高分子駐極體薄膜製作與三維紅外光譜量測

Fabrication and 3-D FTIR Characterization of the Polymeric Electret Films

謝旻晏(Min-Yen Hsieh)

指導教授 ： 游信和

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所在職專班/碩士(2008年)

摘要

本論文採用聚偏二氟乙烯(polyvinylidene fluoride, PVDF)為原料，使用熱壓法與熱拉伸製成不同拉伸比例之薄膜。薄膜之性質及結構由自製之三維紅外光譜儀分析。本論文發現，當PVDF薄膜取向化越高，薄膜從等向性轉變為各向異性越趨明顯，這是由於受機械拉伸後，多數分子偶極從X軸(垂直)方向旋轉到Z軸(厚度)方向之故。此外，取向化越高，PVDF之?相波峰吸收值會逐步降低，?相波峰吸收值則增強，?相的含量大增。隨後使用?相含量最多之薄膜進行循環極化，將試片做成駐極體。極化後之PVDF薄膜之?相在X軸(垂直)方向上之紅外光譜吸收值明顯降低，而Z軸(厚度)方向之紅外光譜吸收值明顯提高，三維紅外光譜觀察到電場極化確實使多數分子偶極從原本的振動方向偏轉到電場(厚度)方向。經由拉伸倍率的增加和電場極化，PVDF分子偶極取向分佈之中心軸位置會往厚度方向移動，且偶極分佈範圍也會隨著取向化程度和電場極化程度更加窄化與集中。極化後之高分子駐極體薄膜之電光係數(r33) 可經由穿透式電光薄膜量測系統測量計算而得約為0.27 pm/V。

關鍵字

高分子駐極體,三維紅外光譜,電光係數

並列摘要

The oriented PVDF film were prepared by hot press and drawn. Different oriented Poly(vinylidene fluoride) PVDF films were investigated by three-dimensional Fourier transform infrared spectroscopy. Samples properties were transformed from isotropic to anisotropic orientation obviously as the drawing ratios increased, this is because the dipoles distribution of samples was preferred oriented toward thickness direction of the film after drawing. In addition, the intensity of ? phase was decreased but ? phase was enhanced as the films orientation increased. Most ? phase transforms to ? phase was occurred. Infrared absorption of the sample thickness direction was increased but the peak in the perpendicular direction was decreased after poling, since the transition moment of the PVDF films was switched toward the field direction. A Gaussian distribution model of infrared intensities is used to predict changes in the center and width of the transition dipole moment orientation distribution. Electro-optical coefficient r33 of the poled polymeric electret was 0.27pm/V after transmission E-O measuring in this study.

並列關鍵字

Polymeric Electret, 3-D FTIR, E-O coefficient

參考文獻

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