The Effects Of Isomeric Alcohols On The Phase Behavior And The Physical Parameters Of The Microemulsion

The thesis consists five chapters. Chapter I. Introduction of microemulsions and the progress in the studies of the phase behaviors of microemulsions. Chapter II, Effects of isomeric alcohols on the phase behavior and solubilization of the microemulsion systems formed by anionic surfactants with theε-βfish-like phase diagram. Chapter III, Studies on the solubilities of the isomeric alcohols in the oleic and aqueous phases using the optimum dilution method. Chapter IV. Studies on the phase behavior and the physical parameters of the microemulsion system, OP-10/oil/alcohol/brine withε-βfish-like diagram. Chapter V, Effects of isomeric alcohols on the phase behavior of the microemulsion formed by OP-10 with different oil/water ratios.Chapter I. Introduction of microemulsions and the progress in the studies of the phase behaviors of microemulsions.The formation,properties and applications of microemulsions were summarized. The progress in the research of the phase behaviors of microemusions was revewed.Chapter II. Effects of isomeric alcohols on the phase behavior and solubilization of the microemulsion systems formed by anionic surfactantsThree isomeric alcohols, 1-butanol, 2-butanol and t-butanol were used as cosurfactants to form the middle-phase microemulsions in the microemulsion systems SDS (SDSN, SDBS)/isomeric alcohol/n-octane/brine (5%NaCl). The phase diagrams were plotted and studied according to theε–βfishlike phase diagram.1. Different butanol isomers have notable effects on theε–βfishlike phase diagrams. As the branches of the carbon chain of the alcohols increase, the"fish"moves upwardly.2. The composition of the interfacial layer was calculated, which depends on the configuration of the alkyl groups, and the mass fraction of alcohol AS increases in the order: 1-butanol<2-butanol2-butanol >1-butanol, opposite to the order of the penetration ability of these isomeric alcohol molecules into the interfacial layer.Chapter III. Studies on the solubilities of the isomeric alcohols in the oleic and aqueous phases using the optimum dilution method.The solubilities of alcohols in the aqueous(AW)and oleic phases(AO)and the mass fration of alcohols in the interfacial layer (AS) in the microemulsion sysrems SDS(SDSN, SDBS)/1-butanol(2-butanol, t-butanol) / n-octane / brine(5%NaCl) were studied using the optimum microemulsion dilution method.1. The values AW, AO and AS are all increased along with the branched chains of the alcohols. That is, the mass fraction of alcohols in water, oil and interfacial layer increases in the same order: 1-butanol<2-butanol SDS> SDBS.Chapter IV. Studies on the phase behavior and the physical parameters of the microemulsion ystem OP-10/oil/alcohol/brine withε-βfish-like diagram.The microemulsion systems, OP-10/isomeric alcohol (1-butanol, 2-butanol, t-butanol)/n-hexane (n-heptane, n-octane)/brine were studied with theε–βfishlike phase diagram.1. The carbon chain of linear alcohols has notable effects on theε–βfishlike phase diagrams. With the carbon chain increasing, the"fish"moves downward.2. From theε–βfishlike phase diagram, the composition of the interfacial layer was calculated, which depends on the configuration of the alkyl groups, and the mass fraction of alcohol AS increases in the order: 1-butanol<2-butanol2-butanol >1-butanol, opposite to the order of the penetration ability of these isomeric alcohol molecules into the interfacial layer. 4. The solubilization ability can be evaluated by the solubility parameter SP*. The solubilizatuion ability of the microemulsion calculated is in the order: 1-butanol >2- butanol>t- butanol. It is expained by the ability of alcohols to bend the elastic modulus of the interfacial layer.5. With the oil chain length increases, the solubilization capacity decreases. Salt concentrations have little influence on the formation of the microemulsion.Chapter V. Effects of isomeric alcohols on the phase behavior of the microemulsion formed by OP-10 with different oil/water ratios.The solubilities of surfactant and alcohol in the oil and water phases, SO,SW and AO,AW, were calculated using theε-βfishlike phase diagram with different ratios of oil to the plus of water and oil.1. As the branched chains of the alcohols incraeses, the parameters, such as AS and AOincreases, which was due to the decrease of the penetration ability of alcohols to the interfacial layer.2. With the carbon chain length of the oil increasing, the amount of alcohol needed to form the middle phase microemulsion increases. The explaination is that the smaller alkane molecule is easier to penetrate into the barrier of the interface, which makes the amphiphilic layer more hydrophobic.3. The alcohol in the interfacial layer and dissolved in the oil and water phases increases with the branches of the alcohols more.