Effect of Counterion and Configurational Entropy on the Surface Tension of Aqueous Solutions of Ionic Surfactant and Electrolyte Mixtures
In order to clarify the adsorption behavior of cationic surfactants on the air/aqueous electrolyte solution surface, we derived the theoretical equation for the surface tension. The equation includes the electrical work required for charging the air/water surface and the work attributable to the con...
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| Format: | Article |
| Language: | English |
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MDPI AG
2010-04-01
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| Series: | Entropy |
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| Online Access: | http://www.mdpi.com/1099-4300/12/4/983/ |
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| author | Youichi Takata Hiroaki Tagashira Atsushi Hyono Hiroyuki Ohshima |
| author_facet | Youichi Takata Hiroaki Tagashira Atsushi Hyono Hiroyuki Ohshima |
| author_sort | Youichi Takata |
| collection | DOAJ |
| description | In order to clarify the adsorption behavior of cationic surfactants on the air/aqueous electrolyte solution surface, we derived the theoretical equation for the surface tension. The equation includes the electrical work required for charging the air/water surface and the work attributable to the configurational entropy in the adsorbed film. By fitting the equation to the experimental data, we determined the binding constant between adsorbed surfactant ion and counterion, and found that the bromide ions, rather than the chloride ions, are preferentially adsorbed by the air/water surface. Furthermore, it was suggested that the contribution of configurational entropy to the surface tension is predominant in the presence of electrolytes because of the increase in the surface density of surfactant molecules associated with decreasing the repulsive interaction between their hydrophilic groups. |
| first_indexed | 2024-12-10T08:13:22Z |
| format | Article |
| id | doaj.art-58b060a742be4920bb40fee299e3feb6 |
| institution | Directory Open Access Journal |
| issn | 1099-4300 |
| language | English |
| last_indexed | 2024-12-10T08:13:22Z |
| publishDate | 2010-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Entropy |
| spelling | doaj.art-58b060a742be4920bb40fee299e3feb62022-12-22T01:56:31ZengMDPI AGEntropy1099-43002010-04-0112498399510.3390/e12040983Effect of Counterion and Configurational Entropy on the Surface Tension of Aqueous Solutions of Ionic Surfactant and Electrolyte MixturesYouichi TakataHiroaki TagashiraAtsushi HyonoHiroyuki OhshimaIn order to clarify the adsorption behavior of cationic surfactants on the air/aqueous electrolyte solution surface, we derived the theoretical equation for the surface tension. The equation includes the electrical work required for charging the air/water surface and the work attributable to the configurational entropy in the adsorbed film. By fitting the equation to the experimental data, we determined the binding constant between adsorbed surfactant ion and counterion, and found that the bromide ions, rather than the chloride ions, are preferentially adsorbed by the air/water surface. Furthermore, it was suggested that the contribution of configurational entropy to the surface tension is predominant in the presence of electrolytes because of the increase in the surface density of surfactant molecules associated with decreasing the repulsive interaction between their hydrophilic groups.http://www.mdpi.com/1099-4300/12/4/983/surface tensionHelmholtz free energyconfigurational entropyadsorption constantbinding constant |
| spellingShingle | Youichi Takata Hiroaki Tagashira Atsushi Hyono Hiroyuki Ohshima Effect of Counterion and Configurational Entropy on the Surface Tension of Aqueous Solutions of Ionic Surfactant and Electrolyte Mixtures Entropy surface tension Helmholtz free energy configurational entropy adsorption constant binding constant |
| title | Effect of Counterion and Configurational Entropy on the Surface Tension of Aqueous Solutions of Ionic Surfactant and Electrolyte Mixtures |
| title_full | Effect of Counterion and Configurational Entropy on the Surface Tension of Aqueous Solutions of Ionic Surfactant and Electrolyte Mixtures |
| title_fullStr | Effect of Counterion and Configurational Entropy on the Surface Tension of Aqueous Solutions of Ionic Surfactant and Electrolyte Mixtures |
| title_full_unstemmed | Effect of Counterion and Configurational Entropy on the Surface Tension of Aqueous Solutions of Ionic Surfactant and Electrolyte Mixtures |
| title_short | Effect of Counterion and Configurational Entropy on the Surface Tension of Aqueous Solutions of Ionic Surfactant and Electrolyte Mixtures |
| title_sort | effect of counterion and configurational entropy on the surface tension of aqueous solutions of ionic surfactant and electrolyte mixtures |
| topic | surface tension Helmholtz free energy configurational entropy adsorption constant binding constant |
| url | http://www.mdpi.com/1099-4300/12/4/983/ |
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