在受流体吸附的聚合物板上发生异型变形
Lingji Hua1, Ali Shomali1, Chi Zhang1
1Chair of Building Physics, Department of Mechanical and Process Engineering, ETH Zürich (Swiss Federal Institute of Technology in Zürich), Zürich 8093, Switzerland.
Langmuir : the ACS journal of surfaces and colloids
|February 13, 2024
概括
机械异构性,而不仅仅是压力,影响了纳米孔状材料在吸收液体时如何变形. 这项研究揭示了异构性质如何导致薄聚合物板块的意外收缩,挑战了有关吸附诱导变形的现有理论.
科学领域:
- 材料科学 材料科学 材料科学
- 化学工程是化学工程的重要组成部分.
- 物理 物理学 物理
背景情况:
- 纳米孔吸附剂在吸收液体分子时表现出机械变形 (膨胀/收缩).
- 目前的理论认为膨胀是拉力,收缩是收缩力.
- 在吸附诱导的变形中,机械异性质的作用尚未完全理解.
研究的目的:
- 为了研究机械异构性对纳米孔材料的吸附诱导变形的影响.
- 探索材料厚度,异构性和变形行为之间的关系.
- 通过提出新的收缩机制来挑战现有的理论.
主要方法:
- 利用混合分子动力学和蒙特卡洛算法来模拟聚合物板块.
- 在不同的水负载条件下研究了板块的变形.
- 在理论分析中采用波力机模型.
主要成果:
- 聚合物板块在吸水时以正体积应变向正常方向膨胀.
- 由于水吸附的表面能量减少,表面粗度增加.
- 与正常变形相比,在平面内变形受到显著限制,特别是在较薄的板块中.
- 观察到1.35纳米厚度左右的板块在整个湿度范围内的平面收缩.
结论:
- 吸附诱导的变形受到多孔材料的机械异构性显著的影响.
- 不同otropic 特性可以导致受制于平面内膨胀,甚至在同otropic 拉力下收缩.
- 这项工作为在异性质材料中吸附诱导的收缩机制提供了新的见解.
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