How the Cation 1-butyl-3-methylimidazolium Impacts on the Interaction between the Entrapped Water and the Reverse Micelles Interface Created with an Ionic Liquid-like Surfactant

LEPORI C; CORREA N.M.; SILBER J.J.; FALCONE R.D.

SOFT MATTER

ROYAL SOC CHEMISTRY

Lugar: CAMBRIDGE; Año: 2016 vol. 12 p. 830 - 844

1744-683X

The behavior of the interfacial water entrapped in reverse micelles (RMs) formed by theionic liquid-like surfactant: 1-butyl-3-methylimidazolium 1,4-bis-2-ethylhexylsulfosuccinate(bmim-AOT) dissolved in benzene (or chlorobenzene) was investigated using noninvasivetechniques such as dynamic (DLS) and static (SLS) light scattering, FT-IR and 1H NMR.DLS and SLS results reveal the formation of discrete spherical and non-interacting waterdroplets stabilized by the bmim-AOT surfactant. Moreover since the droplet sizes values increase asthe W0 (W0 = [Water]/[Surfactant]) values increase, water interacts with the RMs interface.From FT-IR and 1H NMR data, a weaker water-surfactant interaction in bmim-AOT RMs incomparison with the RMs created by sodium 1,4-bis-2-ethylhexylsulfosuccinate (Na-AOT) isdetected. Consequently there are less water molecules interacting with the interface in bmim-AOTRMs, and its hydrogen bond network is not completely disrupted as it is in Na-AOT RMs. Theresults show how the nature of the new cation impact on the interaction between the entrappedwater and the RM interface, modifying the interfacial water structure in comparison with the resultsknown for Na-AOT.