SOLUBILIZATION OF P-ALKYLPHENOLS IN PLURONICS F-68 AND F-127 MICELLES: PARTITION COEFFICIENTS AND EFFECT OF SOLUTE ON THE AGGREGATE STRUCTURE
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Archivos
Fecha
2014-07
Profesor/a Guía
Facultad/escuela
Idioma
en
Título de la revista
ISSN de la revista
Título del volumen
Editor
Sociedad Chilena de Química
Nombre de Curso
Licencia CC
Licencia CC
Resumen
The partition of a series of substituted phenols between water and polymer micelles formed by Pluronic F-68 and F-127 has been studied. The formation of micelles by these block copolymers has been evidenced by steady-state fluorescence and dynamic light scattering. The data show that micelles and larger aggregates are formed above the critical micelle concentration. In presence of p-alkylphenols a micelle rearrangement occurs that leads to the formation of just one and large aggregate. This effect depends both on polymer and phenols structures. The partition coefficients and the standard free energies of transfer from the aqueous to the micellar phases were determined. The incremental free energy for a methylene group are 2.88 kJ mol-1 and 1.65 kJ mol-1 for F-127 and F-68, respectively. This difference is explained in terms of the core sizes that are determined by the length of the PPO block.
Notas
Indexación: Web of Science; Scielo.
Palabras clave
Pluronic, Block copolymers, Polymer micelles, Partition, Free energy of transfer, Critical micelle concentration, Fluorescence probing methods, Dynamic light scattering
Citación
J. Chil. Chem. Soc. vol.59 no.2 Concepción July 2014