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在阴性弹性体中的表面不稳定性
Morgan Barnes1, Fan Feng1, John S Biggins1
1Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, United Kingdom.
Physical review letters
|December 22, 2023
概括
液晶弹性体 (LCE) 经历了大量的收缩. 研究人员发现,在冷却过程中紧LCE诱导了表面地形,从软模式创建了一个独特的交叉切割模式.
科学领域:
- 材料科学 材料科学 材料科学
- 软物质物理学 软物质物理学
- 聚合物科学 聚合物科学
背景情况:
- 液晶弹性体 (LCE) 是一种对刺激有反应的材料,以大,可逆收缩而闻名.
- 它们的相位过渡与软模式和潜在的微观结构不稳定性有关.
- 了解这些不稳定性对于设计基于LCE的执行器和设备至关重要.
研究的目的:
- 在受限制的冷却条件下,研究平面LCE板块中的微结构不稳定性.
- 描述由此产生的表面地形及其与材料性质的关系.
- 阐明观察到的不稳定性的潜在机制.
主要方法:
- 在实验中将一个平面的LCE加热到同otropic阶段,紧一个表面,然后再冷却回去nematic阶段.
- 数字计算非理想的LCE能量函数的微结构放松.
- 使用线性稳定性分析来确定不稳定的性质.
主要成果:
- 受约束的LCE冷却导致表面不稳定和地形的形成.
- 观察到的地形具有与LCE板块厚度相当的振幅和波长.
- 线性稳定性分析揭示了具有斜波向量的无尺度不稳定性.
- 不稳定性达到顶点,无底,无歇斯底里交叉切割模式,由低压软模式组成.
结论:
- 这项研究展示了一种新的方法,通过控制冷却和紧来诱导LCE中的微结构模式.
- 由此产生的交叉切割模式是受约束的LCE软模式的独特后果.
- 这些发现提供了软物质不稳定性和LCE行为机制的见解.
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