利用分子動力學計算改質之聚乙二醇熱力學與力學性質以及泊洛沙姆407之力學性質

Abstract

隨著科技迅速的發展，計算機模擬已經成為非常重要的開發材料方法。在本論文中利用了分子動力學去探討材料之物理性質諸如玻璃轉移溫度、楊式模數以及平方位移。第一部分，我們探討改質電解質的物理性質，目的為維持低玻璃轉移溫度並提升材料硬度。我們發現改變高分子的側鏈時，官能基的大小影響了整個聚乙二醇的流動狀態，並間接影響了它的物理性質。結果得知添加氟官能基的材料在玻璃轉移溫度維持在250K且楊式模數增加到1.6GPa，這樣的物理性質符合我們所要改質的目標。第二部分，同樣是透過分子動力學探討聚合物材料之物理性質，我們發現了在加入水的人工眼角模材料泊洛沙姆-407之中，隨著水的重量百分比越高，楊式模數迅速的下降且由應力應變圖震盪情形趨近於水溶液相態的拉伸狀況發現水主導了整體系統的物理性質。總結來說，我們可以利用分子動力學來做材料物理性質的初步了解並預測。

Owing to the rapid development of the science and technology, computational modeling has become one of the most important ways to discover innovative materials. In this thesis, molecular dynamics is used to study physical properties such as glass transition temperature, Young’s modulus and mean square displacement of the materials. In part one, we aimed to remain low Tg and enhance the stiffness of the materials by discussing the physical properties of the polymer electrolytes. We found that as we modified the side chain of the polyethylene oxide, the volume of the functional groups influences the mobility of the polymer a lot and it also affects the physical properties indirectly. Judging from the results, polymer electrolytes materials which are added with fluoro functional groups has no change in glass transition temperature about 250K but has a lot improvement in Young’s modulus about 1.6GPa. The physical properties meet the goal that we aimed to modify. In part two, molecular dynamics is also used to describe the physical properties of the system. It is also found that as we increase the ratio of the water in the artificial corneal material system which is poloxamer 407, Young’s modulus decrease rapidly and the dramatic fluctuations in stress strain diagram because the H2O dominate the physical properties by molecular dynamics simulations. In conclusion, we can preliminary understanding and predict the physical properties of the materials by using molecular dynamics simulations.