- 學位論文
利用分子動力學法預測奈米冰晶分子之氫鍵結構
Predictions of Annealing of Hydrogen-Bond Structure for Ice Crystal in nanoscale by Molecular Dynamics Method
摘要
本研究係針對奈米尺度系統下冰晶分子之氫鍵結構形成進行研 究。利用分子動力法(MD) 來分析冰晶分子在奈米尺度下之最小位 勢能之晶格結構以及其對於飄浮水分子之影響。本研究採用 Carravetta-Clementi (CC)位勢能來得到分子與分子之間的作用力，在 假設各分子仍然受牛頓第二運動定律支配的條件下，利用電腦對介質 分子的運動作直接模擬。各介質分子由於本身的慣性、分子間的作用 力、以及分子與邊界的相互作用，而產生平移與旋轉速度及位置與角 度的改變。本研究包括下列工作項目：(1)探討氫鍵結構之形成，(2) 研究冰晶結構受溫度之影響，以及(3)預測飄浮水分子在撞擊冰晶後 之表面躍動情形等。
並列摘要
The present study is concerned with the formation and stability of hydrogen-bond structure for ice crystal in nanoscale. Molecular dynamics method is adopted to analyze the ice crystal formed by water molecules. In the molecular dynamics analysis, Newton’s second law of motion is applied for predictions of the motion of any molecules. Translational and angular velocities as well as the locations of all the molecules can be predicted at any instant when the inertial and external forces acting on the molecules have been known. The interactive forces between any two molecules are determined based on Carravetta-Clementi (CC) potential in this study. The van der Waals force and the electrostatic force are evaluated between water molecules and then the translational and angular velocity vectors and the position of the molecules can be predicted. The study includes: (1) the annealing of hydrogen-bond structure for ice crystal, (2) the influence of temperature on the vibration of the molecules within a fixed ice crystal layers, and (3) the leaping behavior of the drifting molecules on the crystal layer surface after they impinge on the surface at different temperatures and incident angles.