使用梅耶尔采样蒙特卡洛对波伊尔温度的方法性评估,并将其应用于隐含溶剂中的聚合物
Andrew J Schultz1, David A Kofke1
1Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260-4200, USA.
The Journal of chemical physics
|October 18, 2024
概括
研究人员开发了新的计算方法来计算聚合物的博伊尔温度 (TB). 这些技术准确地确定TB,这是理解溶液中的聚合物行为和预测凝结关键温度的关键参数.
科学领域:
- 聚合物物理 聚合物物理
- 计算化学计算化学
- 统计力学 统计力学
背景情况:
- 波伊尔温度 (TB) 对聚合物溶液至关重要,它标记了第二次透性病毒系数 (A2) 是零的地方.
- 结核病与聚合物凝结的临界温度有关,特别是长聚合物链 (n → ∞).
- 对结核病的现有实验和计算方法可能是复杂的或需要特定条件.
研究的目的:
- 介绍和评估两种基于迈尔采样蒙特卡洛 (MSMC) 的计算方法来计算聚合物波伊尔温度 (TB).
- 计算TB作为聚合物模型参数的函数,特别是链条刚度.
- 为了将TB与温度Tθ进行比较,其中聚合物尺寸尺寸是随机行走链.
主要方法:
- 开发了两种基于MSMC的方法:一种使用A2的温度导数来指导结核病搜索,另一种使用结核病变异的ODE数值集成.
- 将这些方法应用于链长度从2到512个单体的格子外线性列纳德-斯聚合物.
- 计算单分子旋转半径 (Rg) 来确定Tθ.
主要成果:
- 成功计算了聚合物的TB线作为链条刚性的函数.
- 新的方法避免了对参考状态或通常用于直接A2计算所需的特殊平均值的需求.
- 发现Tθ和TB在无限链长极限 (n → ∞) 中差异约为6%.
结论:
- 提出的MSMC调整提供了高效和公正的计算路线来确定聚合物波伊尔温度 (TB).
- 观察到的Tθ和TB之间的差异表明了不同的物理行为或潜在的系统误差.
- 需要进一步调查,以解决长聚合物极限中Tθ和TB之间的差异.
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