Migration of polyethylene glycol coated gold nanoparticles in surrogate natural barriers
Migration of polyethylene glycol coated gold nanoparticles in surrogate natural barriers
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DOI：
10.1080/00223131.2020.1727371
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发表时间：
2020-04
影响因子：
1.2
通讯作者：
C. Ordonez;N. Watanabe;T. Kozaki
中科院分区：
文献类型：
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作者：
C. Ordonez;N. Watanabe;T. Kozaki
摘要：研究胶体材料通过工程屏障和天然屏障的迁移行为对放射性废物储存库的安全性评估非常重要，因为放射性核素的命运和运输可能受到与胶体的相互作用的显著影响。方法：以聚乙二醇包覆的金纳米颗粒（AuNPs）为模型胶体，通过硅砂的批量和柱状实验研究其性质对其迁移行为的影响。结果：尽管AuNPs和硅砂表面整体负电荷都是不利条件，但较大的AuNPs在硅砂上的沉积和聚集更多。在突破曲线上观察到倾斜的高原，这表明硅砂上由电荷非均质性产生的有限数量的位点可能是aunp和硅砂之间引力的原因。然而，表面负电荷较大的AuNPs对硅砂的亲和性和相互之间的亲和性更强。结论：结果表明，除静电和范德华（vdW）外，其他相互作用也控制着AuNPs的迁移行为，包括表面涂层引起的空间效应，因此在评估纳米颗粒的命运和运输时需要考虑。
ABSTRACT Introduction: Studies on migration behaviors of colloidal materials through engineered and natural barriers are highly important for the safety assessment of radioactive waste repositories since the fate and transport of radionuclides may be significantly affected by interactions with colloids.Methods: Poly (ethylene glycol) coated gold nanoparticles (AuNPs) were used as a model colloid and the effects of the properties of AuNPs on their migration behaviors were investigated in batch and column experiments with silica sand.Results: Deposition of AuNPs on silica sand and aggregation of AuNPs were observed more for larger AuNPs despite the unfavorable conditions of both AuNPs and silica sand having overall negative surface charges. Sloping plateaus were observed in the breakthrough curves, suggesting that a limited number of sites arising from charge heterogeneities on silica sand may be responsible for attractive forces between AuNPs and silica sand. However, stronger affinity toward silica sand and with each other was observed for larger AuNPs which have more significant negative surface charges.Conclusions: The results suggest that interactions other than electrostatic and van der Waals (vdW) are controlling the migration behavior of AuNPs, including steric effects arising from the surface coating, thus need to be considered when assessing fate and transport of nanoparticles.