实验测量纳米粒子固体中的粒子对粒子热传递
Benjamin T Diroll1, Richard D Schaller1,2
1Center for Nanoscale Materials, Argonne National Laboratory, 9700 S Cass Avenue, Lemont, Illinois 60439, United States.
ACS nano
|April 15, 2025
概括
研究人员使用瞬态光谱测量了纳米粒子固体中的热流. 他们发现粒子对粒子的热传递速度很慢,突出了没有共价键的界面热导率差.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
- 物理化学 物理化学
背景情况:
- 纳米粒子固体具有较低的导热率 (0.1-1 W m-1 K-1).
- 表面热导率差是可疑的原因,但直接研究很难.
研究的目的:
- 直接测量纳米粒子固体中的界面导热.
- 为了研究纳米尺度的热传递机制.
主要方法:
- 使用过渡光谱学,使用不同的热供体和受体纳米粒子.
- 观测了依赖时间的温度变化,以量化传热速率.
主要成果:
- 在室温下在~300 ps时观察到的粒子对粒子热传递平衡.
- 在较低的温度下,热传递速度会加快,对静电测量或连接物不敏感.
- 与联体介导运输相比,已经证明粒子对粒子的运输速度要慢得多.
结论:
- 没有共价键的纳米粒子之间的界面热导电比以前假设的要低得多.
- 这一发现解释了纳米粒子固体的低整体导热率.
- 在复合膜中观察到增强的非线性吸收,归因于局部场效应.
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