[Zurück]

T. Stepan, L. Tete, L. Laundry-Mottiar, E. Romanovskaia, Y Hedberg, H. Danninger, M. Auinger:
"Effect of nanoparticle size on the near-surface pH-distribution in aqueous and carbonate buffered solutions";
Electrochimica Acta, 409 (2022), 139923; 10 S.

An analytical solution for the effect of particle size on the current density and near-surface ion distribution around spherical nanoparticles is presented in this work. With the long-term aim to support predictions on corrosion reactions in the human body, the spherical diffusion equation was solved for a set of differential equations and algebraic relations for pure unbuffered and carbonate buffered solutions. It was shown that current densities increase significantly with a decrease in particle size, suggesting this will lead to an increased dissolution rate. Near-surface ion distributions show the formation of a steep pH-gradient near the nanoparticle surface ( < 6 μm) which is further enhanced in the presence of a car-
bonate buffer ( < 2 μm). Results suggest that nanoparticles in pure electrolytes not only dissolve faster than bigger particles but that local pH-gradients may influence interactions with the biological environment, which should be considered in future studies.

Modelling, Thermodynamics, Diffusion, Surface pH-value, Nanoparticles

http://dx.doi.org/10.1016/j.electacta.2022.139923

https://publik.tuwien.ac.at/files/publik_303310.pdf