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.

中文翻译：

---

聚乙二醇包覆的金纳米粒子在替代天然屏障中的迁移

摘要介绍胶体材料通过工程和天然屏障的迁移行为研究对于放射性废物储存库的安全评估非常重要，因为与胶体的相互作用可能会显着影响放射性核素的归宿和运输。方法：聚（乙二醇）包覆金以纳米颗粒 (AuNPs) 作为模型胶体，在批量和柱状实验中研究了 AuNPs 的性质对其迁移行为的影响。 结果：AuNPs 在硅砂上的沉积和 AuNPs 的聚集被观察到更多尽管 AuNPs 和硅砂都具有整体负表面电荷的不利条件，但 AuNPs。在突破曲线中观察到倾斜的平台，表明由硅砂上的电荷异质性引起的有限数量的位点可能是 AuNPs 和硅砂之间吸引力的原因。然而，对于具有更显着负表面电荷的较大 AuNP，观察到对硅砂和彼此之间的亲和力更强。 结论：结果表明，除静电和范德华 (vdW) 之外的相互作用正在控制 AuNP 的迁移行为，包括表面涂层产生的空间效应，因此在评估纳米粒子的命运和传输时需要考虑。