Butyric Acid As A Cosurfactant Microemulsion Solubilization

This thesis consists of five parts. Part I. Introduction. Part II. Phase behavior of microemulsion systems containing butyric acid as a cosurfactant. Part III. Effect of inorganic salts on the phase behavior of microemulsion systems containing alcohol and fatty acid as cosurfactant. Part IV. Studies on the phase behavior and solubilization ability of the microemulsion systems containing Brij-35 and 1-butyric acid. Part V. Synthesis of C₄mimBr and C₄mimBF₄ as well as their applications in microemulsions.Part I. IntroductionThe phase behavior, the solubilization ability and their influencing factors of microemulsion systems were introduced. The phase diagrams depicting the phase behavior of microemulsion systems were reviewed. Three different cosurfactants, alcohol, fatty acid and amine were introduced, and the research progress on microemulsions was discussed and accessed.Part II. Phase behavior of microemulsion systems containing butyric acid as cosurfactantThe phase behavior of microemulsion systems consisting of SDS / butyric acid / n-hexane / brine has been studied with anε-βfishlike phase diagram method.1. The solubility of butyric acid in the microemulsions is higher than that of 1-butanol. In the interfacial layer, the mass fraction of butyric acid is also larger than that of 1-butanol.2. The cations of inorganic salts have notable influence on theε-βphase diagrams, but the anions of inorganic salts have negligible influence on the phase behavior.3. The influence of acid is similar to that of the salt whereas the effect of alkali is different from that of the salt and acid, resulting in the phase diagrams moving upward.4. Increase in temperature was favourable to the solubilization of the system.Part III. Effect of inorganic salts on the phase behavior of microemulsion systems containing alcohol and fatty acid as cosurfactant.The effect of different inorganic salts on the phase behavior of the microemulsion systems consisting of SDS / aliphatic acid or alcohol / alkane / aqueous salt has been studied.1. In SDS / butyric acid / n-hexane / aqueous CaCl₂ microemulsion systems,the solubility of the alcohol (S_a) and the mass fraction of alcohol in the interfacial layer (A^S) were decreased with CaCl₂ concentrations,showing the same pattern of change with the alcohol-based microemulsion systems. The solubilization ability of the microemulsion systems was decreased, showing the opposite pattern of change with the alcohol-based microemulsion systems.2. In the aliphatic acid-based and the alcohol-based microemulsion systems, the solubility of alcohol (S_a) and the solubilization ability (SP^*) both are in the same order MgCl₂ > CaCl₂ SrCl₂ and Ca(NO₃)₂ > CaBr₂> CaCl₂.Part IV. Studies on the phase behavior and solubilization ability of the microemulsion systems containing Brij-35 and 1-butyric acidThe effect of salinity and temperatures on the phase behavior of the microemulsion systems comprising of Brij-35 / aliphatic acid / n-hexane / aqueous salt has been studied.1. In Brij-35 / butyric acid / n-hexane / aqueous (NaCl, NaOH, HCl) microemulsion systems, as the content of NaCl, NaOH, HCl increase, the solubilities of butyric acid (S_a) were decreased. The mass fraction of butyric acid in the interfacial layer (A^S) were increased with the increased content of NaCl and HCl, but decreased with the increased NaOH content.As the content of NaCl and NaOH increase, the maximum solubilization ability of the system (SP^*) was decreased, but SP^* was increased with the increased NaOH contents. 2. As temperature increased, the solubilities of the butyric acid (S_a) and the mass fraction of butyric acid in the interfacial layer (A^S) were decreased, but the maximum solubilization ability (SP*) was increased, in the butyric acid / Brij-35 / n-hexane / 7.5% NaCl solution microemulsion systems.Part V. Synthesis of C₄mimBr and C₄mimBF₄ (Ils) and their applications in microemulsionsIonic liquids C₄mimBr and C₄mimBF₄ were synthesized and characterized by IR and NMR, The effect of the ionic liquids as the additives in water on the phase behavior of microemulsion systems were investigated.