Charge Regulating Macro-ions in Salt Solutions: Screening Properties and Electrostatic Interactions
| Autor: | Tomer Markovich, David Andelman, Yael Avni, Rudolf Podgornik |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Collective behavior
Disjoining pressure FOS: Physical sciences 02 engineering and technology Condensed Matter - Soft Condensed Matter 01 natural sciences Dissociation (chemistry) Effective nuclear charge Ion symbols.namesake Physics - Chemical Physics 0103 physical sciences 010306 general physics Condensed Matter - Statistical Mechanics Debye length Chemical Physics (physics.chem-ph) Condensed Matter - Materials Science Statistical Mechanics (cond-mat.stat-mech) Chemistry food and beverages Materials Science (cond-mat.mtrl-sci) General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Electrostatics Acceptor stomatognathic diseases Chemical physics symbols Soft Condensed Matter (cond-mat.soft) 0210 nano-technology |
| DOI: | 10.48550/arxiv.1804.03063 |
| Popis: | We revisit the charge-regulation mechanism of macro-ions and apply it to mobile macro-ions in a bathing salt solution. In particular, we examine the effects of correlation between various adsorption/desorption sites and analyze the collective behavior in terms of the solution effective screening properties. We show that such a behavior can be quantified in terms of the charge {\em asymmetry} of the macro-ions, defined by their preference for a non-zero effective charge, and their {\em donor/acceptor} propensity for exchanging salt ions with the bathing solution. Asymmetric macro-ions tend to increase the screening, while symmetric macro-ions can in some cases decrease it. Macro-ions that are classified as donors display a rather regular behavior, while those that behave as acceptors exhibit an anomalous non-monotonic Debye length. The screening properties, in their turn, engender important modifications to the disjoining pressure between two charged surfaces. Our findings are in particular relevant for solutions of proteins, whose exposed amino acids can undergo charge dissociation/association processes to/from the bathing solution, and can be considered as a solution of charged regulated macro-ions, as analyzed here. Comment: 13 pages, 8 figures, minor revisions |
| Databáze: | OpenAIRE |
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