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The chromatographic behaviour of a new column packing for high performance size exclusion chromatography based on crosslinked polyacrylamide particles was studied. Experimental retention data for poly(ethylene glycol)and poly(ethylene oxide) standards in water and water-methanol mixtures showed that the separation mechanism is size exclusion, since a universal calibration plot based on hydrodynamic volume was obtained. For polysaccharide standards in water and water-methanol (80/20), the universal calibration was valid for molecular weights above 4 * 10~. Below this value, secondary mechanisms appear to be taking part in the separation since water-methanol (80/20) is a poor solvent for polysaccharides. Crosslinked polyacrylamide packings showed an interactive behaviour with tetrahydrofuran and dimethylformamide as eluents with polystyrene and poly( ethylene glycol )/poly(ethylene oxide) standards and the universal calibration was not valid.

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Medical applications of calcium phosphate biomaterials are limited because of poor mechanical properties and acute inflammation reactions which take place occasionally in the clinic. To increase the usefulness of calcium phosphate biomaterials it is necessary to improve the mechanical properties and biological character. Processing and characterization of porous hydroxyapatite (HA) and dense composite (HA-Spinel) biomaterials have been performed in the present research. Biocompatibility of these biomaterials has been examined in vitro using human and rat immortalized osteoblast cells, and the advantages and limitations of cell culture biocompatibility tests are discussed. X-ray analysis of material structure demonstrated that after sintering at 1450°C, HA-Spinel was changed into tricalcium phosphate (TCP)-Spinel phase structure. Mechanical properties testing showed that the bending strength and compressive strength of HA may be improved by adding Spinel. Biocompatibility examination demonstrated that both human and rat osteoblast cells anchored to the surface of the porous and dense biomaterials in a short time, and subsequently, grew and proliferated normally on the surface of these biomaterials. Cytotoxicity evaluation in vitro by studying material extracts demonstrated that compared with the control group of cells cultured on polystyrene, HA-Spinel possessed slight toxicity. Cell growth in HA-Spinel first extracts was slightly impaired. Tritium labeling and immunofluorescent analysis proved that human osteoblast cells and rat osteoblast cells have normal expression of collagen synthesis on the above biomaterials. Confocal laser scanning microscopy (CLSM) observation showed that collagen fibers were produced on these materials, and the amount of the collagen synthesized on the materials increased with culture time. Subsequent analysis indicated that both HA and HA-Spinel can strongly adsorb serum and albumin proteins from culture media and the amount of protein adsorption was proportional to the porosity in the materials. Protein adsorption on the material surface was saturated usually in 2-4 hours, and 1/3-1/2 of the total protein adsorption was achieved in several minutes. In vitro assay also confirmed that human and rat osteoblast cells can be applied as an in vitro model to evaluate the biocompatibility, cytotoxicity and other biological characteristics. Compared with human osteoblast cells, rat osteoblast cells have a greater proliferation rate. In normal conditions, the proliferation rate of the rat osteoblast cells is 2-4 times that of the human osteoblast cells and for this reason rat osteoblasts seem more sensitive to material extracts.

This project was focused on the synthesis of novel phthalocyanines for the construction of porous molecular crystals that incorporate the desirable properties associated with phthalocyanine complexes. Conventional phthalocyanines are relatively insoluble, therefore, remain difficult to process, characterise and effectively crystallise. To counteract this problem, bulky 2,6-di-iso-propylphenoxy substituents were placed around the aromatic core of the phthalocyanine macrocycle and proved to successfully inhibit the co-facial aggregation which limits their solubility. These bulky groups also direct the crystallisation of the phthalocyanine macrocycle inducing a cubic packing arrangement with significant accessible solvent filled voids. The aim of this work was the modification of this 2,6-di-isopropylphenoxy substituted phthalocyanine to enhance the magnetic and catalytic properties and demonstrate its suitability as a platform for creating iso-reticular systems with increased functionality. It was anticipated that mixed double decker complexes of this derivative and another phthalocyanine macrocycle would form crystals with the same cubic spatial arrangement, while maintaining their high catalytic activity or single molecular magnetism behaviour. Firstly, a larger number of transition metals along with some lanthanide metals have been incorporated within this substituted phthalocyanine, extending the previous work on this system. Furthermore, the corresponding contracted macrocycle boron subphthalocyanine was also investigated. While the 2,6-diisopropylphenyl substituents did not greatly affect the electronic properties of the subphthalocyanine, the solid state properties of the material proved interesting. The lanthanide phthalocyanine complexes were further employed in the preparation of lanthanide double decker phthalocyanines that possess single molecule magnetic properties. While retaining this desired property, they also crystallised to produce clathrates with large solvent filled voids. A different double decker complex which contained two iron metal centres bridged by a single nitrogen atom was also prepared from the octa substituted 2,6-di-iso-propylphenoxy phthalocyanine and an unsubstituted phthalocyanine. This nitrido bridged di-iron phthalocyanine complex displayed similar catalytic activity to previously reported systems of this kind and crystallised to afford cubic crystals with large solvent filled voids. These were shown to be accessible by both solvent and ligand exchange. Suitable bidentate ligands for structural stabilisation could be also incorporated. Finally, the preparation of an alternatively substituted phthalocyanine for the construction of a potential porous molecular crystal was studied. By synthesising a hexamethylindan substituted phthalonitrile, it was possible to obtain a soluble phthalocyanine that crystallised to give a clathrate that contained large one-dimensional voids.

分層次的多孔材料在自然界中非常廣泛的被發現，例如動物的肺部、樹葉以及矽藻的骨骼。最近一些年，大孔(macropores)連同介孔(mesopores)或者(或與)微孔(micropores)等結構的分層次的多孔材料的製備與合成吸引了材料化學領域諸多的注意力，以期他們在催化、吸附解附、藥物釋放、感測器以及組織工程等多種方向中發揮潛在的應用。 / 本論文中我們將介紹一種簡單而靈活的的基於微粒穩定的高內相乳液(Particle-stabilized high internal phase emulsion)的方法，製備得到具有分層次多孔結構的二氧化鈦材料，擁有增強的光催化活性。由微凝膠軟球和二氧化鈦硬球共同作用，我們得到穩定的水包油高內相乳液體系。在除去液體相時將會促使形成幾十微米的大孔結構，約十微米的介孔連通窗格，以及分佈在大孔壁上的約一百納米的微孔，這三種不同尺寸的孔隙結構在三維方向上互相連通。初始合成的二氧化鈦材料由掃描電子顯微鏡(SEM)，X射線衍射(XRD)，壓汞儀來表徵其内部結構，同時測試其相對應的羅丹明光降解效率。結果清晰地顯示，微粒穩定的範本法可以成功的形成擁有多種且互不相同的多層次多孔結構。同時這種具有大孔和微孔的多層次孔隙結構的二氧化鈦材料，表現出非常有效的光化學催化性質，顯示了其在分離、淨化等過程的巨大潛在應用價值。 / Hierarchical porous materials occur widely in nature, including for example the lungs of animals, the leaves of trees, and diatom skeletons. In recent years, the synthesis of new hierarchical porous materials containing macroporous along with micro-and/or mesoporous has attracted considerable attention in material chemistry, because of their potential use in diverse applications such as catalysis, adsorption and separations, drug delivery, sensors and tissues engineering. / In this thesis, we present a simple and flexible method to synthesize hierarchically porous structured titania with enhanced photocatalytic activity using particle-stabilized high internal phase emulsions (Pickering HIPEs). Starting with a highly concentrated emulsion stabilized by both soft microgels and TiO₂solid nanoparticles, three-dimensionally interconnected porous titania materials with ordering on three different scales, that is, macroporous (~50μm), interconnected throat (~10μm), and nanoporous walls (~100 nm), are successfully obtained after drying and sintering. The so-prepared materials are characterized by scanning electron microscopy (SEM), X-ray diffraction, mercury intrusion, and the corresponding photocatalytic activity is evaluated by measuring the photodegradation of Rhodamine B in water. Our results clearly show that particle-stabilized emulsion templating can successfully lead to hierarchical porous material with multiple and discrete pore scales. Moreover, these hierarchically porous TiO₂ containing macroporous along with nanopores walls can be very efficient photocatalysts, suggesting their great potential applications in separation and purification process. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Li, Xiaodong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references. / Abstracts also in Chinese. / 摘要 --- p.I / Abstract --- p.II / Tableof Contents --- p.III / Acknowledgement --- p.VI / Chapter Chapter 1 --- Introduction to Porous Materials: Design, Synthesis and Applications --- p.1 / Chapter 1.1 --- Hierarchical Porous Materials in Nature --- p.1 / Chapter 1.2 --- Artificial Hierarchical Porous Materials --- p.2 / Chapter 1.3 --- Non-Templating Methods --- p.3 / Synthesis of Hierarchical Porous Materials with Single Composition --- p.5 / Chapter 1) --- meso-macroporous zirconium oxides --- p.5 / Chapter 2) --- meso-macroporous titanium oxides --- p.6 / Synthesis of Hierarchical Porous Materials with Multiple Composition --- p.9 / Chapter 1.4 --- Templating Methods --- p.10 / Chapter 1.5 --- Combination of Template and Non-template Methods --- p.12 / Chapter 1.6 --- Potential Application of Porous Materials --- p.13 / HPLC separation --- p.13 / Hierarchical catalysis --- p.14 / Electrode materials for fuel cell applications --- p.15 / Biomaterials engineering --- p.15 / Chapter 1.7 --- Objective of the Research --- p.16 / Chapter References --- p.18 / Chapter Chapter 2 --- Preparation of Hierarchically Structured TiO₂ Using High Internal Phase Emulsions (HIPEs) Stabilized by Binary Nanoparticles as the Templates --- p.22 / Chapter 2.1 --- Introduction to Particle Stabilized HIPEs --- p.22 / Chapter 2.2 --- Experiment Part --- p.26 / Chapter 2.2.1 --- Materials --- p.26 / Chapter 2.2.2 --- pNIPAM-co-MAA microgels synthesis and Characterization --- p.26 / Chapter 2.2.3 --- Synthesis of Hierarchical Porous TiO₂ Materials templating from HIPEs Stabilized by Binary Nanoparticles --- p.29 / Chapter 2.3 --- Results and Discussion --- p.32 / Chapter 2.3.1 --- HIPEs Stabilized Solely by Microgel Particles --- p.32 / Chapter 2.3.2 --- HIPEs Stabilized by Binary Nanoparticles --- p.35 / Chapter 1) --- Sintering effect on the porous TiO₂ monolith --- p.40 / Chapter 2) --- Microgel/TiO₂ ratio effect on the porous materials --- p.45 / Chapter References --- p.52 / Chapter Chapter 3 --- Photo-Catalytic Activity of the TiO₂-based Hierarchically Structured Porous Materials --- p.54 / Chapter 3.1 --- Introduction --- p.54 / Chapter 3.2 --- Experiment Section --- p.55 / Chapter 3.3 --- Result and Discussion --- p.56 / Chapter 1) --- Influence of sintering temperature on the porous materials --- p.56 / Chapter 2) --- Influence of internal phase volume fraction on the photocatalytic activity . --- p.59 / Reference --- p.63 / Chapter Chapter 4 --- Conclusion --- p.64

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