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用双向3ω方法测量水凝的导热率

Daniel H Hsieh¹, Youngmun Lee¹, Mayur S Prabhudesai²

¹Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, 1206 W Green St., Urbana, Illinois 61801, USA.

The Review of scientific instruments

|April 14, 2025

概括

这项研究提出了一种新的方法来测量水凝的导热率,这对于热能存储至关重要. 双向的3ω技术可以准确地确定小水凝样本的导电性,即使含水量不同.

科学领域:

材料科学材料科学材料科学
热力工程是热力工程中的一个.
聚合物科学聚合物科学

背景情况:

水凝是多功能吸水聚合物,用于各种领域.
将相变材料封装在水凝中,用于储存热能是一个不断增长的领域.
精确测量水凝导热率对于优化这些应用至关重要.

研究的目的:

实施和验证双向3ω技术,用于测量小水凝体积的导热率.
为了研究水凝热导电性的水分含量的影响.
为提供一种可靠的方法来表征用于热储的软材料.

主要方法:

采用了针对小样本量 (∼20μl) 优化的双向3ω技术.
采用频域3D建模来模拟传感器设计,并最大限度地减少基板和绝缘的错误.
使用水验证了设置,并测量了聚烯胺和PAMPS水凝的导热性.

主要成果:

实现了准确的导热度测量,而不需要安装额外的参数.
确定了最佳频率范围 (∼1-20 Hz),以减少测量误差.
膨胀的水凝显示出接近水的导热率 (0.6 W m-1 K-1);整洁的水凝测得0.43 W m-1 K-1 (聚烯胺) 和0.42 W m-1 K-1 (PAMPS).

结论:

双向3ω方法是测量水凝导热率的可行技术,特别是在小样本尺寸的情况下.
该方法提供了可靠的数据,对于开发先进的基于水凝的热能储能系统至关重要.
主要来自传感器校准的±7%的误差与已建立的3ω方法一致.

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