Centre for Safety of Substances and Products, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
Institute of Environmental Sciences (CML), Leiden University, Leiden, The Netherlands.
Environ Toxicol Chem. 2018 Apr;37(4):1024-1031. doi: 10.1002/etc.4059. Epub 2018 Feb 15.
Comprehensive experimental quantification and mapping of the aggregation and dispersion state of engineered nanoparticles (NPs) in the presence of humic substances is a great challenge. Dissipative particle dynamic (DPD) simulation was adopted to investigate the aggregation and dispersion mechanisms of NPs in the presence of a humic substance analog. Twelve different types of NPs including 2 metal-based NPs, 7 metal oxide-based NPs, and 3 carbon-based NPs in pure water (pH 3.0) and algae medium (pH 8.0) in the presence of a humic substance analogy were selected for experimental verification of the DPD simulation results. In agreement with results obtained with dynamic light scattering and phase analysis light scattering techniques, the simulations demonstrated that the presence of humic substances reduced the aggregation extent of the NPs. The DPD simulations showed that the stability and dispersity of the NPs increased first, and then decreased with increasing concentrations of humic substances. Moreover, there existed a concentration of humic substances where the NPs became more stable and more dispersed, which was experimentally verified in the case of all the NPs in the pure water and in the algae medium. Furthermore, theory and simulation indicate that both hydrophobic and hydrogen interaction play an important role in controlling the formation of NP aggregates in the presence of humic substances. Electrostatic interaction and steric repulsion are the main mechanisms underlying the effects of humic substances on the aqueous dispersion stability of NPs. Environ Toxicol Chem 2018;37:1024-1031. © 2017 SETAC.
综合实验量化和描绘了在腐殖质存在下工程纳米颗粒（NPs）的聚集和分散状态，这是一个巨大的挑战。耗散粒子动力学（DPD）模拟被用来研究NP在腐殖质类似物存在下的聚集和分散机制。在纯水中（pH3.0）和藻类介质（pH8.0）中，选择了 12 种不同类型的 NPs，包括 2 种金属基 NPs、7 种金属氧化物基 NPs 和 3 种碳基 NPs，以及一种腐殖质类似物，用于 DP 模拟结果的实验验证。与动态光散射和相分析光散射技术的结果一致，模拟表明腐殖质的存在降低了 NPs 的聚集程度。DPD 模拟表明，随着腐殖质浓度的增加，NP 的稳定性和分散性先增加后降低。此外，存在一个腐殖质浓度，使得 NPs 变得更加稳定和分散，这在所有 NP 在纯水和藻类介质中的实验中都得到了验证。此外，理论和模拟表明，疏水相互作用和氢键相互作用在控制腐殖质存在下 NP 聚集的形成中都起着重要作用。静电相互作用和空间排斥是腐殖质对 NPs 水相分散稳定性影响的主要机制。《环境毒理化学》2018；37：1024-1031。2017 年 SETAC 出版。
