本研究將使用靜電紡織，並透過改變製程參數中的工作電壓與工作距離，來製作出高含量的β相聚偏二氟乙烯(PVDF)。因β相於電紡製程中的PVDF的成相行為的探討，於前人研究中莫衷一是，本論文研究主要乃分成兩大部份，第一部份為以巨觀的角度來觀察PVDF，先以SEM觀察其微觀結構，再利用XRD、DSC與FTIR以定量的方式來分析在不同的工作參數下，結晶度與相含量的變化。
其數據變化之趨勢大致可以分成兩類，第一類為隨電壓上升而上升或下降之趨勢，如在工作距離30 cm中線徑從12 kV的221±30.2 nm下降到20 kV的193±24.2 nm；結晶度從12 kV的47 %上升到47.6 %。而第二類為電壓上升產生先升後降或先降後升之趨勢，如在20 cm中線徑從10 kV的98.2±11.2 nm上升到14 kV的138.3±11.8 nm，再下降到20 kV的113.2 nm；結晶度從10 kV的60 %下降到14 kV的57.6 %，再上升到20 kV的58.6 %，這說明了電壓與距離的調整不是簡單直接的影響PVDF奈米絲之樣貌、結晶與相含量。當電壓提升時PVDF高分子溶液會發生兩種變化，第一點是高分子溶液會受到更高的靜電力，溶液所受到的拉伸力會上升，而第二點為紡織速度的上升，因為電壓的上升使得溶液會以更快的速度旋伸。真正影響PVDF奈米絲之樣貌、結晶與相含量是電壓與距離改變所造成的「拉伸應力與旋伸速率」。在不同的實驗參數中拉伸應力與旋伸速率會彼此互相競爭，而佔優勢者將主導PVDF的結晶度、β相與線徑之大小，如距離20 cm的參數中10 kV到14 kV的結晶度是由旋伸速度主導，14 kV到20 kV是由拉伸力作主導。最後在工作電壓10 kV與工作距離20 cm的參數中得到了最高的結晶度(60 %)與β相(70 %)的PVDF奈米薄膜，並得到高拉伸力與低旋伸速率會形成出高結晶度、高β相與低線徑之PVDF奈米薄膜。而文章的第二部份以TEM來分析說明β相結晶的形成以及其樣貌，在研究中利用傅立葉轉換與反傅立葉轉換降低雜訊，來顯示出PVDFβ相結晶的樣貌，並量測其碳鏈之間距為0.43 nm，最後透過比對XRD之β相晶格常數之a軸長度後，來可推測出利用電旋產生的PVDFβ相結晶，可形成碳鏈近乎平行於拉伸方向排列，且形成具備優選方向之奈米結晶相。

This research uses electrospinning to produce high-content β-phase polyvinylidene fluoride (PVDF), and change the working voltage and working distance in the process parameters. Due to the discussion of β-phase and PVDF phase formation behavior in the electrospinning process, there is no agreement in previous studies. This paper is mainly divided into two parts. The first part is to observe PVDF from a macro perspective. First observe its microstructure with SEM, and then use XRD, DSC and FTIR to quantitatively analyze the changes of crystallinity and phase content under different working parameters.
The trend of data changes can be roughly divided into two categories. The first category is the trend of rising or falling with the increase of voltage. For example, in the working distance of 30 cm, the wire diameter decreased from 221.1±30.2 nm at 12 kV to 193.4±24.2 nm at 20 kV; the crystallinity rose from 47% at 12 kV to 47.6%. The second type is the trend of increasing voltage, firstly the phenomenon is rising and then falling or falling and then rising. For example, the wire diameter in 20 cm increases from 98.2±11.2 nm of 10 kV to 138.3±11.8 nm of 14 kV, and then drops to 113.2 nm of 20 kV; the crystallinity drops from 60% of 10 kV to 57.6% of 14 kV, Increase to 58.6% of 20 kV. This shows that the adjustment of voltage and distance does not directly affect the appearance, crystallinity and phase content of PVDF nanowires. When the voltage is increased, the PVDF polymer solution undergoes two changes. The first is that the polymer solution is subjected to higher electrostatic force, and the tensile force of the solution increase. The second point is the increase in spinning speed, because the increase in voltage causes the solution to spin at a faster speed. The resultant effect of the appearance, crystallization and phase content of PVDF nanowires is the "Tensile stress and Spinning rate" caused by changes in voltage and distance.
Finally, the crystallization behavior of PVDF β phase is explained by the stretching force and spinning time, and by observing the experimental results of voltage and distance, it is inferred that the factors affecting β phase and crystallinity are stretching force and spinning rate. In different experimental parameters, the tensile stress and the spinning rate compete with each other, and the dominant one dominates the crystallinity, β phase and wire diameter of PVDF. For example, the crystallinity of 10 kV to 14 kV in the parameter of 20 cm distance is dominated by the spinning (rotating) speed, and 14 kV to 20 kV is dominated by the tensile force. At the last, the PVDF nano fiber with the highest crystallinity (60%) and β phase (70%) is obtained in the parameters of working voltage 10 kV and working distance 20 cm, and the high tensile force and low spinning rate are formed. PVDF nano film with high crystallinity, high β phase and low diameter.
In the second part of the article, TEM was used to analyze the formation and appearance of β-phase crystals. In the research, Fourier transform and inverse Fourier transform were used to reduce noise and show the appearance of PVDF β-phase crystals. The distance between the carbon chains is 0.43 nm. Finally, after comparing the a-axis length of the β-phase lattice constant of XRD, it can be inferred that the PVDF β-phase crystals produced by electrospinning can form carbon chains that are aligned almost parallel to the stretching direction. And a nano crystal phase with a preferred orientation is formed.

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