咪唑类双子型表面活性剂构筑的W/O型微乳液体系的结构与物化性质

【作者】 刘宁宁；

【导师】 柴金岭；

【作者基本信息】 山东师范大学 ， 无机化学， 2015， 硕士

【摘要】 论文包括四部分,第一部分为绪论；第二部分为十六烷基三甲基溴化铵、咪唑离子液体型及Gemini表面活性剂分别构筑的W/O型微乳液的相行为及其比较；第三部分为咪唑离子液体型及Gemini型表面活性剂分别形成的W/O型微乳液的相行为；第四部分为不同温度和油相对烷基咪唑Gemini表面活性剂W/O微乳液体系热力学及结构参数的影响。一、绪论主要介绍了微乳液的组成、结构及微乳液相行为的研究进展。重点讨论了不同表面活性剂、助表面活性剂及温度对微乳液相行为的影响。二、十六烷基三甲基溴化铵、眯唑离子液体型及Gemini表面活性剂分别构筑的W/O型微乳液的相行为及其比较利用W/O微乳液稀释法,研究了CTAB(C16mimBr,16-4-16)/醇(胺)/正辛烷/5%NaCl溶液(ω0=0)W/O型微乳液体系的热力学和结构等。比较了三种不同表面活性剂分别与不同助表面活性剂形成的微乳液体系的热力学参数和结构参数。(1)无论脂肪醇还是脂肪胺作助表面活性剂,各表面活性剂形成的微乳液体系中,醇在界面膜中的摩尔分数Xαi及醇在油相中的摩尔分数Xo由大到小的顺序均为16-4-16>CTAB> C16mimBr。脂肪醇微乳液体系中,醇从连续的油相转移到界面膜的标准吉布斯自由能变-△Go→io值：16-4-16>CTAB> C16mimBr。月旨肪胺微乳液体系的-△Go→io值显著减小,且其大小顺序与脂肪醇微乳液体系的不同。无论脂肪醇还是脂肪胺作助表面活性剂,16-4-16微乳液体系的水核半径Rw均显著小于其他两种表面活性剂微乳液体系。(2)无论脂肪醇还是脂肪胺微乳液体系,Xαi和Xαo值均随助表面活性剂分子碳链的增长而减小,而-△Go→io值及水核半径Rw值增大。16-4-16微乳液体系的Rw变化相对较小(3)脂肪胺微乳液体系的Xαi及Xαo均大于脂肪醇微乳液体系,而-△Go→io,及Rw均小于脂肪醇微乳液体系。三咪唑离子液体型及Gemini型表面活性剂分别形成的W/O型微乳液的相行为在不同温度下,选用不同助表面活性剂,研究了12-4-12(C12mimBr)/脂肪醇/正辛烷/5%NaCl溶液(ω0=20)W/O微乳液的相行为和热力学性质等。(1)在由12-4-12与C12mimBr分别形成的W/O型微乳液中,醇在界面膜中的摩尔分数Xαi和醇在油相中的摩尔分数Xαo,均随醇分子支链的增多而增大；而醇从连续的油相转移到界面膜的标准吉布斯自由能变-△Go→io和微乳液滴的水核半径Rw均随醇分子支链增多而减小。(2)12-4-12微乳液体系的-△Go→io比C12mimBr微乳液体系的更大,说明双子型表面活性剂微乳液体系,醇从连续的油相转移到界面膜上的自发性更强。(3)随温度升高,12-4-12微乳液体系的-△Go→io总体上均增大-△Ho→io与△So→o随温度升高而增大。C12mimBr微乳液体系中,选用正丁醇作助表面活性剂时,热力学性质的变化规律与双子型表面活性剂微乳液体系的相似。C12mimBr微乳液体系,选用仲丁醇和叔丁醇作助表面活性剂时,△So→io,和-△Ho→io,随温度升高而减小。与双子表面活性剂微乳液的变化规律相反。四不同温度和油相对烷基咪唑Gemini表面活性剂W/O微乳液体系热力学及结构参数的影响在不同温度下,选用不同的油相,研究了16-4-16(C16mimBr, CTAB)/正丁醇/烷烃/5%NaCl溶液(wo=20)W/O型微乳液体系的界面组成和结构参数。(1)由16-4-16、C16mimBr及CTAB分别形成的微乳液中,醇在界面膜中的摩尔分数Xαi由大到小的顺序均依次为16-4-16>CTAB>C16mimBr。16-4-16微乳液平衡界面膜所需脂肪醇显著增多。(2)双子表面活性剂16-4-16微乳液体系中,醇从连续的油相转移到界面膜的标准吉布斯自由能变-△Go→io远大于单链表面活性剂CTAB或C16mimBr微乳液体系的值。这与双子表面活性剂疏水链的致密排列有关。(3)微乳液滴水核半径Rw由小到大的表面活性剂顺序为：16-4-16<C16mimBr <CTAB.这可能与16-4-16表面活性剂分子排列更紧密有关。(4)Xia、Xoa值均随烷烃碳链长度的增加而增大。-△Go→io随烷烃碳链长度的增加而减小。可解释为随烷烃碳链长度的增加,烷烃分子穿透能力减弱所致。(5)16-4-16微乳液体系,脂肪醇从连续的油相迁移至界面膜过程,低温下为焓驱动,高温下为熵驱动。CTAB微乳液体系与16-4-16微乳液体系相似。C16mimBr微乳液体系与上述两种表面活性剂微乳液体系恰好相反。更多还原

【Abstract】 The thesis contains four parts. Chapter I. Introduction. Chapter II. Comparison of the phase behavior of W/O microemulsion systems containing Gemini surfactant with those containing traditional surfactant hexadecyl trimethyl ammonium bromide or imidazoliums ionic liquid type surfactant. Chapter III. Phase behavior of W/O microemulsion containing Imidazoliums Ionic Liquid type and Gemini surfactant respectively. Chapter IV. The effect of temperature and oil on the thermodynamic and structural parameters of W/O microemulsion systems stabilized by Gemini imidazoliums surfactant.Chapter I. IntroductionThe composition, structure and research progress of phase behavior of microemulsion systems were introduced. The effects of surfactants, cosurfactants and temperatures on the phase behavior were particularly discussed.Chapter II. Comparison of the phase behavior of W/O microemulsion systems containing Gemini surfactant with those containing traditional surfactant hexadecyl trimethyl ammonium bromide or imidazoliums ionic liquid type surfactant.The thermodynamic and structural parameters of W/O microemulsion systems16-4-16(C16mimBr, CTAB)/alcohol (amine)/octane/5%NaCl solution (wo=20) are studied and compared.(1) Both the mole fraction of the alcohol in the interfacial layer Xia, and the mole fraction of the alcohol in the oil phase Xoa decrease in magnitude in the order:16-4-16> CTAB> C16mimBr for the microemulsions containing aliphatic alcohol or aliphatic amine as cosurfactant.The standard Gibbs free energy change of transferring alcohol from the continuous oil phase to the interfacial layer (-△Goo→i) decreases in magnitude in the order:16-4-16> CTAB> C16mimBr for the microemulsions containing aliphatic alcohol, whereas (?) for the microemulsions containing aliphatic amine changes in the reverse order.Furthermore, compared with the microemulsion systems containing CTAB or Ci6mimBr, Rw values of the microemulsion systemscontaining16-4-16were much smaller.(2) As the carbon chain length of the cosurfactant (alcohol or amine) increases, both Xoa and Xia values would decrease, whereas (/) and Rw would increase for all microemulsion systems. However, Rw values of the microemulsions containing16-4-16never changed significantly.(3) Compared with the microemulsion systems containing aliphatic amine, both Xia and Xoa were much smaller, while (?) and Rw were larger, when alcohol was used as a cosurfactant.Chapter III. Phase behavior of W/O microemulsions containing imidazoliums ionic liquid type or Gemini surfactantThe W/O microemulsions formed by Gemini surfactant12-4-12and the corresponding mono-chain surfactant C12mimBr respectively with an isomeric alcohol as a cosurfactant at different temperatures were studied. The thermodynamic and structural parameters of these systems were obtained and compared.(1) As the number of branches of the alcohol increases, both Xia and Xoa would increase, whereas (?) and Rw would decrease for both microemulsion systems.(2) Compared with the microemulsions containing the mono-chain C12mimBr,(?) for microemulsion containing12-4-12is much lager, indicating that the transfer of alcohol from oil to the interfacial layer is more spontaneous. (3) The values of-△Goo→i,△Hoo→i and△Soo→i mainly increase with temperature for the microemulsion systems containing12-4-12. Simiarly, the thermodynamic parameters of W/O microemulsions containing C12mimBr and butan-1-ol change in a same pattern. However, their pattern of change is opposite when butan-2-ol and2-methyl-propan-2-ol were used as a cosurfactant.Chapter IV. The effect of temperature and oil on the thermodynamic and structural parameters of W/O microemulsion systems containing Gemini imidazoliums surfactantsInterfacial composition and structural parameters of W/O microemulsion systems16-4-16(Ci6mimBr, CTAB)/butan-l-ol/alkane/5%NaCl solution (wo=20) containing various oils at varying temperatures.(1) Xia values decrease in magnitude in the order:16-4-16> CTAB> C16mimBr. It seems that the most amount of the alcohol was needed for the microemulsiom containing16-4-16.(2) Compared with the microemulsion containing CTAB or C16mimBr, the values of-△Goo→i for12-4-12based microemulsion are much larger, due to the tight arrangement of hydrophobic chain of12-4-12molecules.(3) The values of Rw increases in magnitude in the order:16-4-16<C16mimBr<CTAB, which is related to the tight arrangement of hydrophobic chain of Gemini surfactant.(4) Both Xia and Xoa would increase, as the carbon chain length of the alkane molecules (nc) increase, whereas-△Goo→i would decrease. It can be explained that with the length of carbon chain of alkane molecules increases, it is difficult for the alkane molecules to enter into the interfacial layer. （5）For the16-4-16based microemulsions, the transfer of the alcohol from oil tothe interfacial layer is a enthalpy-driven process at low temperatures, whileentropy-driven at high temperatures. Similarly, CTAB based microemulsion is the samewith the16-4-16one, whereas C16mimBr based microemulsion shows an opposite patternof change.更多还原