联结基对两性双子表面活性剂溶液行为的影响研究

发布时间：2018-05-12 06:58

本文选题：两性双子表面活性剂 + 表面张力　；参考：《东北石油大学》2017年硕士论文

【摘要】：表面活性剂构效关系的研究一直是较为活跃的研究领域,开发一种性能优异、用量低、耐温耐盐性能好以及生物降解性优异的表面活性剂成为当前日用化学领域研发的发展方向。本文从两性甜菜碱型Gemini表面活性剂的结构特征出发,设计合成了一系列联结基长度不同的新型两性甜菜碱型Gemini表面活性剂,对其结构与性能关系进行了研究,取得的主要结果如下:1、以十二伯胺、溴乙基磺酸钠、1,2-二溴乙烷、1,4-二溴丁烷、1,6-二溴己烷、溴乙烷等为主要原料,合成出了一系列联结基长度不同的新型两性甜菜碱型Gemini表面活性剂(GSB12-N,N=2,4,6),并且对合成的产物及中间体进行了表征,确定了其分子结构。2、对合成的两性双子表面活性剂水溶液的表面性能进行了研究,发现该系列两性双子表面活性剂都具有良好的表面性能,随着联结基长度的增加,GSB12-N表面活性剂的γcmc先增加后减小,其中当联结基-(CH2)n-中的n为6时,其γcmc达到最低值30.90mN/m,这是由于当联结基长度达到一定值时,可以呈现出柔性,使得双子表面活性剂分子内的两条单链靠近,进而提高表面性能。并且发现该系列表面活性剂具有良好的抗温性及抗盐性,且对反离子的抵抗能力顺序为Na+Ca2+Mg2+。3、利用分子动力学法研究了该系列表面活性剂在气/液界面的聚集行为,主要利用ATB、GAMESS(US)等工具对该系列表面活性剂的结构进行优化计算,利用Gromacs来实现全部的分子动力学计算。结果发现,在T=318K时,其SCD值整体比其他的SCD值大,总体呈现出随着温度的升高,SCD不断地增大的规律,SCD的增大表明疏水尾链趋向于垂直界面排列,分子排列的更为紧密,随着温度的升高,表面活性剂分子的疏水尾链的构象会发生变化,在微观层次上对GSB12系列表面活性剂的耐温性进行了阐述。随着NaCl浓度的增加,表面活性剂的双电层厚度先减小后增加,亲水基团占有面积也是先减小后增加,同时,SCD值也呈现出相同的规律,宏观上表现出表面活性是先增加后减小的规律,发现的规律与实验得到的规律一致,对表面活性剂与无机盐的作用机理进行了阐述。
[Abstract]:The study of the structure-activity relationship of surfactants has been an active research field. Surface active agents with good temperature and salt resistance and biodegradability have become the research and development direction of daily chemistry. Based on the structural characteristics of amphoteric betaine type Gemini surfactants, a series of novel amphoteric betaine type Gemini surfactants with different binding lengths were designed and synthesized. The main results obtained are as follows: 1. The main raw materials are dodecylamine, sodium bromoethylsulfonate, sodium bromoethyl sulfonate, 1,4-dibromobutane, 1-dibromohexane, bromoethane, etc. A series of new amphoteric betaine type Gemini surfactants with different binding lengths were synthesized, and the synthesized products and intermediates were characterized. Its molecular structure was determined. The surface properties of the synthesized amphiphilic Gemini surfactants in aqueous solution were studied. It was found that the series of amphiphilic Gemini surfactants had good surface properties. With the increase of the binding group length, the 纬 cmc of GSB12-N surfactants first increases and then decreases. When n in the binding base is 6, its 纬 cmc reaches the minimum value of 30.90 mn / m, which is due to the flexibility when the binding base length reaches a certain value. The two single chains of Gemini surfactants are close to each other, thus improving the surface properties of Gemini surfactants. It was also found that the series of surfactants had good resistance to temperature and salt, and the order of resistance to counterions was Na Ca2 Mg2. 3. The aggregation behavior of the surfactants at the gas-liquid interface was studied by molecular dynamics. The structure of this series of surfactants was optimized by means of ATBX GAMESSU and Gromacs was used to calculate the molecular dynamics of the surfactants. The results show that the total SCD value of TX 318K is larger than that of other SCD values, and the increasing of SCD shows that the hydrophobic tail chains tend to perpendicular to the interface and the molecules are arranged more closely. With the increase of temperature, the conformation of hydrophobic tail chain of surfactant molecules will change. The temperature tolerance of GSB12 series surfactants is expounded at the micro level. With the increase of NaCl concentration, the double-layer thickness of surfactant decreases first and then increases, and the hydrophilic group occupied area decreases first and then increases. Macroscopically, the surface activity was increased first and then decreased, and the law found was consistent with that obtained by experiment. The mechanism of action of surfactant and inorganic salt was expounded.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O647.2

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