甜菜碱表面活性剂乳化规律研究

发布时间：2018-07-08 21:24

本文选题：甜菜碱 + 乳状液　；参考：《东北石油大学》2016年硕士论文

【摘要】：甜菜碱是典型的两性表面活性剂,它具有独特的双亲性分子结构,同时甜菜碱型两性表面活性剂中的N原子具有很强的碱性,因此它属于具备强碱性N原子的“两性表面活性剂”,具有此类表面活性剂所有的特性,与其他表面活性剂相比,甜菜碱型表面活性剂具有其他类型的表面活性剂所不具备的许多优良性能,学者对它的研究越来越多,尤其在三次采油方面,已从实验室研究逐渐过渡到现场应用。本文主要通过瓶试法、Turbiscan稳定性分析仪以及动力学模型研究甜菜碱乳状液的稳定性;并通过研究甜菜碱对油水界面性质(界面张力、界面粘弹性和界面粘度)的影响来深入探讨甜菜碱的乳化规律。研究结果表明:甜菜碱所形成乳状液的稳定性随着甜菜碱烷基链碳数的增加呈现先逐渐增加然后又逐渐减弱的趋势。甜菜碱的烷基链碳数不同,甜菜碱分子在油水界面表现的亲水亲油性不同。当烷基二甲基磺丙基甜菜碱烷基链碳数为14,烷基二甲基羟丙基磺基甜菜碱烷基链碳数为16时,甜菜碱分子在油水界面达到亲水亲油平衡,界面上吸附的分子最多,界面活性在系列中最好,形成的界面膜排列最紧密,界面膜弹性最大,自修复能力最强,界面膜强度最高,形成的乳状液稳定性最好。两个系列的甜菜碱所形成的乳状液都随甜菜碱浓度的增加乳状液稳定性逐渐增强。在甜菜碱浓度达到临界胶束浓度时,即十四烷基二甲基磺丙基甜菜碱浓度为0.3%,十六烷基羟丙基磺基甜菜碱浓度为0.2%时,尽管甜菜碱分子在界面吸附达到饱和,溶液浓度继续增加,界面张力,界面粘弹性和界面粘度基本不再变化,油水界面膜强度不再增大,但是由于溶液达到临界胶束浓度后,产生了增溶乳化,乳状液的稳定性随溶液浓度增加继续增强。烷基二甲基羟丙基磺基甜菜碱形成的乳状液随着甜菜碱烷基链碳数的增加,稳定性好于烷基二甲基磺丙基甜菜碱所形成的乳状液。烷基二甲基羟丙基磺基甜菜碱是在烷基二甲基磺丙基甜菜碱基础上,在磺丙基基团上引入了羟基,羟基间氢键的作用,一方面增加了溶液中分子的内聚力,分子更易聚集和缠绕,增加了溶液的粘度,另一方面使得分子在界面上排列更加紧密,界面分子间形成氢键网络,界面的分子不易脱附,具有更好的界面活性,界面膜更富有弹性,界面膜的粘度和强度更高,形成的乳状液更稳定。
[Abstract]:Betaine is a typical amphoteric surfactant, which has a unique amphiphilic molecular structure, and the N atom in the amphoteric surfactant of betaine type has a strong alkalinity. So it's a "amphoteric surfactant" with a strong basic N atom, with all the properties of this surfactant, compared with other surfactants. Betaine surfactants have many excellent properties which other types of surfactants do not have. More and more researches have been done on betaine surfactants, especially in tertiary oil recovery, which has been gradually transferred from laboratory research to field application. In this paper, the stability of betaine emulsion was studied by Turbiscan stability analyzer and kinetic model, and the interfacial properties of betaine on oil-water interface (interfacial tension, interfacial tension) were studied. The effect of interfacial viscoelasticity and interfacial viscosity) was used to study the emulsification law of betaine. The results showed that the stability of the emulsion formed by betaine increased gradually with the increase of betaine alkyl chain carbon number and then decreased gradually. The alkyl chain carbon number of betaine is different, and the hydrophilicity of betaine molecules at the oil-water interface is different. When the alkyl dimethyl sulfopropylbetaine alkyl chain carbon number is 14 and the alkyl dimethylhydroxypropylbetaine alkyl chain carbon number is 16:00, the betaine molecule reaches the hydrophilic and oil friendly equilibrium at the oil-water interface, and the most molecules are adsorbed on the interface. The interfacial activity is the best in the series, the interfacial membrane is most closely arranged, the interfacial membrane is elastic, the self-repairing ability is the strongest, the strength of the interfacial membrane is the highest, and the stability of the emulsion is the best. The stability of the emulsion increased with the increase of betaine concentration. When the concentration of betaine reaches the critical micelle concentration, that is, the concentration of tetradecyl dimethyl sulfopropylbetaine is 0.3 and the concentration of cetylhydroxypropylsulfonbetaine is 0.2, although the adsorption of betaine molecules reaches saturation at the interface, The solution concentration continues to increase, interfacial tension, interfacial viscoelasticity and interfacial viscosity do not change basically, and the strength of oil-water interfacial film is no longer increased. However, when the solution reaches the critical micelle concentration, solubilization and emulsification are produced. The stability of emulsion increased with the increase of solution concentration. The stability of the emulsion formed by alkyl dimethyl hydroxypropyl sulfobetaine was better than that formed by alkyl dimethyl sulfopropylbetaine with the increase of betaine alkyl chain carbon number. Alkyl dimethyl hydroxypropyl sulfobetaine is based on alkyl dimethyl sulfopropylbetaine. The hydroxyl group and hydrogen bond between hydroxyl groups are introduced on the basis of alkyl dimethyl propyl betaine. On the one hand, the cohesion of molecules in the solution is increased. Molecules are more easily aggregated and wound, increasing the viscosity of the solution, on the other hand, the molecules are arranged more closely at the interface, the interfacial molecules form a network of hydrogen bonds, and the molecules at the interface are not easy to desorption and have better interfacial activity. The interfacial film is more elastic, the viscosity and strength of the interfacial film are higher, and the emulsion is more stable.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TE39

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