Effect of phosphate buffer on aggregation kinetics of citrate-coated silver nanoparticles induced by monovalent and divalent electrolytes
Effect of phosphate buffer on aggregation kinetics of citrate-coated silver nanoparticles induced by monovalent and divalent electrolytes
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DOI：
10.1016/j.scitotenv.2016.12.117
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发表时间：
2017-03-01
影响因子：
9.8
通讯作者：
Baalousha, M.
中科院分区：
文献类型：
--
作者：
Afshinnia, K.;Baalousha, M.
附着效率（α）是可用于表征纳米颗粒（NPs）聚集行为的重要参数，并且在过去几年中一直是几篇论文的讨论主题。a的重要性在于它是可用于模拟NP环境归宿和行为的关键参数之一。本研究采用紫外-可见和激光多普勒电泳监测柠檬酸盐包被的银纳米粒子（cit-AgNPs）的聚集行为诱导的Na+和Ca 2+作为反离子在存在和不存在的Suwannee河富里酸（SRFA）作为天然有机物的替代品和不同浓度的磷酸盐缓冲液（0-1 mM）。结果表明，磷酸盐缓冲液，其用于保持pH值几乎恒定的反应过程中，是一个重要的决定因素NP聚集行为。增加磷酸盐缓冲液浓度导致cit-AgNP的临界凝固浓度（CCC）降低以降低反离子浓度，并且在相同反离子浓度下增加α，无论是在不存在还是存在SRFA的情况下。SRFA稳定AgNP并将CCC增加到更高的抗衡离子浓度。本研究的结果可用于合理解释文献中报告的具有相似理化性质的NP的α和CCC值的变化，其中当在不同研究中使用不同类型的缓冲液和缓冲液浓度时，报告了不同的α和CCC值。(C)2016爱思唯尔B. V.保留所有权利。
The attachment efficiency (a) is an important parameter that can be used to characterize nanoparticle (NPs) aggregation behavior and has been a topic of discussion of several papers in the past few years. The importance of a is because it is one of the key parameters that can be used to model NP environmental fate and behavior. This study uses UV-vis and laser Doppler electrophoresis to monitor the aggregation behavior of citrate-coated silver nanoparticles (cit-AgNPs) induced by Na+ and Ca2+ as counter ions in the presence and absence of Suwannee River fulvic acid (SRFA) as a surrogate of natural organic matter and different concentrations of phosphate buffer (0-1 mM). Results demonstrate that phosphate buffer, which serves to maintain pH nearly constant over the course of a reaction, is an important determinant of NP aggregation behavior. Increasing phosphate buffer concentration results in a decrease in the critical coagulation concentrations (CCC) of cit-AgNPs to lower counter ion concentration and an increase of a at the same counter ion concentration, both in the absence and presence of SRFA. SRFA stabilizes AgNPs and increases the CCC to higher counter ion concentrations. The outcome of this study can be used to rationalize the variation in a and CCC values reported in the literature for NPs with similar physicochemical properties, where different a and CCC values are reported when different types of buffers and buffer concentrations are used in different studies. (C) 2016 Elsevier B.V. All rights reserved.