文献名： Role of water chemistry on stability, aggregation, and dissolution of uncoated and carbon-coated copper nanoparticles

作者： Ayenachew Tegenaw^a, George A. Sorial^a,, Endalkachew Sahle-Demessie^b, Changseok Han^c

a Environmental Engineering Program, Department of Chemical and Environmental Engineering, College of Engineering and Applied Science, University of Cincinnati, 701 Engineering Research Center, 2901 Woodside Drive P.O. Box 210012, Cincinnati, OH, 45221-0012, UnitedStates

b U.S. Environmental Protection Agency, Office of Research and Development, Center for Environmental Solution and Emergency Response, 26 W.MartinLuther Drive, Cincinnati, OH, 45268, United States

c Department of Environmental Engineering, College of Engineering, INHA University, 100 Inharo, Nam-gu Incheon, 22212, South Korea

摘要：Intentional or accidental release of copper nanoparticles (Cu-NPs) from consumer products during manufacturing, use, and end-of-life management could pose health and ecological risks. This paper presents a detailed study on the role of water chemistry on the fate of uncoated and carbon-coated Cu-NPs dispersed in aqueous cetyltrimethylammonium bromide (CTAB) surfactant in the presence and absence of humic acids (HAs). A range of water chemistry and HAs had minimum impact on hydrodynamic diameter and zeta-potential values of uncoated and carbon-coated Cu-NPs. The water pH significantly (p < 0.001) affected the aggregation of uncoated Cu-NPs unlike that of carbon-coated Cu-NPs; however, the presence of HAs increased the stability of uncoated Cu-NPs. Although CTAB is considered as an efficient dispersant to stabilize Cu-NPs, the effect descended with time for uncoated Cu-NPs. The dissolution of Cu over time decreased with increasing pH for both uncoated (0.5–50% weight) and carbon-coated (0.5–40% weight) Cu-NPs. However, carbon-coated Cu-NPs exhibited significant dissolution (p < 0.001) at neutral pH than uncoated Cu-NPs may be due to the additional carbon it acquired during coating. Increasing HAs concentration from 0 to 15 mg L⁻¹ at pH 5.5 inhibited aggregations but enhanced dissolution of the uncoated and carbon-coated Cu-NPs. These findings inform risk analysis of Cu-NPs including how Cu-NPs fate, mobility and bioavailability are modulated by particles coating and dispersant, HAs presence, water chemistry and exposure time in dispersion media.

关键词：Aggregation; Cu-NPs fate; Ecological risks; Risk analysis; Water chemistry