本論文研究應用實驗與數值方法研究靜電紡絲 (Electrospinning) 製程行為，藉由分析高分子材料聚己內酯 (Polycaprolactone, PCL) 的不同重量百分比30-55 (wt%) 其黏度、流變特性、導電度、表面張力與接觸角之間相互關係，最後透過掃描式電子顯微鏡 (Scanning Electron Microscope, SEM) 拍攝不同濃度纖維織表面形貌，實驗結果發現，PCL之濃度與黏度成正比關係，符合牛頓流體趨勢，且濃度在 30 (wt%) 時導電率最高，值為1.24 μS/cm ，表面張力隨濃度增加而提升，其接觸角平均值落在73°左右，顯示其為疏水性材料，而從SEM結果可發現PCL濃度越低時，電紡絲纖維珠狀物較容易產生，濃度30 (wt%) 時有最小線徑0.06 μm ；濃度55 (wt%) 時纖維線徑為整體濃度範圍最大。數值方法採用ANSYS Fluent套裝軟體中的多相流模組分析靜電紡絲製程中的泰勒錐，利用流體體積法 (Volume of Fluid) 計算並搭配電磁流體模組 (Magnetohydrodynamics, MHD) 模擬靜電紡絲中氣-液介面受電場作用之影響，藉由更改操作電壓、流率、黏度、導電度與表面張力，探討在泰勒錐形成時錐體-射流之影響，模擬結果發現，當電壓越大時，泰勒錐長度會有長到短的趨勢，當流率與黏度越大時，泰勒錐長度則會越長，表面張力越大時泰勒錐越短，導電度大小則對泰勒錐長度無明顯變化，因此藉由模擬的泰勒錐長度與實驗結果比對可知，本研究成功模擬出泰勒錐產生的錐體-射流現象，並且提供實驗前期調配參數上的參考依據。

In this thesis, experimental and numerical methods are applied to study electrospinning process. The interaction between viscosity, rheological properties, electric conductivity, surface tension and contact angle of PCL (Polycaprolactone) polymer from 30 wt% to 50 wt% are analyzed. Then, SEM is used to measure the surface of fiber woven with different concentrations. The experimental results show that the solution weight percentage is proportional to the viscosity; and the highest electric conductivity, 1.24 μS/cm, is measured at 30 wt%. Surface tension is proportional to solution weight percent; the average contact angle is around 73° that indicated PCL is a hydrophobicity material. According to the SEM results, the lower the PCL concentration is used, the more easily the beads on the fibers are produced, and when the fiber diameters for concentration of min. and max. are 0.06 μm of 30 wt% and overall of 55 wt%, respectively. Simulation is based on the multiphase flows module of ANSYS Fluent to analyze the Taylor cone of electrospinning process. Volume of Fluid (VOF) method and Magnetohydrodynamics (MHD) are applied to simulate the influence of liquid-gas interface affected by electrical potential. The influence of changing of operating voltage, flow rate, viscosity, electric conductivity and surface tension was explored. The simulation result shows that when the voltage was increased more, the length of Taylor cone become shorter. The length of Taylor cone become longer as the flow rate and viscosity are increased more. In addition, the length of Taylor cone decreased while the surface tension increased. The electric conductivity shows less influence on the length of Taylor cone. In this study, the Cone-jet of Taylor cone is simulated which can support the measured data of experimental can be the reference for the future application.

致謝 ii
摘要 iii
Abstract iv
符號說明 v
目錄 vi
圖目錄 ix
表目錄 xiv
第一章 緒論 1
1-1前言 1
1-2 研究背景與動機 3
1-3 文獻回顧 5
1-3-1聚己內酯(PCL) 5
1-3-2 靜電紡絲 8
1-4 研究目的 11
第二章 理論基礎 12
2-1靜電紡絲理論分析 12
2-2 影響靜電紡絲製程的參數 15
2-3 靜電紡絲的收集方式 22
2-4 聚合物溶液流變原理 24
2-4-1 聚合物的黏度 24
2-4-2 牛頓與非牛頓流體 25
2-4-3 聚合物的流變行為 26
2-5 軟體介紹 27
2-5-1 計算流體力學簡介 27
2-5-2 ANSYS Fluent介紹 28
2-5-3 Gambit介紹 30
第三章 數值模擬原理與數值方法 32
3-1基本假設條件 32
3-2統御方程式(Governing equation) [67-69] 32
3-3流體體積法(Volume of Fluid) [67, 68, 70] 33
3-3-1物理屬性(Properties)運算 34
3-4連續表面力法(Continuum Surface Force) [67, 71] 35
3-5帕松方程式(Poisson's equation) [74] 37
3-6磁流體動力學(Magnetohydrodynamics, MHD) [75] 37
3-7數值方法 38
3-8 PISO演算法 40
3-9幾何尺寸 46
3-10邊界設定 48
第四章 實驗方法與儀器介紹 50
4-1 PCL溶液調配流程 51
4-1-1 相關材料準備 51
4-1-2 聚合物溶液調配 52
4-2靜電紡絲製程與原理 54
4-3靜電紡絲之設備 55
4-4實驗用測量設備 57
4-4-1流變儀 58
4-4-2導電度計 59
4-4-3表面張力計 60
4-4-4接觸角測量儀 61
4-4-5掃描式電子顯微鏡 63
第五章 結果與討論 64
5-1問題定義 64
5-2電壓變化對錐體-射流影響 66
5-3流率變化對錐體-射流影響 69
5-4黏度變化對錐體-射流影響 72
5-5導電度變化對錐體-射流影響 75
5-6表面張力變化對錐體-射流影響 78
5-7高分子溶液之黏度量測 81
5-8高分子溶液之導電度量測 83
5-9高分子溶液之表面張力量測 85
5-10高分子溶液之接觸角量測 87
5-11高分子溶液濃度與纖維線徑之關係 92
第六章 結論與展望 104
6-1 結論 104
6-2 展望 106
文獻回顧 107

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