粗粒模型用于预测聚乙烯中孔的移动性
Mikael Unge1,2, Hannes Aspåker1, Fritjof Nilsson2,3
1NKT HV Cables, Technology Consulting, SE-721 78 Västerås, Sweden.
Journal of chemical theory and computation
|October 16, 2023
概括
本研究提出了一种新的粗粒度模型,用于模拟聚乙烯中的电荷传输. 该模型准确地表示了聚合物结构,并产生了现实的孔移动性,帮助未来的材料设计.
科学领域:
- 材料科学 材料科学 材料科学
- 计算化学计算化学
- 聚合物物理 聚合物物理
背景情况:
- 聚乙烯的电导率受到其半晶体结构和形态学的显著影响.
- 准确的原子学模拟需要包含明确或隐含的聚合物形态的模型.
- 现有的使用短小聚合物用于无形聚乙烯的方法缺乏现实的结构表示.
研究的目的:
- 开发一种快速高效的粗粒模型,用于在聚乙烯中进行电荷传输模拟.
- 为了实现大型分子系统的模拟,同时考虑聚合物结构.
- 为了提高预测聚乙烯中电荷传输特性的准确性.
主要方法:
- 利用量子化学计算建立六个细分规则,将聚合物链分为代表局部分子轨道的细分.
- 将细分规则应用于无形聚乙烯系统,以确定细分长度分布.
- 采用了动力蒙特卡洛 (KMC) 模拟,用细分无形聚乙烯作为跳跃站点.
主要成果:
- 细分规则产生了与聚乙烯的持久长度可比的细分长度.
- 对无形聚乙烯的模拟孔移动性属于实验范围.
- 计算的激活能量低于实验报告的值.
结论:
- 开发的粗粒度模型为聚乙烯的电荷传输模拟提供了现实的表示.
- 激活能量的差异表明化学缺陷在实验系统中的潜在作用.
- 进一步细化可能涉及将化学缺陷纳入其中,以充分解释实验观测.
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