Abstract

Seemingly unrelated experiments such as electrolyte transport through nanotubes, nano-scale electrochemistry, NMR relaxometry and Surface Force Balance measurements, all probe electrical fluctuations: of the electric current, the charge and polarization, the field gradient (for quadrupolar nuclei) and the coupled mass/charge densities. Using molecular and mesoscopic simulations, it is possible to predict the fluctuations of these observables from the dynamics of ions and solvent molecules, thereby enabling experimentalists to decipher the microscopic properties encoded in the measured electrical noise. This presentation will illustrate this idea, focusing on quadrupolar NMR relaxation as a probe of subpicosecond collective dynamics in aqueous electrolyte solutions, and on the link between the electrode charge fluctuations in nanocapacitors and the dynamics of the interfacial electrolyte.

References:

https://benrotenberg.github.io/erc-senses/

NMR Relaxation Rates of Quadrupolar Aqueous Ions from Classical Molecular Dynamics Using Force-Field Specific Sternheimer Factors. I. Chubak, L. Scalfi, A. Carof, and B. Rotenberg, J. Chem. Theory Comput., 17, 6006 (2021). https://doi.org/10.1021/acs.jctc.1c00690

Quadrupolar $^$Na${+}$ NMR Relaxation as a Probe of Subpicosecond Collective Dynamics in Aqueous Electrolyte Solutions. I. Chubak, L. Alon, E. Silletta, G. Madelin, A. Jerschow, and B. Rotenberg, Nature Commun., 14, 84 (2023). https://doi.org/10.1038/s41467-022-35695-3

Charge fluctuations from molecular simulations in the constant-potential ensemble. L. Scalfi, D.T. Limmer, A. Coretti, S. Bonella, P.A. Madden, M. Salanne, B. Rotenberg, Phys. Chem. Chem. Phys., 22, 10480 (2020). https://doi.org/10.1039/C9CP06285H

Molecular simulation of electrode-solution interfaces. L. Scalfi, M. Salanne, and B. Rotenberg, Ann. Rev. Phys. Chem., 72, 189, (2021). https://doi.org/10.1146/annurev-physchem-090519-024042

Frequency-dependent impedance of nanocapacitors from electrode charge fluctuations as a probe of electrolyte dynamics. G. Pireddu and B. Rotenberg. Phys. Rev. Lett., 130, 098001, (2023). https://doi.org/10.1103/PhysRevLett.130.098001

Electrical noise in electrolytes: a theoretical perspective T. Hoang Ngoc Minh, J. Kim, G. Pireddy, I. Chubak, S. Nair, B. Rotenberg, to appear in Faraday Discuss. (2023) https://doi.org/10.1039/D3FD00026E