在牛顿流体的激光驱动的自由表面流动中具有类似的弹性
Meghanad Kayanattil1, Zhipeng Huang1, Djordje Gitaric1
1Max Planck Institute for the Structure and Dynamics of Matter, 22761 Hamburg, Germany.
概括
液体甘油表现出意想不到的类似的弹性,恢复变形能量,并使泡更快地破裂. 这种弹性持续微秒,挑战了当前流体动力学的理解.
科学领域:
- 流体动力学 流体动力学
- 类风病学 类风病学 类风病学
- 软物质物理学 软物质物理学
背景情况:
- 牛顿流体迅速消散变形能量 (分子间放松时间).
- 剪切弹性通常需要长距离的相关性,挑战液态理解.
- 之前的研究表明,在低变形频率下,可测量的液体弹性.
研究的目的:
- 在液体甘油中研究激光驱动的自由表面泡动力学.
- 描述观察到的弹性及其持久性.
- 了解这种现象的潜在分子机制.
主要方法:
- 在液体甘油中分析泡膨胀和破裂动态.
- 利用高拉伸率 (10^6 s^-1) 来探测材料的行为.
- 测量了泡速度,并将它们与理论预测进行了比较.
主要成果:
- 在糖醇中观察到流动主导的,类似的弹性,独立于表面张力.
- 变形能量回收导致泰勒-库利克速度比预期高出20倍.
- 弹性持续了微秒,远远超过了放松时间.
- 确定了一种应变速率驱动的弹性,在高应变速率下强大.
- 观察到一个转移稳定的甘油表现出类似固体的行为.
结论:
- 观察到的弹性源于挫败的短分子消散,而不是放松时间分布.
- 这种现象涉及到转移稳定的分子群体的集体模式的放松.
- 液体甘油可以在高拉伸率下表现出强大的,类似的弹性,挑战传统的流体模型.
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