离子聚合物结构在离子体融中:分子结构对聚合物和离子体峰值的影响
Lisa M Hall1, Michelle E Seitz, Karen I Winey
1Computational Materials Science and Engineering Department, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA. lhall@sandia.gov
Journal of the American Chemical Society
|December 3, 2011
概括
分子动力学模拟揭示了聚合物结构如何影响离子体融中的离子聚合. 有较大的间距的周期性悬挂带电群产生了最尖的离子体峰值,这对于理解材料特性至关重要.
科学领域:
- 材料科学 材料科学 材料科学
- 聚合物化学 聚合物化学
- 计算化学计算化学
背景情况:
- 离子体是含有离子组的聚合物,由于离子聚合,具有独特的特性.
- 了解离子聚合物的分子层结构是定制离子体特性的关键.
- 以前的模型经常简化了离子体融中的复杂离子聚合.
研究的目的:
- 阐明聚合物结构和离子聚合在离子体融中的关系.
- 调查带电组间距和位置对聚合结构的影响.
- 用实验性X射线散射数据验证模拟结果.
主要方法:
- 具有不同聚合物架构的离子体化的粗粒度分子动力学模拟.
- 对 counterions 的明确处理和充电的珠子间距和位置的系统变化 (在脊椎与吊之间).
- 实验性X射线散射测量Na(+) 中和的聚乙烯-联合烯酸) 离子体.
主要成果:
- 离子聚合物结构强烈依赖于充电的珠子间距,以及它们是否在脊柱或吊中.
- 在所有模拟系统中观察到在对电离子散射中明显的低波向量离子体峰值.
- 具有周期间隔悬挂充电珠和大间距的离子体的峰值最尖,转移到具有随机间距或较短距离的较低波向量. 实验数据证实了这些趋势.
结论:
- 聚合物架构,特别是离子组的间距和位置,决定了离子体化的纳米组织.
- 模拟结果准确地预测了实验散射数据,验证了模型捕捉离子体行为的能力.
- 该研究提供了对离子聚合的定量理解,为具有特定性质的离子体设计提供了信息.
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