表面效应对动态光散射纳米粒径测量的影响

Influence of surface effect on nanoparticle sizing by dynamic light scattering

为探究表面效应对动态光散射法测量纳米粒度的影响,设计一种宽度可调的样品池,采用基于高速线阵CCD的动态光散射测量系统,对不同粒径的标准SiO_2颗粒进行测量。结果表明:样品池宽度小于1.3 mm时,粒径测量值随通道宽度减小线性增大,宽度为0.6 mm时,粒径测量值与自由空间中的测量值差距超过5%;样品池宽度较小时,颗粒布朗运动受到明显影响,动态光散射仪中使用微量样品池时,应根据样品池宽度对测量结果进行修正。

In-order-to-determine-whether-the-surface-effect-affect-the-measurement-result-of-dynamic-light-scattering-or-not,-a-width-adjustable-sample-cell-was-designed,-and-measurements-of-standard-particles-based-on-a-dynamic-light-scattering-system-with-high-speed-linear-CCD-was-performed.-The-results-show-that-when-the-sample-cell-width-is-less-than-1.3-mm,-the-measured-particle-size-increase-linearly-with-the-decrease-of-the-width.-As-the-width-reduces-to-0.6-mm,-the-difference-between-the-measured-values-and-that-in-the-free-space-can-be-more-than-5%.-This-demonstrates-that-the-sample-cell-width-affects-Brownian-motion-of-particles-obviously.-Hence,-the-measured-results-of-dynamic-light-scattering-using-micor-cell-should-be-corrected-accordingly.