| DC 欄位 |
值 |
語言 |
| DC.contributor | 化學學系 | zh_TW |
| DC.creator | 王若晴 | zh_TW |
| DC.creator | Jo-Chin Wang | en_US |
| dc.date.accessioned | 2023-7-19T07:39:07Z | |
| dc.date.available | 2023-7-19T07:39:07Z | |
| dc.date.issued | 2023 | |
| dc.identifier.uri | http://ir.lib.ncu.edu.tw:88/thesis/view_etd.asp?URN=111223005 | |
| dc.contributor.department | 化學學系 | zh_TW |
| DC.description | 國立中央大學 | zh_TW |
| DC.description | National Central University | en_US |
| dc.description.abstract | 本篇論文有兩個系列所組成，系列一為設計出中心為吡唑 (pyrazole)，兩端為對稱長碳鏈之有機液晶材料;以及其二氟化硼 (BF2) 錯合物之材料。藉此探討五員雜環以及含硼錯合物對於液晶性質的影 響，並觀察在不同側鏈基長短下對其液晶性質之影響。利用偏光顯微 鏡觀察液晶相之偏光紋理、熱微差掃描分析儀觀察相變化之熱焓值， 藉此得知其液晶相在不同溫度下的性質表現，經過偏光紋理圖，判定 化合物 1a、2a、1a-BF2 及 2a-BF2 部分為 SmA 以及 SmC 型桿狀液 晶。
並以紫外光/可見光光譜以及螢光光譜，探討該分子的光學性質， 從結果得知將配位基 1a、2a 改為含二氟化硼 (BF2) 之錯合物 1a-BF2 及 2a-BF2 時，可使最大放光波長紅移。並利用熱重分析儀所得之數據， 了解化合物之熱穩定性，得知吡唑 (pyrazole) 配位基以及含二氟化硼 (BF2) 之錯合物在 270 C 以下均有良好的熱穩定性。
本篇論文之系列二為利用含浸法將過渡金屬氧化物 Fe3O4 修飾於 中孔洞碳氮材 N-CMK-9，並應用於高效能鋰(鈉)離子電池之負極材料。 利用氮氣吸脫附分析儀得知 N-CMK-9 具有高比表面積以及多孔之特 性，而修飾上過渡金屬之 Fe3O4@N-CMK-9 則有比表面積降低的趨勢， 藉此可以證明含浸法的成功，而本篇論文亦進一步利用 ICP-MS、XPS
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以及 TEM Mapping 來證明材料中具有氮、鐵元素，而氮元素的異原 子摻雜以及鐵元素的高理論電容量皆有助於電性表現的提升。
Fe3O4@N-CMK-9-30 在鋰離子電池系統以電流密度 100 mA/g 進 行充放電循環測試，經過 50 圈循環後仍保持 1779 mAh/g 的電容量 表現，在電流密度提升到 1000 mA/g 進行充放電循環測試，經過 100 圈循環後仍得到 895 mAh/g 的比電容，顯示此材料不僅擁有相當高的 電容量表現外，也具有良好的循環穩定性。 | zh_TW |
| dc.description.abstract | There are two parts of study in this paper, the first part was designing and synthesizing organic liquid crystal material with pyrazole at the center, and symmetrically flexible side chains on both sides. Another material with pyrazole at the center and coordinated with boron difluoride were also designed. The five-membered heterocyclic ring and boron difluoride complexes in these materials were used to explore the effect on the properties of the liquid crystal. The effects of different numbers of alkoxy groups on the liquid crystals’ properties were also observed. All compounds were characterized by 1H and 13C-NMR spectroscopy, while their phase properties of these mesogenic compounds were characterized and studied by polarized optical microscope (POM) and differential scanning calorimeter (DSC).
Results appeared that some of the compounds were Smectic liquid crystals, which were observed by polarized optical microscope (POM). The optical properties of these compounds were investigated by UV-Vis spectroscopy and fluorescence spectroscopy. Results showed that complexes which were coordinated with boron difluoride can cause the emission wavelength redshift.
The second part was to synthesis anode materials in lithium ion batteries. First, we designed 3-D hollow-type ordered mesoporous carbon with nitrogen-dpoed material, N-CMK-9. It’s high specific surface area and porosity can provide a lot of space for Li+ during insertion-extraction process, and it can also improve the electrochemical performance. In the second step, we introduced Fe3O4 into N-CMK-9. Fe3O4 not only has high
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theoretical capacity (925 mAh/g), but is also naturally abundant and cost-effectiveness. Fe3O4@N-CMK-9-30 displayed a high reversible capacity of 1738 mAh/g after 50 cycles at a current density of 100 mA/g, and 895 mAh/g after 100 cycles at a current density of 1000 mA/g. Fe3O4@N-CMK-9-30 has an very outstanding specific capacity and good rate performance. | en_US |
| DC.subject | 中孔洞材料 | zh_TW |
| DC.subject | 鋰離子電池 | zh_TW |
| DC.subject | Mesoporous material | en_US |
| DC.subject | Lithium ion battery | en_US |
| DC.title | 對稱 Pyrazole 為架構之配位基與其硼錯合物之液晶性質探討與以四氧化三鐵修飾有序中孔洞之碳氮材 N-CMK-9 應用於高效能鋰離子電池負極材料 | zh_TW |
| dc.language.iso | zh-TW | zh-TW |
| DC.type | 博碩士論文 | zh_TW |
| DC.type | thesis | en_US |
| DC.publisher | National Central University | en_US |