Composition and Solubilization of the Microemulsion Systems Containing Triton X-100: Effects of Aqueous Composition and Oil-Water-Ratios

The composition and solubilization of the optimum microemulsion systems containing Triton X-100/pentan-1-ol/aliphatic hydrocarbon/water were studied with the ∊-β fishlike phase diagram method. The solubilities of the alkanol (S A), the mass fractions of the alkanol in the interfacial layer (AS ) and the optimum solubilization parameters (SP∗) of the microemulsion systems with different aqueous phases (salt, acid, alkali) and with different α values were obtained and discussed. The SP∗ values increase significantly with the cation radius of the chlorides (NaCl, KCl, CsCl), but decrease slightly with the anion radius of the sodium halides (NaCl, NaBr, NaI). However, SP∗ values decrease with the increased salinities and NaOH contents. The trend was reversed for the acid systems. When the oil-water ratio (α) increases, the S A and A S values significantly increase, while the SP∗ values increase slowly. As the length of the carbon chain of the alkane molecules increases, both the S A and A S values increase, while the SP∗ values decrease significantly.

A Comparison Study on the Phase Behavior and Solubilization between Cn(Bim)2-2Br-Butyric Acid and CnmimBr-Butyric Acid Microemulsion Systems

The solubility, interfacial composition and solubilization ability of microemulsions containing gemini 1,4-bis(3-alkylimidazolium-1-yl) butane bromide [Cn(Bim)2-2Br]/butyric acid were studied and compared with that of microemulsions containing 1-alkyl-3-methylimidazolium (CnmimBr)/butyric acid. The solubilities of butyric acid (SA), and the mass fractions of butyric acid in the interfacial layer(AS) decrease, while the solubilization parameters (SP*) increase with the increase in the carbon chain length of the surfactants in Cn(Bim)2-2Br based and CnmimBr based microemulsions. A comparison of the gemini Cn(Bim)2-2Br microemulsions with CnmimBr microemulsions indicates that the values of SA and AS are in the order: Cn(Bim)2-2Br < CnmimBr, while SP* values are Cn(Bim)2-2Br > CnmimBr. With salinity increasing, the values of SA and AS decrease, while SP* values increase. With the increase in the alkyl chain length of the oil molecules, the SA values increase, AS and SP* values decrease. Temperature has less influence on the values of SA, AS and SP* of microemulsions containing Cn(Bim)2-2Br/butyric acid.