Near-Infrared Hyperspectral Absorption/Scattering Imaging Method Using Multiple Ground Plates for Evaluating Polymer Composites
Near-Infrared Hyperspectral Absorption/Scattering Imaging Method Using Multiple Ground Plates for Evaluating Polymer Composites
复制标题
使用多个接地板的近红外高光谱吸收/散射成像方法评估聚合物复合材料
DOI：
10.1021/acs.analchem.8b03723
复制
发表时间：
2019
影响因子：
7.4
通讯作者：
Masahiro Ohshima
中科院分区：
文献类型：
--
作者：
Shun Muroga;Yuta Hikima;Masahiro Ohshima
提出了一种多接地近红外漫反射光谱无损评价聚合物复合材料性能的方法。利用波长相关的吸收系数和还原散射系数来评价吸收物质的化学结构和浓度，并通过散射来确定填料在聚合物畴中的大小和分散性。在多个接地板上测量样品的近红外光谱，即“接地板相关”漫反射光谱。随后，消除了外反射对地板相关漫反射光谱的影响。内部反射系数是在没有光入射角度和样品折射率先验信息的情况下，根据净树脂与接地板的漫反射系数之差计算得到的。外反射系数通过样品与白色接地板之间的漫反射间隙来评估。经反射校正后，利用基于双通量理论的光传播物理模型对光谱进行拟合，得到吸收系数和约化散射系数。计算的吸收系数与颗粒浓度呈良好的线性关系。计算得到的折算散射系数与米氏散射理论的理论值一致。结果表明，该方法可以同时评价聚合物复合材料中颗粒填料的浓度和尺寸。
This paper proposes a nondestructive method of evaluating polymer composites using near-infrared (NIR) diffuse reflection spectroscopy with multiple ground plates. Wavelength-dependent absorption and reduced scattering coefficients were acquired to evaluate the chemical structure and the concentration of the substances from absorption and to determine the size and the dispersity of filler in the polymer domain from scattering. NIR spectra of the sample were measured on multiple ground plates, namely, “ground-plate-dependent” diffuse reflection spectra. The effects of the external reflection on the ground-plate-dependent diffuse reflection spectra were subsequently removed. The internal reflection coefficient was calculated based on the difference between the diffuse reflectances of the neat resin and ground plates without prior information on the incident angle of light and the refractive index of sample. The external reflection coefficient was evaluated by the gap of diffuse reflectances between the sample and a white ground plate. After the corrections of reflections, the spectra were fitted by a physical model of light propagation based on the two-flux theory to acquire the absorption and the reduced scattering coefficients. The calculated absorption coefficients indicated a good linear relationship with particle concentration. The calculated reduced scattering coefficients agreed with the theoretical values by Mie scattering theory. It was demonstrated that the proposed method achieved the simultaneous evaluation of particulate-filler concentrations and sizes in polymer composites.