulting materials. Among others, the remarkable catalytic performance of the Cu@MSN material in Huisgen and Sonogashira reactions and its propensity to undergo efficient recycling were proven through laboratory-scale testing. Experimental study of the selective adsorption of iodine vapour onto MSN supports functionalised with silver nanoparticles indicated an excellent retention capacity of such materials
MIGLIORINI, LORENZO. "DEVELOPMENT OF FUNCTIONAL NANOCOMPOSITE MATERIALS TOWARDS BIODEGRADABLE SOFT ROBOTICS AND FLEXIBLE ELECTRONICS." Doctoral thesis, Università degli Studi di Milano, 2020. http://hdl.handle.net/2434/704286.
Повний текст джерелаTeixeira, Fernanda de Sá. "Implantação iônica de baixa energia em polímero para desenvolvimento de camadas compósitas nanoestruturadas condutoras litografáveis." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-23082010-103839/.
Повний текст джерелаElectronics using polymers instead of silicon is a recent research area with promising economic perspectives. Polymer with metallic particles composites presents interesting electrical, magnetic and optical properties and they have been produced by a broad variety of techniques. Metal ion implantation using plasma is one of the used methods to obtain conductor composites. In this work it is performed low energy gold ion implantation in PMMA by using plasma. PMMA has great technological importance once it is broadly used as resist in electron-beam, X-ray, ion and deep UV lithography. As a result of low energy ion implantation in PMMA, a nanometric conducting layer is formed. This new material, named insulator-conductor composite, can allow the creation of micro and nanodevices through well known microelectronics techniques. Electrical measurements are performed in situ as a function of metal ions implanted dose, which allows the investigation of electrical transport of these new materials, which can be modeled by the percolation theory. Simulations using TRIDYN computer code provide the prediction of depth profile of implanted ions. Important characterizations are showed such as Transmission Electron Microscopy, Scanning Tunneling Microscopy, Small Angle X-Ray Scattering, X-Ray Diffraction and UV-vis Spectroscopy. These techniques allow to visualize and to investigate the nanostructured character of the metal-polymer composite. Still as a part of this project, the conducting layers formed are characterized in relation to the maintenance of their characteristics as electron-beam resist.
Wu, Szu-Han, and 吳思翰. "Prepartion of Metal Nanoparticles and Core-Shell Composite Nanoparticles." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/zrs289.
Повний текст джерела國立成功大學
化學工程學系碩博士班
92
This dissertation concerns the preparation of metal nanoparticles and core-shell composite nanoparticles. In the former, nickel and copper nanoparticles have been prepared in ethylene glycol and aqueous surfactant systems. The preparation conditions and product properties were investigated. In the latter, Ni@Au core-shell composites nanoparticles were prepared in ethylene glycol system and covalently bound with methotrexate (MTX). In ethylene glycol system containing trace bases, Ni nanoparticles could be prepared by hydrazine reduction without the input of extra inert gases and the addition of protective agent. FTIR analysis revealed the formation of a protective layer from ethylene glycol and the Ni-catalyzed decomposition products, which prevented from the agglomeration of particles. The TEM, high-resolution TEM, XRD, electron diffraction pattern, magnetic analyses indicated the resultant particles were pure Ni nanoparticles with the mean diameter of 6-9 nm, fcc structure, and superparamagnetic property. With increasing N2H5OH concentration, The mean diameter decreased and approached a constant when [N2H5OH]/[NiCl2]>20. In addition, hydrazine was catalytically decomposed to hydrogen and nitrogen gases by the resultant Ni nanoparticles. The decomposition rate was 3.1 nmol/h mg Ni at 1 atm and 25℃. In a pure aqueous CTAB solution containing trace bases, Ni nanoparticles could be prepared by hydrazine reduction without the input of extra inert gases. the synthesis of nickel nanoparticles without inert gases was studied. TGA study suggested the formation of a bi-layer structure on particle surface, which prevented from the agglomeration of particles. The TEM, high-resolution TEM, XRD, electron diffraction pattern, magnetic analyses indicated the resultant particles were pure Ni nanoparticles with mean diameters of 10-14 nm, fcc structure, and a superparamagnetic property. With increasing N2H5OH concentration, the mean diameter decreased and approached a constant when [N2H5OH]/[NiCl2]>20. In a pure aqueous CTAB solution, Cu nanoparticles could be prepared by hydrazine reduction without the input of extra inert gases. The key point was the use of ammonia solution to adjust the solution pH up to 10. The concentration of Cu2+ ions allowable was as high as 0.2 M. TGA study suggested the formation of a bi-layer structure on particle surface, which prevented from the agglomeration of particles. The TEM, XRD, electron diffraction pattern, UV-VIS spectrum, and XPS analyses indicated the resultant particles were pure Cu nanoparticles with mean diameter of 5-15 nm and fcc structure. With increasing N2H5OH concentration, the mean diameter decreased and approached a constant when [N2H5OH]/[NiCl2]>40. In ethylene glycol, Ni@Au core-shell composites nanoparticles were prepared. In the absence of protective agent, particle agglomeration was observed. In the presence of polyethyleneimine (PEI) as a protective agent, monodisperse Ni@Au composite nanoparticles with a mean diameter of 14.6 nm were obtained. After surface modification, Ni@Au composite nanoparticles were covalently bound with methotrexate (MTX). Averagely 3.63×104 MTX molecules could be bound on each Ni@Au composite nanoparticle.
Tsao, Shao Hsuan, and 曹卲喧. "Silk Fibroin/Metal Nanoparticles Composite in Biomedical and Photoelectric Applications." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/58663679790622378121.
Повний текст джерелаHuang, Guo-Cheng, and 黃國誠. "Synthesis and Characterization of Composite Consisting of Metal Nanoparticles and Conducting Polymers." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/69799259602035184817.
Повний текст джерела國立成功大學
化學工程學系碩博士班
94
Abstract The main objective of the present investigation is to synthesize and characterize the nanocomposites consisting of metal particles and conducting polymers. Aniline or 2,5-dimethoxyaniline(DMA) is used as monomer. AgNO3, CH3SO3Ag or H2PtCl6 is used as oxidant or precursor of metal. First, PDMA-Ag composite is successfully obtained by oxidative polymerization of DMA in poly(styrene sulfonic acid)(PSS) using AgNO3 or CH3SO3Ag as oxidant. In-situ UV-Vible spectroscopy results show that the growth rate of PDMA is strongly affected by NO3 - and CH3SO3 -. The coupling reaction of PDMA and NO3 – was proposed to explain the lower growth rate of PDMA and by using AgNO3 than CH3SO3Ag as oxidant. X-ray photoelectron spectroscopy and FTIR spectroscopy were used to validate the proposed coupling reaction by monitoring the side product and oxidant state of PDMA. The results show that there are more side products and lower oxidized states for the composite structure in the presence of NO3 – than CH3SO3 -, being agreeable to the proposal. Transmission electron microscopy shows that Ag nanoparticles have almost the same size irrespective of anions. Second, composite consisting of Ag or Pt particles and polyaniline nanofibers is successfully obtained by interfacial polymerization and illuminate UV light. CH3SO3Ag or H2PtCl6 is used as precursor of metal. Transmission electron microscopy shows that the polyaniline nanofibers are about 10~40 nm, Ag or Pt particles are about 5~10 nm. Nanocomposites are characterize by FTIR spectroscopy and Thermal Gravimetric Analysis. The result show that the oxidized states almost the same size irrespective of oxidant or precursors of metals. And nanocomposites are more thermal stable than polyaniline nanofibers. The composite consisting of Pt particles can also use as catalyst to oxidant methanol.
Pei-HanLiao and 廖佩涵. "The Synthesis and SERS Applications of Noble Metal Nanoparticles@Mesoporous Silica Composite Materials." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/73726336721335609062.
Повний текст джерела國立成功大學
化學系碩博士班
98
Green chemistry has received considerable attention in recent years, using benign nature sources as reagents to synthesize practical materials have become more ideal. Gelatin a natural polymer is denatured collagen. Due to many amino-functional groups, gelatin can attach to surface of different materials via hydrogen bonds that makes gelatin a superior protector. Most important, gelatin is a nontoxic, highly biocompatible and low cost reagent, which demonstrates its promising applications in materials synthesis. From our previous reports, mesoporous silicas were facilely prepared by using gelatin as organic templates and sodium silicate as silica precursor at proper pH. In this study, we also use the gelatin as a protecting agent for nanoparticles. With similar synthetic procedures, the mesoporous silica containing different metal nanoparticles and silver halides were prepared. In addition, gelatin can also be used as template to get high-yield mesoporous silica spheres in a narrow particle-size distribution under a environmental friendly synthetic condition. In practical applications, the mesoporous silicas containing gold and platinum nanoparticles were used in the surface enhanced Raman scattering (SERS) applications. The mesoporous silicas containing silver halide nanoparticles is able to be potential photo-catalyst. The highly dispersed silica spheres displayed photonic crystal characters.
Sangar, Saurabh Kumar. "Gas phase synthesis, structral and electronic properties of size selected Pd-alloy and metal-graphene composite nanoparticles." Thesis, 2014. http://localhost:8080/iit/handle/2074/6604.
Повний текст джерелаRapecki, Tomasz. "Galwaniczne wytwarzanie nanostrukturalnych kompozytów polimer przewodzący-metal." Doctoral thesis, 2015. https://depotuw.ceon.pl/handle/item/988.
Повний текст джерелаThe main objective of the study was to develop improved galvanic methods of preparation of the composites containing conductive polymers and metal nanoparticles. The other important scientific aim was to clarify the mechanism of the formation of metal crystallites on the surface of the conducting polymer layers. To date the greatest control of the composition of the produced materials was obtained by depositing the polymer and metal from separate solutions. That is why one of the scheduled tasks was to develop a current-controlled method of synthesis of the composites allowing the formation of the materials with desired content of polymer and metal using only one plating solution. This was achieved for the electrodeposition of PPy-Au composite. Special attention was paid to the studies of the mechanism of formation of the metallic phase on the polymer layers, since contradictory reports exist in the literature on the location of nucleation of metals on porous polymer layers. In the presented work detailed studies of nucleation of metals on polymer films were performed. The obtained results were confronted with the literature data. Other important aspect of performed investigations was to describe the influence of electrochemical activity of the electrode surface on the mechanism and rate of the nucleation process. In recent years in the literature some reports appeared on the partial deactivation of the surface of precious metals as a result of free radicals attack. This became the inspiration for examining the nucleation of metals on the substrates treated with radicals. The first thesis chapter contains an introduction to the subject of the research and presentation of the main objectives that have been formulated and realized in the course of carried out research work. In the second chapter, the issues related with the conductive polymers-metal composites are introduced. This part describes the most important properties of conducting polymers, nanoparticles of metals and composite materials and outlines the most interesting areas of their potential application. This chapter also presents the most commonly used electroless and current methods used for preparation of composites containing conductive polymers and metal nanoparticles. The third chapter is devoted to topics related to the process of nucleation of metals on solid substrates. It presents two models describing the mechanism of formation and growth of metal nuclei on a flat surface: Scharifker-Hills model and Scharifker-Mostany model. They are the most commonly used models in electroplating. It also indicates often encountered problems associated with their practical use. The influence of such factors like temperature, overpotential and quality of the substrate on the metal deposition process is also discussed here. Finally, the critical analysis of described in the literature few attempts to apply the above models to characterize the nucleation of metals on the polymer layers is presented. The fourth chapter describes the phenomena related to the influence of free radicals on the activity of metals commonly used as electrode materials. The presented results include chemical analysis and changes of electrocatalytic properties of various materials. It also indicates the areas of potential application of composite layers in which these materials may be exposed to the aggressive environment containing radicals. Finally it presents popular methods of obtaining free radicals under laboratory conditions. In fifth chapter, a list of chemicals used in the work and the description of the apparatus used in the electrodeposition and characteristics of composites containing a conducting polymer and metal are presented. It also presents a brief description of experimental methods used in the laboratory work. The obtained experimental results are presented in chapter sixth, seventh and eighth. Chapter sixth presents the results of the studies on the mechanism of electrochemical deposition of metals on thin porous polymer layers. The measurements were carried out for two systems: polypyrrole-silver and polypyrrole-gold. The first part of the chapter describes developed in the course of the work a reproducible procedure for obtaining and conditioning the PPy layers. Its application allowed to eliminate the phenomenon of uncontrolled electroless deposition of silver on the polymer and allowed a reliable analysis of the process of silver nucleation on polypyrrole. The identification of the place of formation of metal deposited on porous layers of well-conductive form of the polymer was done on the basis of the results of a detailed SEM analysis of Ag and Au deposited on polypyrrole layers at different potentials. Moreover, the correlation between the overpotential of reduction of metal ions and place of the formation of the metal nuclei was analyzed. A graphical model illustrating the process of the formation of the metallic phase on the polymer layers was proposed. The sixth chapter also presents a new method for electrodeposition of the conducting polymer-metal composites, allowing the formation of materials of any content of the two components using one solution. The idea of the proposed method was the use of strong inert complexes of the metal ion such as Au(CN)_2^- what allowed obtaining a stable solution containing both pyrrole and metal ions. The different potential ranges corresponding to the reactions of electro-polymerization and deposition of gold allow avoiding the redox reaction between the noble metal ion and the monomer. Finally the independent deposition of polymer and metal on the electrode surface was possible. During the optimization of the deposition procedure it has been shown that the use of pulse technique for the electrodeposition of PPy-Au layers significantly increased the homogeneity of the obtained materials. The seventh chapter presents the results of research on the process of nucleation of silver on metal (gold, platinum) and glassy carbon, all treated with free radicals generated in the Fenton reaction. It was observed that the density of nucleation of metal on each of the substrates, measured using electrochemical methods and SEM, decreased with prolongation of the contact of substrates with OH˙ radicals. This dependence indicated the decrease in the activity of metals and glassy carbon surfaces treated with radicals, as well as the inability to use the radicals to improve the metal deposition process on those substrates. The results obtained were compared with those on the processes of nucleation of the metal on the polymer layers etched with radicals. In this case OH˙ radicals activated the surface and the nucleation process was accelerated. In the eighth chapter, the results of studies aimed at determining the effect of free radicals on the structure and catalytic properties of polypyrrole-gold composite are presented. The currents of ethanol oxidation were recorded using the composite layers treated with Fenton solution for various time. It revealed that the activity of these materials decreases with increasing time of contact with the radicals. The cause of the deterioration of the catalytic properties of PPy-Au layers was the successive etching of the surface of gold crystallites by the radicals. However, it was found that the presence of a PPy layer on the electrode limited the deactivation of gold nanostructures. Furthermore, this chapter describes a novel method for electrochemical preparation of composites containing conductive polymer and metal. The proposed method involves the deposition of a metal on the surface of polymer films pre-treated with Fenton solution. The analysis of the process of nucleation of silver on the polymer substrates etched with the radicals indicated an increase in number of the active sites on the polymer surface. In the case of PPy-Au composites produced by this method, smaller and more uniform metal crystallites were obtained. But most importantly, the walls of gold crystals deposited on PPy layers exposed to the radicals for a short time showed an increased presence of the different nanostructures. This resulted in better catalytic properties of the composites. The thesis ends with a summary and a list of references.
"Synthesis and characterization of novel proton-conductive composite membranes derived from the hybridization of metal oxyhydroxide nanoparticles and organic polymers for fuel cell applications." Diss., 2010. http://hdl.handle.net/10161/2504.
Повний текст джерелаKumar, Sachin B. "Engineering Bioactive And Multifunctional Graphene Polymer Composites for Bone Tissue Regeneration." Thesis, 2016. http://etd.iisc.ac.in/handle/2005/2684.
Повний текст джерелаKumar, Sachin B. "Engineering Bioactive And Multifunctional Graphene Polymer Composites for Bone Tissue Regeneration." Thesis, 2016. http://etd.iisc.ernet.in/handle/2005/2684.
Повний текст джерелаLee, Jer-yeu, and 李哲宇. "Synthesis and applications of metal nanoparticle graphene compostive." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/77935720624707123100.
Повний текст джерела國立中央大學
化學研究所
98
To increase the solubility of graphene in water, we modified the graphene skeleton with sulfonyl groups. With hydrazine as the reducing agent, SB12 as the surfactant in the aqueous phase, platinum and palladium nanoparticles were produced on the graphene plane skeletons, separating the graphene layers. Sample 1 has 56 wt% Pt, with average of metal particle size of 83.2 nm; sample 2 has 14 wt% Pt, with particle size of 27.3 nm; sample 3 has 32 wt% Pd, with particle size of 2.4 nm, and sample 4 has 16 wt% Pd, with particle size of 8.9 nm. Towards hydrogen storage applications, sample 3 performs the best. Under 510 psi hydrogen pressure, the hydrogen uptake reaches 2.19 wt%. The samples 1~4, when used in catalytic hydrogenation of styrene, all gave better than results commercial catalysts. For samples 1、2, they are better than the commercial Pt / C; and for samples 3、4, they are better than the commercial Pd / C. Ionic liquid [HOCH2CH2NH3][HCO2] was used as a solvent, as a reducing agent, and also as a surfactant, converting Pt metal source to Pt nanoparticles under microwave heating conduction. Following are the characteristics of Pt nanoparticles formed on the plane of graphite oxide and graphene. Sample 5 is on the graphene substrate, with Pt 62 wt%, and the average metal particle size of 5.0 nm, sample 7 on the graphite oxide substrate, with Pt 40 wt%, and the average metal particle size of 18.8 nm, and sample 8 on the graphite oxide substrate, containing Pt 1 wt%, and the average metal particle size of 4.7 nm. Samples 5, 7~8 were seen to have a very special cubic shape. Pt nanoparticles in sample 6 on the graphene substrate, with Pt 13 wt%, and the average metal particle size of 14.6 nm were in multiply truncated cubic shape. The rationale is that the ratio between the concentration of reducing agent and that of metal source is too large under the reaction condition, and the formation and the stacking of metal become too fast to grow to crystals properly in a cubic shape. Sample 8 still formed a cubic shaped nanoparticles, presumably that graphite oxide is rich with the oxygen functionalities which regulate the seeding and growth of the Pt nanoparticles in proximity. Sample 5 and 6 were used in the catalytic hydrogenation of styrene. Better results were obtained for 5 and 6 when compared with that of commercial Pt / C.
Das, Barun. "Investigations Of Graphene, Noble Metal Nanoparticles And Related Nanomaterials." Thesis, 2011. https://etd.iisc.ac.in/handle/2005/2432.
Повний текст джерелаDas, Barun. "Investigations Of Graphene, Noble Metal Nanoparticles And Related Nanomaterials." Thesis, 2011. http://hdl.handle.net/2005/2432.
Повний текст джерелаYu, Ya-Han, and 游雅涵. "Preparation and characterization of DNA-metal nanoparticle composite and its application in solar cells." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/99502245462474825840.
Повний текст джерелаLee, Hsin-Fang, and 李欣芳. "Metalloporphyrins and Metal Nanoparticles Decorated Reduced Graphene Oxide Composites for Application in Electrocatalytic Reaction." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/8rrju4.
Повний текст джерела國立臺北科技大學
化學工程研究所
104
In this work, we used metal nanoparticles with metalloporphyrins decorated reduced graphene oxide composite modified electrode for the electrocatalytic reaction. Considering the nanoparticles, we used that a single step electrochemical fabrication of a PtNPs decorated RGO (RGO-PtNPs) composite for enhanced electrochemical sensing of H2O2 .The fabricated composite modified electrode was further characterized by CV and amperometry methods (i-t) .The amperometric response of the RGO–PtNPs composite modified electrode for the reduction of H2O2 was linear over the concentration ranging from 0.05 μM to 750.6 μM with the limit of detection of 0.016 μM. The sensitivity of the sensor was calculated as 0.686 ±0.072 μM mM-1 cm-2. On the other hand, the metalloporphyrins decorated RGO for the application. RGO supported Mn-TPP nanocomposite was electrochemically synthesized and used for the highly selective and sensitive detection of DA. Besides, the prepared RGO/Mn-TPP nanocomposite modified electrode exhibited an enhanced electrochemical response to DA with less oxidation potential and enhanced response current. The working linear range of the electrode was observed from 0.3 μM - 188.8 μM, the limit of detection was 0.008 μM and the sensitivity was 2.606 μA μM-1 cm-2. In addition, we also reported the preparation and catalytic properties of RGO/Pd-TPP composite modified electrode. The ORR was studied by CV, and LSV. The modified nanocomposite was compared with the commercially purchased Pt/C electrode and shows that the current density was higher than that of the Pt/C electrode with less methanol hindrance. In addition, the prepared composite modified electrode was characterized by the SEM, EIS, NMR, UV, XRD, Infrared Spectroscopic and elemental analysis.
LIN, PEI-HUNG, and 林沛鴻. "Development of metal nanoparticle composites combined with carbon/metal substrate materials for electrochemical analysis and electrical energy storage." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/5ydu7m.
Повний текст джерела國立臺北科技大學
化學工程與生物科技系化學工程碩士班
107
Part 1 Methyl paraoxon (MOX) is a highly toxic organophosphate pesticide. It is recently reported that, MOX can enter the human body through ingestion, inhalation, or by dermal penetration. Due to its high non-degradability, it can bind to the tissues of fruits and vegetables. When it is consumed, it can imposes sub-chronic and chronic diseases, by the inhibition of acetylcholinesterase in human metabolism. Therefore, for the first time, we reported a detection of non-enzymatic electrochemical sensor based on 3D porous phase graphene oxide sheets encapsulated chalcopyrite (GOS@CuFeS2) nanocomposite. Hence, the development of reliable sensors for the real-time detection of pesticides is imperative to overcome practical limitations encountered in conventional methodologies. As synthesized GOS@CuFeS2 nanocomposite film screen-printed carbon modified electrode (SPCE) displays excellent electrocatalytic ability towards MOX. Under optimized working conditions, the modified electrode provides linear response range from 0.073 to 801.5 μM. The detection limit was obtained as 4.5 nM. The sensor displayed outstanding sensitivity as 17.97 µA µM–1 cm–2. This composite could be a promising electrode modifier for electrocatalysis. Finally, the GOS@CuFeS2 nanocomposite modified electrode shows greater real-time practicality in vegetable real samples. The obtained moral parameters from the developed method were compared with the authenticated HPLC results. Part 2 At present, B/N co-doped mesoporous carbon (BNDC) have been synthesized in one-step and employed for high sensitive electrochemical detection of Isoniazid (INZ). The synthetic procedure was simple and produced homogenous doping of heteroatoms with high elemental purity, and mesoporous surface. Further, the surface and physiochemical properties of synthesized BNDC was analysis by Nitrogen (N2) adsorption-desorption analysis, and spectroscopic studies. A high sensitive amperometric sensor of BNDC film modified electrode, towards INZ, delivered superior analytical performance with a broad dynamic range 0.02–1783 µM and detection limit of 1.5 nM. Excellency of electrochemical sensor can be attributed to the large surface area, low pore size, abundant active sites, and enhanced electrical conductivity of synthesized BNDC electrocatalyst. Furthermore, the excellent chemical stability of BNDC advocate the long-term stability and reproducibility of the fabricated electrochemical assay. The practical applicability of the proposed sensor was assessed by detection of INZ in physiological fluids. Part 3 The world’s largest aluminium producer has publicized that will blockout aluminum production all over the country from November 2018 to March 2019, in order to minimize winter air pollution. Presumably, these sort of reports urge the chemists to perceive that recovery or recycle of aluminum is decisive. In this article, our group has recovered aluminium oxide nanoparticles (Al2O3 NPs) through a facile one-step sonochemical methodology. The morphological details of Al2O3 NPs were examined by FE-SEM and TEM; finally, the purity of as-recovered Al2O3 NPs were confirmed by XPS and XRD. The as-recovered Al2O3 NPs were employed for the specific and sensitive detection of omeprazole (OMZ), which comes under the class of proton-pump inhibitor. Under the well-optimized conditions, the graphically plotted calibration curve was attained at Al2O3 NPs/GCE towards the detection of OMZ, which possesses the wider linear range of 0.025-433.3 µM, with the minimal detection limit of 9.1 nM. Furthermore, the recovered material was employed as an active participant in supercapacitor application, which exhibited an appreciable specific capacitance value (688 F/g) at 1 A/g current density in 1 M KOH and maintained 86% capacitance retention even after 3000 GCD cycles.
Ayinde, Wasiu Babatunde. "Synthesis of biopolymer-metal oxide nanoparticles reinforced composites for fluoride and pathogens removal in groundwater." Thesis, 2019. http://hdl.handle.net/11602/1412.
Повний текст джерелаPhDENV
Groundwater has traditionally been perceived to be low in chemical species toxicity and microbiologically 'pure'. However, depending on the geological chemistry, formations and anthropogenic activities creating the frequent occurrence of microbiological contamination and excess toxic chemical constituents, the high quality of groundwater as a drinking water source can easily be compromised rendering it unsafe, thus, leading to severe waterborne epidemics. The rapid increase in fluoride and microbial contamination of groundwater have become a global problem to human health. Fluoride in its acceptable concentration in drinking water (< 1.5 mg/L); is known to be beneficial for human growth and development but becomes detrimental at higher concentrations (> 1.5 mg/L) leading to the prevalence of dental and crippling skeletal fluorosis. On the other hand, consumption of microbiologically contaminated water has led to many types of diseases including diarrhea, cholera, typhoid, dysentery and other serious illnesses often leading to millions of deaths annually worldwide. South Africa had experienced water-borne diseases epidemic in the recent past due to failing water treatment facilities in many parts of the country including rural areas. Fluorosis, diarrhea, and cholera are among the chronic health hazards affecting a large population in South Africa. Continuous outbreaks of water-related diseases have been at an unimaginable high level with a reported increase in death rate. The inefficiency of conventional water treatment plants to remove fluoride and disinfect these pathogens from the contaminated domestic and rural community has led to the development of many techniques. These include membrane filtration, ion-exchange, coagulation-precipitation, adsorption among others of which adsorption process proves to be a more significant technology for fluoride removal. Equally, the emergence of nanomaterials has also proved to be the natural answer to solve problems associated with microbes in water since these are absolute barriers to pathogens whose size exceeds most sorbent pore sizes. Also, materials from natural biopolymers or biomass can be utilized at an affordable cost as effective sorbent material for toxic chemical ions and pathogens removal from contaminated water. Consequently, extensive research works have been channeled into the development of more advanced low cost sustainable functionalized sorbent materials and technologies with multifunctional properties for effective water purification. The present study focused on the development of a functionalized chitosan-cellulose hybrid nanocomposite decorated with metal-metal oxides nanoparticles for simultaneous fluoride and microbial removal from groundwater. This was to increase the selectivity and disruption of such pollutants for effective groundwater purification technology. The thesis is presented in nine chapters: (1) General introduction, problem statement, and motivation, research objectives, hypothesis and delimitations of the research are briefly discussed, (2) This chapter gives the literature review of occurrence and sources of fluoride, various fluoride removal techniques; sources, control measures and prevention of microbial pollution in groundwater; the importance of biosynthesis of nanomaterials as emerging novel water treatment adsorbents, the strength of Point-Of-Use as a means of water treatment, water treatment adsorbents synthesis and types of adsorbents with emphasis on hydroxyapatites and biopolymeric based sorbent materials, (3) Optimization of microwave-assisted synthesis of silver nanoparticle by Citrus paradisi peel extracts and its application against pathogenic water strain, (4) Biosynthesis of ultrasonically modified Ag-MgO nanocomposite and Its potential for antimicrobial activity, (5) Green synthesis of Ag/MgO nanoparticle modified nanohydroxyapatite and its potential for defluoridation and pathogen removal in groundwater (6) Green Synthesis of AgMgOnHaP nanoparticles supported on Chitosan matrix: defluoridation and antibacterial effects in groundwater, (7) Biosynthesis of nanofibrous cellulose decorated Ag-MgO-nanohydoxyapatite composite for fluoride and bacterial removal in groundwater, (8) Defluoridation and removal of pathogens from groundwater by hybrid vi cross-linked biopolymeric matrix impregnated Ag-MgOnHaP nanocomposite (9) Conclusions and Recommendations. It is important to point out that Chapters 3 to 8 contains a collection of the research deliverables produced in forms of paper publications and manuscripts and are summarized in a systemic order of experimental protocol. This first output (Chapter 3) of this study evaluated the optimization of a time-dependent microwave-assisted biosynthesis of silver nanoparticles using aqueous peel extracts of Citrus paradisi (Grapefruit red) as a reducing, stabilizing and capping agent with emphasis on its antibacterial property. Optical, structural and morphological properties of the synthesized Citrus paradisi peel extract silver nanoparticle (CPAgNp) were characterized using UV-visible spectrophotometer, transmission electron microscope (TEM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), Brunauer–Emmett–Teller (BET) and X-ray diffractometer (XRD). The antimicrobial activity was evaluated using the well- and disc-diffusion as well as microdilution methods. Characteristic surface plasmon resonance (SPR) wavelength in the range of 420-440 nm at an optimized intensity growth rate typical of silver nanoparticles was obtained. Microwave irradiation accelerates the reaction medium within seconds of nucleation compared to conventional heating methods of synthesis. The influence of the reaction mixtures affected the SPR patterns on the different nucleation, stability and nanoparticle growth. The mixing ratio of 2:3 (C. paradisi peel extracts: 1 mM AgNO3) was chosen as the optimum reaction mixing ratio relative to the bio-reduction intensity of SPR process contributing to the particle size growth of CPAgNps. The presence, interaction and shifting of the functional groups in the FT-IR spectra of biosynthesized CPAgNps indicated that bioactive compounds present in C. paradisi peel extract were responsible for the bio-reduction of the silver ion to silver nanoparticles. The electron micrographs of the synthesized CPAgNps showed a face-centered cubic (FCC) unit phase structure, spherically-shaped nanoparticles size of 14.84 ± 5 nm with a BET pore diameter of 14.31 nm. The use of biological material allowed the control of the size and stability of the nanoparticle but was obtained in low quantity. The Citrus paradisi peel extract mediated AgNp were found to possess a broad-spectrum antimicrobial activity against water-borne pathogenic microbes in the order: Escherichia coli > Staphylococcus aureus > Klebsiella pneumonia. In Chapter 4, a synergistic bi-layered Ag-MgO nanocomposite from Ag and MgO precursor salts using a natural source from the waste product (citrus fruits outer cover) as a reducing and capping agent was successfully synthesized by a simple rapid, integrated bio-mediated microwave and ultrasonic methods. This was carried out to investigate the interfacial interaction and the encapsulated growth rate behind their combination in obtaining an enhanced antibacterial activity against common water fecal pathogen (Escherichia coli). The growth sequence, structural and morphology interface as well as the composition of the nanocomposite were examined and evaluated by the different characterization techniques. The respective potential application as an antimicrobial agent was evaluated and compared against Escherichia coli. The bio-mediated core-shell Ag-MgO nanocomposite showed characteristic synergetic UV-visible absorption bands at 290 nm for MgO nanoparticle and at around 440 nm for Ag nanoparticle, which moved to a lower wavelength of 380 nm in the composite. The shifting to a lower wavelength confirmed the reduction in the particle size as influenced by the growth rate optical property of biomolecular capped Ag-MgO nanocomposite from the phytochemical constituents in the peel extract of the Citrus paradisi. FTIR analysis further elaborated the role of the organic moieties in the Citrus paradisi extracts acting as the capping and stabilizing agent in the formation of the core-shell Ag-MgO nanocomposite. SEM analysis revealed an agglomeration of layered clustered particles, which was poly-dispersed while XRD showed the cubical crystal lattice network phase structure of the Ag-MgO nanocomposite. The TEM micrograph vii showed a structurally uniform and spherical biosynthesized Ag-MgO nanocomposite with a diameter of about 20–100 nm with an average particle size of 11.92 nm. The bi-layered Ag-MgO nanocomposite exhibited a higher level broad-spectrum of antibacterial potential on E. coli with 22 mm zone of inhibition and MIC of 20 (μg/mL) in comparison with the Ag (9 mm; 40 μg/mL) and MgO (9 mm; 80 μg/mL) nanoparticles. The leaching and toxicity level of the time-dependent releases of metal ions indicates that the effluents contain a lower concentration of Ag and Mg ions as compared to World Health Organization permissible limit of < 100 ppb (Ag). The biosynthesized Ag-MgO nanocomposite exhibited an enhanced antibacterial activity synergistic effect against E. coli than Ag and MgO nanoparticles, thus, proving to be a potential disinfect material against common pathogens in water treatment. Chapter 5 presented the biosynthesis, characterization, and assessment of simultaneous fluoride and pathogen removal potential in aqueous solutions of a multi-layered Ag-MgO/nanohydroxyapatite (Ag-MgOnHaP) composite. The successful incorporation of Ag-MgO into nanohydroxyapatite (Ag-MgOnHaP) sorbent via an in-situ solution-gelation (sol-gel) method was ascertained from UV-visible absorption spectrum bands at 290 and 440-378 nm typical of MgO and Ag nanoparticles combination in Ag-MgOnHaP composite. FTIR analysis showed the main surface functional groups involved to be –OH, C=N, carbonate and phosphate species on the backbone of Mg-O-Mg vibrational mode. The hydroxyl and amine groups indicated the interaction of a variety of metabolites components present in citrus peel extract as bio-reductive compounds associated with the Ag-MgO and also in fluoride ion exchange. SEM, TEM images and XRD analysis showed a well-dispersed discretely embedded layered-spherical Ag-MgOnHaP nanocomposite without any form of agglomeration after ultrasound exposure ranging in size from 20 to 100 nm with an average mean particle size diameter of 16.44 nm. The high purity of the synthesized Ag-MgOnHaP nanocomposite was confirmed by the presence Ag, Mg and O impregnated on the nanohydroxyapatite template from EDS spectrum analysis. Batch sorption studies using the nanocomposite under different experimental parameters were conducted and optimized. Equilibrium fluoride adsorption capacity of 2.146 mg/g at 298 K was recorded with more than 90% fluoride removal at optimized conditions of 60 min, 10 mg/L initial F- concentration, 0.3 g/L dosage, and pH 6 at 250 rpm. pHpzc of Ag-MgOnHaP nanocomposite was established to be 8. The equilibrium data were best fitted to the Freundlich isotherm model and followed the pseudo-second-order kinetics model at room temperature. The presence of competing anions such as Cl−, NO3−, does not have an impact on percentage fluoride uptake efficiency, but SO42− and CO32− reduce the F- removal efficiency. Moreover, as the concentration of the co-anions increased, fluoride adsorption uptake decreases. The biosynthesized nanohydroxyapatite incorporated Ag/MgO nanoparticle adsorbent (Ag-MgOnHaP) showed strong antibacterial activity against Escherichia coli and Klebsiella pneumonia when compared to hydroxyapatite alone. The presence and interaction between the Ag, MgO nanoparticles with the respective bacterial genomes was suggested to have accounted for this bioactivity. The synthesized Ag-MgOnHaP sorbent was found to portray a better sorption capacity compared to other adsorbents of similar composition in the literature and could be successfully regenerated with 0.01 M NaOH with fluoride removal of 74.24% at the 4th cycle of re-use. The impregnation of metal-metal oxide nanoparticles on sustainable natural biopolymers from waste products was presented in Chapters 6, 7 and 8. The use of these sustainable natural biopolymers (chitosan and cellulose) was targeted with more emphasis on surface functionalization, improved structural diversity and improved specific surface area with the sole aim of increasing the adsorptive capacity of fluoride ions as well as antimicrobial properties. The selected polymers were chosen because of their biodegradability, viii non-toxicity, renewability, selectivity and abundance in nature, which makes them promising starting materials for the purpose of sustainable water treatment. Chapter 6 presents the successful sol-gel biosynthesis, characterization, potential application for fluoride and pathogens removal from aqueous solution using Ag-MgOnHaP embedded on a chitosan polymer backbone (AgMgOnHaP@CSn) sorbent material. The overall formation of the AgMgOnHaP@CSn nanocomposite from different surface functionalization precursors and phases were supported by the various characterization methods such as UV–vis spectroscopy, SEM-EDS, FTIR, TEM, and Brunauer–Emmett–Teller (BET) techniques. Batch fluoride sorption experiments were conducted to assess fluoride uptake efficiency through optimization of several operational parameters such as contact time, adsorbent dosage, initial pH and co-competing anions. The antimicrobial activity of the synthesized AgMgOnHaP@CSn nanocomposites was also determined. The presence and bio-reduction processes of both Ag and MgO chemical species due to the interaction and coordination of bonds within the bioactive functional species of the polymer matrix was confirmed by the emergence of a sharp peak appearing at around 290 nm to a broad plateau plasmon absorbance above 440 nm on the AgMgOnHaP@CSn nanocomposite. FTIR analysis further supported the presence of the main bioactive functional species to be –OH, –NH2 CO32−, PO43-, Mg–O-Mg amongst other groups on the material surface. SEM and TEM displayed homogeneously dispersed particles within the aggregated biopolymeric composite with a diameter ranging between 5-30 μm. Pore sizes were observed to be in the micro-mesoporous range with an average size of about 35.36 nm and a pore diameter of 33.67 nm. The optimized conditions were as follows: 30 mins contact time, a dose of 0.25 g/50 mL, adsorbate concentration of 10 mg/L F-, initial pH 7 while adsorption capacity decreases with increase in temperature. AgMgOnHaP@CSn composite has a pHpzc value of ≈ 10.6 and the maximum sorption capacity was established to be 6.86 mg/g for 100 mg/L F- concentration at 303 K. The effect of co-existing anions was observed to be of the following order: Cl- < NO3- < SO42- << CO32-. The fluoride sorption experimental data was well described by Langmuir adsorption isotherm while the sorption reaction mechanisms were diffusion-controlled and followed the pseudo-second-order sorption model. F- sorption process could best be described as a combination of ligand exchange, electrostatic attraction, and improved structural surface modification. The antimicrobial susceptibility analysis through the zone of inhibition (mean and standard deviation) showed the potency to pathogens of the following order: Staphylococcus aureus > Escherichia coli. Chapter 7 gives an insight into the development of cellulose nanofibrous matrix (isolated from saw-dust) decorated with Ag-MgO-nanohydroxyapatite (CNF-AgMgOnHaP) and its application in fluoride and pathogen removal from contaminated water. The synthesized CNF-AgMgOnHaP, unlike the cellulose nanofiber, showed characteristic absorption bands in UV–vis spectroscopy between 270-290 nm typical of MgO together with a broad band around 420 nm associated with the characteristic of silver nanoparticles. FTIR spectrometry suggested the presence of nanohydroxyapatite (nHaP) and MgO species impregnation within the CNF matrix. SEM, TEM, XRD, and EDS analysis showed a well-established structural and morphological modifications between cellulose nanofiber alone, biosynthesized CNF-AgMgOnHaP and fluoride sorbed CNF-AgMgOnHaP nanocomposite. A granulated aggregation of micro-mesoporous particles with an improved BET surface area of 160.17 m²/g was developed. Optimum fluoride sorption capacity was 8.71 mg/g for 100 mg/L F- solution at 303 K. F- sorption capacities decreased as the operating temperatures increases. Optimum F- removal of 93 % was achieved at optimum conditions established: pH 5, solid/liquid ratio of 0.25 g/ 50 mL, 10 mg/L F-, contact time 10 min, temperature 25 ± 3 °C and shaking speed of 250 rpm. Percent F- removal decreased with increasing initial adsorbate concentration. The pHpzc value of the CNF-AgMgOnHaP occurred at ≈ 4.7. Co-existing ions were observed to have an effect on the adsorption of F- in the following order: NO3- < Cl- < SO42- <
NRF
Palanisamy, Selvakumar, and 史庫馬. "Fabrication and Characterization of Carbon based Metal oxide and Metal nanoparticles Composites for the Application in Electrochemical Sensors and Biosensors." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/34753h.
Повний текст джерела國立臺北科技大學
能源與光電材料外籍生專班研究所
102
Highly sensitive and selective novel electrochemical sensors and biosensors were fabricated using various composite modified electrodes, such as carbon nanomaterials/metal oxide and or metal nanoparticles. The reduced graphene oxide (RGO) and a zinc oxide (ZnO) composite modified electrode has been used for the enzyme free detection of hydrogen peroxide (H2O2). Moreover, it also has been used as an immobilization matrix of glucose oxidase to construct the glucose biosensor. The model enzymes such as hemoglobin (HB) and GOx were immobilized at multiwalled carbon nanotubes (MWCNTs) and ZnO composite surface and used for the selective detection of H2O2 and glucose, respectively. Another glucose biosensor and H2O2 has been developed using a hydrothermally synthesized graphene/cobalt oxide nanoparticles (GN/Co3O4-NPs) composite. The electrochemically fabricated RGO/silver nanoparticles (Ag) composite has also been used as an immobilization matrix for GOx. An electrochemical sensor for the selective and simultaneous detection of dihydroxy benzene isomers (hydroquinone (HQ), catachol (CC) and resorcinol (RC) has been fabricated using RGO/copper nanoparticles (RGO/Cu-NPs) composite modified electrode. The direct electrochemistry and electrochemical, electrocatalytic behavior of immobilized GOx and Hb at composite modified electrodes have also been studied in detail. The surface morphology of fabricated composites has been investigated by scanning electron microscopy (SEM) or field emission scanning electron microscopy (FESEM). The selectivity, stability and the practical applications of the developed electrochemical sensors and biosensors have also been studied. The electroanalytical parameters such as sensitivity, linear detection range and detection limit have also been evaluated for the fabricated sensors. In addition, surface coverage concentration (Г) and electron transfer rate constant (Ks) have also been calculated for enzymatic biosensors.
Jiang, De-hao, and 江得豪. "Supercritical fluid assisted synthesis of graphene/metal nanoparticle composite catalysts for improving dehydrogenation performance of LiAlH4." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/78068168109287880882.
Повний текст джерела國立中央大學
材料科學與工程研究所
101
Lithium aluminum hydride (LiAlH4)has high hydrogen density so it’s a potential hydrogen storage materials. In this study, we tried to improve the hydrogen storage properties of LiAlH4 by ball milling process. We introduced different carbon materials, metal/carbon composites, other catalysts. According to Temperature-Programmed Desorption (TPD)analysis, We found that by Supercritical carbon dioxide (scCO2)process synthesized Fe/Graphene composites obviously decreased the dehydrogenation temperature of LiAlH4. It’s catalytic effect better than VCl3, TiO2. By the materials analysis, between air process and scCO2 process, the later is more monodisperse than air process. So size effect and distribution play the most important role to improve catalytic properties. At 100 oC isothermal dehydrogenation dynamics analysis, LiAlH4 (BM30 min)release 4 wt% hydrogen after 10.8 hr while LiAlH4 + 10 wt% Fe/Graphene only need 10 minute. The results of experimental indicate that the Fe/Graphene is the best catalyst for LiAlH4.
Garcia-Berrios, Edgardo. "Investigation of Composites of Carbon Black and Metallocycles, and Functionalized Transition-Metal Nanoparticles as Chemiresistive Vapor Sensors." Thesis, 2011. https://thesis.library.caltech.edu/6419/5/Thesis.pdf.
Повний текст джерелаAn electronic nose is a man-made implementation of an olfactory system that is comprised of an array of broadly cross-reactive sensors. Electronic noses are used in the food industry, environmental monitoring, explosive detection and medical diagnosis. Our laboratory has focused in the development and implementation of arrays of low power, inexpensive chemiresistive thin films, that are able to identify and quantify a diverse collection of vapors and mixtures of vapors. Novel bioinspired sensors, and array chamber architectures are constantly been developed and improved to fulfill the desired performance of such arrays in different applications. This work details the development and the sensing performance of novel sensor materials based on composites of carbon black and metalloporphyrins, and organically-functionalized gold (Au) and titanium (IV) dioxide (TiO2) nanoparticles.
Composites of carbon black and metalloporphyrin complexes were developed and optimized to sensitively detect and classify a series of organic vapors. Such sensors films also exhibited a high sensitivity towards trace levels of ammonia (NH3(g)) and 2,4,6-trinitrotoluene (TNT) in air. Such composites broaden the types of materials that can be used for this type of low-power chemiresistive vapor sensing, and broaden the types of analytes that can be sensitively detected to include inorganic gases and explosives, as well as organic vapors.
Au and TiO2 nanoparticles were synthesized and functionalized with a variety of ligands. These materials allowed for molecular control of the interparticle physicochemical properties such as electron transfer. Details about the performance of each unique functionalized Au or TiO2 nanoparticle film upon exposure to a variety of organic vapors was described as a function of ligand length, structure and other physicochemical properties. The discrimination performance for arrays of such sensors was also evaluated.
Wang, Shan-Yu, and 王善猷. "Controllable Synthesis of Metal Nanoparticle/Graphene Nanoribbon Composites and Application for Surface-enhanced Raman Scattering Detection." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/86219858173091049272.
Повний текст джерела國立臺灣科技大學
化學工程系
104
In this study, we have developed a facile and effective wet-chemistry-based oxidative process for producing GNRs by lengthwise cutting and unraveling of CNT side walls with a very low usage of concentrated sulfuric acid. By introducing KNO3 in the starting CNT pretreatment, the yield of GNRs can reach nearly 100%. In addition, it is possible to reduce 90% usage of the concentrated H2SO4. The experimental findings presented in this study show that engineering of the inter- and intratube intercalation of CNTs by suitable intercalation molecules is a key factor to achieve not only high-yield GNR synthesis but also low usage of concentrated H2SO4. In addition, we also present a controllable synthesis of Ag/GNR composites with two topics: (i) different functionality of Ag/MWGNRs (ii) different width of Ag/GNRs at the same oxidation degrees. These two syntheses of topics were by a two-step reaction route. First, we synthesized and functionalized GNRs by a facile carbon nanotube chemical unzipping. The functionalization of GNRs could be controlled, confirming by XPS characterizations. Second, Ag NPs can be decorated onto the GNRs surface through a wet-chemical-based redox reaction. Detailed hybrid materials characterizations including UV-Vis spectroscopy show that Ag/GNR composites were successfully synthesized in our experiment. We further systematic studied the Raman response of the Ag/GNR composites using Rhodamine 6G (R6G) as the Raman probe. The result indicates that the Ag/GNR composites show superior SERS performance with low detection concentration of 10-9 M of R6G and high enhance factor (EF) of 3.62×107.
Xiao-NingTsai and 蔡孝寧. "Study on Preparation of Stable HPMC Composite Solution with Metal/Oxide Nanoparticle by Steric Stabilization and Load Capacity, Macro-scale Tribological Behavior of Composite Films." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/v3n3cm.
Повний текст джерела國立成功大學
機械工程學系
106
Hydroxypropyl methylcellulose (HPMC) is a kind of biopolymer with the character-istics of biodegradability, environment friendly, great mechanical properties and tribological properties. Therefore, it is suitable to develop as substituted materials of plastic. However, HPMC deforms easily when it bears the loading, causing real con-tact area and the adhesive force between HPMC and counter(AISI52100) increase, so that the HPMC film is easily damaged due to adhesive wear, and leading to lose efficacy on wear resistance. Hence, nanoparticles(NPs) Al, Cu, Al2O3, CuO have been used as fillers, by means of procedure, nano- suspension with dispersant (Span80) were prepared, and mixed with HPMC solution to prepare composite solu-tions and composite films. The study examined the basic properties (quality analysis, thickness, surface roughness, morphology), load capacity and macro-scale tribologi-cal behaviors. Results showed that Span80 could provide steric stabilization, and dispersed the NPs effectively in suspension. After suspension mixed with HPMC so-lution, HPMC made composite solution more stable. The load capacity of composite film remarkably enhanced, especially Cu/HPMC composite film. In terms of tribo-logical behaviors, the NPs Al and Cu occur deformation after wear test of low load-ing, the wear resistances had rose. Spherical CuO and sphere-like Al2O3 occurred rolling effect as third-body at interface during the test, so that the coefficient of fric-tion and wear rate decreased significantly. Since HPMC is soluble in water and or-ganic solvents (ethanol, and so on), the composite solution could be separated into additive and solution easily by appropriate pore size of filters, preventing pollution and recycling limited resources.
LIN, SHIH-HAO, and 林世豪. "Preparation of Metal Nanoparticle Composites and Combination with Screen Printing Carbon Electrodes for Biological and Environmental Detection." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/k5tvfj.
Повний текст джерела國立臺北科技大學
化學工程與生物科技系化學工程碩士班
107
Part 1 Herein, the synthesis of novel non-aggregated spinel nickel ferrite, NiFe2O4 nanosheets (NiFe2O4 NSs) and its application towards the selective electrocatalytic reduction of hydrogen peroxide are described. Initially, NiFe2O4 NSs is synthesized by one-step hydrothermal approach, and numerous characterizations deliberately explain the compound's composition and structure. Finally, the NiFe2O4 NSs underwent direct non-enzymatic electrochemistry and succeeded, it as mimicking Horseradish Peroxidase properties. The significance of non-aggregated NiFe2O4 NSs together with good electrocatalytic properties leads the material to the platform for electrochemical sensors. Moreover, NiFe2O4 NSs is fabricated and validated as an enzyme-free biosensor for the sensitive detection of H2O2. The demonstrated sensor revealed excellent detection of H2O2 with the pico-molar detection limit (12.4 pM), and also it offered good analytical parameters with more extensive linear range and higher sensitivity. Likewise, the non-enzymatic biosensor annexes good durability, reproducibility, and selectivity towards the determination of H2O2. Due to the nourishing capacity of the prepared NiFe2O4 NSs, it is employed for the enzyme-free detection of H2O2 in human blood and rat brain serum samples. Part 2 The diabetes mellitus was reported as one of the leading reasons for death around the world. Consequently, most of the researches were ardent to the detection of blood sugar level. Therefore, the morphology, as well as the sensing properties of renowned materials, should have optimized and engineered for higher sensitivity towards glucose. For the first time, an extensively utilized active component of a glucose sensor, Cuprous oxide (Cu2O) is synthesized and dealt with various annealing temperatures at 400, 600, and 800 ˚C. The impacts of annealing temperatures on morphology, electro-active surface area, and the glucose sensing properties of cuprous oxides are investigated and spotted that, 600 ˚C is an effective annealing temperature. Then, we developed an electrochemical biosensor through the economic SPCE modification method. As a result, the modified electrode showed exceptional electrocatalytic ability towards glucose and the anodic peak current is correlated with the concentrations of glucose. It obtained more extensive working range between 31 nM and 1423 μM and with very low detection limit and appreciable sensitivity. This method is successfully applied to the recognition of glucose level in the samples of human blood serum and whole blood. Part 3 After a long-term toxicity study on Bisphenol A (BPA), the European Union and U.S food and drug administration updating the rules regarding the usage of BPA by extending the prohibition of BPA to include in the production of papers, on February 2018. Therefore, it is essential to establish the trace level BPA detectors in paper samples. In this report, the synthesis of novel ZnO nanoclusters wrapped with reduced graphene oxide (ZnO NCs/rGO) and its application towards the selective electrocatalytic detection of BPA are described. Initially, ZnO NCs/rGO is synthesized by the one-step hydrothermal approach, and various characterizations explains the compound's compositions and structure. The significance of ZnO NCs/rGO together with good electrocatalytic properties leads this material to the platform for electrochemical sensor. Finally, ZnO NCs/rGO was fabricated and validated as an effective sensor for the sensitive detection of BPA. The demonstrated sensor revealed excellent detection of BPA with the very low detection limit (2.1 nM), and also it offered good analytical parameters with more extensive linear range and higher sensitivity. Likewise, the sensor annexes good durability, reproducibility, and selectivity towards the determination of BPA. Due to the nourishing capacity of the prepared ZnO NCs/rGO, it is employed for the detection of BPA in tissue paper samples.
Zong-Lin, Tsai. "Novel Optical Properties of the Composites of InGaN/GaN Multiple Quantum Wells and CdSe Quantum Dots With Metal Nanoparticles." 2006. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-0307200615535800.
Повний текст джерела