2024-03-29T06:07:32Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1405252020-04-14T10:35:30Zcom_10261_5063com_10261_5col_10261_5066
Comelles, Francesc
Ribosa, Isabel
González, Juan José
García Ramón, María Teresa
2016-11-22T08:27:18Z
2016-11-22T08:27:18Z
2017-03-15
Journal of Colloid and Interface Science 490: 119–128 (2017)
http://hdl.handle.net/10261/140525
10.1016/j.jcis.2016.11.022
http://dx.doi.org/10.13039/501100003329
Hypothesis
Mixtures of the cationic surfactant hexadecyltrimethylammonium bromide (CTA-Br) and the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (bmim-BF4) in aqueous solutions are expected to behave as typical binary cationic surfactant system taking into account the surface activity displayed by the ionic liquid, instead of considering the IL as a water cosolvent.
Experiments
Surface tension and conductivity measurements have been conducted as a function of the total concentration of the mixtures at different surfactant mole fraction (αCTA-Br) to investigate the surface active properties.
Findings
Turbidity immediately appearing when the compounds are mixed in water suggests the spontaneous formation of the low soluble compound hexadecyltrimethylammonium tetrafluoroborate (CTA-BF4), together with the salt formed by the respective counterions bmim+and Br− in solution. For αCTA-Br ≠ 0.5, furthermore of the mentioned compounds, the spare bmim-BF4 (for αCTA-Br < 0.5) or CTA-Br (for αCTA-Br > 0.5), are also present in the aqueous solution. Systems containing excess of bmim-BF4 show a low critical aggregate concentration (cac), but an unexpected high surface tension at cac (γcac ≈ 53–56 mN/m), as pure CTA-BF4. For systems containing excess of CTA-Br, cac increases but γcac decreases up to 36 mN/m. Mixtures of pure CTA-BF4 and bmim-BF4 or CTA-Br behave as typical binary surfactant systems.
eng
http://creativecommons.org/licenses/by-nc-nd/4.0/
openAccess
CTA-Br
Bmim-BF4
Cationic surfactants
CTAB
Ionic liquid
Surface tension
Conductivity
Bynary Systems
Synergism
Hexadecyltrimethylammonium bromide (CTA-Br) and 1-butyl-3-methylimidazolium tetrafluoroborate (bmim-BF4) in aqueous solution: An ephemeral binary system
artículo