Effect of monovalent and divalent cations, anions and fulvic acid on aggregation of citrate-coated silver nanoparticles
Effect of monovalent and divalent cations, anions and fulvic acid on aggregation of citrate-coated silver nanoparticles
复制标题
DOI：
10.1016/j.scitotenv.2013.02.093
复制
发表时间：
2013-06-01
影响因子：
9.8
通讯作者：
Lead, J. R.
中科院分区：
文献类型：
--
作者：
Baalousha, M.;Nur, Y.;Lead, J. R.
纳米颗粒（NP）聚集行为的动力学性质是当前环境和毒理学纳米科学研究的重要内容。本研究旨在阐明不同电解质对柠檬酸盐包覆银NPs （cito - agnps）聚集的影响。与仅使用DLS和仅报告z-d(h)的其他研究相比，使用UV-vis光谱和动态光散射（DLS， z-平均流体动力直径（z-d(h)）和尺寸分布分析数据）可以改善数据质量和解释，因为z-d(h)的变化可能与分析误差和不确定性有关，而不仅仅是NPs的聚集或溶解。二价阳离子(CaCl2、Ca（NO3)(2)、CaSO4、MgCl2和MgSO4）对cite - agnps聚集的影响比一价阳离子（NaCl、NaNO3、Na2SO4）更强（约50-65倍），正如预期的那样。对于含有一价阳离子的电解质，硝酸盐和硫酸盐阴离子没有特异性的离子效应。然而，氯离子的加入导致表观聚集增强，这可能是由于AgCl NPs的形成吸收/附着在citi - agnps的表面。Suwannee River黄腐酸增强了citi - agnps的稳定性，并将所有类型电解质的临界凝血浓度转移到更高的电解质浓度。一价和二价阳离子混合存在时的聚集动力学是加性的，并受优势阳离子控制。提出了一个经验公式(α（混合物）= α (Na) + (50 ~ 65)Ca)，该公式再现了腐殖质和阳离子存在下电解质混合物的影响，可用于帮助预测cite - agnps在环境和生态毒理学介质中的聚集行为。2013 Elsevier B.V.版权所有
The dynamic nature of nanoparticle (NP) aggregation behavior is of paramount interest to many current studies in environmental and toxicological nanoscience. The present study seeks to elucidate the influence that different electrolytes have on the aggregation of citrate-coated silver NPs (cit-AgNPs). The use of both UV-vis spectroscopy and dynamic light scattering (DLS, both z-average hydrodynamic diameter (z-d(h)) and size distribution analysis data) allowed improvement in the data quality and interpretation as compared to other studies using only DLS and reporting solely the z-d(h), as the change in the z-d(h) can be related to analytical errors and uncertainties rather than only aggregation or dissolution of NPs. Divalent cations (CaCl2, Ca(NO3)(2), CaSO4, MgCl2 and MgSO4) have stronger influence (ca. 50-65 fold) on aggregation of cit-AgNPs as compared to monovalent cations (NaCl, NaNO3, Na2SO4), as expected. For electrolytes with monovalent cations, there was no specific ion effect of nitrate and sulfate anions. However, the addition of chloride anions resulted in enhanced apparent aggregation, possibly due to the formation of AgCl NPs that sorb/attach to the surface of cit-AgNPs. Suwannee River fulvic acid enhances the stability of cit-AgNPs and shifts the critical coagulation concentrations to higher electrolyte concentrations for all types of electrolytes. Aggregation kinetics in the presence of mixture of monovalent and divalent cations is additive and controlled by the dominant cations. An empirical formula (alpha(mixture) = alpha(Na) + (50 to 65)Ca) is proposed that reproduces the effect of mixtures of electrolytes in the presence of humic substances and cations that can be used to help predict the aggregation behavior of cit-AgNPs in environmental and ecotoxicological media. 0 2013 Elsevier B.V. All rights reserved.