单个多电解质链的崩和膨胀动力学与水力动力相互作用
1Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan.
The Journal of chemical physics
|April 24, 2024
概括
我们研究了线性多电解质 (PE) 如何崩和膨胀. 静电相互作用显著改变了崩动态,使得长聚合物扩张速度比崩慢.
科学领域:
- 聚合物物理 聚合物物理
- 软物质物理学 软物质物理学
- 计算化学计算化学
背景情况:
- 多电解质 (PE) 呈现出由静电相互作用影响的复杂的结构动态.
- 了解崩和膨胀的时间尺度对于预测溶液中的PE行为至关重要.
- 水力动力相互作用在聚合物动力学中起着重要作用.
研究的目的:
- 研究线性多电解质 (PE) 的崩和膨胀动态.
- 为了确定链条长度和静电相互作用如何影响崩和膨胀的时间表.
- 为了建立链条长度 (N) 的崩 (tcol) 和扩张 (texp) 的缩放关系.
主要方法:
- 我们使用了散射粒子动力学 (DPD) 模拟.
- 使用了带有远程静电和显式离子的珠弹PE模型.
- 在不同的盐度和离子大小下分析了tcol和texp对链长度 (N) 的依赖.
主要成果:
- 对于中性聚合物,发现缩放指数为塌的α = 0.94 ± 0.01,扩张的β = 1.97 ± 0.10.
- 静电相互作用将崩指数转移到α ≈ 1.4 ± 0.1 在盐度为10−4到10−2M的范围内.
- 扩张缩放 (β ≈ 2) 在很大程度上保持不变,不依赖于盐度或离子大小.
- 离子与单体尺寸比率的减少减少了崩指数α.
- 始终观察到β>α,表明长期PEs的扩张比崩慢.
结论:
- 静电相互作用显著改变线性多电解质的崩动态.
- 扩张过程对于长长的多电解质来说,无论盐度或离子大小如何,都始终比崩慢.
- 不同的动力路径控制了崩和膨胀过程,导致观察到的时间尺度不对称.
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