Interfacial tension (using a drop-shape analysis technique), fluorescence (of widely used spectroscopic molecular probe, pyrene), and 1H NMR measurements were to monitor the adsorption at aqueous solution–air interface self-aggregation behaviour (critical micelle concentration, CMC) of room-temperature ionic liquids (ionic liquids) 1-alkyl-3-methylimidazolium family cations, [Cnmim]+, with different linear alkyl chain lengths, CnH2n+1 (½n = 1–7), counter-ions, namely [Cnmim]Cl (n 2–14),...

The aggregation behavior in aqueous solution of a number ionic liquids was investigated at ambient conditions by using three techniques: fluorescence, interfacial tension, and (1)H NMR spectroscopy. For the first time, fluorescence quenching effect has been used for determination critical micelle concentrations. This study focuses on following liquids: [Cnmpy]Cl (1-alkyl-3-methylpyridinium chlorides) with different linear alkyl chain lengths (n=4, 10, 12, 14, 16, or 18), [C12mpip]Br...

The current study focuses on several phosphonium-based ionic liquids, namely, trihexyltetradecylphosphonium chloride, acetate, and bis{(trifluoromethyl)sulfonyl}amide. objective was to the influence of pressure as well that anion properties this type liquids. Densities in pure liquids a function temperature have been determined. Other thermodynamic properties, such isothermal compressibility, isobaric expansivity, thermal coefficient, calculated. Density measurements performed at broad range...

Anionic and cationic alkyl-chain effects on the self-aggregation of both neat aqueous solutions 1-alkyl-3-methylimidazolium alkylsulfonate salts ([CnH2n+1mim][CmH2m+1SO3]; n = 8, 10 or 12; m 1 4 8; 8) have been investigated. Some these constitute a novel family pure catanionic surfactants in solution. Examples this class materials are rare; they distinct from mixed cationic–anionic (obtained by mixing two salts) gemini (with more amphiphilic groups bound covalent linker). Fluorescence...

The effects of the addition three inorganic salts, namely, NaCl, Na(2)SO(4), and Na(3)PO(4), on liquid-liquid (L-L) phase diagram aqueous solutions containing model ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF(4)], were investigated. All salts trigger salting-out effects, leading to significant upward shifts L-L demixing temperatures systems. magnitude depends both water-structuring nature salt its concentration; that is, are correlated with strength solution Gibbs...

A set of 1-alkyl-3-methylimidazolium alkanesulfonate ionic liquids, [Cnmim][CkSO3], formed by the variation alkyl chain lengths both in cation and anion (n = 1–6, 8, or 10; k 1–4, 6), was synthesised, with sixteen them being novel. The liquids were characterised 1H 13C NMR spectroscopy, mass spectrometry. Their viscosities densities as a function temperature, well melting points decomposition temperatures, determined. molecular volumes, experimental calculated, found to depend linearly on sum + k).

A family of short-chain catanionic fluorinated surfactants with potential for reduced environmental impact, excellent surface activity and fluorine efficiency.

We investigated the mutual solubility of mixtures phosphonium-based ionic liquids with alkanes, alkanols, fluorinated alkanes and alkanols. The solubilities other solute molecules like water, formamide, 1,4-dioxane, benzene, dimethylsulfoxide were also tested. Whenever possible, corresponding temperature-composition (T-x) phase diagrams at atmospheric pressure built from cloud-point temperature determinations. influence size was tested binary trihexyl(tetradecyl)phosphonium acetate, [P6 6...

Abstract Enhancing oil recovery from currently available reservoirs is a major issue for petroleum companies. Among the possible strategies towards this, chemical flooding through injection of surfactants into wells seems to be particularly promising, thanks their ability reduce oil/water interfacial tension that promotes mobilization. Environmental concerns about use synthetic led growing interest in replacement with biological origin, such as lipopeptides and glycolipids produced by...

In this work, we explore the mutual solubility of a number mixtures commonly used ionic liquids (imidazolium, pyridinium, phosphonium and ammonium liquids) with partially fluorinated n-alcohols (C7 to C10) or perfluoroheptane. The corresponding T–x diagrams at atmospheric pressure were measured through cloud-point temperature determinations. For some selected systems under near-critical isopleth conditions, effects also studied. results are discussed in terms (i) shifts immiscibility...

This work extends the scope of previous studies on phase behavior mixtures ionic liquids with benzenes or its derivatives by determining solid-liquid and liquid-liquid diagrams containing an liquid a fluorinated benzene. The systems studied include 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide plus hexafluorobenzene 1,3,5-trifluorobenzene triflate N-ethyl-N-methylpyrrolidinium exhibit different kinds behavior: (usual) occurrence eutectic points; (not-so-usual) presence...

Ionic liquid analogues of Girard's reagent exhibit thermomorphism with water that leads to efficient extraction dyes and metals from water.

We present a study on the phase equilibrium behaviour of binary mixtures containing two 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide-based ionic liquids, [C(n)mim] [NTf(2)] (n=2 and 4), mixed with diethylamine or triethylamine as function temperature composition using different experimental techniques. Based this work, systems showing an LCST one system possible hourglass shape are measured. Their behaviours then correlated predicted by Flory-Huggins equations UNIQUAC...

High-water-content water-in-supercritical CO2 (W/CO2) microemulsions are considered to be green, universal solvents, having both polar and nonpolar domains. Unfortunately, these systems generally require environmentally unacceptable stabilizers like long and/or multifluorocarbon-tail surfactants. Here, a series of catanionic surfactants more friendly fluorinated C4-C6 tails have been studied in terms interfacial properties, aggregation behavior, solubilizing power water CO2. Surface tensions...

Zwitterionic salts: highly hydrophilic materials, incorporating some characteristics of zwitterions, ionic liquids, and inorganic salts with potential applications in the biomedical field separation technology.

The melting temperatures of [Cnmpy]Cl (4 ≤ even n 18) were determined by a dynamic method and confirmed differential scanning calorimetry. latter technique was also used to measure the corresponding enthalpies fusion. marking onset decomposition eight ionic liquids thermogravimetry. solid–liquid liquid–liquid phase equilibria binary mixtures pyridine or nicotine with four 1-alkyl-3-methylpyridinium chloride family ([Cnmpy]Cl = 4, 6, 10, 16) investigated. T–x diagrams measured at atmospheric...

It is often believed that both ionic liquids and surfactants generally behave as non-specific denaturants of proteins. In this paper, it shown amphiphilic bearing a long alkyl chain target molecule, where the molecule appended via carboxylic ester functionality, can represent super-substrates enable catalytic activity an enzyme, even at high concentrations in solution. Menthol has been chosen for slow controlled fragrance delivery, was found rate menthol release be by chemical structure...

The use of 5-phenyltetrazole, a bioisostere benzoic acid, as an anion source to prepare ionic liquid is described for the first time. Tetrabutylphosphonium 5-phenyltetrazolate undergoes phase separation from water with lower critical solution temperature behavior, in contrast completely miscible tetrabutylphosphonium benzoate, and also exhibits strong complexation both eutectic peritectic behavior that has not previously been observed liquid+water systems. anhydrous trihydrate salts were...

To facilitate potential applications of water-in-supercritical CO2 microemulsions (W/CO2 μEs) efficient and environmentally responsible surfactants are required with low levels fluorination. As well as being able to stabilize water–CO2 interfaces, these must also be economical, prevent bioaccumulation strong adhesion, deactivation enzymes, tolerant high salt environments. Recently, an ion paired catanionic surfactant acceptable fluorinated C6 tails was found very effective at stabilizing...

Strong, electrostatically-directed hydration was observed for tethered sulfobetaine dizwitterions, with a hydrophilic regime even hexyl inter-zwitterion spacer.