在模型聚合物薄膜中的动态异质性和界面梯度之间的相互作用
Austin D Hartley1, William F Drayer1, Asieh Ghanekarade1
1Department of Chemical, Biological, and Materials Engineering, The University of South Florida, Tampa, Florida 33620, USA.
The Journal of chemical physics
|November 30, 2023
概括
在玻璃形成液体中,散装动态异质性和表面梯度之间的相互作用是复杂的. 表面动力学比散装动力学更快,但比散装动力学更不相关,挑战了简单的"风湿学温度"模型.
科学领域:
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
- 软物质物理学 软物质物理学
背景情况:
- 玻璃成型液体表现出动态异质性,区域以不同的速度放松.
- 接口引入玻璃过渡温度 (Tg) 和放松时间 (τ) 的梯度.
- 大量和界面异质性之间的相互作用是不太了解的.
研究的目的:
- 调查散装动态异质性如何影响并受到聚合物薄膜界面梯度的影响.
- 澄清玻璃成型液体中的动态异质性和界面效应之间的关系.
主要方法:
- 使用了分子动力学模拟.
- 采用了异构组合的组合.
- 研究聚合物薄膜以分析纳米级的动力学.
主要成果:
- 表面放松时间 (τ) 频谱较宽,但与大体相比,其转移到较短的时间.
- 表面动力学比散装动力学具有较少的空间相关性.
- 缓慢的动态延伸到更深处的电影,而不是在界面上的快速动态.
结论:
- 动态中的表面梯度与散装异质性不同,不仅仅反映了更高的表面梯度.
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