非水胶束电动色谱分离邻苯二甲酸酯类化合物

非水胶束电动色谱(NAMEKC)兼具非水毛细管电泳的优点和胶束电动色谱的分离机制,尤其适于对强疏水性化合物进行分离分析。在以甲酰胺为非水溶剂的电泳介质中,采用十二烷基硫酸钠（SDS）形成胶束相,开展NAMEKC方法的研究。通过添加水溶液、调节水溶液酸度、添加有机溶剂、改变SDS浓度等操作条件的考察,在15 min 内实现了3种美国环保局优先监测的污染物——邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二丁酯的分离。分离度最小者为1.5,检测限优于3.04 mmol/L(以信噪比为3计)。3种典型的强疏水性物质的成功分离,显示出NAMEKC方法在分离疏水性物质方面的优势,扩展了NAMEKC在电中性有机物分析中的应用。     

Effect of cosolvents on the binding interaction between poly(ethylene oxide) and sodium dodecyl sulfate

The micellization of sodium dodecyl sulfate (SDS) in different glycol-water solvent mixtures was studied using the isothermal titration calorimetric (ITC) technique. At the same time, microcalorimetric titrations were also carried out to monitor the binding interaction of SDS and poly(ethylene oxide) (PEO) in the presence of different cosolvents. The demicellization of SDS in mixtures of water and cosolvents is different from that in water due to the reduction in solvent polarity and charge interaction of surfactants. The critical micelle concentration (cmc) first decreases with the addition of a small amount of cosolvents and then increases at higher cosolvent concentrations. The thermodynamics of surfactant micellization can be analyzed using the solubility parameters of solvent mixtures. For the binding interaction between SDS and PEO in different solvent mixtures, the dehydration process at low SDS concentrations is replaced by the chain solubilization process with decreasing solvent polarity. With further reduction in the solvent polarity, the binding interaction between SDS and PEO becomes weak and no aggregates can be formed beyond a certain glycol concentration. The binding interaction between SDS and PEO in different solvent mixtures was analyzed and ascribed to the effects of PEO solubility and hydrophobicity of SDS.     

Toward the Rationalization of Facilitated Hydrotropy: Investigation with the Ternary Dimethyl Isosorbide / Benzyl Alcohol / Water System

Solubility enhancement has been achieved by facilitated hydrotropy for the dimethyl isosorbide (DMI) / benzyl alcohol / water system. Facilitated hydrotropy has been studied via three different approaches: the solubilization in water of a hydrophobic dye, the evolution of the surface tension and dynamic light scattering, all as a function of the benzyl alcohol concentration. The facilitated hydrotropy has been rationalized from the solubilization properties of the system according to the ratio between the insoluble hydrotrope (here benzyl alcohol, a preservative used in parenteral injections) and the bio-sourced co-solvant (here the dimethyl isosorbide ether, DMI, a solvent used in pharmaceutical formulation). The presence of self-associated nanostructures has been detected by dynamic light scattering (DLS). It appears that the cosolvent, DMI, has an antagonistic action: DMI increases the facilitated hydrotrope (benzyl alcohol) solubility in the aqueous solution (favoring solute solubilization) but simultaneously decreases the hydrotropic efficiency of benzyl alcohol.     

Hydrotrope-induced autocatalysis in the biphasic alkaline hydrolysis of aromatic esters

The alkaline hydrolysis of aromatic esters exhibits autocatalytic kinetics when performed under two-phase conditions without any mixing solvent. The molecular structures of such aromatic esters determine whether the autocatalysis occurs or not. It has been established that enhancing the solubility of the hydrophobic ester in water by the hydrotropic salts yielded by the hydrolysis itself accelerates the apparent reaction rate. By kinetically independent measurements, the solubilization process of the ester was verified to be the rate-determining step. It has been observed that the solubilization process can be influenced by factors such as the initial addition of hydrotropic salt, the volumetric ratio of the oil/aqueous phase, and the concentration of alkali.     

Dissolution behavior of homologously generated surfactant molecular complexes (SMC) in aqueous media: A clue to the elucidation of the phenomenon "solubilization"

The solution behavior of homologously obtained crystalline surfactant molecular complexes (SMCs) that are generated between quaternary ammonium bromide and several additive materials has shed light on the recognition of fundamentals of solubilization. It has been revealed that the SMCs derived from long-alkyl-chain surfactants are sufficiently dissolved in water through the path of micellar dispersion above the cmc's of the complex surfactants, whereas the short-chain homologues cannot dissolve in water but dissociate the complexes, resulting in a heterogeneous phase made up of the liberated additives. The fact agrees perfectly with the familiar aspects of solubilization by surfactant; i.e., the longer the alkyl chain of the surfactant becomes, the more effective it is for solubilization. Based on these results, it has been deduced that the possibility for any pair of surfactant and solubilizate (additive) to realize solubilization simply depends on the relative importance of equilibrium of dissociation or association of the SMC species in aqueous medium.     

Effect of Additives on the Selectivity and Reactivity of Enzymes

Enzymes have been widely used as efficient, eco‐friendly, and biodegradable catalysts in organic chemistry due to their mild reaction conditions and high selectivity and efficiency. In recent years, the catalytic promiscuity of many enzymes in unnatural reactions has been revealed and studied by chemists and biochemists, which has expanded the application potential of enzymes. To enhance the selectivity and activity of enzymes in their natural or promiscuous reactions, many methods have been recommended, such as protein engineering, process engineering, and media engineering. Among them, the additive approach is very attractive because of its simplicity to use and high efficiency. In this paper, we will review the recent developments about the applications of additives to improve the catalytic performances of enzymes in their natural and promiscuous reactions. These additives include water, organic bases, water mimics, cosolvents, crown ethers, salts, surfactants, and some particular molecular additives.     

Aqueous Systems for Liquid Scintillation Counting: Use of Hydrotropes

Liquid hydrotropic systems, i.e., mixtures of hydrotropes and water‐forming hydrophilic and hydrophobic regions, allow the solubilization of organic scintillators in essentially aqueous media. Such systems were applied to liquid scintillation counting with 4‐[4‐(5‐phenyloxazol‐2‐yl)benzyl]morpholine as scintillator, a 2,5‐diphenyloxazole (PPO) derivative that proved well‐soluble in acidic hydrotrope systems. Its fluorescence properties were studied. Phenylalanine labeled with ³H or ¹⁴C was used to test counting. While ¹⁴C counting worked acceptably, ³H counting was comparatively inefficient, probably due to the short lifetime of β‐particles in aqueous environments.     

On the molecular mechanism of stabilization of proteins by cosolvents: role of Lifshitz electrodynamic forces

Several ionic and nonionic additives are known to affect structural stability of proteins in aqueous solutions. At a fundamental level, the mechanism of stabilization or destabilization of proteins by cosolvents must be related to three-body interactions between the protein, additive, and the water medium. In this study, the role of the Lifshitz-van der Waals electrodynamic interaction between various additives (sucrose, glycerol, urea, poly(ethylene glycol)-200, betaine, taurine, proline, and valine) and bovine serum albumin (BSA) in water medium was examined. The electrodynamic interaction energy was attractive for all of the additives studied here when both far ultraviolet and infrared relaxations of the additives were included in their dielectric susceptibility representations. However, when only the infrared contribution was included for structure stabilizers and both far ultraviolet and infrared contributions for the structure destabilizers, the resulting electrodynamic interaction energy (E/kT) followed the structure stabilizing and/or destabilizing behavior of the additives; that is, the interaction was attractive for urea and PEG200 (structure destabilizers), whereas it was repulsive for sucrose, glycerol, betaine, taurine, alanine, valine, and proline (structure stabilizers). The electrodynamic interaction energy E/kT at any given surface-to-surface separation distance between the additives and BSA was positively correlated (r(2) = 0.92) with the experimental thermal denaturation temperature (T(d)) of BSA in 1 M solutions of the additives. These analyses provided a mechanistic basis for the experimental observations of exclusion of the structure-stabilizing additives from the protein-water interface and binding of the structure-destabilizing additives to the protein surface. The role of water structure in the three-body electrodynamic interaction is discussed. It is hypothesized that in the case of additives that enhance water structure the hydration shells formed around the additives effectively dampen the contribution of ultraviolet frequencies to the dielectric susceptibility of the additives and thus impart repulsive electrodyanamic interaction between the additive and the protein, whereas the opposite occurs in the case of additives that breakdown the hydrogen-bonded structure of water.     

Effects of Mixed Anionic-Cationic Surfactants and Alcohol on Solubilization of Water-in-oil Microemulsions

The solubilization of water in w/o microemulsions formed with mixed-surfactants containing one anionic and one cationic surfactant and alcohol was studied as a function of alkyl chain length of oil (C6 to C16), mixed-surfactant (sodium dodecyl sulfate, SDS, and cetyltrimethylammonium bromide, CTAB, or cetylpyridinium bromide CPB), and alcohol (1-butanol, 1-pentanol, 1-hexanol). The results show that the solubilization of water in microemulsion systems increases significantly with the mixed-surfactants due to the synergistic effect resulting from the strong Coulombic interactions between cationic and anionic surfactants and the solubilizing efficiency increases as the chain length or concentration of alcohol increases. With increasing the oil chain length the solubilization for water increases, decreases, and has the chain length compatibility effect when the systems contain 1-hexanol, 1-butanol, 1-pentanol, respectively. The total solubilizing capacity increases as the surfactant concentration (keep the ratio of SDS to butanol constant) increases.     

Electroosmotic Flow of a General Electrolyte Solution through a Fibrous Medium

Although hydrotropy is extensively used in industry, the molecular mechanism of hydrotropic solubilization has not been completely elucidated yet. In this paper the interaction between a nonionic surfactant (ethoxylated fatty alcohol containing between five and six oxyethylenic units) and sodium p-toluene sulfonate is examined. Surface tension measurements confirm that the hydrotropic effect occurs at a concentration in which the hydrotropes self-associate. Photon correlation spectroscopy studies show that for this concentration of hydrotropes a drastic reduction in the surfactant micellar radius occurs. Furthermore the luminescence of the hydrotrope used as a fluorescence probe indicates that at low concentrations p-toluene sulfonate dissolves in the surfactant micelles but beyond the minimum concentration for hydrotropic solubilization the hydrotrope is present in the aqueous phase. These results suggest that the hydrotropic effect is related to alterations in the water structure induced by the hydrotrope molecules and to the presence of hydrotrope aggregates that furnish an appropriate niche for the surfactant amphiphile.     

Aqueous block copolymer-surfactant mixtures and their ability in solubilizing chlorinated organic compounds. A thermodynamic and SANS study

Within the topic of surfactant enhanced solubilization of additives sparingly soluble in water, volumetric, solubility, conductivity, and small-angle neutron scattering (SANS) experiments on mixtures composed of alpha,omega-dichloroalkane, surfactant, copolymer, and water were carried out at 298 K. The triblock copolymers (ethylene oxide)132(propylene oxide)50(ethylene oxide)132 (F108) and (ethylene oxide)76(propylene oxide)29(ethylene oxide)76 (F68) were chosen to investigate the role of the molecular weight keeping constant the hydrophilic/hydrophobic ratio. The selected surfactants are sodium decanoate (NaDec) and decyltrimethylammonium bromide (DeTAB) with comparable hydrophobicity and different charged heads. The alpha,omega-dichloroalkanes were chosen as contaminant prototypes. For the water + surfactant + copolymer mixtures, both the volume and the SANS results straightforwardly evidenced that (1) monomers of NaDec and copolymer unimers generate small mixed aggregates, (2) monomers of DeTAB combined with copolymer unimers do not form aggregates, and (3) unimeric copolymer is solubilized into NaDec and DeTAB micelles. The alpha,omeaga-dichloroalkanes presence induces the F108 aggregation even at very low copolymer composition. The addition of surfactant disintegrates the F108 aggregates and, consequently, the additive is expelled into the aqueous phase. Once F108 is in the unimeric state, it forms copolymer-micelle aggregates which incorporate the oil. In the case of F68 both the volumetric and the SANS data reveal that the additive does not alter the copolymer unimeric state. Moreover, they show that for the aqueous DeTAB-F68 system the additive trapping in both the copolymer-micelle aggregate and the pure micelles takes place being enhanced in the former aggregate in agreement with solubility experiments. For the NaDec-F68 mixtures, an additional solubilization process in the premicellar copolymer-surfactant microstructures occurs. SANS and conductivity data show that the additive incorporation into the mixed and the pure micelles does not essentially influence the structural properties of the aggregates.     

CTAB/n-C5H11OH/H2O体系对青霉素G钾盐水解的抑制作用

微乳液是由表面活性剂、助表面活性剂、水、油等组成的各向同性、低粘度的热力学体系［１］,在生物、环境及其相关领域有着十分重要的应用［２］．近年来,以微乳液为微反应器进行化学反应已引起重视［３－１０］青霉素是一种很重要的抗生素药物,它在阴暗干燥的空气中较...     

Effect of Mobile-Phase Additives on Separation of Gold Nanoparticles by Size-Exclusion Chromatography

Two spherical gold nanoparticles (diameters 5.3 and 38 nm, respectively) were used to appraise the separation performance of various mobile-phase additives in size-exclusion chromatography (SEC). The three additives were sodium citrate (SC), sodium chloride (NaCl), and sodium dodecylsulfate (SDS). The problem of adsorption on gold nanoparticles occurs when SC and NaCl are used as mobile-phase additives. In contrast, the adsorption problem is overcome by using SDS as mobile-phase additive; furthermore, SDS prevents gold nanoparticles from coagulating during separation. This paper demonstrates the feasibility of using SDS as mobile-phase additive in SEC for size separation of gold nanoparticles and also demonstrates how SEC may be used to investigate interactions between a mobile-phase additive and gold nanoparticles.     

Effect of sphere to rod transition on the probe microenvironment in sodium dodecyl sulphate micelles: A time resolved fluorescence anisotropy study

The effect of different hydrotropic salts on the microenvironment at the anionic head group region of sodium dodecyl sulphate (SDS) micelle has been studied through time-resolved fluorescence anisotropy measurements of a solubilized probe, coumarin-153 (C153). The organic cations of the hydrotropic salts used in this study, i.e. aniline hydrochloride (AHC) and o-, m- and p-toluidine hydrochlorides (OTHC, MTHC and PTHC, respectively), differ in their charge to size ratio and hydrophobicity. Present study utilizes the sensitivity of the fluorescence technique to understand the changes in the micropolarity and microviscosity experienced by the fluorescent probe, C153, solubilized in the micellar Stern layer, on addition of different hydrotropic salts. Significant changes are observed in the rotational relaxation dynamics of the probe with increasing concentration of the salts. The changes in the rotational relaxation dynamics clearly reflect the sphere to rod transition in the SDS micelles and correspond nicely with the reported results from dynamic light scattering measurements. The growth behavior of SDS micelles is found to be sensitive to the hydrophobicity of the organic cations. The charge to size ratio of the organic cations also indicated to play a role in inducing the sphere to rod transition in the SDS micelles. The interesting observation made from this study is that the sphere to rod transition of SDS micelles is largely facilitated by the presence of the hydrotropic salts and such a transition is successfully indicated by the simple fluorescence anisotropy measurements of a probe in the micelle carried out in the presence of different hydrotropic salts.     

Hydrophilic alcohol ethoxylates as efficiency boosters for microemulsions

Highly amphiphilic polyalkane-PEO diblock copolymers drastically increase the solubilization capacity of surfactants in microemulsions if they are used in small quantities as additive to the surfactant. This effect goes along with an additional reduction of the already very low interfacial tension between water and oil. Lamellar phases, which usually develop when the surfactant becomes more efficient, are suppressed to a large extent. In this work we use another type of additive, namely hydrophilic alcohol ethoxylates. These amphiphiles are identical with the previously used block copolymers with respect to the hydrophilic moiety. However, they contain only small hydrocarbon groups ranging from C8 to C18. A typical example from the hydrophilic alcohol ethoxylates is C12E100. Both additive types increase surfactant efficiency equally with respect to mass fraction in the mixture. Because the alcohol ethoxylate additives decorate the surfactant film only on the aqueous side, they influence the curvature of the surfactant membrane or, in other words, the temperature behavior of the microemulsion. Together with nonionic surfactants, however, the shift of the one-phase region to higher temperatures is only a few degrees Celsius. Just as with the polyalkane-PEO block copolymers, the hydrophilic alcohol ethoxylates suppress lamellar phases. This behavior is especially pronounced if the hydrophobic groups are small or the PEO chains are long. We found that hydrophobic units as short as C 8 are sufficient to largely anchor the PEO chains at the interface. If C12 or C18 hydrocarbon unit are used instead, the PEO chains are fully interfacially active, even if the hydrophilic chain contains up to about 500 EO units. We applied the new additives in bicontinuous and in droplet microemulsions and used nonionic, as well as ionic, surfactants, namely C10E4 and AOT. In contrast to polyalkane-PEO blockcopolymers the new additives are easy to synthesize and are commercially available. Therefore, they might be interesting in applications.     

Study of sodium dodecyl sulfate-poly(propylene oxide) methacrylate mixed micelles

Sodium dodecyl sulfate (SDS)-poly(propylene oxide) methacrylate (PPOMA) (of molecular weight M(w) = 434 g x mol(-1)) mixtures have been studied using conductimetry, static light scattering, fluorescence spectroscopy, and 1H NMR. It has been shown that SDS and PPOMA form mixed micelles, and SDS and PPOMA aggregation numbers, N(ag SDS) and N(ag PPOMA), have been determined. Total aggregation numbers of the micelles (N(ag SDS) + N(ag PPOMA)) and those of SDS decrease upon increasing the weight ratio R = PPOMA/SDS. Localization of PPOMA inside the mixed micelles is considered (i) using 1H NMR to localize the methacrylate function at the hydrophobic core-water interface and (ii) by studying the SDS-PPO micellar system (whose M(w) = 400 g x mol(-1)). Both methods have indicated that the PPO chain of the macromonomer is localized at the SDS micelle surface. Models based on the theorical prediction of the critical micellar concentration of mixed micelles and structural model of swollen micelles are used to confirm the particular structure proposed for the SDS-PPOMA system, i.e., the micelle hydrophobic core is primarily composed of the C12 chains of the sodium dodecyl sulfate, the hydrophobic core-water interface is made up of the SDS polar heads as well as methacrylate functions of the PPOMA, the PPO chains of the macromonomer are adsorbed preferentially on the surface, i.e., on the polar heads of the SDS.     

Spectrophotometric study of interaction and solubilization of procaine hydrochloride in micellar systems

The interaction of Procaine hydrochloride (PC) with cationic, anionic and non-ionic surfactants; cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and triton X-100, were investigated. The effect of ionic and non-ionic micelles on solubilization of Procaine in aqueous micellar solution of SDS, CTAB and triton X-100 were studied at pH 6.8 and 29°C using absorption spectrophotometry. By using pseudo-phase model, the partition coefficient between the bulk water and micelles, K_x, was calculated. The results showed that the micelles of CTAB enhanced the solubility of Procaine higher than SDS micelles (K_x = 96 and 166 for SDS and CTAB micelles, respectively) but triton X-100 did not enhanced the solubility of drug because of weak interaction with Procaine. From the resulting binding constant for Procaine-ionic surfactants interactions (K_b = 175 and 128 for SDS and CTAB surfactants, respectively), it was concluded that both electrostatic and hydrophobic interactions affect the interaction of surfactants with cationic procaine. Electrostatic interactions have a great role in the binding and consequently distribution of Procaine in micelle/water phases. These interactions for anionic surfactant (SDS) are higher than for cationic surfactant (CTAB). Gibbs free energy of binding and distribution of procaine between the bulk water and studied surfactant micelles were calculated.      

Experimental and theoretical investigation of the micellar-assisted solubilization of ibuprofen in aqueous media

Surfactants can be used to increase the solubility of poorly soluble drugs in water and to increase drug bioavailability. In this article, the aqueous solubilization of the nonsteroidal, antiinflammatory drug ibuprofen is studied experimentally and theoretically in micellar solutions of anionic (sodium dodecyl sulfate, SDS), cationic (dodecyltrimethylammonium bromide, DTAB), and nonionic (dodecyl octa(ethylene oxide), C12E8) surfactants possessing the same hydrocarbon "tail" length but differing in their hydrophilic headgroups. We find that, for these three surfactants, the aqueous solubility of ibuprofen increases linearly with increasing surfactant concentration. In particular, we observed a 16-fold increase in the solubility of ibuprofen relative to that in the aqueous buffer upon the addition of 80 mM DTAB and 80 mM C12E8 but only a 5.5-fold solubility increase upon the addition of 80 mM SDS. The highest value of the molar solubilization capacity (chi) was obtained for DTAB (chi = 0.97), followed by C12E8 (chi = 0.72) and finally by SDS (chi = 0.23). A recently developed computer simulation/molecular-thermodynamic modeling approach was extended to predict theoretically the solubilization behavior of the three ibuprofen/surfactant mixtures considered. In this modeling approach, molecular-dynamics (MD) simulations were used to identify which portions of ibuprofen are exposed to water (hydrated) in a micellar environment by simulating a single ibuprofen molecule at an oil/water interface (modeling the micelle core/water interface). On the basis of this input, molecular-thermodynamic modeling was then implemented to predict (i) the micellar composition as a function of surfactant concentration, (ii) the aqueous solubility of ibuprofen as a function of surfactant concentration, and (iii) the molar solubilization capacity (chi). Our theoretical results on the solubility of ibuprofen in aqueous SDS and C12E8 surfactant solutions are in good agreement with the experimental data. The ibuprofen solubility in aqueous DTAB solutions was somewhat overpredicted because of challenges associated with accurately modeling the strong electrostatic interactions between the anionic ibuprofen and the cationic DTAB. Our results indicate that computer simulations of ibuprofen at a flat oil/water interface can be used to obtain accurate information about the hydrated and the unhydrated portions of ibuprofen in a micellar environment. This information can then be used as input to a molecular-thermodynamic model of self-assembly to successfully predict the aqueous solubilization behavior of ibuprofen in the three surfactant systems studied.     

Solubilization of single-walled carbon nanotubes by using polycyclic aromatic ammonium amphiphiles in water--strategy for the design of high-performance solubilizers

We describe the design of polycyclic aromatic compounds with high performance that dissolve single-walled carbon nanotubes (SWNTs). Synthetic amphiphiles trimethyl-(2-oxo-2-phenylethyl)-ammonium bromide (1) and trimethyl-(2-naphthalen-2-yl-2-oxo-ethyl)-ammonium bromide (2) carrying a phenyl or a naphtyl moiety were not able to dissolve/disperse SWNTs in water. By contrast, trimethyl-(2-oxo-2-phenanthren-9-yl-ethyl)-ammonium bromide (3) solubilized SWNTs, although the solubilization ability was lower than that of trimethyl-(2-oxo-2-pyrene-1-yl-ethyl)-ammonium bromide (4) (solubilization behavior observed by using 4 was described briefly in reference 4a). Transmission electron microscopy (TEM), as well as visible/near-IR, fluorescence, and near-IR photoluminescence spectroscopies were employed to reveal the solubilization properties of 4 in water, and to compare these results with those obtained by using sodium dodecyl sulfate (SDS) and hexadecyltrimethylammonium bromide (HTAB) as solubilizers. Compound 4 solubilized both the as-produced SWNTs (raw-SWNTs) and purified SWNTs under mild experimental conditions, and the solubilization ability was better than that of SDS and HTAB. Near-IR photoluminescence measurements revealed that the chiral indices of the SWNTs dissolved in an aqueous solution of 4 were quite different from those obtained by using micelles of SDS and HTAB; for a SWNTs/4 solution, the intensity of the (7,6), (9,5), and (12,1) indices were strong and the chirality distribution was narrower than those of the micellar solutions. This indicates that the aqueous solution of 4 has a tendency to dissolve semiconducting SWNTs with diameters in the range of 0.89-1.0 nm, which are larger than those SWNTs (0.76-0.97 nm) dissolved in the aqueous micelles of SDS and HTAB.     

Formation of 1-Butyl-3-methylimidazolium Bis(2-ethyl-1-hexyl)sulfosuccinate Stabilized Water-in-1-Butyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)imide Microemulsion and the Effects of Additives

A new strategy is proposed here to formulate a bis(2-ethyl-1-hexyl)sulfosuccinate (AOT^?) stabilized water-in-ionic liquid microemulsion without any additives. Replacing the inorganic counter ion Na⁺ by the organic 1-butyl-3-methylimidazolium ([Bmim]⁺) ion greatly improves the solubility of AOT^? in hydrophobic 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([Bmim]Tf₂N) (IL) and favors the formation of water-in-IL (W/IL) microdroplets. The existence of the W/IL microdroplets has been confirmed by dynamic light scattering, Fourier transform infrared absorption spectroscopy and ultraviolet–visible absorption spectroscopy. Also, presented for the first time are the effects of salts and alcohols on the microstructure and water solubilization capacity of the ternary H₂O/[Bmim]AOT/[Bmim]Tf₂N system. For inorganic salts, larger concentrations of the salt and higher charge density of the cation result in smaller microdroplet size and weak water solubilization capacity. For 1-hexanol, a high concentration of this alcohol results in small microdroplet size but high water solubilization capacity. Analyses indicate that the salts compress the electric double layers of W/IL microemulsions, decrease the size of the microdroplets and consequently reduce the water solubilization capacity; the alcohol, however, facilitates the aggregation of AOT^?, increases the number of W/IL microdroplets, and therefore improves the water solubilization capacity of the system.