A partir de polietilè d'alta densitat i de fibres lignocel·lulòsiques provinents del trèmol (Populus tremula) s'han obtingut uns materials amb propietats úniques denominats compòsits. Aquests compòsits, amb un màxim de 40% de fibres lignocel·lulòsiques han estat tractats i modificats amb diferents agents (silà A-174 i epolè C-18) per millorar la compatibilitat entre la matriu de polietilè i el reforç fibrós. En una primera etapa les fibres lignocel·lulòsiques han estat pretractades amb cada un dels diferents tipus d'agents d'adhesió utilitzats i comentats prèviament, per seguidament barrejar aquestes fibres (en proporcions del 10, 20, 30 i 40%) amb la matriu d'HDPE. Una vegada els dos components s'han homogeneïtzat, es sotmeten a un procés de mòlta per aconseguir, mitjançant compressió, les provetes corresponents. Finalment, el conjunt de provetes ha estat exposat a condicions climàtiques dràstiques (baixa temperatura i fatiga tèrmica, dues característiques significatives de l'hivern canadenc) durant períodes variables de temps (0, 15, 30, 60 i 90 dies).Per tal d'avaluar tots i cada un dels paràmetres més significatius d'aquests compòsits, s'ha fet una caracterització orientada en dues vessants: estudi de la compatibilitat entre components del compòsit i estudi dels canvis estructurals que pateixen els compòsits degut a fenòmens d'envelliment provocats per exposició a les condicions climàtiques prèviament comentades.L'estudi de compatibilitat es fonamenta en les possibles interaccions que s'originen entre els dos components en funció del tipus de tractament al que ha estat sotmès el compòsit (silà i epolè). Per valorar aquestes interaccions, s'han estudiat diferents propietats mecàniques, com ara la resistència a la tracció, el mòdul d'elasticitat, la deformació a trencament, la resiliència i la tenacitat, mitjançant una màquina universal d'assaigs. Tanmateix també s'ha fet una caracterització espectrefotomètrica FT-ir per comprovar els diferents mecanismes d'adhesió que actuen en la interfase fibra- matriu en funció del tipus de tractament i una caracterització morfològica, utilitzant la tècnica de microscòpia electrònica de rastreig (SEM). Amb els resultats obtinguts de la caracterització espectrefotomètrica, també s'ha realitzat un seguiment de la influència que cada component fa en la modificació del grau de cristal·linitat de l'altre.L'estudi dels canvis estructurals que pateixen els compòsits degut a fenòmens d'envelliment s'ha fet partint de l'evolució de les propietats mecàniques bàsiques en funció dels diferents períodes d'exposició, on s'han caracteritzat els mateixos paràmetres definits anteriorment. Mitjançant valoració espectrefotomètrica s'han mesurat els canvis microestructurals (principalment de configuració), així com les modificacions en el grau de cristal·linitat que han tingut lloc sobre cada un dels diferents components del compòsit.Cal afegir que les possibilitats que ofereix la tècnica espectrefotomètrica FT-ir ha permès dur a terme la realització d'aquesta tesi. L'estudi dels canvis en la microestructura dels compòsits esdevinguts a partir dels fenòmens prèviament esmentats no hauria pogut fer-se sense la possibilitat d'un processament adequat dels espectres, així com d'una subtracció espectral que permet la detecció de moltes bandes complexes i difícils de detectar mitjançant altres tècniques d'anàlisi. / Los materiales compuestos se han obtenido a partir de polietileno de alta densidad y fibras lignocelulósicas que provienen del alamo temblón. Estos materiales con un máximo del 40% de refuerzo lignocelulósico han sido tratadas y modificadas con distintos tipos de agentes de acoplamiento (Silano A-174 y epoleno C-18) para mejorar la compatibilidad entre la matriz y el refuerzo.Las fibras tratadas previamente con cada uno de los distintos tipos de agentes de adhesión utilizados, se mezclan en distintas proporciones de las mismas (10,20,30 y 40%) con la matriz de HDPE. Una vez ambos componentes se han homogenizado se someten a un proceso de molturación para obtener probetas tipo halterio mediante compresión. Estas probetas se han sometido durante distintos períodos de tiempo (hasta 90 días) a condiciones de exposición drásticas (baja temperatura y fatiga térmica, características significativas del invierno canadiense).Para evaluar los parámetros más significativos de estos materiales compuestos se ha caracterizado la compatibilidad entre la matriz y el refuerzo, asimismo también se han estudiado los cambios estructurales que sufren estos materiales debido a fenómenos de envejecimiento provocados por la exposición de los mismos a las condiciones climáticas previamente comentadas.Els estudio de compatibilidad se centra en las posibles interacciones que se originen entre ambos componentes en función del tipo de tratamiento al que se ha sometido dicho material compuesto (silano y epoleno). Para valorar las interacciones que se generen entre ambos componentes, se ha ensayado distintas propiedades mecánicas (resistencia a tracción, módulo de elasticidad, deformación a rotura, resilencia y tenaciadad, utilizando la máquina universal de ensayos. Asimismo, también se ha caracterizado mediante espectroscopia de infrarrojo (FTIR) los posibles mecanismos de adhesión que tienen lugar entre la matriz y el refuerzo en función del tipo de tratamiento, asi como la caracterización morfológica utilizando la técnica de microscopía electrónica de barrido (SEM). A partir de los resultados obtenidos se ha podido seguir la influencia que tiene cada componente en la modificación de los respectivos grados de cristalinidad. El estudio de los cambios estructurales a los que se han visto sometido los distintos materiales compuestos, debido a fenómenos de envejecimiento, se ha realizado mediante el seguimiento de la evolución de las propiedades mecánicas en función de los distintos períodos de exposición. Mediante valoración espectofotométrica se han medido los cambios micorestrucutrales (cambios de configuración), así como las modificaciones en el grado de cristalinidad sobre cada uno de los componentes de material compuesto. / Composite materials have been obtained from high density polyethylene (HDPE) and lignocellulosic fibers from aspen wood. These materials with a maximum of 40% of lignocellulosic reinforcement have been treated and modified with different types of coupling agents (Silane A-174 and epolene C-18) to improve the compatibility between the matrix and the reinforcement.Four contents (10.20.30 and 40%) of fibers treated previously with each one of the different types of adhesion or coupling agents, are mixed with HDPE matrix. The above mixture was compression-molded into dog-bone shaped tensile test specimens. The molding temperature was slowly raised to 150ºC and samples were held at this temperature for 20 min. Then the samples were slowly cooled to room temperature keeping constant pressure during cooling. These test specimens have been submitted during different periods of time (up to 90 days) to drastic conditions of exposition (low temperature and thermal stress, main characteristics of the Canadian winter).In order to evaluate the most significant parameters of these composite materials, we have studied two ways: the compatibility between both components: matrix and reinforcement and the structural changes to composites due to phenomena of aging caused by the exposition of these materials to the drastic climatic conditions previously commented.The study of compatibility has been centered in the possible interactions that are originated between both components as a function of lignocellulosic fiber pretreatment. In order to evaluate the interactions that are generated between both components, different mechanical test has been tested (tensile strength, elasticity modulus, deformation at break, resilence and toughness) by mean an Instron Testing Machine. Moreover, the possible mechanisms of adhesion that take place between the matrix and the reinforcement as a function of different pretreatments has been characterized by means infrared spectroscopy (FTIR), and by the morphologic characterization using the scanning electronic microscopy (SEM). From the obtained results it has been possible to follow the influence that has each component in the modification of the respective degrees of crystallinity.The study of the structural changes of different composite materials, due to aging phenomena, has been analized by means of the pursuit of the evolution of the mechanical properties based on the different periods of exposure time. Furthermore the microstructural changes (basically configurational and crystallinity) has been evaluated by means of spectroscopy technique. The obtained results indicate that the macroscopic properties of the composite materials must depend on the lignocellulosic fiber content and whether or not a coupling agent is used. SEM micrographs of fracture surfaces show that the addition of coupling agents enhances their dispersion in the continuous HDPE phase. They also show that the silane coupling agent facilitates the direct contact between the lignocellulosic fibers and HDPE matrix more than untreated and epolene treated composites do. The tensile strength depends on both the lignocellulosic fiber content and the type of coupling agent used. The other mechanical properties (elasticity modulus, elongation at break and toughness) mainly depend on the lignocellulosic fiber content and, to a lesser extent, on the presence of a coupling agent. Silane-treated composites show the best mechanical performance as a consequence of significant interactions at the interface between the HDPE matrix and the lignocellulosic fibers.The differences observed between the various composites studied are explained by means of different adhesion mechanisms. Interdiffusion takes place in untreated composites; multiple mechanism of adsorption-wettability, interdiffusion and, to a lesser extent, chemical bonds take place in epolene treated composites, and finally, the adhesion in composites modified with silane is mainly a chemical mechanism of covalent bonds.

A thesis submitted in candidacy for the Degree of Doctor of Technology: Electrical Engineering, Technikon Natal, 2001. / This thesis details a study conducted to investigate the dynamic stability of an existing active control model (ACFl) of a composite structure embedded with a piezoelectric sensor and actuator for the purpose of vibration measurement and control. Criteria for stability are established based on the second method of Lyapunov which considers the energy of the system. Results show that ACFl is asymptotically stable although piezoelectric control effects persist when the feedback gain is set to zero. Meanwhile, it is required that there should be no control effects occurring through the piezoelectric actuator when the gain is set to zero. In this study, a new active control model (ACF2) is developed to satisfy the stability criteria, which satisfies the requirement of no piezoelectric control effects when the gain is set to zero. In ACF2 - as well as ACFl - the displacement and potential fields are discretised using the finite element method. In light of the locking phenomena associated with discrete displacements - which is expected to be pronounced in the case of discrete potentials due to their element geometry, ACF2-mixed is developed. ACF2 and ACF2-mixed control methodologies are similar except that in ACF2 both the displacement and potential field are discretised whereas in ACF2-mixed, only the displacement field is discretised and the potential field is continuous. Consequent to ACF2 and ACF2-mixed, stability analysis of the resulting time integration scheme is investigated as well. The results show that the damping forces due to the piezoelectric effect do not add energy to the structure. Hence, asymptotic stability is achieved. The time integration scheme yielded a small error, consistent with the literature. Numerical results revealed that ACFl exhibits a high degree of locking which is relaxed in ACF2 whereas ACF2-mixed exhibits envisaged results when compared with the other two models. Therefore, the ACF2 and ACF2-mixed will provide engineers with an alternative simulation model to solve actively controlled vibration problems hitherto. / D

No description available.

Department of Mechanical, Industrial and Aeronautical Engineering MSc (Mechanical Engineering) / Aramid fibre reinforced epoxy composites were hybridised by the addition of electrospun PAN (polyacrylonitrile) and ECNF (electrospun carbon nanofibre) doped PAN nanomats. One of the major concerns in polymer composites is the effect of the interlaminar properties on the overall mechanical properties of the composite. Electrospun carbon nanofibres were used as doping agents within PAN nanofibres, and coated in between aramid epoxy laminates to improve the interlaminar properties. PAN nanomats and ECNF doped PAN nanomats were created by the use electrospinning on the surface of aramid fibre sheets. Multiscale hybrid aramid reinforced composites were then fabricated. Mechanical characterization was carried out to determine the effect of PAN and CNF doped PAN nanofibre mats on aramid fibre reinforced epoxy. It was found that PAN reinforced nanomats had improved the mechanical properties and more specifically, when doped by ECNFs, the volume fraction of ECNFs played a vital role. An addition of 1% vol. CNF doped 0.1% vol. PAN reinforcement within a 30% vol. aramid fibre composite (control composite), improved the tensile strength and elastic modulus by 17.3% and 730% respectively. The 0.5% vol. PAN reinforced AFC (aramid fibre composite) specimens revealed a major increase in the flexural strength by 9.67% and 12.1%, when doped by both 0.5% vol. ECNFs and 1% vol. ECNFs respectively. The 0.5% vol. CNF doped reinforcement increased the impact energy by over 40%, for both the 0.1% vol. and 0.2 % vol. PAN reinforced aramid hybrid specimens. The 0.5% vol. CNF doped 0.5% vol. PAN had increased by 30% when compared to a non-doped sample. Morphological studies indicated interlaminar shearing between plies was affected by CNF agglomerations. This was discovered when determining the impact properties of the multiscale doped hybrid composites. Electrospun nanofibres however, assisted in improving the interlaminar regions within aramid epoxy by mechanical locking within the epoxy, and creating an adhesive bond using Van der Waals forces and electrostatic charges between nanofibre and macro fibre. Hybridising aramid epoxy with the use of nanofibres assisted in improving various mechanical properties. Impact degradation was one disadvantage of hybridising using CNF doped PAN nanofibre reinforcements. / MT2017

Ph.D., Faculty of Science, University of the Witwatersrand, 2011 / ABSTRACT Page | iiAbstract i The deposition of carbon during catalytic reactions has a long history, with major efforts initially focused towards their prevention rather than synthesis. However the discovery of fullerenes and later that of carbon nanotubes by Iijima, shifted scientific focus towards the synthesis, characterization and application of carbon deposits. This renewed interest in carbon based materials, has revealed a universe of extraordinarily shaped carbon materials (SCMs) in the nano and micro range, from tubes and helices to horns and most recently graphene. It has been noted that there exists a relationship between the morphology of the carbon material and its inherent properties, making them highly prized for numerous technological applications. However before these carbon materials can be effectively exploited control over their selective synthesis is necessary, a problem that has been solved with only limited success. As such, there still exists a need to develop synthetic strategies that would yield shaped carbon materials selectively. More importantly, it is essential that a better understanding of the growth factors that lead to differently SCMs is obtained. In this study we have highlighted the parametric conditions for optimum growth of carbon helices, as well as that of carbon fibers with unique structure. We have found that catalyst morphology and the carbon source are key aspects, which control carbon material growth and morphology. The synthesis of carbon materials using bi and tri-metallic supported catalyst systems revealed that Cu was an effective promoter for obtaining helices, particularly at low temperatures (≤ 550 ˚C). On further investigation, Cu was shown to exhibit incredible carbon deposition capabilities at temperatures as low as 200 ˚C. Adjustments of the catalyst preparation conditions (support, metal counter ion, solvent and reduction temperature) and synthesis temperature, revealed that the yield and morphology of the carbon deposit could be altered to selectively produce both straight and helical carbon fibers. A TEM tomography study revealed that the copper particles that gave distorted decahedra formed helical fibers, while trigonal bi-pyramidal particles gave linear fibers. Various plate-like particles revealed that as the number of sides of a catalyst particle varied (3, 4, 5 or 6) there was a corresponding change in the Abstract Page | iv carbon fiber helicity. A relationship between catalyst particle morphology and fiber morphology was thus established. TEM analysis also revealed that catalyst particles underwent rapid reconstruction during carbon fiber synthesis, and that the carbon source (gas environment) was influential in this reconstruction event. A NiOx (unsupported) catalyst was prepared and reactions with various substituted alkyne hydrocarbons were undertaken. Analysis revealed that different alkynes produced carbon fibers with varying morphologies. Using different alkynes in a sequential manner led to the formation of ‘co-block’ carbon fibers with an A-B-A-B... or A-B-C... morphology. Using different alkynes followed by acetylene led to the selective synthesis of straight, Y-junction or irregular carbon fibers. Accompanying these results was the observation that in each case the catalyst particle morphology was unique. Reaction of NiOx with trichloroethylene, in which trichloroethylene acted as a source of carbon for fiber growth, also restructured the Ni catalyst into a tetrahedral shape that gave tripod-like carbon growth. It was found that, substituted alkynes (and alkenes) provided a means for controlling catalyst particle morphology and hence carbon fiber morphology. The study has highlighted the relationship that exists between catalyst and SCM morphology, as well as the effect of hydrocarbons, not only as a source of carbon for SCM growth but also as a means of controlling catalyst morphology and SCM structures.

SC-15 epoxy is used in many industrial applications and it is well known that the mechanical and viscoelastic properties of epoxy can be signicantly enhanced when reinforced with nanofillers. In this work, SC-15 epoxy is reinforced by loading with magnetically-active nanofillers and cured in a modest magnetic field. Because of the signicant magnetic response of the nanofillers, this is a low cost and relatively easy technique for imposing a strong magnetic anisotropy to the system without the need of a superconducting magnet. It is also found that this method is an effective way of enhancing the mechanical properties of epoxy. Three systems were prepared and studied. The first is a dilute system of various concentrations of Fe2O3 nanoparticles in SC-15 epoxy. The second system is a combination of Fe2O3 nanoparticles and chemically-functionalized single-walled carbon nanotubes (SWCNT(COOH)s) in SC-15 epoxy. The third is a dilute system of SWCNT(COOH)s decorated with Fe3O4 particles t hrough a sonochemical oxidation process in SC-15 epoxy. Samples have an initial cure of 6 hrs in a magnetic led of 10 kOe followed by an additional 24 hours of post curing at room temperature. These are compared to the control samples that do not have initial field curing. Tensile and compressive stress-strain analysis of the prepared systems shows that mechanical properties such as tensile strength, tensile modulus and compressive strength are enhanced with the inclusion of these nanofillers. It is also found that there is an anisotropic enhancement of these properties with respect to the imposed curing field. An interesting phenomenon is observed with the increase in modulus of toughness and fracture strain with nanotube inclusion. / These parameters are drastically enhanced after curing the systems in a magnetic field. While there is a modest shift in glass transition temperature during viscoelastic analysis, the thermal stability of the created systems is not compromised. Results of these mechanical enhancements will be compared with other nanoloading techniques from literature. / by Olga Malkina. / Thesis (Ph.D.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

A series of interesting core/shell silver/phenol formaldehyde resin (PFR) nano/microstructures were also synthesized through an efficient microwave process by self-assembly growth. Various morphologies, including monodispersed nanospheres, nanocables, and microcages were obtained by changing the fundamental experimental parameters, such as the reaction time and the surfactants (Pluronic P123 or CTAB). The results indicated that the presence of triblock copolymer Pluronic P123 would result in hollow silver/PFR microcages, while CTAB would prefer the formation of ultralong silver/PFR coaxial nanocables. In the absence of surfactants, monodispersed core/shell silver/PFR nanospheres could be obtained. The size of the nanospheres can be controlled in the range of 110 to 450 nm by changing the molar ratio of reagents (phenol:hexamine). The morphology and composition of the as-prepared products were characterized. The formation mechanism of the products was discussed based on the obtained results. / Bifunctional mesoporous core/shell Ag FeNi3 nanospheres were synthesized by reducing iron(III) chloride, nickel(II) chloride and silver nitrate with hydrazine in ethylene glycol under microwave irradiation. The efficient microwave-hydrothermal process significantly shortened the synthesis time to one minute. The toxicity of Ag FeNi3 nanospheres were tested by exposing to zebrafish, they were less toxic than silver nanoparticles. In vitro MRI confirmed the effectiveness of the Ag FeNi3 nanospheres as sensitive MRI probes. The interaction of Rhodamine Band nanospheres showed greatly enhanced fluorescence over the FeNi3 nanoparticles. / Finally, a series of ZnO microarchitectures including monodispersed spindles, branches, flowers, paddies, and sphere-like clusters were prepared by an efficient microwave-hydrothermal process. The ZnO mophologies could be effectively controlled by changing the reaction conditions such as the reaction temperature, the reactant concentrations and the solvent system. Simple microspindles, interesting flowers and paddies could be obtained in the presence of hexamine, and the more attractive sphere-like clusters could be synthesized by introducing phenol. The formation mechanisms of different morphologies are discussed in detail. These interesting ZnO structures may have potential applications in electronic and optoelectronic devices. / Inorganic nanostrucured materials have attracted much attention owing to their unique features and important applications in biomedicine. This thesis describes the development of rapid and efficient approaches to synthesize inorganic nanostructures, and introduces some potential applications. / Magnetic nanostructures, such as necklace-like FeNi3 magnetic nanochains and magnetite nanoclusters, were synthesized by an efficient microwave-hydrothermal process. They were used as magnetic resonance imaging (MRI) contrast agents. Magnetic FeNi3 nanochains were synthesized by reducing iron(III) acetylacetonate and nickel(II) acetylacetonate with hydrazine in ethylene glycol solution without any template under microwave irradiation. This was a rapid and economical route based on an efficient microwave-hydrothermal process which significantly shortened the synthesis time to mins. The morphologies and size of the materials could be effectively controlled by adjusting the reaction conditions, such as, the reaction time, temperature and concentrations of reactants. The morphology and composition of the as-prepared products were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The size of the aligned nanospheres in the magnetic FeNi 3 chains could be adjusted from 150nm to 550nm by increasing the amounts of the precursors. Magnetic measurements revealed that the FeNi3 nanochains showed enhanced coercivity and saturation magnetization. Toxicity tests by exposure of FeNi3 nanochains to the zebrafish larvae showed that the as-prepared nanochains were biocompatible. In vitro magnetic resonance imaging (MRI) confirms the effectiveness of the FeNi 3 nanochains as sensitive MRI probes. Magnetite nanoclusters were synthesized by reducing iron(III) acetylacetonate with hydrazine in ethylene glycol under microwave irradiation. The nanoclusters showed enhanced T2 relaxivity. In vitro and in vivo MRI confirmed the effectiveness of the magnetite nanoclusters as sensitive MRI probes. We also investigated the biodistribution of the nanoclusters in rat liver and spleen. / Jia, Juncai. / Adviser: Jimmy C. Yu. / Source: Dissertation Abstracts International, Volume: 73-06, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

I believe that my research work will provide an in-depth understanding of the basic chemical and physical properties of plasmonic gold nanorods. These works can inspire future applications of plasmonic nanostructures on biotechnology, optoelectronics and solar energy conversion. - / I will first introduce my studies on high-index-faceted gold nanocrystals. Elongated tetrahexahedral (THH) gold nanocrystals have been prepared in high yields using a seed-mediated growth method. Structural characterizations reveal that they are single crystals enclosed by 24 high-index facets. Electrochemical measurements have proven that these THH Au nanocrystals are more chemically active than octahedral Au nanocrystals that are enclosed by low-index {1111} facets. Next, I will demonstrate the formation of large-area, 3D ordered assemblies of Au nanostructures that have different sizes and shapes, including nanorods, polyhedra, nanocubes, and bipyramids, by droplet evaporation. The nature of the resultant assemblies is strongly dependent on the shape of Au nanostructures for single-component systems; while the assembly of binary nanorod mixtures is dependent on the relative diameters of two nanorod samples for the nanorods used in our experiments. / Most applications of plasmonic nanostructures are based on their interactions with other chemical/physical species. In my research work, gold nanorods interacting with photochromic molecules and fluorophores are extensively studied. For the case of photochromic molecules, I have demonstrated a plasmonic switch on the basis of the resonance coupling between single Au nanorods and photochromic molecules. An individual plasmonic switch is composed of a single nanorod and the surrounding photochromic molecules. Its modulation depth reaches 7.2 dB. The estimated power and energy required for operating such a single-nanorod plasmonic switch are ∼13 pW and ∼39 pJ. For the case of fluorophores, I will give a systematic description of my research on plasmon-fluorophore interactions. Excitation polarization-dependent plasmon-enhanced fluorescence, polarized emission, and modulation of fluorophore emission spectra by localized plasmon resonances will be experimentally demonstrated. The interactions between the plasmonic nanorods and the fluorophore molecules can be temporally separated into plasmon-enhanced excitation and coupled emission processes under unsaturated excitation conditions. Finite-difference time-domain (FDTD) method will be employed to explain the origin of the excitation and emission polarization dependence. A term "plasmophore", which is corned by Lakowicz et al., is quoted to describe the artificially prepared quantum emitters that are composed of plasmonic structure and fluorophore. / Noble metal nanocrystals have drawn great attention in a wide range of research fields due to their extraordinary localized surface plasmon resonances, which are essentially collective charge density oscillations confined in metallic nanostructures. Their applications range from bioimaging, sensing and therapy in life sciences to plasmonic circuits and optical data storage in micro-optoelectronics. More attractively, they can be used to enhance light harvesting in solar energy conversion systems. In this thesis, I will systematically describe the preparation and assembly of gold nanorods and their interactions with fluorophores and photochromic molecules, both experimentally and theoretically. / Ming, Tian = 金納米棒的生長、組裝以及他們與螢光團或光至變色分子的相互作用 / 明天. / Adviser: Jianfang Wang. / Source: Dissertation Abstracts International, Volume: 73-06, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Ming, Tian = Jin na mi bang de sheng chang, zu zhuang yi ji ta men yu ying guang tuan huo guang zhi bian se fen zi de xiang hu zuo yong / Ming Tian.

Kwok, Yiu-fai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 87-89). / Abstracts in English and Chinese. / ABSTRACT --- p.I / ACKNOWLEDGMENTS --- p.II / TABLE OF CONTENT --- p.III / LIST OF FIGURES --- p.V / Chapter 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Motivation of this project --- p.1 / Chapter 1.3 --- Organization --- p.2 / Chapter 2 --- LITERATURE SURVEY --- p.3 / Chapter 2.1 --- Ionic Conducting Polymer Film (ICPF) --- p.3 / Chapter 2.2 --- Electroactive Polymer (EAP) --- p.4 / Chapter 2.3 --- Micro Active Guide Wire Catheter System --- p.5 / Chapter 2.4 --- Space Application - Dust Wiper --- p.6 / Chapter 2.5 --- Micro gripper --- p.8 / Chapter 2.6 --- Summary of literature survey --- p.14 / Chapter 3 --- METAL-POLYMER COMPOSITIONS --- p.15 / Chapter 3.1 --- Introduction --- p.15 / Chapter 3.2 --- Perfluorosulfonic acid polymer (Nafion) --- p.15 / Chapter 3.3 --- Working principle of ICPF --- p.19 / Chapter 3.4 --- Different types of composition --- p.21 / Chapter 3.4.1 --- Chromium-Gold-polymer composite --- p.23 / Chapter 3.4.2 --- Platinum-Gold-polymer composite --- p.25 / Chapter 3.4.3 --- Silver-polymer composite --- p.27 / Chapter 3.4.4 --- Silver/Copper-gold polymer composite --- p.27 / Chapter 3.4.5 --- Gold-polymer composite --- p.28 / Chapter 4 --- ICPF FABRICATION --- p.30 / Chapter 4.1 --- Introduction --- p.30 / Chapter 4.2 --- ICPF fabrication process --- p.31 / Chapter 4.3 --- Surface pre-treatment --- p.33 / Chapter 4.4 --- Gold thin film deposition (Evaporation) --- p.34 / Chapter 4.4.1. --- Filament evaporation --- p.35 / Chapter 4.4.2 --- Electronic-beam evaporation --- p.39 / Chapter 4.4.3 --- Structural analysis of evaporation --- p.40 / Chapter 4.5 --- Chemical electroplating --- p.42 / Chapter 4.5.1. --- Deposition rate calibration --- p.44 / Chapter 5 --- DESIGN AND PACKAGE --- p.46 / Chapter 6 --- LASER MICROMACHINING --- p.49 / Chapter 6.1 --- Introduction to Laser micromachining --- p.49 / Chapter 6.2 --- C02 laser --- p.50 / Chapter 6.3 --- Nd:YAG Laser --- p.51 / Chapter 6.4 --- Laser micromachining of ICPF actuator --- p.52 / Chapter 7 --- EXPERIMENTAL RESULTS AND ANALYSIS --- p.61 / Chapter 7.1 --- Introduction --- p.61 / Chapter 7.2 --- Measurement setup --- p.62 / Chapter 7.3 --- Width test --- p.68 / Chapter 7.4 --- Length test --- p.73 / Chapter 7.5 --- Voltage test --- p.76 / Chapter 8 --- MICRO GRIPPER ACTUATION --- p.79 / Chapter 8.1 --- Development of micro gripper --- p.79 / Chapter 8.2 --- Micro gripper --- p.80 / Chapter 9 --- CONCLUSION --- p.82 / Chapter 10 --- APPENDIX --- p.83 / Chapter 10.1 --- Procedures in using E-beam evaporator --- p.83 / Chapter 10.2 --- Procedures in using Thermo couple evaporator --- p.85 / Chapter 11 --- REFERENCE --- p.87

by Fung-luen Kwong. / Thesis submitted in: August 1998. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 130-131). / Text in English; abstract also in Chinese. / by Fung-luen Kwong. / Acknowledgements --- p.i / Abstract --- p.ii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Development of ceramic materials --- p.1 / Chapter 1.2 --- Alumina-Zirconia advanced ceramics --- p.2 / Chapter 1.3 --- About this thesis --- p.3 / Chapter 2 --- Related work and Motivation --- p.6 / Chapter 2.1 --- Introduction --- p.6 / Chapter 2.2 --- Powder synthesis --- p.7 / Chapter 2.2.1 --- Mechanical milling --- p.7 / Chapter 2.2.2 --- Sol-gel methods --- p.8 / Chapter 2.2.3 --- CVD methods --- p.12 / Chapter 2.2.4 --- Hydrothermal processing --- p.12 / Chapter 2.2.5 --- Wear of Zr02 milling media --- p.14 / Chapter 2.3 --- Powder fabrication --- p.14 / Chapter 2.3.1 --- Dry pressing --- p.14 / Chapter 2.3.2 --- Isostatic pressing --- p.19 / Chapter 2.3.3 --- Hot pressing --- p.23 / Chapter 2.4 --- Sintering mechanism --- p.26 / Chapter 2.4.1 --- Solid state sintering --- p.26 / Chapter 2.4.2 --- Liquid state sintering --- p.36 / Chapter 2.5 --- Toughening mechanism --- p.39 / Chapter 2.5.1 --- Stress-induced transformation toughening --- p.39 / Chapter 2.5.2 --- Microcrack toughening --- p.42 / Chapter 2.6 --- Motivation --- p.42 / Chapter 3 --- Experiments --- p.45 / Chapter 3.1 --- Methodology --- p.45 / Chapter 3.1.1 --- Procedures --- p.45 / Chapter 3.1.2 --- Verified parameters and potential difficulties --- p.53 / Chapter 3.2 --- Instrumentation --- p.56 / Chapter 3.2.1 --- Electronic balance --- p.56 / Chapter 3.2.2 --- Instron 4486 loading machine --- p.60 / Chapter 3.2.3 --- High temperature furnace --- p.63 / Chapter 3.2.4 --- Scanning electron microscope (SEM) --- p.65 / Chapter 3.2.5 --- Hardness tester --- p.67 / Chapter 3.2.6 --- X-ray powder diffraction --- p.69 / Chapter 4 --- Results ´ؤ The effects of conditions in fabrication --- p.71 / Chapter 4.1 --- Wet chemical reaction --- p.71 / Chapter 4.2 --- Pressure dependence analysis --- p.75 / Chapter 4.3 --- Sintering behavior --- p.80 / Chapter 4.3.1 --- Sintering temperature analysis --- p.80 / Chapter 4.3.2 --- Sintering duration analysis --- p.85 / Chapter 4.3.3 --- Program for counting pores --- p.94 / Chapter 5 --- Results ´ؤ The effects of Additives to Al203 - ZrO2 --- p.96 / Chapter 5.1 --- Introduction --- p.96 / Chapter 5.1.1 --- Effects of adding metal aluminum --- p.97 / Chapter 5.1.2 --- Effects of adding magnesium oxide --- p.103 / Chapter 6 --- Conclusions --- p.108 / Source code of the programs for counting pores --- p.111 / TIFF 6.0 --- p.124 / Bibliography --- p.131