Adorjan A J, Lock J A, Taylor T W, Tin P, Meyer W V, Smart A E
Department of Physics, Kent State University, Kent, Ohio 44242-0001, USA.
Appl Opt. 1999 May 20;38(15):3409-16. doi: 10.1364/ao.38.003409.
The utility of the one-beam cross-correlation dynamic light-scattering system for sizing small particles in suspension was previously limited by its small-intensity signal-to-baseline ratio for strongly turbid suspensions. We describe three improvements in the optical system and sample cell that raise the ratio to a value comparable with that of other cross-correlation dynamic light-scattering systems. These improvements are (i) using a square cross-sectional sample cell to minimize the attenuation of the incident beam and singly scattered light, (ii) placing a 200-microm-wide slit between the sample cell and the detector fibers to mask off the region of weak single scattering and strong multiple scattering from the detectors' field of view, and (iii) aligning the center of the detectors' field of view with the region of strongest single scattering. We analyze a number of suspensions of polystyrene latex spheres with a diameter between 65 and 562 nm in water using this improved one-beam instrument and find that the measured radius is determined in a 2-min data collection time to better than +/-10% for volume fractions of the suspended polystyrene latex spheres up to a few percent.
单光束互相关动态光散射系统用于测量悬浮液中小颗粒尺寸的实用性，此前受到其在强混浊悬浮液中强度信号与基线比值较小的限制。我们描述了光学系统和样品池的三项改进措施，这些措施将该比值提高到与其他互相关动态光散射系统相当的值。这些改进措施包括：（i）使用方形横截面的样品池，以最小化入射光束和单次散射光的衰减；（ii）在样品池和探测器光纤之间放置一个200微米宽的狭缝，以遮挡探测器视场中弱单次散射和强多次散射的区域；（iii）将探测器视场的中心与最强单次散射区域对齐。我们使用这种改进后的单光束仪器分析了多种直径在65至562纳米之间的聚苯乙烯乳胶球在水中的悬浮液，发现对于悬浮聚苯乙烯乳胶球体积分数高达百分之几的情况，在2分钟的数据采集时间内，所测量的半径的确定精度优于±10%。
