| Full text | |
| Author(s): |
Keppeler, Nicolas
[1]
;
Galgano, Paula D.
[1]
;
Santos, Soraya da Silva
[1]
;
Malek, I, Naved
;
El Seoud, Omar A.
[1]
Total Authors: 5
|
| Affiliation: | [1] Univ Sao Paulo, Inst Chem, BR-05508000 Sao Paulo, SP - Brazil
Total Affiliations: 1
|
| Document type: | Journal article |
| Source: | JOURNAL OF MOLECULAR LIQUIDS; v. 328, APR 15 2021. |
| Web of Science Citations: | 1 |
| Abstract | |
The effects of the length of alkyl side chain (C-m) of ionic liquid-based surfactants (ILBSs) on their adsorption at the water/air interface, and aggregation in aqueous solutions were investigated for the series 1-(n-hexadecyl)-3-C-m-imidazolium bromides and chlorides, where C-m = C-1-C-4 for the bromides, and C-1-C-5 for the chlorides. These physicochemical properties were calculated from surface tension, conductivity, and fluorescence data. It was found that increasing the length of C-m (i.e., volume of the head group) leads to enhancement of surface activity, increase in the area per surfactant molecule at the water/air interface (A(min)) and the degree of counter-ion dissociation (alpha(mic)). Our data also indicated that increasing the volume of the head group results in a decrease of the critical micelle concentration (cmc), Gibb's free energy of adsorption and micellization, and microscopic polarity of interfacial water. In order to delineate the effects of the presence of unsaturation in the HG, we included members that carry C-m = vinyl and allyl in the bromide series. The effect of these groups was found to be similar to removing a methylene group from C-m. The dependence of the solubilization of a lipophilic dye (Sudan IV) and a drug (nitrendipine) on the length of C-m was also studied. (C) 2021 Elsevier B.V. All rights reserved. (AU) | |
| FAPESP's process: | 14/22136-4 - Use of green solvents and their mixtures for optimizing chemical processes |
| Grantee: | Omar Abou El Seoud |
| Support Opportunities: | Research Projects - Thematic Grants |