本篇是以分子動力學模擬研究水分子環繞各種尺寸金奈米粒子的吸附機制與動態行為。我們選擇原子數分別為13, 55, 147正二十面體結構的金奈米粒子為研究對象，粒徑分別約為7.92Å, 13.2Å, 18.5Å。對水分子做密度剖面圖可發現水分子在金的表面有兩層吸附。我們也計算水分子的平均氫鍵數。在吸附層內的氫鍵數較高於一般塊材水，而且我們發現吸附層內的氫鍵方向許多都平行於吸附面。另外還對水分子做了方向次序參數的計算，探討吸附層水分子四面體結構與塊材水分子四面體結構的不同。以上計算還比較不同金奈米粒子尺寸所造成的差異。在動態行為方面，計算速度自相關函數、氫鍵自相關函數，平均平方位移。

Molecular dynamic simulation is utilized to investigate the adsorption mechanism of water molecules surrounding Au nanoparticle of different sizes. We selected 13, 55, 147 atoms icosahedral gold nanopartilce in our model and their diameter are 7.92Å, 13.2Å, 18.5Å, respectively. We calculated density profile of water molecules and found that there were two adsorption layers out of the surface of gold nanoparticles. We also calculated average number of hydrogen bonds per water . It is higer in the adsorption layer than in bulk water region and we found that the direction of hydrogen bonds are numerously parallel with gold surface in the adsorption layer. We also claculated orientational order parameter for water molecules and explore the difference of the tetrahedral structure of the water molecules between the adsorption layer and bulk water region. Besides, we compared of cases of different gold sizes.

目錄 I
圖目錄 IV
表目錄 VI
中文摘要 VII
Abstract VIII

第一章 緒論 1
研究背景 1
文獻回顧 3
本文架構 6
第二章 分子動力學理論 7
2.1 系綜 9
2.2 勢能函數 10
2.2.1 水分子之間的勢能函數 10
2.2.2 金原子之間的勢能函數 14
2.2.3 金原子與水分子之間的勢能函數 15
2.3 積分運動方程式演算法 17
2.2.4 Velocity Verlet演算法 17
2.4 週期邊界條件 19
第三章 數值模擬方法 20
3.1 無因次化 20
3.2 鄰近表列方法 22
第四章 模擬設定 26
第五章 結果與討論 34
第六章 結論與建議 49
參考文獻 51

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