This thesis investigates the use of nanotechnology in an extensive literature search in the field of cement and concrete. A summary is presented. The research was divided into two categories: (1) nanoparticles and (2) nanofibers and nanotubes. The successes and challenges of each category is documented in this thesis. The data from the literature search is taken and analyzed using statistical prediction by the use of the Monte Carlo and Bayesian methods. It shows how statistical prediction can be used to analyze patterns and trends and also discover optimal additive dosages for concrete mixes. / by Jonathan Glenn. / Thesis (M.S.C.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2016. / The subject of this current study concerns highly concentrated emulsions of the explosive grade. A distinguishing characteristic of these systems is a high internal to external phase volume ratio. The volume fraction of the aqueous phase of such an emulsion generally far exceeds the close packing limit. Continuous phase of the system is a supersaturated aqueous solution of ammonium nitrate inorganic salt. In combination with high internal phase concentration, this inevitably leads to the destabilisation of the system. The thermodynamic instability of such systems is attributed to two major factors: 1) crystallisation of dispersed phase and 2) coalescence of the individual droplets within the bulk. This poses a significant problem since destabilisation of the bulk emulsion in turn leads to partial or complete loss of sensitivity to detonation of the final product of which highly concentrated emulsion is the base. Since the invention of such types of bulk explosives, a considerable and on-going effort has targeted the improvement of the stability of these systems, with a scope primarily focused on the use of various surfactant agents with different properties as well as stabilising mixtures containing numerous surfactants. In recent years, a new approach has been explored: the stabilisation of highly concentrated emulsions with the use of solid fumed silica nanoparticles. This is a promising new field of study, already being implemented by manufacturers and actively developing. The focus of this present study is to investigate and lay the ground work for further research in the principally new approach towards the stabilisation of highly concentrated emulsions with the use of the polyhedral oligomeric silsesquiozane nanomolecules. These are unique compounds possessing hybrid inorganic-organic structures and properties, and carrying a range of advantages over currently implemented surfactants. As opposed to silica nanoparticles, these compounds are not solid particles but can be regarded as molecular silica. This investigation will focus on the general possibility of implementation of such compounds as stabiliser agents for emulsions in general, and highly concentrated emulsions of the explosive grade in particular, and the resultant effects on the stability. Effects on stability will be investigated both when used solely and in combination with common surfactants. In addition, stability both on shelf and under stress will be investigated within the framework of the study.

Este trabalho tem como objetivo principal a utilização da técnica “bottom-up" para a construção de nanoestruturas de ouro por meio de técnicas voltamétricas sobre uma superfície de Carbono Vítreo. Estas estruturas foram caracterizadas por métodos microscópicos e voltamétricos. A dimensão crítica das nanoestruturas foi obtida por meio de uma curva Gausseana de distribuição de alturas e diâmetros, fornecendo um valor médio de 35 nm por 150 nm de diâmetro. As nanoestruturas obtidas foram modificadas pela deposição de uma camada automontada de cistamina (um tiól), resultando num substrato adequado para futuras aplicações como a imobilização de enzimas. Os comportamentos eletroquímicos da dopamina e do ácido ascórbico, sobre eletrodos de ouro, Carbono Vítreo e Nanoestruturado, foram avaliados para a caracterização das modificações dos eletrodos. A diferença dos potenciais de pico de oxidação do AA sobre eletrodos de Carbono Vítreo e de ouro, de cerca de 300 mV, possibilitou avaliar o recobrimento do Carbono Vítreo com nanoestruturas pela diminuição da corrente de pico. Já a dopamina foi utilizada neste trabalho para determinar a presença da camada automontada de cistamina sobre a superfície das nanoestruturas de ouro, uma vez que sua resposta voltamétrica mostra um deslocamento do potencial de pico quando realizada sobre Au e sobre Au modificado com a camada automontada. / The subject of this work is focused in the utilization of a “bottom-up" approach to develop an Au nanostructured electrodeposits on the glassy carbon surface by a voltammetric procedure. These Au nanostructures have been characterized either by microscopic and voltammetric techniques. The critical dimensions of nanostructures has been evaluated by a Gausean normal data distribution curve and presented, as results a mean height of 35 nm and a mean diameter of 150 nm. The Au nanostructures were further modified by the deposition of a cystamine (thiol) self-assembled monolayer, yielding a suitable substrate for enzyme immobilization, as a possible future application. The electrochemical behaviour of dopamine and ascorbic acid on gold, Glassy Carbon and nanostructures was studied aiming to characterize the modified electrode. The 300 mV shift in the oxidation peak potential for ascorbic acid on gold in relation to Glassy Carbon allows to calculate the nanostructure coverage factor by the peak current inhibition as 43%. Finally, dopamine was employed to detect the self assembled monolayer formation on the Au nanostructure through its voltammetric behaviour. The variation in the oxidation potential for DA on gold and self assembled monolayer was used as an indicator for such modification.

表面等離子體基元共振是自由電子在納米尺寸的集體共振效應，該效應會產生一系列新奇的性質。貴金屬納米結構由於可以產生表面等離子體基元共振而受到各個領域廣泛的關注。在共振激發的情況下，貴金屬納米結構具有極大的散射和吸收截面積以及極強的進場放大效應。這些奇特的性質可以應用於傳感、成像、光學調製、光熱療、光催化和太陽能電池等領域。金和銀納米結構由於其表面等離子體基元共振波長處在可見和近紅外波段而受到廣泛研究。然而，在某些應用中純金或純銀納米結構不能起到很好的作用。例如，金和銀對很多化學反應的催化活性很弱或者沒有催化活性。如果把金和銀與其他金屬複合在一起就可以同時獲得表面等離子基元共振和其他效應。在我的博士研究期間，我製備了Au/Ag 和Au/Pd 複合雙金屬納米結構和研究了該複合結構的表面等離子體基元共振的性質和在氫氣傳感和光催化中的應用。 / 由於在金屬納米結構的製備中晶種起著至關重要的作用，所以我首先研究了晶種的晶體結構和形狀對雙金屬納米結構合成的影響。我研究了銀和鈀分別在相同條件下在單晶金納米棒、多晶金納米棒和納米雙錐種子上的生長過程。研究發現當晶種是單晶金納米棒時，銀和鈀的生長形成長方體雙金屬納米結構。然而，當晶種是多晶的金納米棒和納米雙錐時，銀和鈀的生長生成納米棒雙金屬結構。銀和鈀在多晶金納米棒上的生長由兩端開始，而在多晶金納米雙錐上的生長由臺階面開始。這表明在雙金屬納米結構的生長過程中納米晶種的晶體結構對最終納米結構的形貌具有決定性的作用，而納米晶種的形狀對生長動力學有明顯的影響。 / 在Au/Ag納米晶製備過程中，我發現Au/Ag納米晶具有四個表面等離子體基元共振峰。於是我對這四個共振峰的演變和共振模式進行了實驗和理論研究。電動力學模擬表明能量最低的共振峰是縱向的電偶極共振，能量次低的共振峰是沿橫向的電偶極共振，兩個高能量的共振峰是沿著橫向的電八極共振。遲滯效應和兩個垂直橫向激發的干涉是導致形成兩個電八極共振的關鍵因素。研究發現隨著銀殼厚度的增加，縱向電偶極共振峰藍移，橫向電偶極共振峰先藍移后稍微紅移，兩個電八極共振沒有明顯的峰位移動。四個表面等離子體基元共振的強度都隨著銀殼厚度的增加而增強。 / 鈀被廣泛地應用於氫氣傳感和催化反應中。於是我研究了Au/Pd 雙金屬納米結構的氫氣傳感和光催化性能。在氫氣傳感研究中，我製備了兩種不同結構的Au/Pd 納米結構。一種具有連續的鈀殼層，另一種鈀殼層不連續。對於具有連續鈀殼層的納米結構，氫氣的傳感性能隨著鈀殼層厚度的增加而增加。實驗發現當納米結構暴露在4%的氫氣中時表面等離子體基元共振峰移動高達56 nm。不連續鈀殼層的納米結構的氫氣傳感性能不如連續鈀層的納米結構。我進一步對Au/Pd 雙金屬納米結構的光催化性能進行了研究。所選取的催化反應是Suzuki 偶聯反應。研究結果表明Au/Pd 納米結構可以有效地捕獲光能來促進化學反應。由於Au/Pd 納米結構使表面等離子體基元共振功能和催化功能緊密集成在一個納米結構中，因此表面等離子基元共振部份所捕獲的光能可以有效地傳遞到催化功能部份而實現光催化。研究發現熱電子效應和光熱轉化效應同時加速化學反應。其中光熱轉化在我的實驗中體現為非局部加熱效應，熱電子對化學反應的促進作用依賴于環境溫度。因此，光熱轉化效應可以促進熱電子轉移效應。 / 本論文的研究結果有助於人們瞭解具有表面等離子體基元共振性質的雙金屬納米機構的設計和應用。對Au/Ag雙金屬納米結構表面等離子體基元共振性質的研究不僅加深了人們對雙金屬表面等離子體基元共振的瞭解而且對利用不同共振模式實現特定功能有著指導意義。對Au/Pd雙金屬納米結構在氫氣傳感和催化反應應用中的研究明確表面雙金屬表面等離子體納米結構可以實現單一組成不具備的功能，這在一定程度上有助於擴展表面等離子基元共振在生命科學、能源和環境領域的應用。 / Noble metal nanocrystals have attracted great interest from a wide range of research fields because of their intriguing properties endowed by their localized surface plasmon resonances, which are the collective oscillations of free electrons. Under resonant excitation, metal nanostructures exhibit very large scattering and absorption cross sections and large near-field enhancement. These extraordinary properties can be used in different applications, such as plasmonic sensing and imaging, plasmon-controlled optics, photothermal therapy, photocatalysis, solar cells, and so on. Gold and Silver nanocrystals have plasmon resonances in the visible and near-infrared regions. However, gold and silver are not suitable for some applications. For example, they are generally inactive for catalyzing chemical reactions. The integration of plasmonic metals with other metals can offer superior or new physical/chemical properties. In this thesis, I prepared Au/Ag and Au/Pd bimetallic nanostructures and studied their lasmonic properties and applications in hydrogen sensing and photocatalysis. / Seeds have a crucial importance in the synthesis of bimetallic nanostructures. I therefore first studied the roles of the crystalline structure and shape of seeds on the overgrowth of bimetallic nanostructures. The overgrowth of silver and palladium on single crystalline Au nanorods, multicrystalline Au nanorods, and nanobipyramids were studied under the same conditions for each metal. The growths of silver and palladium on single crystalline Au nanorods gave cuboidal nanostructures, while rod-shaped nanostructures were obtained from the growths of silver and palladium on multicrystalline Au nanorods and nanobipyramids. Moreover, the growths of silver and palladium on multicrystalline Au nanobipyramids started at the stepped side facets, while the growths started at the twin boundaries on multicrystalline Au nanorods. These results unambiguously indicate that the crystalline structure of seeds plays a significant role on the final morphologies of multimetallic nanostructures, while the seed shape has a prominent effect on the growth kinetics. / Four plasmon resonance bands were observed in Au/Ag bimetallic nanocrystals. I then studied the evolution and nature of the four plasmon bands during the silver coating on Au nanorods both experimentally and theoretically. Electrodynamic simulations revealed that the lowest-energy peak belongs to the longitudinal dipolar plasmon mode, the second-lowest-energy peak is the transverse dipolar plasmon mode, and the two highest-energy peaks can be attributed to octupolar plasmon modes. The retardation effect and the interference between two perpendicularly polarized excitations along the edge directions are important for the formation of the distinct highest-energy and second-highest-energy octupolar plasmon modes, respectively. As the Ag shell thickness is increased, the longitudinal plasmon mode blue-shifts, the transverse plasmon mode first blue-shifts and then red-shifts slightly, and the two octupolar plasmon modes stay at nearly constant wavelengths. The extinction intensities of all the four plasmon bands increase with the increase of the overall particle size. / Palladium is widely used in hydrogen sensing and catalysis. I therefore studied the applications of Au/Pd bimetallic nanostructures in hydrogen sensing and photocatalysis. Two types of Au/Pd bimetallic nanostructures, nanostructures with continuous and discontinuous Pd shells, were employed to study their hydrogen sensing performances. For the nanostructures with continuous Pd shell, the hydrogen sensing performances were improved with the increase in the Pd shell thickness. A plasmon shift of 56 nm was observed when the hydrogen concentration was 4%. The nanostructures with discontinuous Pd shell exhibited smaller plasmon shifts compared with those with continuous Pd shell. For the photocatalytic application of Au/Pd bimetallic nanostructures, I studied their photocatalytic performance for Suzuki coupling reactions. The results indicate that plasmonic Au/Pd bimetallic nanostructures can efficiently harvest light energy for chemical reactions. The intimate integration of plasmonic and catalytic components in one nanostructure enables the light energy absorbed by the plasmonic component to be directly transferred to the catalytic component. Both hot electron transfer and photothermal heating contribute to the plasmon-enhanced chemical reactions. The photothermal effect is a nonlocal heating and the contribution of the hot electron transfer effect is dependent on the environmental temperature. Therefore, the photothermal heating effect can promote the hot electron transfer effect. / I believe that my research work will be very helpful for the design and application of plasmonic bimetallic nanostructures. My study on the plasmonic properties of Au/Ag bimetallic nanocrystals has deepened the understanding of the plasmons of Au/Ag nanorods and will be helpful for utilizing the different modes to achieve specific functions. The hydrogen sensing and photocatalysis of Au/Pd bimetallic nanostructures have shown that the integration of functional components with plasmonic nanostructures can achieve unconventional properties, which will flourish the applications of plasmons in life sciences, energy, and environmental areas. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Jiang, Ruibin = 雙金屬納米結構表面等離子體基元共振的研究及其在氫氣傳感和化學反應中的應用 / 江瑞斌. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references. / Abstracts also in Chinese. / Jiang, Ruibin = Shuang jin shu na mi jie gou biao mian deng li zi ti ji yuan gong zhen de yan jiu ji qi zai qing qi chuan gan he hua xue fan ying zhong de ying yong / Jiang Ruibin. / Abstract --- p.I / Acknowledgements --- p.VI / Table of Contents --- p.VIII / List of Figures --- p.X / List of Tables --- p.XIII / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Localized surface plasmon resonances --- p.1 / Chapter 1.2 --- Applications of localized surface plasmon resonances --- p.3 / Chapter 1.3 --- Overview of this thesis --- p.13 / Chapter 2 --- Theory, Simulation, and Experimental Methods for the Investigation of LSPRs --- p.20 / Chapter 2.1 --- Theoretical methods --- p.20 / Chapter 2.2 --- Simulation methods --- p.30 / Chapter 2.3 --- Experimental methods --- p.35 / Chapter 3 --- Preparation of Metal Nanostructures --- p.43 / Chapter 3.1 --- Preparation methods for Au nanocrystals --- p.43 / Chapter 3.2 --- Seed-mediated growth method --- p.46 / Chapter 3.3 --- Metal nanostructure preparations --- p.54 / Chapter 4 --- Crystalline Structure-Determined Growth of Bimetallic Nanocrystals --- p.62 / Chapter 4.1 --- Au nanocrystal seed preparation --- p.64 / Chapter 4.2 --- Au/Ag bimetallic nanocrystals --- p.66 / Chapter 4.3 --- Au/Pd bimetallic nanocrystals --- p.71 / Chapter 4.4 --- Summary --- p.77 / Chapter 5 --- Plasmons of Au/Ag Core/Shell Bimetallic Nanocrystals --- p.83 / Chapter 5.1 --- Variations of plasmons with Ag shell thickness --- p.86 / Chapter 5.2 --- Nature of the different plasmon modes --- p.94 / Chapter 5.3 --- Summary --- p.99 / Chapter 6 --- Au/Pd Bimetallic Nanostructures for Hydrogen Sensing --- p.105 / Chapter 6.1 --- Au nanorods with continuous Pd shell for hydrogen sensing --- p.107 / Chapter 6.2 --- Au nanorods with discontinuous Pd shell for hydrogen sensing --- p.114 / Chapter 6.3 --- Theoretical simulations --- p.117 / Chapter 6.4 --- Summary --- p.119 / Chapter 7 --- Plasmon-Enhanced Chemical Reactions --- p.124 / Chapter 7.1 --- Mechanisms of plasmon enhancement in chemical reactions --- p.125 / Chapter 7.2 --- Plasmon-enhanced Suzuki coupling reactions --- p.129 / Chapter 7.3 --- Summary --- p.149 / Chapter 8 --- Conclusions --- p.156 / Curriculum Vita --- p.160

各種納米結構的光學反應，已成為一被相當關注的課題，在物理理論和應用技術的層面上被廣泛研究。在本文中，我們利用格林函數方法(GFF)，研究了新月形圓柱体和兩接近中的圓柱体的靜電共振。格林函數方法裏涉及一表面積分方程式，我們求該方程的解便可以得出各不同形狀的納米結構的電勢。格林函數方法是一容易使用、高效率的方法，並且在研究納米結構的光學行為的問題上得出準確結果。 / 在論文的第一部分，我們計算了新月形圓柱体和兩接近中的圓柱体的杆光譜，從而研究該兩個結構的靜電共振。然而，當這兩個結構中有接觸點時，系統中便有一奇點，因此我們不能直接使用格林函數方法研究這情況。為了解決這問題，我們首先使用了變換光學的方法，求得該結構的雙極因子，再從中得到其有效介電常數的譜密度。為了比較非接觸情況中離散的杆光譜和接觸情況中的連續杆光譜，我們進一步定義了一累積分佈函數，它是其譜密度的累積分佈函數。我們從而發現當系統由非接觸的情況漸近接觸時，其離散的杆光譜便趨向其相應的連續杆光譜。 / 在論文的第二部分，我們直接研究了新月形圓柱体和兩接近中的圓柱体的勢分佈和電埸分佈。我們發現在新月形圓柱体和兩接近中的圓柱体的系統中，能量會分別將集中於其金屬間隔和空氣間隔附近的區域。當我們適當地選擇系統的參數時，其共振及能量更能進一步增強。我們亦確認了使用格林函數方法和使用保角變換方法兩者得出的結果的是吻合的。我們的研究結果可以幫助設計電漿子捕光裝置。 / The optical responses of various nanostructures have attracted a considerable attention and they have been extensively studied from the theoretical and technological points of view. In this thesis, we have studied the electrostatic resonance of crescent-shaped cylinder and two approaching cylinders by the Green function formalism (GFF). In the GFF, a surface integral equation is formulated for the scalar potential for an arbitrary number of nanostructures of various shapes. GFF is easy to apply and gives accurate results for the optical behaviors of these nanostructures. / In the first part of the thesis, we have studied the electrostatic resonance of crescent-shaped cylinder and two approaching cylinders by calculating the pole spectrum. However, in the touching case, there is a singular point and thus the GFF cannot be applied directly. To circumvent this problem, the spectral density is found from the polarizability of the nanostructure, which can be obtained analytically by the transformation optics approach. To compare the discrete pole spectrum of the non-touching cases with the continuous spectrum of the touching case, we have used the cumulative distribution function of the spectral density. We are then able to show that the discrete pole spectrum approaches to the continuous pole spectrum as the system approaches from non-touching cases to the touching case. / In the second part of the thesis, the electrostatic resonance is investigated by directly finding the local field distributions of crescent and two approaching cylinders under a uniform applied electric field. It is shown that there is an energy concentration within the metal narrow gap and the air narrow gap in the cases of crescent and two approaching cylinders respectively. It is also found that when parameters are carefully chosen, the nanoconcentration of energy will be greatly enhanced. The numerical GFF results are confirmed with the analytic results by conformal transformation. The results are useful in designing plasmonic light-harvesting devices. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Yung, Sai Kit = 電漿子納米結構中的能量集中 : 格林函數方法 / 翁世杰. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 71-74). / Abstracts also in Chinese. / Yung, Sai Kit = Dian jiang zi na mi jie gou zhong de neng liang ji zhong : Gelin han shu fang fa / Weng Shijie. / Abstract --- p.i / 摘要 --- p.iii / Acknowledgements --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Optical responses in plasmonic systems --- p.1 / Chapter 1.2 --- Objective of the thesis --- p.5 / Chapter 2 --- Review on Green function formalism --- p.7 / Chapter 2.1 --- Integral equation formalism --- p.7 / Chapter 2.2 --- Periodic corrugated interfaces --- p.11 / Chapter 2.3 --- Solution by mode expansion --- p.16 / Chapter 2.4 --- Numerical solution --- p.18 / Chapter 3 --- Pole spectrums of crescent-shaped cylinder and approaching cylinders --- p.21 / Chapter 3.1 --- Review of Green function formalism on the spectral representation of the effective dielectric constant --- p.22 / Chapter 3.2 --- Numerical results --- p.29 / Chapter 3.2.1 --- Spectral representation of the effective dielectric constant of crescent-shaped cylinders --- p.29 / Chapter 3.2.2 --- Spectral representation of the effective dielectric constant of approaching cylinders --- p.37 / Chapter 4 --- Energy concentration of crescent and approaching cylinders --- p.44 / Chapter 4.1 --- Energy concentration of crescent-shaped cylinder --- p.45 / Chapter 4.2 --- Energy concentration of approaching cylinders --- p.53 / Chapter 5 --- Conclusion --- p.58 / Chapter 5.1 --- Suggestion of future works --- p.60 / Chapter A --- Conformal transformation --- p.61 / Chapter A.1 --- Conformal transformation on crescent-shaped cylinder: nontouching case --- p.61 / Chapter A.2 --- Conformal transformation on approaching crescent-shaped cylinders --- p.66 / Bibliography --- p.71

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.

在本論文中，我們利用簡單的濕化學氧化鋅(ZnO)納米線陣列模板法成功地製備了一系列具有不同化學成份、晶體結構和形貌的準一維鋅-鐵-氧納米結構陣列。 / 垂直排列的ZnO納米線陣列首先生長在不同的襯底上，然后进一步被用作其他納米結構陣列的生長模板。ZnO納米線不僅僅起到骨架定型的作用，最終還可以为后續納米結構提供原料组分。通過控制ZnO和氯化鐵溶液的反應時間，在煅燒后，我們可以製備ZnO/鐵酸鋅(ZnFe₂O₄)納米線纜陣列，以及化學/非化學計量的ZnFe₂O₄、ZnFe₂O₄/α-三氧化二鐵(α-Fe₂O₃)和α-Fe₂O₃納米管陣列。ZnFe₂O₄和α-Fe₂O₃納米管陣列都表現出了對可見光的吸收，它們的帶隙經估算分別是2.3 eV和1.7 eV。 / 通過電子能量損失譜(EELS)，可以得到ZnFe₂O₄納米管陣列的一些細節的結構信息。我們分別研究了兩個不同系列(溫度和化學計量)的ZnFe₂O₄納米管。研究發現，樣品的磁性和它們的晶體結構有著非常緊密的關係。首先，對於溫度系列的樣品，當樣品的燒結溫度從600 °C降到400 °C時，更多的三價鐵離子(Fe³⁺)佔據了尖晶石結構中的A位置(四面體位置)而並非它們本應佔據的平衡B位置(八面體位置)。這種偏離了正常尖晶石結構的情況使得A和B位置上的Fe³⁺的超交換作用增加，進而增加了樣品的阻隔溫度(TB)，磁各向異性常數(K)，3K和300 K下的飽和磁化強度(MS)和3K下的矯頑力(HC)。同時使3K和300K下的MS的比值變小。其次，對於化學計量系列的樣品，通過比較在同一燒結溫度下製備的化學計量和非化學計量的ZnFe₂O₄納米管，我們發現在鐵鋅比大於2的納米管中，Fe³⁺佔據A和B位置的比例和化學計量的樣品是类似的。這些多出的Fe³⁺也會增加超交換作用，從而導致較大的TB, K, MS(3K和300 K)，HC(3K)和較小的MS(3 K)/MS(300 K)比值。最後，作為非化學計量的極端情況，α-Fe₂O₃納米管在小的外加磁場下表現出了典型的Morin相變，在大的外加磁場下出現了場致spin-flop轉變。 / 另一方面，我們發現，當使用羅丹明B(RhB)作為指示劑時，ZnO/ZnFe₂O₄納米線纜陣列表現出了優於纯ZnO和纯ZnFe₂O₄納米管陣列的可見光降解活性，但是它們的降解路徑各不相同。ZnO由於染料敏化機制而具有可見光降解能力，但是其降解活性最差。ZnO/ZnFe₂O₄納米線纜陣列和ZnFe₂O₄納米管陣列的基本降解原理是相同的，那就是，利用有可見光活性的ZnFe₂O₄中的光生電子和空穴所生成的活性自由基降解RhB。但是，ZnO/ZnFe₂O₄納米線纜陣列的降解能力明顯優於ZnFe₂O₄納米管陣列，這是由於ZnO與ZnFe₂O₄之間的II型能帶匹配顯著地促進了光生電子和空穴的分離。 / In the present thesis, several kinds of pseudo-one-dimensional Zn-Fe-O nanostructure arrays with tunable chemical compositions, crystal structures and morphologies are successfully synthesized via a simple wet-chemical ZnO-nanowire-array templating method. / Vertically-aligned ZnO nanowire arrays are firstly fabricated on several different substrates and then serve as templates for other nanostructured arrays growth. The ZnO nanowires not only act as morphology-defining skeleton but also contribute chemically to the final composition of the nanostructures. By controlling the reaction time between ZnO and FeCl₃ solution, ZnO/ZnFe₂O₄ nanocable arrays, stoichiometric ZnFe₂O₄ nanotube arrays, nonstoichiometric ZnFe₂O₄ nanotube arrays, ZnFe₂O₄/α-Fe₂O₃ nanotube arrays and α-Fe₂O₃ nanotube arrays can be synthesized in a controlled manner after calcination. Both ZnFe₂O₄ and α-Fe₂O₃ nanotube arrays exhibit visible light absorption and their bandgap are estimated to be ~2.3 eV and ~1.7 eV, respectively. / The detailed structural information of the ZnFe₂O₄ nanotube arrays are obtained by electron energy loss spectroscopy (EELS). In particular, EELS are carried out for two different series (i.e., temperature and stoichiometric series). The magnetic properties of these samples are found to closely correlate to their structural characteristics. Firstly, with the decrease of the calcination temperature from 600 °C to 400 °C, more Fe³⁺ions occupy A sites (tetrahedral sites in spinel structure) rather than their equilibrium B sites (octahedral sites in spinel structure). The deviation from the normal spinel structure leads to the enhancement of superexchange interactions between Fe³⁺ions in A and B sites, and thus results in an increase in blocking temperature (TB), magnetic anisotropic constant (K), saturation magnetization (MS, at 3 K and 300 K), coercivity (HC, at 3 K) and a decrease in MS(3 K)/MS(300 K) ratios. Secondly, by comparing stoichiometric and nonstoichiometric ZnFe₂O₄ nanotubes calcinated at the same temperature, we found that the nonstoichiometric nanotubes (Fe:Zn > 2) shows similar ratios of Fe³⁺in A and B sites to that of the stoichiometric one. The extra Fe³⁺in the crystal also enhances the superexchange interactions of Fe³⁺, which results in larger TB, K, MS(at 3 K and 300 K) and HC(at 3 K), and smaller MS(3 K)/MS(300 K) ratio. Lastly, α-Fe₂O₃ nanotubes, as an extreme case of the nonstoichiometric sample, show typical Morin-transition characterization under small external field, and field-induced spin-flop transition at large external field. / On the other hand, we found that the visible-light-driven photodegradation activities of ZnO/ZnFe₂O₄ nanocable arrays are superior to those of the ZnO nanowire arrays and ZnFe₂O₄ nanotube arrays using RhB as the probe molecules. All the three nanostructures show degradation of RhB molecules under visible light irradiation, but they take different degradation pathways. The degradation of RhB in the presence of ZnO nanowire arrays is attributed to the dye-sensitized mechanism, and the photodegradation activity is the worst. ZnO/ZnFe₂O₄ nanocable arrays and ZnFe₂O₄ nanotube arrays have the same degradation mechanism, that is, reactive radicals produced by photogenerated electron-hole pairs in the visible-light-active ZnFe₂O₄ are responsible for the photodegradation of RhB. However, the nanocable arrays show much higher degradation capability. This is owing to the type II band alignment between ZnO and ZnFe₂O₄, which greatly promotes the separation of photogenerated electronsand holes in ZnFe₂O₄. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Guo, Xuan = 準一維鋅-鐵-氧納米結構陣列 : 控制製備, 磁學性質以及光催化方面的應用 / 郭璇. / Thesis (Ph.D.) Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 107-117). / Abstracts also in Chinese. / Guo, Xuan = Zhun yi wei xin-tie-yang na mi jie gou zhen lie : kong zhi zhi bei, ci xue xing zhi yi ji guang cui hua fang mian de ying yong / Guo Xuan.

Chan Chun Wai = 納米鈀硅合金的熱性質 / 陳進偉. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 18-20). / Text in English; abstracts in English and Chinese. / Chan Chun Wai = Na mi ba gui he jin de re xing zhi / Chen Jinwei. / Acknowledgements --- p.III / Abstract --- p.IV / 摘要 --- p.V / Chapter Chapter One ´ؤ --- Introduction / Chapter 1.1 --- Novel materials in the 21st century --- p.1 / Chapter 1.2 --- What are Nanocrystalline Materials? --- p.1 / Chapter 1.3 --- The superior properties of Nanocrystalline Materials --- p.2 / Chapter 1.4 --- Fabrication of Nanocrystalline Materials --- p.3 / Chapter 1.5 --- Flaws of the as-produced Nanophase Materials --- p.4 / Chapter 1.6 --- Theory of Phase Separation --- p.4 / Chapter 1.7 --- Nucleation and Growth --- p.6 / Chapter 1.7.1 --- Homogeneous nucleation / Chapter 1.7.2 --- Heterogeneous nucleation / Chapter 1.8 --- Spinodal Decomposition / Chapter 1.8.1 --- How SD differs from the classical diffusion process? / Chapter 1.8.2 --- Dynamics of SD / Chapter 1.8.3 --- How can we distinguish SD from Nucleation and Growth? / Chapter 1.8.4 --- Pore-free nanophase materials produced by Liquid Phase SD / Chapter 1.9 --- Thermal properties of the pore-free nanostructured Pd82Si18 Alloy --- p.12 / Chapter 1.9.1 --- A review of grain growth in nanophase materials / Chapter 1.9.2 --- Grain growth study on LSD Pd82Si18 alloy 一 aim and prospect / References --- p.18 / Figures --- p.21 / Chapter Chapter Two 一 --- Experimental / Chapter 2.1 --- Introduction --- p.28 / Chapter 2.2 --- From preparation of samples to microstructure analysis --- p.28 / Chapter 2.2.1 --- Alloying / Chapter 2.2.2 --- Fluxing / Chapter 2.2.3 --- Rapid Solification / Chapter 2.2.4 --- Annealing / Chapter 2.2.5 --- Microstructure analysis / Figures --- p.31 / Chapter Chapter Three ´ؤ --- Results and discussions / Thermal stability of bulk nanostructured alloys prepared by liquid phase spinodal decomposition --- p.34 / References --- p.40 / Table --- p.43 / Figures --- p.44 / Chapter Chapter Four ´ؤ --- Conclusions --- p.61

by Ng Kwok Leung = 納米鈀硅合金之機械特性 / 吳國良. / Thesis submitted in 2000. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / by Ng Kwok Leung = Na mi ba gui he jin zhi ji xie te xing / Wu Guoliang. / Acknowledgements --- p.ii / Abstract --- p.iii / 摘要 --- p.iv / Chapter Chapter 0 --- Prelude- A brief history of materials --- p.1 / Chapter Chapter 1 --- Introduction --- p.4 / Chapter 1.1 --- Introduction --- p.4 / Chapter 1.2 --- How are nanostructured materials produced? --- p.5 / Chapter 1.3 --- General properties of nanostructured materials --- p.7 / Chapter 1.4 --- Mechanical behaviour of nanostructured materials --- p.8 / Chapter 1.5 --- The solution --- p.12 / References --- p.20 / Figures --- p.22 / Chapter Chapter 2 --- Experimental --- p.30 / Chapter 2.1 --- Specimen preparation --- p.30 / Chapter 2.2 --- Means of analysis --- p.32 / Figures --- p.36 / Chapter Chapter 3 --- Synthesis of large nanostructured Pd82Si18 alloy --- p.39 / Abstract --- p.39 / References --- p.44 / Table and Figures --- p.45 / Chapter Chapter 4 --- Tensile behaviour of nanocrystalline Pd82Si18 alloy --- p.54 / Introduction --- p.54 / Experimental --- p.55 / Results --- p.57 / Discussions --- p.58 / References --- p.59 / Table and Figures --- p.60