Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5409518 | Journal of Molecular Liquids | 2016 | 9 Pages |
Abstract
The present study investigated the co-solubilization of three representative low-brominated diphenyl ethers (low-BDEs) in nonionic surfactant micelles. Co-solubilization effects were quantified in terms of molar solubilization ratio (MSR), micelle-water partition coefficient (log Km), extent of synergism/inhibition (RÎMSR), first stepwise association constant (K1), the average number of solute molecules per micelle (SM), excess Gibbs energy (ÎG0 excess), and interaction parameter (Ï/RT). The solubilities of low-BDEs during co-solubilization were increased (i.e., synergism) in all of the surfactants tested, relative to their respective solubilities during solubilization. In each surfactant system, synergism was weaker for BDE-15/BDE-28 than that for BDE-15/BDE-47 because BDE-15 and BDE-28 may be partitioned more uniformly in the micelle core than BDE-47, which increased the possibility of their competition. Unexpectedly, BDE-28 and BDE-47 with similar log Kow values demonstrated enhanced co-solubility. This phenomenon was attributed to the positive electrostatic potentials of bromines (computed by Gaussian program) on BDE-28 and BDE-47 which may provide additional attractions to oxygen atoms of the hydrophilic chains. The synergism observed for BDE-15/BDE-28 and BDE-15/BDE-47 was stronger in the Brij35 system than that in Brij58 and Brij78 systems, suggesting that a surfactant with lower aggregation number and/or longer hydrophilic chain length can avoid the competition between solutes for the micelle core. This study may improve the understanding of multi-solutes interactions in surfactant micelles.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Xingjian Yang, Guining Lu, Kaibo Huang, Rui Wang, Xingchun Duan, Chen Yang, Hua Yin, Zhi Dang,