TY - JOUR
T1 - Colloidal stability of hematite nanoparticles in the presence of a common quaternary ammonium compound at environmentally-relevant concentrations
AU - Aruguete, Deborah M.
AU - Zhuang, Andy
AU - Canonaco, Cameron
AU - Sheckler, Trevor
AU - Schmidt, Corryn
AU - Borgohain, Rituraj
N1 - Publisher Copyright:
© 2023 The Royal Society of Chemistry.
PY - 2023/11/15
Y1 - 2023/11/15
N2 - The fate and behavior of environmental nanomaterials can be strongly affected by organic molecules, including surfactants. Quaternary ammonium compounds (QACs) are cationic surfactants of increasing concern in the environment due to their massive everyday use and continuous release into water and soil. To examine QAC-NP interactions, ∼38 nm hematite (α-Fe2O3) nanoparticle (NP) suspensions were mixed end-over-end with cetyltrimethylammonium chloride (CTAC), a commonly-used QAC, for 22 hours (23 °C) at environmentally-relevant concentrations of 0, 10, 100, and 1000 μg L−1. Iron concentrations were measured to determine how many NPs remained in suspensions after mixing, along with characterization of the hydrodynamic diameter (Z-average) and zeta potential. Without CTAC, the NPs were destabilized by contact with air-water interfaces (AWIs) with [Fe] decreasing from 17.65 ± 3.26 mg L−1 to an [Fe]final of 6.33 ± 2.90 mg L−1. However, at 100 and 1000 μg CTAC L−1, the NPs were stabilized and NP loss reduced with [Fe]final values of 9.50 ± 1.20 mg L−1 and 11.69 ± 1.25 mg L−1, respectively. Measurements of surface tension and contact angles on CTAC-exposed glass were performed to explore possible stabilization mechanisms. Results suggest that in systems with air-water interfaces such as unsaturated pores or turbulent waters, elevated QAC content might alter the environmental fate and transport of iron oxide and other positively-charged NPs.
AB - The fate and behavior of environmental nanomaterials can be strongly affected by organic molecules, including surfactants. Quaternary ammonium compounds (QACs) are cationic surfactants of increasing concern in the environment due to their massive everyday use and continuous release into water and soil. To examine QAC-NP interactions, ∼38 nm hematite (α-Fe2O3) nanoparticle (NP) suspensions were mixed end-over-end with cetyltrimethylammonium chloride (CTAC), a commonly-used QAC, for 22 hours (23 °C) at environmentally-relevant concentrations of 0, 10, 100, and 1000 μg L−1. Iron concentrations were measured to determine how many NPs remained in suspensions after mixing, along with characterization of the hydrodynamic diameter (Z-average) and zeta potential. Without CTAC, the NPs were destabilized by contact with air-water interfaces (AWIs) with [Fe] decreasing from 17.65 ± 3.26 mg L−1 to an [Fe]final of 6.33 ± 2.90 mg L−1. However, at 100 and 1000 μg CTAC L−1, the NPs were stabilized and NP loss reduced with [Fe]final values of 9.50 ± 1.20 mg L−1 and 11.69 ± 1.25 mg L−1, respectively. Measurements of surface tension and contact angles on CTAC-exposed glass were performed to explore possible stabilization mechanisms. Results suggest that in systems with air-water interfaces such as unsaturated pores or turbulent waters, elevated QAC content might alter the environmental fate and transport of iron oxide and other positively-charged NPs.
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U2 - 10.1039/d3en00544e
DO - 10.1039/d3en00544e
M3 - Article
AN - SCOPUS:85177824071
SN - 2051-8153
VL - 10
SP - 3476
EP - 3485
JO - Environmental Science: Nano
JF - Environmental Science: Nano
IS - 12
ER -