2014 |
Rios, H; Collio, G A; Urzúa, M; Vargas, V Binding of Phenols with Amphipathic Cationic Polyelectrolytes Artículo de revista Journal of Macromolecular Science Part B-Physics, 53 (3), pp. 428-439, 2014, ISSN: 0022-2348. Resumen | Enlaces | BibTeX | Etiquetas: amphipathic aqueous-solution, association, binding, cooperative decyl, liquid-chromatography, micelles, partition-coefficients, phenols, polyelectrolytes, salts solubilization, sulfonates @article{RN207, title = {Binding of Phenols with Amphipathic Cationic Polyelectrolytes}, author = { H. Rios and G.A. Collio and M. Urz\'{u}a and V. Vargas}, url = {/brokenurl#<Go to ISI>://WOS:000331602300006}, doi = {10.1080/00222348.2013.845067}, issn = {0022-2348}, year = {2014}, date = {2014-01-01}, journal = {Journal of Macromolecular Science Part B-Physics}, volume = {53}, number = {3}, pages = {428-439}, abstract = {The association of phenols, such as p-cresol, tribromophenol, and trichlorophenol, with several amphipathic poly (n-alkylmethyldiallylammonium) chlorides in aqueous solution was studied by ultrafiltration. The n-alkyl residues were octyl, decyl, and dodecyl and the binding degrees were significantly higher than those found with the hydrophilic poly (diallyldimethylammonium) chloride. The results agreed well with the Satake and Yang's treatment and Hill's empirical equation for the association process, thereby revealing, in both cases, an increasing cooperative effect as the polyelectrolyte side chain increased in length for the same phenol, and when the hydrophobic nature of the phenol increased for the same kind of polyelectrolyte. From the phenomenological association constants, the estimated molar standard free energies of association ranged from -19kJmol(-1), for the more hydrophilic phenoxide-polyelectrolyte pair, to -28kJmol(-1) for the more hydrophobic pairs. The main result is that the amphipathic nature of these polyelectrolytes makes them efficient systems to trap anionic contaminants, better than hydrophilic flocculants.}, keywords = {amphipathic aqueous-solution, association, binding, cooperative decyl, liquid-chromatography, micelles, partition-coefficients, phenols, polyelectrolytes, salts solubilization, sulfonates}, pubstate = {published}, tppubtype = {article} } The association of phenols, such as p-cresol, tribromophenol, and trichlorophenol, with several amphipathic poly (n-alkylmethyldiallylammonium) chlorides in aqueous solution was studied by ultrafiltration. The n-alkyl residues were octyl, decyl, and dodecyl and the binding degrees were significantly higher than those found with the hydrophilic poly (diallyldimethylammonium) chloride. The results agreed well with the Satake and Yang's treatment and Hill's empirical equation for the association process, thereby revealing, in both cases, an increasing cooperative effect as the polyelectrolyte side chain increased in length for the same phenol, and when the hydrophobic nature of the phenol increased for the same kind of polyelectrolyte. From the phenomenological association constants, the estimated molar standard free energies of association ranged from -19kJmol(-1), for the more hydrophilic phenoxide-polyelectrolyte pair, to -28kJmol(-1) for the more hydrophobic pairs. The main result is that the amphipathic nature of these polyelectrolytes makes them efficient systems to trap anionic contaminants, better than hydrophilic flocculants. |
2013 |
Rios, H; Collio, G A; Leal, M; Urzúa, M; Vargas, V Association of 4-N-Alkylbenzene Sulfonates with Hydrophobically Modified Poly (Diallyldimethylammonium) Chlorides Artículo de revista Journal of Macromolecular Science Part B-Physics, 52 (6), pp. 841-851, 2013, ISSN: 0022-2348. Resumen | Enlaces | BibTeX | Etiquetas: aryl association, cationic chloride), cooperative effects, sulfonates @article{RN149, title = {Association of 4-N-Alkylbenzene Sulfonates with Hydrophobically Modified Poly (Diallyldimethylammonium) Chlorides}, author = { H. Rios and G.A. Collio and M. Leal and M. Urz\'{u}a and V. Vargas}, url = {/brokenurl#<Go to ISI>://WOS:000316342200006}, doi = {10.1080/00222348.2012.737284}, issn = {0022-2348}, year = {2013}, date = {2013-01-01}, journal = {Journal of Macromolecular Science Part B-Physics}, volume = {52}, number = {6}, pages = {841-851}, abstract = {The association of poly (diallyldimethylammonium) chloride (PDDAC) hydrophobically modified with octyl, decyl, and dodecyl chlorides, with 4-n-alkylbenzene sulfonates, was studied in aqueous solution by ultrafiltration. Experimental data agree well with the Hill's equation for the association process. The association degree increases with the size of the sulfonate anion and decreases as the polyelectrolyte side chains length increases. This kind of polyelectrolyte is able to form hydrophobic microdomains lowering the availability of association sites due to a hypercoiling process. The association process was, in all cases, cooperative, having a maximum with the octyl derivative. The association degrees were significantly higher than those found with PDDAC itself. The standard free-energy contribution to the association process was between 19 and 20 kJ/mol of benzene sulfonate. These values are comparable with those recently found for a family of hydrophobic cationic polyelectrolytes at the water/chloroform interface. Therefore, in terms of the association process, it does not matter if the polyelectrolyte is adsorbed at a liquid/liquid interface or if it is soluble in a pure phase. The contribution of the methylene groups was very small, ranging from 0.20 to 0.50 kJ/mol. This reveals that the main interaction governing the association is the aromatic ringammonium group interaction.}, keywords = {aryl association, cationic chloride), cooperative effects, sulfonates}, pubstate = {published}, tppubtype = {article} } The association of poly (diallyldimethylammonium) chloride (PDDAC) hydrophobically modified with octyl, decyl, and dodecyl chlorides, with 4-n-alkylbenzene sulfonates, was studied in aqueous solution by ultrafiltration. Experimental data agree well with the Hill's equation for the association process. The association degree increases with the size of the sulfonate anion and decreases as the polyelectrolyte side chains length increases. This kind of polyelectrolyte is able to form hydrophobic microdomains lowering the availability of association sites due to a hypercoiling process. The association process was, in all cases, cooperative, having a maximum with the octyl derivative. The association degrees were significantly higher than those found with PDDAC itself. The standard free-energy contribution to the association process was between 19 and 20 kJ/mol of benzene sulfonate. These values are comparable with those recently found for a family of hydrophobic cationic polyelectrolytes at the water/chloroform interface. Therefore, in terms of the association process, it does not matter if the polyelectrolyte is adsorbed at a liquid/liquid interface or if it is soluble in a pure phase. The contribution of the methylene groups was very small, ranging from 0.20 to 0.50 kJ/mol. This reveals that the main interaction governing the association is the aromatic ringammonium group interaction. |
2014 |
Binding of Phenols with Amphipathic Cationic Polyelectrolytes Artículo de revista Journal of Macromolecular Science Part B-Physics, 53 (3), pp. 428-439, 2014, ISSN: 0022-2348. |
2013 |
Association of 4-N-Alkylbenzene Sulfonates with Hydrophobically Modified Poly (Diallyldimethylammonium) Chlorides Artículo de revista Journal of Macromolecular Science Part B-Physics, 52 (6), pp. 841-851, 2013, ISSN: 0022-2348. |