Surfactant Compound With Formation Of Phase Phase Behavior And The Solubilization Of Microemulsion System Performance

The thesis contains four parts. Chapter I. Introduction. Chapter II. The phasebehavior and synergetic solubilization of C₁₂mimBr-SDBS based microemulsions.Chapter III. The phase behavior and the solubilization of microemulsion systems withC₁₂mimBr-Brij35 mixed surfactant. Chapter IV. Effects of HCl、NaOH and NaClconcentrations on SDBS-Brij35 based microemulsion systems.Chapter I. IntroductionMixed surfactant systems, especially the microemulsion systems formed bynonionic-nonionic, ionic-nonionic or anionic-cationic surfactant mixtures wereintroduced. The structural characteristics, theory and application of middle-phasemicroemulsions were reviewed.Chapter II. The phase behavior and synergetic solubilization ofC₁₂mimBr-SDBS based microemulsionsThe phase behavior and synergetic solubilization ability of C₁₂mimBr-SDBSbased microemulsion systems were investigated systematically by theε^βfishlikephase diagrams. The effects of alcohols, alkanes and NaCl concentrations on theε^βfishlike phase diagrams of C₁₂mimBr-SDBS （molar ratio 8:2） / alcohol / alkane / brinemicroemulsion systems were also investigated.The middle-phase microemulsions would form at the XC₁₂mimBrrange of 0-0.1and 0.7-1.0. The amounts of surfactant and alcohol needed to balance the interfaciallayer of the mixed surfactant based microemulsion systems were smaller than those ofindividual C₁₂mimBr and SDBS based microemulsion system. C₁₂mimBr–SDBSbased microemulsion systems show superior synergetic solubilization ability （SP*）.The solubilization ability （SP*） becomes greater and less surfactant and alcoholwere needed to balance the interfacial layer of the system, as NaCl concentrations orthe carbon chain length of the alcohol molecules increase. When the carbon chainlength of the alkane molecules increases, the penetration ability of the alkanemolecules to the interfacial layer to decrease the lipophilicity of the interfacial layer decreased. Therefore, the solubilization ability （SP*） of the C₁₂mimBr-SDBS basedmicroemulsion decreases.ChapterⅢ. The phase behavior and the solubilization ofmicroemulsion systems with C₁₂mimBr-Brij35 mixed surfactantThe phase behavior and the solubilization of microemulsion systems formed bycationic surfactant C₁₂mimBr and nonionic surfactant Brij35 were conducted. Theeffects of temperature and the concentrations of NaCl aqueous solutions on theε-βfishlike phase diagrams for Brij35 / butan-1-ol/ n-octane / NaCl aqueous solution andC₁₂mimBr-Brij35 （mole ratio 5:5） / butan-1-ol/ n-octane / NaCl aqueous solutionmicroemulsion systems were studied in comparison.The experiments show that less surfactant and alcohol were needed to balancethe interfacial layer of C₁₂mimBr-Brij35 based microemulsions than the C₁₂mimBrbased or Brij35 based microemulsion system. The mixed surfactant basedmicroemulsion systems exhibit good synergetic solubilization ability.As temperature and NaCl concentrations in aqueous phase increase, thesolubilization ability （SP*） of the microemulsion systems decreases. The addition ofionic surfactant C₁₂mimBr reduces the temperature or salinity sensitivity of thenonionic surfactant. The solubilization ability of the microemulsions with nonionicsurfactant Brij35 can also be improved with the ionic surfactant C₁₂mimBr.Chapter IV. Effects of HCl、NaOH or NaCl concentrations onSDBS-Brij35 based microemulsion systemsThe phase behavior and the solubilization ability of SDBS-Brij35 / butan-1-ol /n-octane / 5.0% NaCl aqueous solution microemulsion systems were studied. Theeffects of HCl、NaOH or NaCl concentrations on SDBS-Brij35 based microemulsionsystems were also investigated systematically.The solubility of the alcohol （εB） in the SDBS-Brij35 based microemulsionsystems was slightly decreased compared to the pure SDBS based or pure Brij35based microemulsion systems. The number of moles of the surfactant SMSand alcoholAMSor the mass fraction of alcohol ASin the interfacial layer of SDBS-Brij35 based microemulsion systems decrease, while the molar fraction of alcohol in the interfaciallayer XASincreases. When the mole ratio of SDBS to Brij35 was 1:1, themicroemulsion system has the strongest synergistic solubilization effect.Less alcohol and more surfactant were needed to balance the interfacial layer ofSDBS-Brij35 based microemulsion systems, as HCl、NaOH or NaCl concentrationsincrease. Therefore, the solubilization ability （SP*） of SDBS-Brij35 （mole ratio 1:1）based microemulsion systems decreased.