基于图像动态光散射的二维纳米颗粒粒度测量

Two-Dimensional Particle-Size Measurement of Nanoparticles in Imagery by Using Dynamic Light Scattering

提出了一种基于图像动态光散射原理测量二维纳米颗粒粒度的新方法,称为平移转动-图像动态光散射(TR-IDLS)法。采用会聚的偏振高斯光束照射样品池中处于布朗运动的二维纳米粒子,分别采集纳米粒子的水平偏振散射光信号和垂直偏振散射光信号。根据两个偏振方向上散射光光强波动的时间相关函数,计算出纳米颗粒的平移和转动扩散系数的分布,进而从扩散系数中获得颗粒的长宽比、等效直径和厚度的分布。采用该方法测量了球形标准纳米颗粒和片状云母颗粒的粒径。采用电镜获得了片状云母颗粒的形状和等效直径,并与TR-IDLS方法的实验结果进行比较,验证了TR-IDLS方法的可行性。

We propose a new method to measure two-dimensional particle size of nanoparticles in imagery based on the principle of dynamic light scattering, which is called the translation-rotation image-dynamic light-scattering(TR-IDLS) method. The nanoparticles in Brownian motion in the sample pool are illuminated by a focused polarized Gaussian beam;then, the horizontal and vertical polarized scattering signals of the nanoparticles are recorded. According to the time-correlation function applied to the fluctuation of scattered-light intensity in the two polarization directions, the distributions of translational-and rotational-diffusion coefficients of nanoparticles are calculated, and the aspect-ratio, equivalent-diameter, and thickness distributions are obtained. The spherical standard nanoparticles and mica-flake particles are measured by this method. The shape and equivalent diameter of the mica-flake particles obtained by scanning electron microscopy are compared with the experimental results obtained by the TR-IDLS method, thereby verifying the feasibility of the TR-IDLS method.