热,低约束系统的通用弹性
Cheng-Tai Lee1, Matthias Merkel1
1CPT, CNRS, Aix Marseille Univ, Université de Toulon, (UMR 7332), Turing Center for Living Systems, Marseille, France.
Physical review letters
|January 29, 2025
概括
无热系统从应变中获得刚性,这种现象延伸到有限的温度. 这项研究揭示了热和能量刚性如何相互作用,解释了各种材料的温度依赖弹性特性.
科学领域:
- 软物质物理学 软物质物理学
- 材料科学是一种材料科学.
- 统计力学就是统计力学.
背景情况:
- 无热 (零温度) 低约束系统表现出独特的机械特性,在外部应变下变得刚硬.
- 现有的理论很好地解释了在零温度下应变引起的刚性.
- 将这些理论扩展到有限的温度对于理解现实世界的物质行为至关重要.
研究的目的:
- 为了扩展低约束系统的理论,从无热到有限的温度.
- 为弹性性质 (张力和剪切模量) 导出第一原则的表达式,作为温度和应变的函数.
- 为各种不够约束的系统提供统一的理论框架.
主要方法:
- 理论上从第一原理的推导,在不热过渡点附近.
- 衍生表达式的数值确认.
- 分析系统微观结构以确定关键参数.
主要成果:
- 导出异构张力 (t) 和取决于温度 (T) 的剪切模量 (G),异构应变 (ε) 和剪切应变 (γ) 的表达式.
- 确定了三个关键参数:热刚性 (κS),能量刚性 (κE) 和一个应变相互作用参数 (bε).
- 证明了热和能量刚性在串行作用,解释了在零应变时观察到的缩放关系t∼G∼T^{1/2}.
结论:
- 开发的理论成功地统一了各种不受约束的系统的物理,包括聚合物网络,膜和生物组织.
- 这些发现为这些系统中弹性性质的温度依赖提供了一个简单的解释.
- 三参数模型提供了一个强大的工具,用于预测和理解低约束材料的机械行为.
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