(627d) Leaching Rate of Silver Ions from Engineered Nanosilver
AIChE Annual Meeting
2021
2021 Annual Meeting
Computational Molecular Science and Engineering Forum
Recent Advances and Applications of Molecular Modeling Virtual
Tuesday, November 16, 2021 - 10:05am to 10:30am
Here, the mechanisms of silver ion release from nanosilver particles and their leaching rate is studied by reactive Molecular Dynamics simulations. Specifically, the effect of particle characteristics (size, crystallinity, specific surface area) and environmental conditions (temperature, concentration) on the leaching rate of nanosilver is quantified. Figure 1 shows the fraction of silver ions in nanosilver particles as function of particle size obtained by reactive molecular dynamics simulations (circles). The results are in excellent agreement with experiments of flame- and wet-made nanosilver (triangles) in aqueous suspensions. For comparison, the estimated silver ion fractions assuming one (squares) and two (diamonds) silver oxide layers are shown.Small nanosilver particles (with diameter of 3 â 4 nm) exhibit a large fraction of silver ions, present in the form of silver oxide at the particle surface. This fraction corresponds to a double layer of silver oxide. In contrast, larger nanosilver (7 â 8 nm) exhibit a smaller fraction of silver ions (corresponding to a single layer), consistent with experiments (Sotiriou et al., 2012).
The employed reactive molecular dynamics simulations are used, for the first time, to quantify the nanosilver oxidation rate and ion release rate from the particle surface in aqueous solutions that are responsible for the nanosilver toxic manifestations. Understanding the mechanism of silver ion release rate from nanosilver particles will determine their environmental fate and adverse effects on human health. Minimising these release rates will also enable the expanded use of silver nanoparticles and their nanocomposites as bioimaging materials or plasmonic biosensors.
References
Sotiriou, G. A., Meyer, A., Knijnenburg, J. T., Panke, S., & Pratsinis, S. E. (2012). Quantifying the origin of released Ag+ ions from nanosilver. Langmuir, 28(45), 15929-15936.