Thermodynamics of Charge Regulation near Surface Neutrality
The interaction between two adjacent charged surfaces immersed in aqueous solution is known to be affected by charge regulation─the modulation of surface charge as two charged surfaces approach each other. This phenomenon is particularly important near surface neutrality where the stability of objec...
Publié dans: | Langmuir : the ACS journal of surfaces and colloids. - 1985. - 38(2022), 27 vom: 12. Juli, Seite 8477-8483 |
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Auteur principal: | |
Autres auteurs: | |
Format: | Article en ligne |
Langue: | English |
Publié: |
2022
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Accès à la collection: | Langmuir : the ACS journal of surfaces and colloids |
Sujets: | Journal Article Research Support, Non-U.S. Gov't Colloids Ions |
Résumé: | The interaction between two adjacent charged surfaces immersed in aqueous solution is known to be affected by charge regulation─the modulation of surface charge as two charged surfaces approach each other. This phenomenon is particularly important near surface neutrality where the stability of objects such as colloids or biomolecules is jeopardized. Focusing on this ubiquitous case, we elucidate the underlying thermodynamics and show that charge regulation is governed in this case by surface entropy. We derive explicit expressions for charge regulation and formulate a new universal limiting law for the free energy of ion adsorption to the surfaces. The latter turns out to be proportional to kBT, and independent of the association energy of ions to surface groups. These new results are applied to the analysis of unipolar as well as amphoteric surfaces such as oxides near their point of zero charge or proteins near their isoelectric point |
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Description: | Date Completed 13.07.2022 Date Revised 24.08.2022 published: Print-Electronic Citation Status MEDLINE |
ISSN: | 1520-5827 |
DOI: | 10.1021/acs.langmuir.2c01352 |