Effect of natural organic matter on aggregation behavior of C₆₀ fullerene in water

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• 作者：Hamid Mashayekhi ; Saikat Ghosh ; Peng Du ; Baoshan Xing ; ^{bx@pssci.umass.edu}
• 关键词：Fullerene ; Dispersion ; Aggregation kinetics ; Natural organic matter
• 刊名：Journal of Colloid and Interface Science
• 出版年：2012
• 期刊代码：125_00219797
• 类别：ch
• 出版时间：15 May, 2012
• 卷：374
• 期：1
• 页码：111-117
• 文件大小：715 K

摘要

The stability of C₆₀ fullerene particles in water affects its mobility, bioavailability, and toxicity to organisms. Natural organic matters (NOMs) have pronounced effects on the aggregation behavior of C₆₀ fullerene. This study was to examine the effects of NOM structural properties on the aggregation behavior of fullerene water suspension (FWS). Fulvic acid (FA), tannic acid (TA), and two structurally different humic acids (HA1 and HA7) were studied. HA1 and HA7 were sequentially extracted HAs, where HA7 was more hydrophobic than HA1 and had a higher molecular weight. Aggregation was induced by addition of varying amounts of Ca²⁺ to the FWS with 2 mg/L of each NOM. The absolute value of zeta potential |味| of pure FWS increased after addition of any type of NOM. Addition of Ca²⁺ to the FWS + NOM system decreased |味| of fullerene almost uniformly for all types of NOM. FWS critical coagulation concentration (CCC) was equal to 14.5, 6.5, 5.4, and 3.7 mM Ca²⁺ for HA7, HA1, FA, and TA, respectively. The order of increasing CCCs was positively correlated to the NOMs molecular weight and negatively to their polarity. A nearly constant 味 for FWS + NOM system at a wide range of Ca²⁺ concentrations suggested the steric stability rather than electrostatic one. This study highlighted the role of NOM in the fate of manufactured nanoparticles in the environment and linked the structural properties of NOM to their interaction with manufactured nanoparticles.