Adding metal particles into the material is an effective method to improve the physical and chemical properties of nonpolar materials. However, the concentration of metal particles inside material cannot be adequately measured through conventional methods, such as scanning electron microscope or optical microscope. In this article, based on terahertz time-domain spectroscopy (THz-TDS) system, we propose a “Terahertz Linear Scatter” method to realize the quantitative analysis of metal particles concentration in nonpolar materials. Taking the composite graphene-nanosilver film as an example, THz wave can penetrate graphene with high transmittance, while it will be effectively scattered by nanosilver particles. Importantly, the small volume of the metal particles makes the attenuation of received signals change in a linear fashion. Based on this principle, the concentration of metal particles in nonpolar materials can be identified rapidly and accurately. The corresponding determination coefficient R2 can be as high as 0.9669. These results are of great significance for the analysis of various materials containing metal particles.

中文翻译：

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基于太赫兹线性散射法的复合材料中金属颗粒浓度的定量分析

在材料中加入金属颗粒是改善非极性材料理化性能的有效方法。然而，通过扫描电子显微镜或光学显微镜等常规方法无法充分测量材料内部金属颗粒的浓度。在本文中，我们基于太赫兹时域光谱（THz-TDS）系统，提出了一种“太赫兹线性散射”方法来实现非极性材料中金属颗粒浓度的定量分析。以石墨烯-纳米银复合薄膜为例，太赫兹波可以以高透光率穿透石墨烯，同时会被纳米银粒子有效散射。重要的是，金属颗粒的小体积使接收信号的衰减以线性方式变化。基于此原理，可以快速准确地识别非极性材料中金属颗粒的浓度。相应的决定系数R2可以高达0.9669。这些结果对于分析含有金属颗粒的各种材料具有重要意义。