臺灣博碩士論文加值系統

本論文主要是利用膽固醇液晶(cholesteric liquid crystal; CLC)同軸纖維來開發即時響應及能偵測多種類有機蒸氣之膽固醇液晶氣體感測元件，由於膽固醇液晶分子的週期性排列能反射特定波長，因此可藉由光線通過CLC纖維膜後之反射頻譜的變化來針對待測氣體分子進行量測與分析。首先利用同軸靜電紡絲技術來製作高分子物質與膽固醇液晶的複合型奈米纖維，並分別針對工業常見的溶劑：丙酮、丁酮來進行檢測；實驗中觀察不同的製程參數對於纖維結構的影響，且利用攝影機錄製偏光顯微鏡下的CLC纖維在有機氣體環境下的響應，並藉由其RGB與灰階來探討與分析CLC纖維在不同氣體環境下的反射光訊號變化情形。此外，亦分析該CLC纖維膜在有機氣體之擾動下的CLC分子平面排列(planar alignment)失效之反應時間。

In this thesis, the electrospun cholesteric liquid crystal (CLC) coaxial fiber was applied to develop a gas sensor with real-time detecting organic vapor. Because the periodic arrangement of cholesterol liquid crystal molecules can reflect a specific wavelength, so we can detect the gas molecules by means of measuring the change of the spectrum of the reflected light passing through the CLC fiber membrane. First, coaxial electrospinning technology was used to fabricate polymer and cholesterol liquid crystal composite nanofibers, and then the proposed fibers were applied to monitor the solvents of acetone and butanone respectively. The effects of different process parameters on the fiber structure were studied, and the dynamic response of the CLC fibers to the organic vapor was recorded by the camera under the polarized optical microscope. By analyzing the RGB and grayscale of the reflected light signal, the reaction of the CLC fibers to the organic molecules was investigated and analyzed. In addition, the response time of the CLC molecular from the planar alignment to disordered state under the disturbance of the organic gas was also studied.

致 謝 II
摘 要 III
Abstract IV
目錄 V
圖目錄 VII
表目錄 X
第一章 緒論 1
1.1 研究背景 1
1.2 研究方法 2
第二章 理論基礎 3
2.1 靜電紡絲簡介 3
2.1.1 溶液性質 4
2.1.2 操作參數 8
2.1.3 環境因素 11
2.1.4 同軸靜電紡絲 13
2.2 液晶簡介 14
2.2.1 液晶種類 14
2.2.2 膽固醇液晶的光學特性 17
2.3 膽固醇液晶氣體感測器技術 19
第三章 實驗方法與量測 22
3.1 實驗材料介紹 23
3.2 同軸靜電紡絲設備 24
3.3 同軸靜電紡絲製作 25
3.3.1 膽固醇液晶混合液配製 25
3.3.2 高分子PVP溶液配製 25
3.3.3 同軸靜電紡絲的製程 26
3.4 有機氣體檢測 27
3.4.1 偏光顯微鏡觀察 27
3.4.2 影像灰階與RGB處理 28
3.4.3 判定響應時間終點 29
第四章 實驗結果與討論 30
4.1 同軸靜電紡絲之製程參數探討 30
4.1.1 高分子溶液濃度與液晶流速 30
4.1.2 施加電壓 34
4.1.3 收集距離 36
4.2 膽固醇液晶氣體感測器特性分析 38
4.2.1 液晶纖維感測有機氣體時的偏光顯微鏡觀察 38
4.2.2 RGB &灰階分析 39
4.2.3 實驗穩定性檢測 40
4.2.4 有機氣體檢測 41
第五章 結論與未來展望 44
5.1 結論 44
5.2 未來展望 45
參考文獻 46

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