Tensoatividade de ácidos húmicos de procedências distintas
| Autor: | Eduardo Juan Soriano Sierra, Nito Ângelo Debacher, Thalita Grando Rauen, Maria Marta de Souza Sierra |
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| Jazyk: | angličtina |
| Rok vydání: | 2002 |
| Předmět: | |
| Zdroj: | Química Nova, Vol 25, Iss 6a, Pp 909-913 (2002) Química Nova, Volume: 25, Issue: 6a, Pages: 909-913, Published: NOV 2002 |
| ISSN: | 1678-7064 0100-4042 |
| Popis: | The surface activity of humic acids (HA) is a parameter which might be considered in the evaluation of all types of aggregation of these substances. In this work the surface tension of aquatic and terrestrial-HA aqueous solutions was observed under varied conditions of pH, concentration and ionic strength. Results showed that HA present surface activity for a extent range of concentration. The surface tension decreases with HA concentration increasing and, for all samples exist a concentration value above which a reduction in the rate of the solute migration to the solution surface is observed. This value is sensibly reduced and sharpened with the increasing of the ionic strength. Surface tension is also reduced with the acidity increasing, being a minimum reached between pH 3 and 5. Observed effects are explained in view of conformational arrangements of HA which tend to agglomerate in micelle-like domains in aqueous solutions. |
| Databáze: | OpenAIRE |
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