Center for Environmental Nanoscience and Risk (CENR), University of South Carolina , Columbia, South Carolina 29208, United States.
Environ Sci Technol. 2013;47(21):12426-33. doi: 10.1021/es402541z. Epub 2013 Oct 21.
There is a pressing need for the development of standard and reference nanomaterials for environmental nanoscience and nanotoxicology. To that aim, suspensions of polyvinylpyrrolidone (PVP)-coated ceria nanoparticles (NPs) were produced. Four differently sized monodispersed samples were produced by using different PVP chain lengths. The chemical and physical properties of these NPs were characterized as prepared and in different ecotoxicology exposure media. Dynamic light scattering analysis showed that the samples were monodispersed, with an unchanged size when suspended in the different media over a 72 h period. Electron microscopy confirmed this and revealed that the larger (ca. 20 nm) particles were aggregates composed of the smaller individual particles (4-5 nm). Electron energy loss spectroscopy (EELS) showed that the smallest and largest samples were composed almost entirely of cerium(III) oxide, with only small amounts of cerium(IV) present in the largest sample. Dissolved cerium concentrations in media were low and constant, showing that the NPs did not dissolve over time. The simple synthesis of the these NPs and their physical and chemical stability in different environmental conditions make them potentially suitable for use as reference materials for (eco)toxicology and surface water environmental studies.
目前迫切需要开发用于环境纳米科学和纳米毒理学的标准和参考纳米材料。为此，制备了聚乙烯吡咯烷酮（PVP）包覆的氧化铈纳米颗粒（NPs）悬浮液。通过使用不同的 PVP 链长，制备了四种不同尺寸的单分散样品。对这些 NPs 的化学和物理性质进行了表征，包括制备时以及在不同的生态毒理学暴露介质中的性质。动态光散射分析表明，这些样品在 72 小时内悬浮在不同的介质中时具有单分散性，且尺寸不变。电子显微镜证实了这一点，并表明较大的（约 20nm）颗粒由较小的单个颗粒（4-5nm）组成。电子能量损失光谱（EELS）表明，最小和最大的样品几乎完全由氧化铈组成，而最大的样品中仅存在少量的氧化铈（IV）。介质中溶解的铈浓度较低且恒定，表明 NPs 不会随时间溶解。这些 NPs 的简单合成及其在不同环境条件下的物理和化学稳定性使它们有可能适合用作（生态）毒理学和地表水环境研究的参考材料。
