1007398-58-4Relevant academic research and scientific papers
Reactivity of anionic nucleophiles in ionic liquids and molecular solvents
Betti, Cecilia,Landini, Dario,Maia, Angelamaria
, p. 1689 - 1695 (2008)
The nucleophilic reactivity of a representative series of anions has been measured in [hmim][ClO4] 3i, [hm2im][ClO4] 3′i, and [hmim][PF6] 3l ILs in the reaction with n-alkyl methanesulfonates and compared with that found in common molecular solvents (MeOH, DMSO, PhCl). The reactivity is found to depend on both the imidazolium cation-anion interaction and the specific solvation by water present in the IL, the water playing the main effect, in particular with hydrophilic anions. Removal of the largest quantity of water remarkably increases the ion pair reactivity in the IL up to rate constant value k comparable with those obtained in DMSO and in low polarity media (PhCl).
Effect of Hydroxyl Groups in a Cation Structure on the Properties of Ionic Liquids
Krasovskiy,Chernikova,Glukhov,Kapustin,Koroteev
, p. 2379 - 2385 (2018)
Two series of imidazolium ionic liquids with the bis(trifluoromethylsulfonyl)imide anion were synthesized, which differ by the presence of a hydroxyl group at the ω-position of the alkyl substituent in the cation structure (nC = 2–8). The properties of the liquids were studied by DSC, TGA, and IR and NMR spectroscopy. Their thermal stability was studied, and the melting points, viscosity, and volatility in vacuum were measured. The effect of OH groups in the structure of the ionic liquid on its properties was evaluated.
The Influence of an Organic Salt on Micellization Behavior of Tetradecyltrimethylammonium Bromide in Aqueous Solutions of Trisubstituted Ionic Liquid [Odmim][Cl]
Pal, Amalendu,Punia, Renu
, p. 41 - 52 (2020)
The influence of sodium benzoate (Na-Bz) on micellization behavior of the cationic surfactant tetradecyltrimethylammonium bromide (TTAB) in aqueous media of trisubstituted imidazolium-based ionic liquid (IL), 1,2-dimethyl-3-octylimidazolium chloride [odmim][Cl], was investigated using conductometry, tensiometry, fluorescence,1H NMR, Dynamic Light Scattering (DLS), and Rheology techniques. It was observed that with an increase in salt concentration, the critical micelle concentration (CMC) values of the system decrease. The CMC and various thermodynamic parameters like standard Gibbs free energy of micellization (ΔG0 m), standard enthalpy change (ΔH0 m), and standard entropy change (ΔS0 m) were calculated using conductometry and surface parameters such as surface pressure at the interface (Пcac), maximum surface excess concentration (Гmax), minimum surface area per molecule (Amin), and pC20 (adsorption efficiency) were calculated using the tensiometry technique. The aggregation number (Nagg) was calculated using fluorescence measurements. 1H NMR spectra shed light on interactions between the salt and the cationic surfactant in 0.1 wt% IL. DLS gives information about the size distribution of micelles in solution at different concentrations of salt.
Thermodynamic and aggregation properties of aqueous dodecyltrimethylammonium bromide in the presence of hydrophilic ionic liquid 1,2-dimethyl-3-octylimidazolium chloride
Pal, Amalendu,Pillania, Ankita
, p. 818 - 824 (2015)
The effect of a trisubstituted imidazolium based hydrophilic ionic liquid (IL), 1,2-dimethyl-3-octylimidazolium chloride [odmim][Cl] on the thermodynamic and aggregation properties of dodecyltrimethylammonium bromide (DTAB) at temperatures 298.15-318.15 K has been studied by conductivity measurements in aqueous media. From the temperature dependence of critical micelle concentration (cmc), various thermodynamic parameters of micellization viz. standard free energy change (ΔGm°), standard enthalpy change (ΔHm°) and standard entropy change (ΔSm°) have been evaluated. Further fluorescence probe analysis has been utilized to obtain cmc value in order to validate the cmc values obtained from conductivity measurements. The micelles formed just like in aqueous medium and cmc values were found to be changing at different wt% of IL than in water. The cmc value of aqueous DTAB solution decreases until 2.0 wt% of IL in the medium. The properties of aqueous DTAB solution change in a different way at higher concentration of IL. The variation in chemical shifts of surfactant protons in the presence of IL revealed that the electrostatic interactions have a prominent influence on the DTAB micellization in IL/water systems. It is shown that the modification in aggregation properties of DTAB is related to the lipophilicity of interacting ions.
