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Studying Large Amplitude Oscillatory Shear Response of Soft Materials
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流动驱动的拉伸波动决定了延长的关联聚合物网络的非线性粘性弹性
Songyue Liu1, Thomas C O'Connor1
1Carnegie Mellon University, Department of Materials Science and Engineering, Pittsburgh, Pennsylvania, USA.
Physical review letters
|September 15, 2025
概括
关联性聚合物网络在延伸流动过程中表现出广泛的拉伸波动,导致速度依赖的延伸粘度. 这种分子动力学模拟揭示了一个新的链机制驱动这些动力学.
科学领域:
- 聚合物物理 聚合物物理
- 材料科学 材料科学 材料科学
- 计算化学计算化学
背景情况:
- 关联性聚合物网络表现出复杂的粘弹性行为.
- 最近的管模型预测表明,这些网络在延伸流动过程中存在广泛的伸展波动.
- 了解这些动态对于预测材料性质至关重要.
研究的目的:
- 为了验证管模型对协同聚合物网络中拉伸波动的预测.
- 调查这些材料中速度依赖的延伸粘度的起源.
- 探索基于H-结合网络非线性粘弹性的分子机制.
主要方法:
- 没有平衡的分子动力学 (MD) 模拟.
- 对于双价关联网络的反应式珠弹模型.
- 不同的协会强度和延伸张力速率.
主要成果:
- 模拟证实了协会聚合物网络中的广泛拉伸波动.
- 一种新的链机制,涉及连续的关联/解离,驱动这些波动.
- 由于均的拉伸分布,在延伸应力中观察到一个速率独立的平原.
结论:
- 波动动态和链是协会网络扩展粘度的关键.
- 当前的平均场模型无法捕捉由分子反应波动主导的非线性粘性弹性.
- 模拟MD提供了关键的见解,协会聚合物网络的复杂行为.
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