光响应离子液体表面活性剂的合成及性质研究

发布时间：2018-05-01 09:13

本文选题：光响应离子液体表面活性剂 + 表面张力　；参考：《河南师范大学》2017年硕士论文

【摘要】：从绿色化学的发展理念出发,新型、环保、多功能的表面活性剂以其独特的物理化学性质倍受世界各地科研人员的关注。在表面活性剂的疏水链中嵌入光敏基团,同时在亲水头基以离子液体润饰,如此合成出的光响应离子液体表面活性剂兼具了传统的双亲性及特殊光学活性。本文以四丁基苯胺为原料,通过重氮偶合,威廉姆森成醚反应,取代等反应合成的中间体与甲基咪唑反应合成第一种产物:4-丁基偶氮苯-4'-(乙氧基)甲基咪唑溴化盐(AZMIMBr),然后通过交换树脂将产物AZMIMBr与氟硼酸反应合成第二种产物:4-丁基偶氮苯-4'-(乙氧基)甲基咪唑四氟硼酸盐(AZMIMBF4)。实验进一步研究了十二烷基羟乙基二甲基溴化铵(C_(12)HDAB)与AZMIMBr混合后的胶束化过程,并考察了紫外光照对不同配比下胶束体系光学性质的影响。采用核磁共振技术对已合成的两种产物进行表征,然后对产物的熔点及热稳定性进行热分析,接着,滴体积法和电导率法彼此验证,准确测定其临界胶束浓度。实验数据表明,两种表面活性剂在25℃下的CMC分别为2.20、1.14 mM,由于表面活性剂的CMC主要与分子结构有关,AZMIMBr样品溶液的CMC要大于AZMIMBF4样品溶液的CMC,在具有相同的较大非极性基团和咪唑阳离子基团的情况下,造成CMC差异的就是反离子Br-、BF4-的作用,样品AZMIMBr中溴离子的极性较大,亲水性更强,减弱了疏水基与溶剂之间的排斥力,而样品AZMIMBF4中氟硼酸根的极性小,有疏水作用,更加有利于胶束的形成。在电导率曲线图中,临界胶束浓度值随温度的增加而增大,反离子结合度β随温度升高而降低,这与反离子的水化半径和极性有关。实验还测定了AZMIMBF4的Krafft点(40℃),以确定其最佳溶解温度。由于它们的疏水链中特有的偶氮苯基团,通过365 nm紫外光照射,对光化学调控下的表面性质进行研究。对比紫外照射前后的临界胶束浓度变化,证实了表面活性剂在紫外光照下,由稳定的反式结构转变为不稳定的顺式结构的变化行为,并通过紫外可见吸收光谱、核磁共振仪等仪器,测定了达到光稳态所需的紫外照射时间以及不同时间下的反转率。结合偏光显微镜及小角度X射线衍射技术手段,探究了紫外光照对两种产物在水溶液中构筑成的溶致液晶体系的影响,发现本实验中所合成的表面活性剂在溶剂水体系中形成的液晶相的类型与紫外光照与否及在水中的浓度大小有很大的关系。实验进一步探讨了表面活性剂AZMIMBr与C_(12)HDAB复配对整个溶液体系各项性质的影响以及紫外光照对混合体系分子聚集行为的影响。不同配比下的AZMIMBr/C_(12)HDAB混合溶液的临界胶束浓度利用滴体积法和电导率法测出,实验表明随C_(12)HDAB加入量的增加,CMC依次增大,但都位于两者之间,偏向于单一AZMIMBr的CMC。通过对混合溶液胶束化热力学过程进行分析,发现相关参数显示出和单一AZMIMBr变化规律相似的趋势。同时通过紫外吸收光谱、偏光显微镜、动态光散射等技术测量了紫外光诱导下的混合表面活性剂微观结构的变化,为光响应表面活性剂在纳米材料、生物医学等领域中的应用提供了一定的实验和理论依据。
[Abstract]:Starting from the concept of green chemistry, a new, environmentally friendly, multifunctional surface active agent has attracted the attention of researchers all over the world with its unique physical and chemical properties. The photosensitive group is embedded in the hydrophobic chain of the surfactant and the hydrophilic head base is embellished with ionic liquid, so the surface activity of the photosensitive ionic liquid has been synthesized. In this paper, four Ding Ji aniline was used as the raw material. The first product was synthesized by the reaction of diazo coupling, Williamson ethers reaction, substitution reaction, substitution reaction and methimidazole, 4- Ding Ji azobenzene -4'- (Yi Yangji) methimidazole bromide (AZMIMBr), and then produced by exchange resin. Second products were synthesized by the reaction of AZMIMBr with fluboric acid: 4- butyl azobenzene -4'- (Yi Yangji) methyl imidazole tetrafluorobate (AZMIMBF4). The micellization process of twelve alkyl hydroxyethyl two methammonium bromide (C_ (12) HDAB) and AZMIMBr was further studied, and the optical properties of the micellar system under different proportions of ultraviolet light were investigated. Two kinds of synthesized products were characterized by NMR. Then the melting point and thermal stability of the products were analyzed. Then, the drop volume method and the conductivity method were verified with each other to accurately determine the critical micelle concentration. The experimental data showed that the CMC of the two surface activator at 25 C was 2.20,1.14 mM, respectively. The CMC of the surface active agent is mainly related to the molecular structure. The CMC of the AZMIMBr sample solution is greater than the CMC of the AZMIMBF4 sample solution. In the case of the same large non polar group and the imidazole cationic group, the CMC difference is the reaction of the reverse ion Br-, the action of BF4-, the sample AZMIMBr is more polar, more hydrophilic and weaker. The repellent force between the hydrophobic group and the solvent, and the polarity of the fluorobate root in the sample AZMIMBF4 is small and has the effect of hydrophobicity, which is more beneficial to the formation of the micelle. In the conductivity curve, the critical micelle concentration increases with the increase of temperature, and the anti ion binding degree decreases with the increase of temperature, which is related to the hydration radius and polarity of the reverse ion. The experiment also determined the Krafft point of AZMIMBF4 (40 degrees C) to determine the optimum dissolution temperature. The surface properties under photochemical regulation were studied by 365 nm UV irradiation due to the unique azobenzene group in their hydrophobic chain. The changes of the critical micelle concentration before and after UV irradiation were compared. At the same time, the stable trans structure is transformed into an unstable CIS structure, and the UV irradiation time and the reversal rate are measured by UV visible absorption spectroscopy and nuclear magnetic resonance apparatus. Ultraviolet light microscopy and small angle X ray diffraction techniques have been used to explore ultraviolet light. According to the effect of the lyotropic liquid crystal constructed by the two products in aqueous solution, it is found that the type of the liquid crystal phase formed in the solvent water system in this experiment has a great relationship with the ultraviolet light or not and the concentration of the water in the water. The experiment further explored the combination of surfactant AZMIMBr and C_ (12) HDAB. The effects on the properties of the whole solution system and the influence of ultraviolet light on the aggregation behavior of the mixed system. The critical micelle concentration of AZMIMBr/C_ (12) HDAB mixed solution under different proportions is measured by the drop volume method and the conductivity method. The experiment shows that CMC increases with the increase of the amount of C_ (12) HDAB, but both are located between the two. By analyzing the thermodynamic process of micellization of mixed solution, CMC., which is biased toward a single AZMIMBr, found that the related parameters showed a similar trend with the single AZMIMBr change law. At the same time, the microstructure of the mixed surfactant induced by ultraviolet light was measured by UV absorption spectroscopy, polarizing microscope and dynamic light scattering. It provides some experimental and theoretical basis for the application of photoresponse surfactants in nanomaterials, biomedicine and other fields.

【学位授予单位】：河南师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O647.2

【参考文献】