彈性高分子電解質溶液之低頻介電係數計算

Calculation of Dielectric Coefficient of Flexible Polyelectrolyte Solution Under Low Frequency

王士綸(Shih-Luen Wang)

指導教授 ： 陸駿逸

國立臺灣大學/理學院/物理研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.00054

摘要

我們計算了稀薄高分子電解質溶液的低頻介電常數，高分子在溶液中的運動對介電常數造成的影響將在本文中討論。在低頻下，影響介電常數的主要因素是帶電載子在介電層中沿著高分子鏈方向運動所造成的電流。這種電流與高分子在溶液中的形狀以及運動方式有關。因此要計算低頻介電常數不僅要考慮溶液中介電層的性質，更要考慮高分子的運動狀態，因此，高分子運動模型的加入，對於動態介電常數的計算是不可或缺的。
在本文中我們以Rouse模型來描述高分子的運動型態。靜態（假設高分子不會動）與動態（考慮高分子運動）的結果皆在本文中做了探討。靜態結果與先前文獻中計算freely joint chain的介電常數的結果拿來做了比較，並且發現兩者相當接近。動態的結果關注於動態介電常數與靜態介電常數的差異，亦即，高分子的運動造成的介電常數改變。我們的結果顯示高分子運動所造成的介電常數改變與高分子單體（monomer）的性質有密切的關係。

關鍵字

介電係數

並列摘要

We calculated the dielectric function of a dilute solution of flexible polyelectrolyte under low frequency. The effect of the polymer dynamics is considered. Under low frequency, the major factor that affect the dielectric coefficient is the current generated by the motion of charge carriers within double layer along polymer chain. This current is related to the shape and motion of polymer chain. Thus, to calculate the dielectric coefficient under low frequency need to consider not only the property of double layer, but also the way how polymer chain moves. Thus, the consideration of polymer dynamics is crucial for the calculation of the dynamic dieletric coefficient.
In this article, Rouse model is applied here for the polymer dynamics. Both static and dynamic results are discussed. The static result is compared to the earlier result from a freely joint chain[1] and showed a similarity. The dynamic effects are considered as a correction added on the static result, which is showed to be controled by the local properties of polymer such as the diffusion coefficient of monomer.

並列關鍵字

dielectric coefficient

參考文獻

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