石墨烯纳米颗粒悬浮中的负内在粘度是由水力动态滑动诱导的
Adyant Agrawal1, Catherine Kamal2, Simon Gravelle3
1Institute for Computational Physics, University of Stuttgart, 70569 Stuttgart, Germany.
ACS nano
|October 24, 2025
概括
水中的石墨烯纳米板可以惊人地降低粘度,即使在纯水以下,由于独特的水力动力滑动. 这种效应通过模拟得到证实,为设计滑剂和油墨等先进材料提供了新的可能性.
科学领域:
- 流体动力学 流体动力学
- 材料科学 是一种材料科学.
- 纳米技术纳米技术
背景情况:
- 纳米粒子悬浮物通常随着度的增加而增加粘度.
- 像石墨烯这样的原子薄的纳米材料表现出异常的粘度行为,有时显示的粘度低于溶剂.
- 这种被称为负内在粘度的现象已在实验中观察到,但缺乏分子水平的确认.
研究的目的:
- 通过分子动力学模拟,研究石墨烯纳米板悬浮在水中的剪切粘度.
- 在现实的石墨烯水系统中确认和阐明负内在粘度背后的分子机制.
- 探索石墨烯面积比和度对悬浮粘度的影响.
主要方法:
- 在高Péclet数 (Pe ≥100) 的水中对几纳米石墨烯板进行分子动力学 (MD) 模拟.
- 不同的石墨烯面积比率从4.5到12.0.
- 与在稀释状态下连续边界积分建模的比较.
主要成果:
- 内在粘度随着石墨烯面积比的增加而下降,在大约5.5.5的面积比之后变为负面.
- 在石墨烯-水接口的水力动力滑动被确定为主要原因,抑制粒子旋转并促进与流量对齐.
- 粘度最初随着石墨烯度的增加而下降,降至纯水以下,然后由于颗粒聚合在更高度下增加.
结论:
- 分子动力学模拟强有力的证实了石墨烯-水系统的负内在粘度,由水力动力学滑动驱动.
- 这些发现为原子薄纳米材料悬浮中的异常粘度提供了分子层面的理解.
- 这项研究对开发具有可调节质性质的新型滑剂,油墨和纳米复合材料具有重大意义.
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