University of California, Santa Barbara, USA.
Environ Sci Technol. 2010 Mar 15;44(6):1962-7. doi: 10.1021/es902987d.
There is a pressing need for information on the mobility of nanoparticles in the complex aqueous matrices found in realistic environmental conditions. We dispersed three different metal oxide nanoparticles (TiO(2), ZnO and CeO(2)) in samples taken from eight different aqueous media associated with seawater, lagoon, river, and groundwater, and measured their electrophoretic mobility, state of aggregation, and rate of sedimentation. The electrophoretic mobility of the particles in a given aqueous media was dominated by the presence of natural organic matter (NOM) and ionic strength, and independent of pH. NOM adsorbed onto these nanoparticles significantly reduces their aggregation, stabilizing them under many conditions. The transition from reaction to diffusion limited aggregation occurs at an electrophoretic mobility from around -2 to -0.8 microm s(-1) V(-1) cm. These results are key for designing and interpreting nanoparticle ecotoxicity studies in various environmental conditions.
在实际环境条件下的复杂水基质中，纳米颗粒的迁移性信息是迫切需要的。我们将三种不同的金属氧化物纳米颗粒（TiO2、ZnO 和 CeO2）分散在取自与海水、泻湖、河流和地下水相关的八种不同水介质的样品中，并测量了它们的电泳迁移率、聚集状态和沉降速率。在给定的水介质中，颗粒的电泳迁移率主要由天然有机物（NOM）和离子强度决定，而与 pH 值无关。NOM 吸附在这些纳米颗粒上，显著减少了它们的聚集，在许多条件下稳定了它们。从反应控制到扩散控制聚集的转变发生在电泳迁移率约为-2 至-0.8μm s-1V-1cm 的范围内。这些结果对于在各种环境条件下设计和解释纳米颗粒的生态毒性研究至关重要。
