动态光散射法测量颗粒粒径的溯源性

分别对动态光散射粒径测量仪的入射波长、散射角度、测量池温度进行校准,并对影响测量结果准确性各因素的不确定度分量进行了评价,校准后动态光散射仪的测量结果可溯源至国家计量标准。为消除多重散射、颗粒间相互作用、颗粒粒径分布对动态光散射测量结果的影响,建立了动态光散射测量结果修正方法。其中为消除多重散射及颗粒间相互作用的影响,需采用多浓度测量或线性回归的方法得到特定浓度下的颗粒粒径;为修正颗粒粒径分布对动态光散射测量结果的影响,需先采用SEM方法准确测量颗粒粒径分布,然后根据光强加权动力学平均粒径和数量平均粒径的理论公式,得到二者之间的差异。

Traceability of Dynamic Light Scattering Method for Particle Size Measurement

Layer wavelength, scattering angle and cell temperature of dynamic light scattering （DLS） instrument were calibrated, and the uncertainty of factors which had significant effects on DLS was also analyzed. The final measurement results obtained by this calibrated DLS instrument could trace to national metrology standards. For the purpose of eliminating multi-scattering effect, interaction effect between particles, and particle distribution effect on DLS results, correlation methods for DLS result were developed. By carrying out measurements in different sample concentration or linear regression method, multi-scattering effect and interaction effect between particles could be eliminated and neglected. While by obtaining particle distribution of sample using SEM, light intensity-weighted mean particle size and number mean particle size could be obtained, and finally, particle size distribution effect on DLS result could be corrected.