Spectroscopic Ellipsometry of Asphalt Binder: A Study of Optical Constants
Spectroscopic Ellipsometry of Asphalt Binder: A Study of Optical Constants
复制标题
沥青结合料的光谱椭圆光度法：光学常数的研究
DOI：
--
复制
发表时间：
2020
影响因子：
1.7
通讯作者：
M. Lee
中科院分区：
文献类型：
--
作者：
M. Mazumder;Raju Ahmed;M. Hasan;Soon;M. Lee
光谱椭偏法是一种测定任何薄表面光学性质的有力技术。本文介绍了一种用椭圆偏振光谱法表征温沥青粘结剂光学性质的方法，并给出了相关结果。采用LEADCAP和Sasobit制备了温沥青粘结剂薄膜，并用变角椭偏仪对其进行了表征。从模型拟合的光谱中提取每个样品（原始和老化）的折射率和消光系数。老化前后样品的折射率和消光系数变化明显。老化前后样品的折射率n在1.55 ~ 1.62之间，消光系数k在0.01 ~ 0.06之间，具有良好的反射率。加LEADCAP的PG 64-22在可见光波段的折射率最高，消光系数最低。结果表明，leadcap改性粘结剂对可见光的反射率最高。观察到粘结剂的开裂性能与吸收系数有相关性。本文报道的方法可以应用于任何类型的沥青粘结剂，以确定其在宽波长范围内的光吸收和反射特性。
Spectroscopic ellipsometry is a powerful technique for determining optical properties of any thin surface. A method for characterizing optical properties of warm asphalt binder using spectroscopic ellipsometry along with associated results has been presented in this paper. Thin films of warm asphalt binders were produced using LEADCAP and Sasobit and characterized using a variable angle spectroscopic ellipsometry. Refractive index and extinction coefficient of each of the samples (original and aged) were extracted from model fitted spectra. Clear variation in refractive index and extinction coefficient was observed among the samples before and after aging. The samples were found to be highly reflective with refractive index ‘ n ’ in the range 1.55–1.62 and extinction coefficient ‘ k ’ in the range of 0.01–0.06, both before and after aging. Reflectivity of PG 64-22 with LEADCAP exhibited the highest refractive index and the lowest extinction coefficient in visible wavelength of light among the samples. The results indicated that the highest reflection of visible light can be observed from LEADCAP-modified binder. Cracking properties and absorption coefficient of the binders are observed to have a correlation. The method reported here can be applied to any type of asphalt binder to determine its light absorption and reflection characteristics for a wide range of wavelength.