Urban C, Schurtenberger P
Polymer Institute, ETH Zurich, Zurich, CH-8092, Switzerland
J Colloid Interface Sci. 1998 Nov 1;207(1):150-158. doi: 10.1006/jcis.1998.5769.
The ability to characterize colloidal suspensions by means of dynamic light scattering is in general limited to systems with negligible contributions from multiple scattering. For larger particle sizes with high scattering contrast this immediately limits the technique to very low concentrations. A promising solution of this problem is to suppress multiple scattering in dynamic light scattering experiments using cross-correlation schemes. Based on these considerations we have constructed a so-called 3D cross-correlation experiment with which we are able to characterize extremely turbid suspensions. We have measured monomodal and bimodal suspensions of latex particles of relatively high volume fraction. The results show clearly that we are able to measure the dynamic structure factor in concentrated polydisperse suspensions with dynamic light scattering. Combining static and dynamic light scattering measurements for characterizing turbid suspensions the single scattering particle form factor and also the static structure factor can be evaluated. We demonstrate that the implementation of a 3D cross-correlation scheme is a powerful method in suppressing multiple scattering contributions in light scattering experiments and opens a wide field of characterization of colloidal dispersions with high turbidity without having to resort to high dilution. Copyright 1998 Academic Press.
通过动态光散射来表征胶体悬浮液的能力通常仅限于多次散射贡献可忽略不计的系统。对于具有高散射对比度的较大粒径，这立即将该技术限制在非常低的浓度。解决这个问题的一个有前景的方法是在动态光散射实验中使用互相关方案来抑制多次散射。基于这些考虑，我们构建了一个所谓的三维互相关实验，利用该实验我们能够表征极其浑浊的悬浮液。我们测量了具有相对高体积分数的乳胶颗粒的单峰和双峰悬浮液。结果清楚地表明，我们能够通过动态光散射测量浓多分散悬浮液中的动态结构因子。结合静态和动态光散射测量来表征浑浊悬浮液，可以评估单散射粒子形状因子以及静态结构因子。我们证明，三维互相关方案的实施是抑制光散射实验中多次散射贡献的一种有效方法，并且开辟了一个无需高稀释就能广泛表征高浊度胶体分散体的领域。版权所有1998年学术出版社。
