成人做爰免费视频免费看_成人a级高清视频在线观看,成人a大片在线观看,成人a大片高清在线观看,成人av在线播放,一a一级片,一级黄 中国色 片,一级黄 色蝶 片,一级黄色 片生活片

 文獻名： Stability and Aggregation of Metal Oxide Nanoparticles in Natural Aqueous Matrices

 

作者： Arturo A. Keller , Hongtao Wang , Dongxu Zhou , Hunter S. Lenihan , Gary Cherr , Bradley J. Cardinale , Robert Miller  and Zhaoxia Ji 

University of California, Santa Barbara, Tongji University, Shanghai, China, University of California, Davis, and University of California, Los Angeles

 

摘要：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 (TiO2, ZnO and CeO2) 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 μm s−1 V−1 cm. These results are key for designing and interpreting nanoparticle ecotoxicity studies in various environmental conditions.