Fabrication of Uniform Hierarchical Mesoporous Wrinkled Silica Nanoparticles and Their Applications : Chemical Mechanical Planarization, Solar Cell, and Electrorheological Fluid

다국어 초록 (Multilingual Abstract)

Mesoporous silica nanomaterials have received much attention due to their dramatic increased surface to volume ratio. These porous structures have been used extensively in a variety of applications such as catalyst supporters, adsorption, separation, drug delivery, electrodes, and hard templates for fabrication of nanocomposites due to their unique features. Among various structures of mesoporous silica nanomaterials, spherical mesoporous silica nanoparticles have attracted much attention because they provide excellent pore accessibility and smooth molecular diffusion. Therefore, various methods for the fabrication of spherical mesoporous silica nanoparticles with a range of pore structure types have been reported, and have contributed to the development of fields such as packing materials for chromatography, drug delivery, cosmetics, and adsorption. However, despite the variety of methods for preparing spherical mesoporous silica nanoparticles, it should be still required to develop fabrication methods of spherical mesoporous silica nanoparticles with uniformity and high yields.
This dissertation introduces a method for fabricating uniform hierarchical mesoporous wrinkled silica nanoparticles. Furthermore, formation mechanism of the uniform spherical mesoporous silica naoparitcles was discussed by investigating the factors affecting the particle size and pore size of the naoparitcles. Thus, a complete method for high-yield production of uniform hierarchical mesoporous wrinkled silica nanoparticles with tunable particle size and pore size is provided. The prepared uniform mesoporous silica nanoparticles manifested better performance than non-porous silica nanoparticles of the same size in applications of abrasives in chemical mechanical planarization, scattering materials in dye sensitized solar cells, and hard templates for fabricating nanocomposite of ER fluids, demonstrating the superiority of the mesoporous structure. This dissertation suggests that silica nanoparticles with mesoporous structure offer the potential for performance enhancement in applications where non-porous silica spheres are currently used.

목차 (Table of Contents)

• 1. Introduction 1
• 1.1. Background 1
• 1.1.1. Nanostructured Materials 1
• 1.1.1.1. Nanomaterials 1
• 1.1.1.2. Silica Nanomaterials 2
• 1.1.1.3. Mesoporous Silica Nanomaterials 7
• 1.1.1.4. Spherical Mesoporous Silica Nanomaterials 8
• 1.1.2. Applications 12
• 1.1.2.1. Chemical Mechanical Planarization 12
• 1.1.2.2. Dye Sensitized Solar Cells 14
• 1.1.2.3. Electrorheological Fluids 17
• 1.2. Objectives and Outlines 18
• 1.2.1. Objectives 18
• 1.2.2. Outlines 18
• 2. Experimental Details 22
• 2.1. Fabrication of Uniform Hierarchical Mesoporous Wrinkled Silica Nanoparticles 22
• 2.1.1. Fabrication of uniform hierarchical mesoporous wrinkled silica nanoparticles (WSNs) 22
• 2.1.2. Characterization of hierarchical mesoporous wrinkled silica nanoparticles 23
• 2.1.3. The chemical mechanical polishing performance evaluation of the WSNs as slurry abrasives 23
• 2.1.4. Performance of dye sensitized solar cells with scattering layer of WSNs 24
• 2.2. Fabrication of Hierarchical Mesoporous Wrinkled Silica Nanoparticle based-SiO2/TiO2 Hollow Nanoparticles 26
• 2.2.1. Fabrication of hierarchical mesoporous wrinkled silica nanoparticle based-SiO2/TiO2 hollow nanoparticles 26
• 2.2.2. Characterization of hierarchical mesoporous wrinkled silica nanoparticle based-SiO2/TiO2 hollow nanoparticles 27
• 2.2.3. Electrorheological properties of electrorheological fluid based on hierarchical mesoporous wrinkled silica nanoparticle based-SiO2/TiO2 hollow nanoparticles 27
• 3. Results and Disccusions 29
• 3.1. Fabrication of Uniform Hierarchical Mesoporous Wrinkled Silica Nanoparticles 29
• 3.1.1. Fabrication of uniform hierarchical mesoporous wrinkled silica nanoparticles (WSNs) 29
• 3.1.2. Characterization of hierarchical mesoporous wrinkled silica nanoparticles 39
• 3.1.3. The chemical mechanical polishing performance evaluation of the WSNs as slurry abrasives 57
• 3.1.4. Performance of dye sensitized solar cells with scattering layer of WSNs 65
• 3.2. Fabrication of Hierarchical Mesoporous Wrinkled Silica Nanoparticle based-SiO2/TiO2 Hollow Nanoparticles 80
• 3.2.1. Fabrication of hierarchical mesoporous wrinkled silica nanoparticle based-SiO2/TiO2 hollow nanoparticles 80
• 3.2.2. Characterization of hierarchical mesoporous wrinkled silica nanoparticle based-SiO2/TiO2 hollow nanoparticles 83
• 3.2.3. Electrorheological properties of electrorheological fluid based on hierarchical mesoporous wrinkled silica nanoparticle based-SiO2/TiO2 hollow nanoparticles 98
• 4. Conclusion 112
• Reference 115
• 국문초록 123