基于偏振图像动态光散射的非球形纳米颗粒测量  

Measurement of non-spherical nanoparticles based on polarized image dynamic light scattering

作　　者：王炳尧 蔡小舒[1] 蔡天意 周骛[1] WANG Bingyao;CAI Xiaoshu;CAI Tianyi;ZHOU Wu(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093

出　　处：《上海理工大学学报》2024年第4期382-391,共10页Journal of University of Shanghai For Science and Technology

基　　金：上海市科学技术委员会扬帆计划资助项目(22YF1429600)。

摘　　要：纳米材料的功能特性与其粒度和形貌有很大关系。图像动态光散射法是一种快速、准确、非接触的纳米颗粒测量方法。将图像动态光散射与偏振散射结合,提出了一种测量非球形纳米颗粒形貌的方法。根据偏振散射理论,当入射光为垂直线偏振光,颗粒的散射光在不同偏振方向的偏振散射特性与颗粒的形貌有关,可以用线偏振度参数描述。在90°散射角方向采用偏振相机,对球形和非球形纳米颗粒在0°,45°,90°,135°偏振方向上的动态光散射信号进行测量,结果表明:球形颗粒的线偏振度接近1,八面体颗粒的线偏振度略小于1,棒状颗粒的线偏振度小于1且随长径比增加而减小,纳米片及纳米线等非球形颗粒的线偏振度都有不同程度的减小。定义线偏振度为光学球体度,用以表征颗粒形貌,采用偏振图像动态光散射方法可以快速测量纳米颗粒的形貌分布。The functional properties of nanomaterials are closely related to their particle size and morphology.Image dynamic light scattering is a fast,accurate,non-contact method for measuring nanoparticles.Combining image dynamic light scattering with polarization scattering,a method for measuring the morphology of non-spherical nanoparticles was proposed.Theoretical analysis showed if the incident light was vertically linearly polarized,the scattered light at different polarization direction related to the shape of measured particles.A polarizing camera was used to measure the dynamic light scattering signals of spherical and non-spherical particles at 0°(vertical direction),45°,90°(horizontal direction)and 135°at 90°scattering angle.The results show that the degree of linear polarization of spherical particles is close to 1,that of octahedral particles is slightly less than 1,and that of rod particles is less than 1.The degree of linear polarization of non-spherical particles such as nanoplates and nanowires has been reduced to different degrees.The linear degree of polarization was defined as the optical sphericity to characterize the particle morphology.The particle morphology distribution of nanoparticles can be rapidly measured by using the polarization image dynamic light scattering method.

关 键 词：动态光散射法 纳米颗粒 颗粒形貌 偏振光散射 分布 

分 类 号：O436[机械工程—光学工程]