Journal article
Effect of pH and Ionic Strength on the Deposition of Charge-Regulating Macro-Ions
Journal of dispersion science and technology, v 25(5), pp 603-608
01 Jan 2005
Featured in Collection : UN Sustainable Development Goals @ Drexel
Abstract
We examine here the adsorption of weak, acidic, rigid macro-ions onto oppositely charged surfaces using a mean field model. The analysis takes into account the effect of the nominal suspension pH on the charge distribution inside the macro-ion layer, as well as the counter-ion distribution in the adsorbed layer and in the solution surrounding the substrate. We find that, as expected, the adsorbed layer thickness decreases with the pH (namely, with the degree of charge dissociation) and with the solution ionic strength. The macro-ion adsorption can, in some cases, over-compensate for the substrate charge, thereby allowing layer-by-layer deposition. We find that charge inversion is obtained, for a given substrate, if the macro-ion pK is lower than a critical value. For a given macro-ion, charge inversion takes place if the substrate charge density exceeds a critical value that scales as the square root of the macro-ion charge density. In both cases charge inversion is obtained only in the regime where the suspension pH is comparable to the pK.
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Details
- Title
- Effect of pH and Ionic Strength on the Deposition of Charge-Regulating Macro-Ions
- Creators
- Nily Dan - Drexel University
- Publication Details
- Journal of dispersion science and technology, v 25(5), pp 603-608
- Publisher
- Taylor & Francis Group
- Resource Type
- Journal article
- Language
- English
- Web of Science ID
- WOS:000224440300006
- Scopus ID
- 2-s2.0-7244250104
- Other Identifier
- 991019312368504721
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InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Web of Science research areas
- Chemistry, Physical