Modeling ion binding to humic substances: Elastic polyelectrolyte network model
A new model for the electrostatic contribution to ion binding to humic substances is proposed and applied to published data for proton binding to fulvic and humic acids. The elastic polyelectrolyte network model treats humic substance particles as composed by two parts, an external one directly in c...
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_07437463_v26_n5_p3134_Orsetti |
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todo:paper_07437463_v26_n5_p3134_Orsetti2023-10-03T15:38:42Z Modeling ion binding to humic substances: Elastic polyelectrolyte network model Orsetti, S. Andrade, E.M. Molina, F.V. Average values Carboxylic sites Charged polymers Donnan potential Electrolyte solutions Electrostatic contributions Electrostatic effect Experimental data Gel fraction Humic acid Humic substances Intramolecular hydrogen bond Ion activities Ion binding Model prediction New model Open structure Polyelectrolyte networks Polymer networks Proton binding Electrostatics Gels Ions Organic acids Photodegradation Polyelectrolytes Hydrogen bonds A new model for the electrostatic contribution to ion binding to humic substances is proposed and applied to published data for proton binding to fulvic and humic acids. The elastic polyelectrolyte network model treats humic substance particles as composed by two parts, an external one directly in contact with the solution, and an internal part or gel traction which is considered, from a statistical point of view, as a charged polymer network swelled by the electrolyte solution, in the framework of the Flory polymer network theory. The electrostatic effect is given by a Donnan-like potential, which can be regarded as an average value over the gel fraction of the humic particle. The gel fraction expands as the pH and humic charge are increased, determining the Donnan potential and consequently the ion activity inside the gel. The model was fitted to published experimental data with good agreement. The model predictions are discussed, and the behavior suggests, for some cases, the presence of a transition between closed and open structures attributed to the presence, at low pH, of intramolecular hydrogen bonds which are removed as the carboxylic sites become deprotonated. © 2010 American Chemical Society. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_07437463_v26_n5_p3134_Orsetti |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Average values Carboxylic sites Charged polymers Donnan potential Electrolyte solutions Electrostatic contributions Electrostatic effect Experimental data Gel fraction Humic acid Humic substances Intramolecular hydrogen bond Ion activities Ion binding Model prediction New model Open structure Polyelectrolyte networks Polymer networks Proton binding Electrostatics Gels Ions Organic acids Photodegradation Polyelectrolytes Hydrogen bonds |
| spellingShingle |
Average values Carboxylic sites Charged polymers Donnan potential Electrolyte solutions Electrostatic contributions Electrostatic effect Experimental data Gel fraction Humic acid Humic substances Intramolecular hydrogen bond Ion activities Ion binding Model prediction New model Open structure Polyelectrolyte networks Polymer networks Proton binding Electrostatics Gels Ions Organic acids Photodegradation Polyelectrolytes Hydrogen bonds Orsetti, S. Andrade, E.M. Molina, F.V. Modeling ion binding to humic substances: Elastic polyelectrolyte network model |
| topic_facet |
Average values Carboxylic sites Charged polymers Donnan potential Electrolyte solutions Electrostatic contributions Electrostatic effect Experimental data Gel fraction Humic acid Humic substances Intramolecular hydrogen bond Ion activities Ion binding Model prediction New model Open structure Polyelectrolyte networks Polymer networks Proton binding Electrostatics Gels Ions Organic acids Photodegradation Polyelectrolytes Hydrogen bonds |
| description |
A new model for the electrostatic contribution to ion binding to humic substances is proposed and applied to published data for proton binding to fulvic and humic acids. The elastic polyelectrolyte network model treats humic substance particles as composed by two parts, an external one directly in contact with the solution, and an internal part or gel traction which is considered, from a statistical point of view, as a charged polymer network swelled by the electrolyte solution, in the framework of the Flory polymer network theory. The electrostatic effect is given by a Donnan-like potential, which can be regarded as an average value over the gel fraction of the humic particle. The gel fraction expands as the pH and humic charge are increased, determining the Donnan potential and consequently the ion activity inside the gel. The model was fitted to published experimental data with good agreement. The model predictions are discussed, and the behavior suggests, for some cases, the presence of a transition between closed and open structures attributed to the presence, at low pH, of intramolecular hydrogen bonds which are removed as the carboxylic sites become deprotonated. © 2010 American Chemical Society. |
| format |
JOUR |
| author |
Orsetti, S. Andrade, E.M. Molina, F.V. |
| author_facet |
Orsetti, S. Andrade, E.M. Molina, F.V. |
| author_sort |
Orsetti, S. |
| title |
Modeling ion binding to humic substances: Elastic polyelectrolyte network model |
| title_short |
Modeling ion binding to humic substances: Elastic polyelectrolyte network model |
| title_full |
Modeling ion binding to humic substances: Elastic polyelectrolyte network model |
| title_fullStr |
Modeling ion binding to humic substances: Elastic polyelectrolyte network model |
| title_full_unstemmed |
Modeling ion binding to humic substances: Elastic polyelectrolyte network model |
| title_sort |
modeling ion binding to humic substances: elastic polyelectrolyte network model |
| url |
http://hdl.handle.net/20.500.12110/paper_07437463_v26_n5_p3134_Orsetti |
| work_keys_str_mv |
AT orsettis modelingionbindingtohumicsubstanceselasticpolyelectrolytenetworkmodel AT andradeem modelingionbindingtohumicsubstanceselasticpolyelectrolytenetworkmodel AT molinafv modelingionbindingtohumicsubstanceselasticpolyelectrolytenetworkmodel |
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1807323362189377536 |