Novel behavior of heat of micellization of pluronics F68 and F88 in aqueous solutions
It is well understood that the heat of micellization for surfactants is monotonically decreased along with an increase in temperature. However, this behavior for polymeric surfactants has never been carefully examined. In this study, the heat of micellization of poly(ethylene oxide)-poly(propylene o...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 24(2008), 24 vom: 16. Dez., Seite 13858-62 |
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| Weitere Verfasser: | , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2008
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article |
| Zusammenfassung: | It is well understood that the heat of micellization for surfactants is monotonically decreased along with an increase in temperature. However, this behavior for polymeric surfactants has never been carefully examined. In this study, the heat of micellization of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers (Pluronics F68 and F88) in water as a function of temperature is carefully examined by using a high-sensitivity differential scanning calorimeter (HSDSC). The critical micelle temperature (CMT) decreases along with an increase in the concentration of Pluronic F68 (or F88). The heat of micellization decreases along with an increase in the temperature, as expected, when the CMT is higher than 55 and 42 degrees C for Pluronics F68 and F88, respectively. It is interesting to observe that the heat of micellization increases along with the temperature while the temperature is below 55 and 42 degrees C for Pluronics F68 and F88, respectively. The enthalpy-entropy compensation phenomenon for the micellization of Pluronics F68 and F88 in connection with the hydrophobicity is discussed |
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| Beschreibung: | Date Completed 01.05.2009 Date Revised 10.04.2009 published: Print Citation Status PubMed-not-MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/la803272y |