太赫兹介电谱与组分含量的关系分析及应用

Relationships between Terahertz Dielectric Spectra and Component Content and Their Applications

研究了固体有机样品的太赫兹介电谱与组分体积含量之间的关系。通过分析有效介质理论中的CRI（Complex Refractive Index）模型,得到样品的介电参数与组分体积含量的关系式。利用太赫兹时域光谱技术测得室温下两种氨基酸样品在0.5～2.7 THz的介电性质,样品的折射率、介电系数及介电损耗均随氨基酸体积含量增加而增大。选取氨基酸介电损耗谱特征峰位处的介电参数,根据CRI模型进行拟合,得到折射率与体积含量的线性关系式,介电系数和介电损耗与体积含量的二次函数关系式。研究结果有利于扩展太赫兹波段的定性定量分析手段,并对聚合物基复合材料制备有一定参考意义。

We study the relationship between terahertz dielectric spectra and the volume content of solid mixture sample components. Through the analysis of CRI （Complex Refractive Index） model, which is an effective medium theory, the relationship between dielectric parameters and volume content of samples is obtained. Two kinds of amino acid samples are measured by terahertz time-domain spectroscopy（THz-TDS） to obtain their dielectric properties in the range of 0.5-2.7 THz at room temperature. In this frequency band, their refractive index, dielectric coefficient and dielectric loss of samples increase with increasing volume fraction of amino acids. According to the CRI model, we obtain the linear relations between refractive index and volume fraction of glutamine and histidine, as well as the quadratic relations between complex permittivity and volume fraction at feature peaks of THz dielectric loss spectra.The results could help to expand means of qualitative and quantitative analysis, and also provide a reference for polymer matrix composites preparation.