Lin Wei, Kobayashi Motoyoshi, Skarba Michal, Mu Changdao, Galletto Paolo, Borkovec Michal
Department of Inorganic, Analytical, and Applied Chemistry, University of Geneva, 1211 Geneva 4, Switzerland.
Langmuir. 2006 Jan 31;22(3):1038-47. doi: 10.1021/la0522808.
Heteroaggregation (or heterocoagulation) rate constants have been measured in mixtures of well-characterized colloidal particles of opposite charge with multiangle static and dynamic light scattering. This technique permits routine measurements of absolute heteroaggregation rate constants, also in the presence of homoaggregation. Particularly with multiangle dynamic light scattering, one is able to estimate absolute heteroaggregation rate constants accurately in the fast aggregation regime for the first time. Heteroaggregation rate constants have also been measured over a wide range of parameters, for example, ionic strength and different surface charge densities. Amidine latex particles, sulfate latex particles, and silica particles have been used for these experiments, and they were well characterized with respect to their charging and homoaggregation behavior. It was shown that heteroaggregation rate constants of oppositely charged particles increase slowly with decreasing ionic strength, and provided the surface charge is sufficiently large, the rate constant is largely independent of the surface charge. These trends can be well described with DLVO theory without adjustable parameters.
通过多角度静态和动态光散射测量了具有相反电荷的特征明确的胶体颗粒混合物中的异质聚集（或异质凝聚）速率常数。该技术允许常规测量绝对异质聚集速率常数，即使在存在同质聚集的情况下也是如此。特别是通过多角度动态光散射，人们首次能够在快速聚集状态下准确估计绝对异质聚集速率常数。还在广泛的参数范围内测量了异质聚集速率常数，例如离子强度和不同的表面电荷密度。脒乳胶颗粒、硫酸盐乳胶颗粒和二氧化硅颗粒已用于这些实验，并且它们在充电和同质聚集行为方面得到了很好的表征。结果表明，带相反电荷颗粒的异质聚集速率常数随离子强度降低而缓慢增加，并且如果表面电荷足够大，速率常数在很大程度上与表面电荷无关。这些趋势可以用DLVO理论很好地描述，无需调整参数。
