The Determination of Affinity Distributions: A Numerical Algorithm and its Application for Estimating the Energetic Heterogeneity of Complexing Silicas and Humic Substances
The characterization of energetic heterogeneity has been discussed in the investigation of ion-binding and chemisorption processes. Both the calculation and the interpretation of the distribution of affinity constants are ambiguous. Methodological difficulties arise connected to the fact that electr...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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SAGE Publications
2000-04-01
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| Series: | Adsorption Science & Technology |
| Online Access: | https://doi.org/10.1260/0263617001493431 |
| _version_ | 1797284042372022272 |
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| author | Yu. Kholin S. Myerniy G. Varshal |
| author_facet | Yu. Kholin S. Myerniy G. Varshal |
| author_sort | Yu. Kholin |
| collection | DOAJ |
| description | The characterization of energetic heterogeneity has been discussed in the investigation of ion-binding and chemisorption processes. Both the calculation and the interpretation of the distribution of affinity constants are ambiguous. Methodological difficulties arise connected to the fact that electrostatic effects are difficult to separate from energetic heterogeneity because of the chemical biography of a given material. Only a close similarity between the distribution functions calculated for different ionic strengths allows the electrostatic interactions to be neglected. The numerical estimation of the distribution functions is complicated by the ill-posed nature of the problem. Some computational methods are briefly compared and methods for providing robust and unbiased estimations outlined. In contrast to differential distribution functions, the computation of integral ones may be transformed into the conventionally correct problem. On this basis, a fast and robust method for calculating integral distribution functions is proposed. In addition, this ensures numerically stable estimations of differential distribution functions. The method has been applied to a study of the energetic heterogeneity of 20 silicas chemically modified with aliphatic amines. When H + ions are chemisorbed, the energetic heterogeneity observed is dependent on the surface topography and its hydration state. In addition, the binding properties of ashless fulvic and humic acids relative to H + , Hg 2+ and Pb 2+ ions have been examined. The existence of functional groups with different acidities and complexing abilities has been established. |
| first_indexed | 2024-03-07T17:43:17Z |
| format | Article |
| id | doaj.art-c484924843b443ef8e5ab71feb21cf80 |
| institution | Directory Open Access Journal |
| issn | 0263-6174 2048-4038 |
| language | English |
| last_indexed | 2024-03-07T17:43:17Z |
| publishDate | 2000-04-01 |
| publisher | SAGE Publications |
| record_format | Article |
| series | Adsorption Science & Technology |
| spelling | doaj.art-c484924843b443ef8e5ab71feb21cf802024-03-02T15:53:59ZengSAGE PublicationsAdsorption Science & Technology0263-61742048-40382000-04-011810.1260/0263617001493431The Determination of Affinity Distributions: A Numerical Algorithm and its Application for Estimating the Energetic Heterogeneity of Complexing Silicas and Humic SubstancesYu. Kholin0S. Myerniy1G. Varshal2 Chemical Faculty, V.N. Karazin Kharkov National University, Svoboda Sq. 4, 61077 Kharkov, Ukraine Chemical Faculty, V.N. Karazin Kharkov National University, Svoboda Sq. 4, 61077 Kharkov, Ukraine V.I. Vernadskii Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Kosygina Str. 19, 117975 Moscow, RussiaThe characterization of energetic heterogeneity has been discussed in the investigation of ion-binding and chemisorption processes. Both the calculation and the interpretation of the distribution of affinity constants are ambiguous. Methodological difficulties arise connected to the fact that electrostatic effects are difficult to separate from energetic heterogeneity because of the chemical biography of a given material. Only a close similarity between the distribution functions calculated for different ionic strengths allows the electrostatic interactions to be neglected. The numerical estimation of the distribution functions is complicated by the ill-posed nature of the problem. Some computational methods are briefly compared and methods for providing robust and unbiased estimations outlined. In contrast to differential distribution functions, the computation of integral ones may be transformed into the conventionally correct problem. On this basis, a fast and robust method for calculating integral distribution functions is proposed. In addition, this ensures numerically stable estimations of differential distribution functions. The method has been applied to a study of the energetic heterogeneity of 20 silicas chemically modified with aliphatic amines. When H + ions are chemisorbed, the energetic heterogeneity observed is dependent on the surface topography and its hydration state. In addition, the binding properties of ashless fulvic and humic acids relative to H + , Hg 2+ and Pb 2+ ions have been examined. The existence of functional groups with different acidities and complexing abilities has been established.https://doi.org/10.1260/0263617001493431 |
| spellingShingle | Yu. Kholin S. Myerniy G. Varshal The Determination of Affinity Distributions: A Numerical Algorithm and its Application for Estimating the Energetic Heterogeneity of Complexing Silicas and Humic Substances Adsorption Science & Technology |
| title | The Determination of Affinity Distributions: A Numerical Algorithm and its Application for Estimating the Energetic Heterogeneity of Complexing Silicas and Humic Substances |
| title_full | The Determination of Affinity Distributions: A Numerical Algorithm and its Application for Estimating the Energetic Heterogeneity of Complexing Silicas and Humic Substances |
| title_fullStr | The Determination of Affinity Distributions: A Numerical Algorithm and its Application for Estimating the Energetic Heterogeneity of Complexing Silicas and Humic Substances |
| title_full_unstemmed | The Determination of Affinity Distributions: A Numerical Algorithm and its Application for Estimating the Energetic Heterogeneity of Complexing Silicas and Humic Substances |
| title_short | The Determination of Affinity Distributions: A Numerical Algorithm and its Application for Estimating the Energetic Heterogeneity of Complexing Silicas and Humic Substances |
| title_sort | determination of affinity distributions a numerical algorithm and its application for estimating the energetic heterogeneity of complexing silicas and humic substances |
| url | https://doi.org/10.1260/0263617001493431 |
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