Department of Inorganic and Analytical Chemistry, University of Geneva, Sciences II, Quai Ernest-Ansermet 30, 1205 Geneva, Switzerland.
Department of Inorganic and Analytical Chemistry, University of Geneva, Sciences II, Quai Ernest-Ansermet 30, 1205 Geneva, Switzerland.
Sci Total Environ. 2015 Dec 1;535:131-40. doi: 10.1016/j.scitotenv.2014.11.063. Epub 2014 Nov 27.
Modification of particle surfaces by adsorption of polymers is a process that governs particle behavior in aqueous environmental systems. The present article briefly reviews the current understanding of the adsorption mechanisms and the properties of the resulting layers, and it discusses two environmentally relevant cases of particle modification by polymers. In particular, the discussion focuses on the usefulness of methods based on light scattering to probe such adsorbed layers together with the resulting properties of the particle suspensions, and it highlights advantages and disadvantages of these techniques. Measurement of the electrophoretic mobility allows to follow the development of the adsorption layer and to characterize the charge of the modified particles. At saturation, the surface charge is governed by the charge of the adsorbed film. Dynamic light scattering provides information on the film thickness and on the behavior of the modified suspensions. The charge and the structure of the adsorbed layer influence the stability of the particles, as well as the applicability of the classical theory of Derjaguin, Landau, Verwey, and Overbeek (DLVO). This fundamental knowledge is presented in the light of environmental systems and its significance for applied systems is underlined. In particular, the article discusses two examples of environmental processes involving adsorption of polymers, namely, the modification of particles by natural adsorption of humic substances and the tailoring of surface properties of iron-based particles used to remediate contaminated aquifers.
通过聚合物吸附来修饰颗粒表面是控制颗粒在水相环境系统中行为的一个过程。本文简要回顾了目前对吸附机制和所得层性质的理解，并讨论了聚合物对颗粒进行修饰的两个与环境相关的实例。特别是，讨论集中在基于光散射的方法在探测此类吸附层以及颗粒悬浮液的所得性质方面的有用性，并强调了这些技术的优缺点。电泳迁移率的测量可用于跟踪吸附层的发展并表征改性颗粒的电荷。在达到饱和时，表面电荷由吸附膜的电荷决定。动态光散射可提供有关薄膜厚度和改性悬浮液行为的信息。吸附层的电荷和结构会影响颗粒的稳定性，以及对德加古因、朗道、维尔威和奥弗拜克（DLVO）经典理论的适用性。本文根据环境系统介绍了这些基础知识，并强调了其对应用系统的重要性。特别是，本文讨论了涉及聚合物吸附的两个环境过程的实例，即天然腐殖质对颗粒的修饰和用于修复受污染含水层的铁基颗粒表面性质的调整。
