Hexadecyltrimethylammonium bromide (CTA-Br) and 1-butyl-3-methylimidazolium tetrafluoroborate (bmim-BF4) in aqueous solution: An ephemeral binary system
| Autor: | M. Teresa Garcia, Juan José González, Isabel Ribosa, Francesc Comelles |
|---|---|
| Přispěvatelé: | Ministerio de Economía y Competitividad (España) |
| Rok vydání: | 2017 |
| Předmět: |
Tetrafluoroborate
Inorganic chemistry 02 engineering and technology Ionic liquid 010402 general chemistry Mole fraction 01 natural sciences Biomaterials Surface tension chemistry.chemical_compound Colloid and Surface Chemistry Pulmonary surfactant Bynary Systems Binary system Cationic surfactants CTA-Br chemistry.chemical_classification Conductivity Aqueous solution Synergism CTAB 021001 nanoscience & nanotechnology 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Bmim-BF4 chemistry Counterion 0210 nano-technology |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| ISSN: | 0021-9797 |
| DOI: | 10.1016/j.jcis.2016.11.022 |
| Popis: | 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. The authors thank the Spanish Ministry of Economia y Competitividad (CTQ2013-41514-P) for financial support. |
| Databáze: | OpenAIRE |
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