| Attributs | Valeurs |
|---|
| type
| |
| Is Part Of
| |
| Subject
| |
| Title
| - Effects of Oxyethylene Chain Length and Temperature onPartitioning of Homogeneous Polyoxyethylene NonionicSurfactants between Water and Isooctane
|
| has manifestation of work
| |
| related by
| |
| Author
| |
| Abstract
| - Partition coefficients of homogeneous poly(oxyethylene glycol n-dodecyl ether) C12H25(OCH2CH2)iOH (i= 2−9) between water and isooctane were determined from experimental measurements in the temperaturerange 20−40 °C. All surfactants were found to have partition coefficients lower than unity, which indicatesthat their hydrophobic character is more important than their hydrophilic one. An increase in ethyleneoxide number from 2 to 9 induces an exponential increase of the partition coefficient of 3 orders of magnitude,while an increase of 20 °C in the temperature decreases its magnitude only 0.5 of an order of magnitude.The hydroxyl group contribution to the free energy of transfer of the surfactant molecules from water toisooctane was found to be more important than that of an ethylene oxide group. An increase in temperatureleads to an important decrease in its contribution, while the ethylene oxide contribution remains practicallyconstant. Contributions of the functional groups of the surfactant molecules to the free energy of partitioningare evaluated in order to build up a database to predict the partitioning of nonhomogeneous nonionicsurfactants of the same family within the temperature range investigated.
|
| article type
| |
| is part of this journal
| |
