用动态光散射现代谱估计法测量纳米颗粒

Measurement of nano-particles by dynamic light scattering based on spectral estimation

为了解决目前动态光散射软件信号分析法采用的自相关和功率谱估计存在分辨率和方差较低,以及能谱泄漏问题,提出了基于现代功率谱估计的动态光散射信号分析法。对该系统所采用的现代功率谱估计算法和测量系统进行了研究。首先,介绍了动态光散射测量法涉及的光子相关光谱理论和散射光谱估计理论。接着,描述了基于现代功率谱估计的动态散射光谱法,特别是其中阶数p的计算方法。然后,介绍了测量系统,包括硬件部分的光学系统和信号采集处理系统,软件部分的系统开发流程。最后,对粒径分别为30、50、100nm的乳胶球标准颗粒溶液(透光率为96%)进行了实验。实验结果表明:现代谱估计分析法的测量均值误差和重复性误差的平均值分别为1.88%和1.62%,满足国标要求的均值误差和重复性误差<2%。

A new dynamic light scattering analysis method based on modern power spectral estimation was proposed to resolve problems on lower resolution and variance,and power spectrum leakage in the current dynamic light scattering software.The modern power spectrum estimation algorithm and measurement system were studied.Firstly,the photon correlation spectroscopic theory and the scattering spectrum estimation of dynamic light scattering measurement were introduced.Then,the dynamic scattering spectrum based on modern power spectrum estimation was descripted in detail,and the order of p was calculated particularly.Furthermore,the measurement system was described,in which the hardware components included optical systems and signal processing system and the software showed the development process.Finally,a experiment was carried out on the latex particle sample solution with the particle diameters of 30,50,100nm and solution transmission of 96%.The results show that the average values of the measurement error and repeatability error are 1.88%and 1.62%,respectively,which can achieve the national standard that the measurement and repeatability errors should be less than 2%,respectively.