Abstract
While important for many industrial applications, chemical reactions responsible for the charging of solids in water are often poorly understood. We theoretically investigate the charging kinetics of solid-liquid interfaces and find that the time-dependent equilibration of surface charge contains key information not only on the reaction mechanism, but also on the valency of the reacting ions. We construct a nonlinear differential equation describing surface charging by combining chemical Langmuir kinetics and electrostatic Poisson-Boltzmann theory. Our results reveal a clear distinction between late-time (near-equilibrium) and short-time (far-from-equilibrium) relaxation rates, the ratio of which contains information on the charge valency and ad- or desorption mechanism of the charging process. Similarly, we find that single-ion reactions can be distinguished from two-ion reactions, as the latter show an inflection point during equilibration. Interestingly, such inflection points are characteristic of autocatalytic reactions, and we conclude that the Coulombic ion-surface interaction is an autocatalytic feedback mechanism.
Original language | English |
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Article number | 058001 |
Number of pages | 6 |
Journal | Physical Review Letters |
Volume | 130 |
Issue number | 5 |
DOIs | |
Publication status | Published - 3 Feb 2023 |
Bibliographical note
Funding Information:We thank Ben Werkhoven and Cheng Lian for fruitful discussion, and an anonymous referee for pointing us to the pressure-jump experiments in Refs. . This work is part of the D-ITP consortium, a program of the Netherlands Organisation for Scientific Research (NWO) that is funded by the Dutch Ministry of Education, Culture and Science (OCW).
Publisher Copyright:
© 2023 American Physical Society.
Funding
We thank Ben Werkhoven and Cheng Lian for fruitful discussion, and an anonymous referee for pointing us to the pressure-jump experiments in Refs. . This work is part of the D-ITP consortium, a program of the Netherlands Organisation for Scientific Research (NWO) that is funded by the Dutch Ministry of Education, Culture and Science (OCW).
Keywords
- Chemical kinetics dynamics & catalysis
- Chemical reactions
- Charged colloids
- Liquid-solid interfaces
- Polymers & Soft Matter
- Statistical Physics
- Nonlinear Dynamics