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Preparation of nanotubes and nanofibers from silicon carbide precursor polymers by using polymer blend and spinning techniques
http://hdl.handle.net/10087/2933
http://hdl.handle.net/10087/2933a0fdca6b-f84e-4bbb-ba72-5001893e65ca
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
PhD1-316.pdf (7.4 MB)
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| Item type | 学位論文 / Thesis or Dissertation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2008-02-15 | |||||
| 著者 |
Correa, Pacheco Zormy Nacary
× Correa, Pacheco Zormy Nacary |
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| タイトル | ||||||
| タイトル | Preparation of nanotubes and nanofibers from silicon carbide precursor polymers by using polymer blend and spinning techniques | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| その他のタイトル | ||||||
| その他のタイトル | ポリマーブレンドおよび紡糸技術を用いた炭化ケイ素前駆体ポリマーからのナノチューブとナノファイバーの調製 | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | Nanotubes | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | Nanofibers | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | Silicon Carbide | |||||
| キーワード | ||||||
| 主題Scheme | Other | |||||
| 主題 | Spinning | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_46ec | |||||
| 資源タイプ | thesis | |||||
| 著者(ヨミ) | ||||||
| 姓名 | コレアパチェコ, ソルミナカリ | |||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Many potential applications have been proposed for silicon carbide (SiC)\nnanostructures, including high-strength composites, nanosensors and nanodevices.\nLimitations in processing are an important barrier that has to be overcome in order to\ndevelop these applications.\nThe aim of this study is to explore the possibility of fabricating SiC nanotubes\nand to improve the elaboration process of SiC nanofibers prepared by using polymer\nblend and spinning techniques.\nIn the general introduction, the structure of SiC and the recent uses of\npolycarbosilane (PCS) as a SiC precursor for nanofibers are discussed. A review of the synthesizing methods for SiC nanotubes and nanofibers and their possible applications\nare presented.\nThe present work proposes the use of polymer blend technique in order to\nprepare the SiC nanotubes and nanofibers. Due to the versatility of the polymer blend\nindustrially, it could be used to mass-production of nanostructures. The polymer blend\ntechnique presented is based on the use of a precursor polymer with a ceramic residue and a thermally decomposable polymer without carbon residue after heating.\nChapter 1 presents an attempt to prepare nanotubes from core/shell particles by\nusing polymer blend and wet-spinning techniques. Polystyrene (PS) was used as a core decomposable polymer and polydimethylsilylvinylacetylene (PDMSVA) as the shell silicon carbide precursor polymer. The core/shell particles were prepared by emulsion\npolymerization. They were subjected to wet-spinning, stretched mechanically six times their original length, stabilized by UV and also in air, and finally heat-treated in an inert atmosphere. Nanotubes were prepared although the silicon carbide precursor\npolymer (PDMSVA) was insufficiently stabilized.\nPreparation of nanotubes from poly(methyl methacrylate) / polycarbosilane\n(PMMA/PCS) and poly(methyl methacrylate) / polyacrylonitrile / polycarbosilane\n(PMMA/PAN/PCS) core/shell particles by the aforementioned techniques is presented in\nChapter 2. The core/shell particles were prepared by the spray drying method. They were subjected to wet-spinning, stretched, stabilized and heat-treated. Few nanotubes were obtained from the PMMA/PAN/PCS heat-treated sample because the stretching\ntechnique was not efficient in order to elongate all the core/shell particles.\nRecently, SiC fibers have found many applications in composites at higher\ntemperatures in oxidizing environments. One of the most important factors related to the\nchemical composition of these fibers is the oxygen content because it decreases the\nmechanical properties of the fibers used for such applications.\nIn this study, how to improve the preparation process in order to obtain SiC\nnanofibers with low oxygen content was sought.\nChapter 3 refers to preparation and study of the oxidation behavior of nanofibers\nderived from polycarbosilane by using polymer blend and melt-spinning techniques.\nPolycarbosilane (PCS) and novolac-type phenol-formaldehyde resin (PF) were dissolved in tetrahydrofuran (THF) and after removal of THF, the polymer blend was melt-spun.\nThe polymer blend fibers were soaked in an acid solution in order to cure the phenolic matrix. The stabilized polymer blend fibers were heated at 1000 oC under a nitrogen atmosphere and kept in nitric acid solution to remove the matrix carbon.\nThe oxidation behavior was characterized. A part of the nanofibers was further heated at\n1500 oC. Nanofibers of several 100 nm in diameter were prepared. A large amount of\noxygen was introduced into the nanofibers during the oxidation process. After heating at 1500 oC, the nanofibers changed from an amorphous phase to β-SiC.\nIn Chapter 4, the microstructural changes of nanofibers were examined. The preparation procedure was the same as that of Chapter 3, but the nanofibers were heated\nto two different temperatures, 1000 oC and 1200 oC. The nanofibers heated at 1200 oC\nwere straight, longer and had a smoother surface compared with the nanofibers heated at 1000 oC. The nanofibers heated at 1200 oC had higher resistance to oxidation by nitric acid treatment than the nanofibers heated at 1000 oC, revealing the importance of the heat treatment temperature.\nFinally, the general conclusions are presented. | |||||
| 内容記述 | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 学位記番号：工博甲316 | |||||
| 書誌情報 | 発行日 2007 | |||||
| フォーマット | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | application/pdf | |||||
| 著者版フラグ | ||||||
| 出版タイプ | AM | |||||
| 出版タイプResource | http://purl.org/coar/version/c_ab4af688f83e57aa | |||||
| 出版者 | ||||||
| 出版者 | 群馬大学工学研究科 | |||||
| 資源タイプ | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | Thesis or Dissertation | |||||
| 学位名 | ||||||
| 学位名 | 博士（工学） | |||||
| 学位授与機関 | ||||||
| 学位授与機関名 | 群馬大学 | |||||
| 学位授与年月日 | ||||||
| 学位授与年月日 | 2007-03-23 | |||||
| 学位授与番号 | ||||||
| 学位授与番号 | 12301甲第316号 | |||||
| 更新日 | ||||||
| 値 | 2019-11-28 | |||||
