Microemulsion Phase Behavior. Alkyl Glucosides And Bromo Dodecyl Pyridine And Bromo Dodecyl Pyridine Adsorption Kinetic Studies

This thesis contains four parts: Part I. Progress in the research of phase behavior of microemulsion. Part II. Studies on the Winsor type phase diagram of the middle phase microemulsion of alkyl polyglucoside. Part III. Studies on the microemulsion of dodecylpyridinium bromide (DPB)/ n-butanol/ n-octane/ 2.5% NaCl aqueous solution with fishlike phase diagram. Part IV. Studies on the adsorption kinetics of DPB aqueous solution.Part I. Progress in the research of phase behavior of microemulsionThe drawing method, characteristics and calculations of related parameters of microemulsin phase diagram, such as Winsor type,δ-γfishlike andε-βfishlike phase diagrams were reviewed. From Winsor phase diagram, the phase inversions, the volume of each phase and the minimum concentration of alcohol (or salt) needed to form the middle phase microemulsion were observed easily. Little other parameters are obtained from this kind of phase diagram. Fromδ-γfishlike phase diagram some physicochemical parameters, such as composition of the hydrophilic-lipophilic balanced layer, the solubilities of surfactant and alcohol in the oil phase etc. can be obtained. Fromε-βfishlike phase diagram, the phase volumes and the alcohol width can be observed and the related parameters were better calculated, and the solubility of the system can be better discussed according to theε-βfishlike phase diagram.Part II. Studies on the Winsor type phase diagram of the middle phase micro- emulsion of alkyl polyglucosideThe Winsor type phase diagram for the quaternary system alkyl polyglucoside (C₈G_1.46, C₁₀G_1.46, C₁₂G_1.46, C_8/10G_1.31 or C_12/14G_1.43)/ alcohol/ alkane/ water were studied by using the alcohol concentration scanning method. The results show that increasing the alcohol concentration results in a series of phase inversion Winsor Iâ†'IIIâ†'II. The longer the hydrocarbon chain length of APG molecule is, the less both the alcohol concentration needed to form middle phase microemulsion and the alcohol concentration range from forming to disappearing of the microemulsion are. Increasing the APG concentration, the total amount of alcohol needed to form the middle-phase microemulsion increases, but that for unit APG concentration decreases. The alcohols with longer hydrocarbon chains, the alkanes with shorter hydrocarbon chains and"salting-out"effect facilitate the phase inversion of Winsor Iâ†'IIIâ†'II.Part III. Studies on the microemulsion formed by DPB/ n-butanol/ n-octane/ 2.5% NaCl solution with fishlike phase diagramTheδ^γfishlike phase diagram for the system DPB/ n-butanol/ n-octane/ 2.5% NaCl solution was examined. Increasingδat constantγcauses a phase inversion from an oil-in-water droplet microemulsion (Winsor I) in contact with excess oil (2) to a water-in-oil microemulsion (Winsor II) in contact with excess water (2 ) via a middle phase microemulsion (Winsor III) in contact with excess oil and water (3). The composition of the balanced interfacial layer was determined by using HLB equation. The composition of points O (at this point the middle phase microemulsion forms) and E (at this point the single-phase microemulsion forms) were also calculated. Theε^βfishlike phase diagram for above system was also plotted, the related parameters were better calculated, and the solubilization of the system was better discussed according to theε-βfishlike phase diagram.Part IV. Studies on the adsorption kinetics of DPB aqueous solutionThe adsorption kinetics of DPB aqueous solution was measured by maximum bubble pressure method (MBPM). The adsorption mechanism and the influencing factors on the adsorption kinetics were investigated. The result shows that in the initial stage the adsorption process is diffusion-controlled and then it changes to adsorption-controlled toward the end of the process when the concentration of surfactant is large enough. The influence of temperature, alcohols and salts on the adsorption kinetics was discussed.