颗粒动态散射光分形特征的提取及温度影响

Extraction of the fractal characteristic of dynamic light scattering and the influence of temperature

颗粒的动态散射光信号具有分形特征,通过对其分析可获取颗粒粒径的信息。本文研究了颗粒动态散射光的波动及其分形特征的提取,并通过对颗粒平移扩散系数的分析,研究了温度对动态散射光分形维数的影响。采用粒径为60nm、90nm、200nm、300nm、450nm的标准聚苯乙烯颗粒进行了实测,分别求取了不同温度下颗粒动态散射光信号的分形维数。实验结果表明,当颗粒粒径相同时,温度越高,分形维数越大;当温度相同时,粒径越小,分形维数越大。

Dynamic light scattering signals from particles have fractal characteristics, which can be used to get information of the particle size. The fluctuation of the dynamic light scattering signals and the extraction of the light scattering signals fractal characteristics were analyzed, and the influence of temperature on the fractal dimension of the light scattering signals was researched by analyzing the translational diffusion constant. In the experiment, five kinds of standard polymer microspheres with mean diameters 60, 90, 200, 300, 450nm were adopted respectively when the temperature was 18℃, 20℃, 22℃, 24℃, 26℃, 28℃, 30℃, and the Box Dimensions of light scattering signals from those standard microspheres were obtained in different temperature. The experiment results indicate that for the microspheres of the same diameter, the higher the temperature, the bigger the fractal dimensions of the light scattering signals, and when the temperature is invariable, the smaller the micropheres, the bigger the fractal dimensions of the light scattering signals.