以蒙地卡羅法探討蒸氣誘導式相分離法的成膜過程

Abstract

本研究工作以蒙地卡羅法為基礎，先建立了一套模擬濕式法成膜過程的分子模擬程序。依據高分子、溶劑和非溶劑粒子之間的熱力學和動力學參數，建立鄰近方格間的交換速率方程式，並依此決定其交換機率，然後進行隨機模擬，觀察手指狀結構薄膜的成形。 接著我們將此套模擬程序更改設定，將原本的凝聚槽成分改為含有水分子粒子的空氣，對蒸氣誘導式相分離法製膜程序進行模擬，探討薄膜形成過程以及分析溶劑揮發度和溶劑與水互溶性的影響。模擬結果顯示：薄膜結構為海綿狀，且溶劑揮發度的提高，薄膜結構變得較緻密；而溶劑與水的互溶性的提高，會導致顆粒狀薄膜結構的生成。

Membrane formation by immersion precipitation is simulated on a lattice model by Monte Carlo diffusion process in which particles move according to the change in local energy. And our approach obtained a description of the coagulation process to produce a finger-like morphology. The simulation approach is further extended to simulate membrane formation by vapor induced phase separation (VIPS) method. Our approach allows to describe the membrane formation process and to study the effect of solvent volatility and miscibility of solvent and vapor. The simulation results show that membrane structure become denser with increase of solvent volatility, and dust-like morphology is obtained with higher miscibility between solvent and vapor.