Impact of surface coating and environmental conditions on the fate and transport of silver nanoparticles in the aquatic environment.
Impact of surface coating and environmental conditions on the fate and transport of silver nanoparticles in the aquatic environment.
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DOI：
10.1016/j.scitotenv.2016.05.199
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发表时间：
2016-10
期刊：
影响因子：
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通讯作者：
Laura-Jayne A. Ellis;E. Valsami-Jones;J. Lead;Mohammed Baalousha
中科院分区：
文献类型：
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作者：
Laura-Jayne A. Ellis;E. Valsami-Jones;J. Lead;Mohammed Baalousha
本文报道了表面涂层（聚乙烯吡咯烷酮（PVP）和柠檬酸盐）和水化学对AgNPs在水生微观环境中的命运和行为的影响。研究了AgNPs在低离子强度（超纯水- upw）和高离子强度（中等硬水- MHW）制备中，以及在Suwannee River Fulvic Acid （SRFA）模拟天然有机物（NOM）存在下的迁移和转化。通过沉积-扩散模型验证了AgNPs在微观环境中的迁移和命运，并通过紫外-可见光谱（UV-vis）监测了AgNPs的聚集行为。用超滤法分析溶解银和颗粒银浓度（% Ag）。利用透射电子显微镜（TEM）捕获AgNPs的成像。结果表明，PVP-AgNPs （PVP-AgNPs）在28天内保持稳定，在每种水条件下，大约96小时（4天）后，PVP-AgNPs在整个柱上的浓度分布相似。沉积-扩散模型通过使用原始未改变的AgNP大小来拟合参数，表明扩散主导迁移，从而证实了PVP-AgNP在每种条件下的稳定性。相比之下，柠檬酸AgNPs在更复杂的水制剂（MHW）中基本上不稳定。在MHW中，以聚集为主，其次是沉积/溶解控制的运输。与不添加SRFA的研究相比，在MHW中添加SRFA对柠檬酸盐包覆的AgNPs产生了较小的稳定作用，产生了更小尺寸的AgNPs （TEM）和混合沉积和扩散迁移。结果表明，表面涂层和溶液化学对AgNP的稳定性有重要影响，相应的建模将支持对AgNP在环境中的整体命运的实验理解。
The role of surface coating (polyvinylpyrrolidone (PVP) and citrate) and water chemistry on the fate and behavior of AgNPs in aquatic microcosms is reported in this study. The migration and transformation of the AgNPs was examined in low (ultrapure water-UPW) and high ionic strength (moderately hard water – MHW) preparations, and in the presence of modeled natural organic matter (NOM) of Suwannee River Fulvic Acid (SRFA). The migration and fate of the AgNPs in the microcosms was validated using a sedimentation-diffusion model and the aggregation behavior was monitored by UV–visible spectrometry (UV–vis). Dissolved and particulate Ag concentrations (% Ag) were analyzed by ultrafiltration methods. Imaging of the AgNPs was captured using transmission electron microscopy (TEM).Results indicate that PVP-coated AgNPs (PVP-AgNPs) remained stable for 28 days with similarly distributed concentrations of the PVP-AgNPs throughout the columns in each of the water conditions after approximately 96 h (4 days). The sedimentation-diffusion model confirmed PVP-AgNP stability in each condition, by showing diffusion dominated transport by using the original unaltered AgNP sizes to fit the parameters. In comparison, citrate AgNPs were largely unstable in the more complex water preparations (MHW). In MHW, aggregation dominated behavior followed by sedimentation/dissolution controlled transport was observed. The addition of SRFA to MHW resulted in small stabilizing effects, to the citrate coated AgNPs, producing smaller sized AgNPs (TEM) and mixed sedimentation and diffusion migration compared the studies absent of SRFA. The results suggest that surface coating and solution chemistry has a major impact on AgNP stability, furthermore the corresponding modeling will support the experimental understanding of the overall fate of AgNPs in the environment.