为了解决动态光散射纳米颗粒测量技术无法测量高浓度颗粒粒径的难题,提出了一种基于偏振门的动态光散射测量法。从动态光散射和Mie理论出发,理论分析了在高浓度溶液下多重散射效应对散射光偏振态和颗粒粒度测量结果的影响。根据散射光偏振特点,结合偏振门检测技术,改进了传统的动态光散射光学系统。实验研究了在低浓度和高浓度溶液时,不同偏振角度下的散射光强和粒度测量值,完善了散射光的偏振理论。采用90°偏振门检偏,通过各种浓度下的实验,证明了方法的可行性。该方法较之目前同类方法具有原理和结构简单,系统易于维护的特点。

In order to solve the problem that the method of nanoparticle sizing by dynamic light scattering can not be used in the measurement of particle size in concentrated solution, a new method by dynamic light scattering based on polarization gating is proposed. From the dynamic light scattering and Mie scattering theory, the effects of multiple scattering on the state of polarization of the scattered light and measurement results of particle size in concentrated solution are analyzed. According to the polarization characteristics of scattered light, the traditional dynamic light scattering optical system is improved which is combined with polarization-gate detection technology. The scattered light intensity and the measurement results of particle size at different polarization angles in low and high concentrations experimetally, the theoretical analysis of the polarization characteristics of scattered light are improved. The feasibility of the method is proved by the experiments with variety of concentration under the polarization gating of 90-degree. Comparing with the current methods, this method has the features of simplicity in principle and setup, and easy to maintain features.