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M.Sc. (Chemistry) / According to the International Union of Applied Chemistry (IUPAC) mesoporous silica materials are a class of materials which contain pore size with diameters ranging from 2 to 50 nm. Due to their attractive features such as large surface area along with tunable pore size, accessible silano groups and easy functionalization make them with special properties to be employed as stationary phases for different chromatographic applications such as clean up, preconcentration, purification and separation of analytical samples. Organic–inorganic mesoporous hybrid materials are a new class of materials obtained when an inorganic material, such as mesoporous silicas are surface modified using an organic material via silylation. The main advantage of these hybrid materials is that they are formed by combining dissimilar properties of inorganic and organic materials into one material. Whereas the inorganic materials provide rigidity and thermal stability, the organic components provide flexibility, dielectric, ductility, and processability. Therefore the advantages of these hybrid materials lead them to be used over a wide range of applications. The main objective of this study was to synthesize organic-inorganic hybrid mesoporous silica materials for use as stationary phases for solid phase extraction and high performance liquid chromatography columns. The materials were prepared under basic conditions using silica gel and tetraethyl orthosilicate used as a source of silica and modified by either surface polymerization or grafting methods using octadecyltrimethoxysilane followed endcapping with hexamethyldisilazane. The materials were characterized before and after surface modification using different analytical methods. Scanning electron microscopy (SEM) pictures showed that the morphology of the materials remained unchanged after surface modification.

This thesis mainly consists of two parts, the synthesis of several kinds of technologically interesting crystalline metal oxide nanoparticles via high temperature nonaqueous solution processes and the formation of core-shell structure metal oxide composites using some of these nanoparticles as the core with silica, titania or polymer as shell via a modified microemulsion approach. In the first part, the experimental procedures and characterization results of successful synthesis of crystalline iron oxide (Fe3O4) and indium oxide (In2O3) nanoparticles are reported. Those nanoparticles exhibit monodispersed particle size, high crystallinity and high dispersibility in non-polar solvents. The particle size can be tuned by the seed mediated growth and the particle shape can also be controlled by altering the capping ligand type and amount. The mixed bi-metal oxides such as cobalt iron oxide and lithium cobalt oxide will be discussed as well. In the second part, the synthesis and characterization of various surface coated metal oxides, including silica, titania and polymer coated nanocomposites are reported. The silica coating process is presented as a highlight of this part. By using a microemulsion system, core-shell structure silica coated iron oxide and indium oxide nanocomposites are successfully prepared. Furthermore, the thickness of the silica coating can be controlled from 2 nm to about 100 nm by adjusting the reaction agents of the micelle system. By extending the procedure, we will also discuss the titania and polymer coating preparation and characterization.

O presente trabalho descreve o desenvolvimento de um método analítico baseado na pré-concentração em fase sólida em fluxo de íons cobalto com posterior determinação por espectrofotometria. Como adsorvente sólido empregou-se a sílica gel modificada com 2-aminoetil-3-aminobutilmetildimetoxisilano (AAMDMS) e impressa ionicamente com o íon Co+2 (SGI). O sistema de pré-concentração em fluxo é baseado na retenção catiônica dos íons cobalto em uma mini-coluna preenchida com SGI, com conseqüente eluição com HNO3 0,5 mol L-1. Os íons cobalto eluídos reagem posteriormente com o complexante 1-(2-piridilazo)-2-naftol (PAN), formando um complexo de cor verde detectado espectrofotometricamente em 575 nm. As condições otimizadas foram: pH da amostra (9,2); concentração do tampão (amoniacal) da amostra (0,01 mol L-1); concentração do surfactante (LSS) (3,0 mmol L-1); vazão de pré-concentração (9,0 mL min-1); concentração do tampão (amoniacal) da solução do PAN (0,75 mol L-1); concentração do PAN (100 mmol L-1); pH da solução do PAN (10,2); comprimento da bobina reacional (225 cm); vazão total de eluição (7,0 mL min-1). A seletividade da SGI frente os íons cobalto foi atestada por meio da constante de seletividade relativa K’(KSGI/Kbranco), rendendo valores de 10,9 e 10,2 para (KSGI/ K sílica funcionalizada) e (KSGI/ Ksílica gel), respectivamente no sistema Co2+/Ni2+. Para o sistema Co2+/Cu2+ os valores encontrados foram 6,4 e 11,4. Além disso, foi realizado teste de interferência por meio de soluções binárias contendo diferentes proporções cobalto:interferente [1:1, 1:10, 1:100 (m/m)]. Os íons avaliados foram Ni2+, Cu2+, Fe2+, Pb2+, Cd2+, Mn2+, Zn2+, Cr3+ e, com exceção do íon zinco, na proporção 1:1 nenhum interferência foi observada. A precisão (n=10, repetibilidade) para os padrões de 10,0 e 90,0 μg L-1 rendeu desvios padrão relativos de 2,63 e 1,5%, respectivamente. O método apresentou os respectivos limites de detecção e quantificação de 0,51 e 1,71 μg L-1 e um fator de pré-concentração de 7,21 vezes. O método proposto foi aplicado em amostras de água, urina e material certificado de referência. / The present work describes the development of analytical method based on solid phase flow preconcentration of cobalt ions with further determination by spectrophotometry. Modified silica gel with 2-aminoethyl-3- aminobutylmethyldimethoxysilane (AAMDMS) and ionically imprinted with Co2+ ions (ISG) was employed as solid adsorbent. The flow preconcentration system is based on cationic retention of cobalt in a mini-column filled with ISG, with further elution with 0.5 mol L-1 HNO3. The cobalt ions eluted react subsequently with the complexant 1- (2-pyridylazo)-2-naphthol (PAN), forming a green complex detected spectrophotometrically at 575 nm. The optimized conditions were: sample pH (9.2); buffer (amoniacal) concentration of the sample (0.01 mol L-1), surfactant (SLS) concentration (3.0 mmol L-1); flow rate preconcentration (9.0 mL min-1); buffer solution concentration of PAN (0.75 mol L-1); PAN concentration (100 mmol L-1), pH of PAN solution (10.2); length of reaction coil (225 cm), total elution flow rate (7.0 mL min-1). The selectivity of ISG towards cobalt ions was attested by the constant selectivity for K'(KSGI / Kblank), yielding values of 10.9 and 10.2 for (KSGI / K functionalized silica) and (KSGI / Ksilica gel), respectively in the Co2+/Ni2+ system. For the system Co2+/Cu2+ the values were 6.4 and 11.4. Moreover, interference testing was performed by binary solutions containing different cobalt:interferent proportions [1:1, 1:10, 1:100 (m/m)]. The evaluated ions were Ni+2, Cu +2, Fe2+, Pb+2, Cd+2, Mn +2, Zn +2, Cr+3, and except by zinc, in 1:1 proportion no interference was observed. The precision (n=10, repeatability) for the standards 10.0 and 90.0 μg L-1 yield relative standard deviation of 2.63 and 1.5%, respectively. The method showed the respective detection and quantification limits of 0.51 and 1.71 μg L-1 and a preconcentration factor of 7.21. The proposed method was applied in water samples, urine and certified reference material.

by Chung Pui Shan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 105-110). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.iii / Table of contents --- p.v / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Metal clusters embedded in fused silica glass --- p.2 / Chapter 1.2 --- Ion implantation of metal clusters --- p.3 / Chapter 1.3 --- Feature of MEVVA implantation --- p.5 / Chapter 1.4 --- Motivation and organization of this thesis --- p.7 / Chapter Chapter 2. --- Sample Preparation and Characterization Methods / Chapter 2.1 --- MEVVA implantation --- p.9 / Chapter 2.2 --- TRIM simulation --- p.11 / Chapter 2.3 --- Sample preparation --- p.14 / Chapter 2.4 --- Rutherford backscattering spectroscopy (RBS) --- p.16 / Chapter 2.5 --- X-ray diffraction (XRD) technique --- p.17 / Chapter 2.6 --- X-ray photoelectron spectroscopy (XPS) --- p.21 / Chapter 2.7 --- Transmission electron microscopy (TEM) technique --- p.24 / Chapter 2.8 --- Spectroscopic ellipsometry (S.E.) --- p.25 / Chapter 2.9 --- Z-scan technique --- p.32 / Chapter Chapter 3. --- Characterization of Single Implanted Samples / Chapter 3.1 --- Experimental results and discussion / Chapter 3.1.1 --- RBS --- p.35 / Chapter 3.1.2 --- XRD --- p.38 / Chapter 3.1.3 --- XPS --- p.42 / Chapter 3.1.4 --- XTEM --- p.49 / Chapter 3.1.5 --- S.E --- p.54 / Chapter 3.1.6 --- Z-scan measurements --- p.60 / Chapter 3.2 --- Summary --- p.65 / Chapter Chapter 4. --- Characterization of Sequentially Cu-Ni Implanted Samples / Chapter 4.1 --- Experimental results and discussion / Chapter 4.1.1 --- XRD --- p.66 / Chapter 4.1.2 --- XPS --- p.68 / Chapter 4.1.3 --- XTEM --- p.77 / Chapter 4.1.4 --- Z-scan measurements --- p.87 / Chapter 4.2 --- Summary --- p.91 / Chapter Chapter 5. --- Conclusion and Future Works / Chapter 5.1 --- Conclusion --- p.92 / Chapter 5.2 --- Future works --- p.93 / Appendix / Appendix I --- p.94 / Chapter ☆ --- Sample preparation procedures for XTEM / Appendix II --- p.97 / Chapter ☆ --- Alignment procedures of S.E. / Chapter ☆ --- Implementation of the Merlin system / Appendix III --- p.101 / Chapter ☆ --- Calibration of S.E. / Reference --- p.105

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Surface plasmon resonance (SPR) biosensors have attracted great attention in scientific research in the past three decades. Extensive studies on the immobilisation of biorecognition elements have been conducted in pursuit of higher sensitivity, but trialled formats have focussed on a thin layer modification next to the plasmon film, which usually requires in situ derivatization. This thesis investigates an 'off-chip' immobilisation strategy for SPR biosensing using silica particles and considers the implications of a particle-modified evanescent field on the signal amplitude and kinetics, for an exemplar affinity binding between immobilised IgG and its anti-IgG complement. Submicron silica particles were synthesized as carriers for the bio-recognition elements. They were then immobilised to form a sub-monolayer on the gold film of an SPR biosensor using two methods: thiolsilane coupling and physical adsorption aided by mechanical pressure. The bio-sensitivity towards an antigen/antibody interaction was lower than an SPR biosensor with an alkanethiolate SAM due to the difference in ligand capacity and position in the evanescent field. The binding kinetics of antigen/antibody pair was found to follow the Langmuir model closely in a continuous flow configuration but was heavily limited by the mass transport from the bulk to the sensor surface in a stop-flow configuration. A packed channel configuration was designed with larger gel particles as ligand carriers, packed on top of a gold film to create a column-modified SPR biosensor. This sensor has comparable bio-sensitivity to the previous sub-monolayer particle-modified systems, but the binding and dissociation of the analyte was heavily dependent on mass transport and binding equilibria across the column. A bi-directional diffusion mechanism was proposed based on a two-compartment mass transport model and the expanded model fitted well with the experimental data. The column-modified sensor was also studied by SPR imaging and analyte band formation was observed and analysed. Using the lateral resolution, a multiplexing particle column configuration was explored, and its potential in distinguishing a multicomponent analyte.

by Leung Kit Sum = 透過X光電子譜研究射頻濺射之銅復合物石英 / 梁潔心. / Thesis submitted in: August 2002. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 77-78). / Text in English; abstracts in English and Chinese. / by Leung Kit Sum = Tou guo X guang dian zi pu yan jiu she pin jian she zhi tong fu he wu shi ying / Liang Jiexin. / Abstract --- p.i / 論文摘要 --- p.iii / Acknowledgement --- p.iv / Table of Content --- p.v / List of Figures --- p.ix / List of Tables --- p.xi / Chapter CHAPTER 1 --- INTRODUCTION / Chapter 1.1 --- Nanoparticles and Nanophase Materials --- p.1 / Chapter 1.2 --- Nonlinear Optical Phenomena and Their Physical Origin --- p.4 / Chapter 1.2.1 --- Dielectric Confinement --- p.6 / Chapter 1.2.2 --- Quantum Confinement --- p.8 / Chapter 1.2.2.1 --- Intraband Transition --- p.9 / Chapter 1.2.2.2 --- Interband Transition --- p.9 / Chapter 1.2.2.3 --- Hot-electron Transition --- p.11 / Chapter 1.3 --- Importance of Optical Nonlinearity --- p.11 / Chapter 1.3.1 --- Self-Phase Modulation --- p.11 / Chapter 1.3.2 --- Self-Focusing/Defocusing --- p.12 / Chapter 1.4 --- Sample Preparation --- p.12 / Chapter 1.4.1 --- Sputtering --- p.13 / Chapter 1.5 --- Characterization of Nanocomposites --- p.15 / Chapter 1.6 --- Aim of the Project --- p.15 / References --- p.17 / Chapter CHAPTER 2 --- INSTRUMENTATION / Chapter 2.1 --- Introduction --- p.20 / Chapter 2.2 --- Sputter Deposition --- p.20 / Chapter 2.2.1 --- Glow Discharge --- p.21 / Chapter 2.2.2 --- Radio-Frequency Sputtering (RF Sputtering) --- p.24 / Chapter 2.2.3 --- Magnetically Enhanced Sputtering --- p.24 / Chapter 2.2.4 --- Instrumentation --- p.25 / Chapter 2.2.4.1 --- Target Assemblies --- p.27 / Chapter 2.2.4.2 --- Shutter --- p.28 / Chapter 2.2.4.3 --- Substrate Holder --- p.28 / Chapter 2.2.4.4 --- Power Supply --- p.28 / Chapter 2.2.5 --- Experimental --- p.29 / Chapter 2.3 --- X-ray Photoelectron Spectroscopy (XPS) --- p.29 / Chapter 2.3.1 --- Instrumentation --- p.31 / Chapter 2.3.2 --- Application to metal nanoclusters composite glass --- p.33 / Chapter 2.3.2.1 --- Compositional Analysis --- p.33 / Chapter 2.3.2.2 --- Depth Profiling --- p.33 / Chapter 2.3.3.3 --- Auger Parameters --- p.33 / Chapter 2.4 --- Transmission Electron Microscopy (TEM) --- p.34 / Chapter 2.4.1 --- Sample Preparation --- p.35 / Chapter 2.4.1.1 --- Sample Thickness Determination --- p.35 / Chapter 2.4.1.2 --- Ion Milling --- p.36 / Chapter 2.4.2 --- Instrumentation --- p.36 / Chapter 2.4.3 --- Contrast and Image Formation --- p.38 / Chapter 2.4.3.1 --- Bright and Dark Field Image --- p.38 / Chapter 2.4.3.2 --- Mass and Thickness Contrast --- p.40 / Chapter 2.4.3.3 --- Diffraction Contrast --- p.40 / References --- p.42 / Chapter CHAPTER 3 --- COMPOSITION AND NANUSTRUCTURE OF COPPER DOPED FUSED SILICA / Chapter 3.1 --- Introduction --- p.44 / Chapter 3.2 --- Experiment --- p.45 / Chapter 3.3 --- Results and Discussion --- p.47 / Chapter 3.3.1 --- Effect of Input RF Power on the Growth of Film --- p.47 / Chapter 3.3.2 --- Theoretical Calculation of Cluster Size by Ratio of Surface to Total Amount of Copper --- p.55 / Chapter 3.3.3 --- TEM Studies of Copper Nanoclusters --- p.57 / Chapter 3.3.4 --- Further Discussion: Effect of Current and Voltage on the Determination of Deposition Rate --- p.60 / Chapter 3.3.5 --- Atomic Distribution and Chemical State of Copper Nanocluster --- p.60 / Chapter 3.3.6 --- Effect of Pressure on the Growth of Film --- p.66 / Chapter 3.3.6.1 --- How Pressure Affects Cluster Growth --- p.70 / Chapter 3.3.7 --- Effect of Deposition time on the Growth of Film --- p.71 / Chapter 3.3.7.1 --- How Film thickness Affects Cluster Growth --- p.75 / Chapter 3.4 --- Summary --- p.75 / References --- p.77 / Chapter Chapter 4 --- CONCLUSION AND FUTURE DIRECTIONS / Chapter 4.1 --- Conclusion --- p.79 / Chapter 4.2 --- Future Directions --- p.79 / Chapter 4.2.1 --- Generation of Active Matrix Nanocomposite --- p.79

Apart from being a support, the three substrates had their own roles in the growth of CNTs. Bamboo charcoal also acted as a catalyst provider. Au-coated silicon wafer participated in the formation of the silica/CNT composite nanowires. Copper foil itself was a catalyst. The silicate, the Au/Si droplet, and the copper particles were the catalysts for the growth of CNTs in these three substrates, respectively. The formation of the CNTs followed the vapor-liquid-solid (VLS) route which involved the decomposition of ethanol vapor into carbon, carbon dissolution inside the liquid catalyst and precipitation to form CNTs. / CNTs could be grown in a very wide temperature range (700-1400°C), but specific substrate for a particular temperature range was needed. The structures of the CNTs varied with the CVD processing conditions. The forms and the amount of catalytic material entering the interior of the CNTs depended on the characteristics of the catalyst for that process / The products formed on different substrates had their own characteristic features . Hollow or silicate filled CNTs with silicate droplet tips were formed on the surface of bamboo charcoal. Their diameter was in hundreds of nanometers and the length was about several microns. CNT-coated silica core-shell structures were obtained on Au-coated silicon wafer. The graphitic carbon shell was formed in thickness about 145 nm for the sample prepared at 1185°C, but amorphous carbon shell was produced in thickness more than 300 nm for the sample prepared at 1236°e. Lastly, CNTs with bamboo-like structure were synthesized on the copper foil substrate. The CNTs were getting thicker from 70 nm to 170 nm when temperature was increased from 700°C to 1000°C. The yield increased with temperature and annealing time if the sample was annealed for less than 30 min. / We report the growth of carbon nanotubes (CNTs) on different types of substrates with or without catalytic materials by using different approaches. The roles of the substrates and the catalysts in the formation of the CNTs are studied . We also characterized and identified the structural properties of the CNTs products. In this work, three types of substrates had been used, namely biomorphic bamboo charcoal , Au-coated silicon wafer, and copper foil. The CNTs were grown on different substrates by chemical vapor deposition (CVD) method at temperature range between 700°C and 1400°C. Ethanol vapor was used as the carbon source, while tetraethyl orthosilicate (TEOS) vapor was also applied to the process for bamboo charcoal. / Zhu, Jiangtao = 碳納米管在不同類型基底上的生長 / 朱江濤. / Adviser: D. H. L. Ng. / Source: Dissertation Abstracts International, Volume: 72-11, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2009. / 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. / Zhu, Jiangtao = Tan na mi guan zai bu tong lei xing ji di shang de sheng chang / Zhu Jiangtao.