绿色表面活性剂分子结构对智能胶束体系形成的影响

The relationship between the molecular structure and properties has always been a key basic problem in Chemistry. The green surfactants, such as bile salts, esterquats and amino acid surfactants, are chosen as the objects of study. The investigations about temperature-responsive, photo-responsive, pH-responsive and CO2-responsive micellar systems are based on these green cationic and anionic surfactants with different molecular structures, the mixed cationic and anionic surfactant systems, and cyclodextrin-surfactant mixed systems as an important “supramolecular cyclodextrin amphiphiles”. The micellization, microstructures, rheological properties and phase behaviors of these systems at different temperatures or different pH values have been investigated thoroughly; After the addition of the corresponding green additives, the microstructures and rheological properties of these systems before and after UV irradiation or before and after bubbling CO2 have been compared. The formation rules of these stimuli-responsive micellar systems have been summarized. And the influences of molecular structures of surfactants and cyclodextrins on stimuli-responsive micellar systems have been studied. The formation of smart micellar systems have been interpreted from the molecular level based on molecular dynamics simulation. This investigation will reveal the influence of molecular structures of surfactants on formation conditions of the various smart micellar systems and the microstructural transition rules of aggregates, and provide the basic data and experimental basis for the theoretical development of smart micellar systems.

分子结构与性能之间的关系一直是化学学科的关键基础性问题。以胆汁盐、酯基季铵盐及氨基酸型等绿色表面活性剂为研究对象，对这些具有不同分子结构的绿色正离子和负离子表面活性剂、正负离子表面活性剂复配体系以及环糊精-表面活性剂复配体系这类重要的“超分子环糊精两亲分子”，进行温度响应、光响应、pH响应和CO2响应胶束体系的研究。对不同温度下或不同pH下这些体系的胶束化作用、微观结构、流变性质和相行为进行深入研究；在体系中加入相应绿色添加剂后，对其在紫外光照射前后或CO2通入前后，聚集体的微观结构及流变性质进行比较。归纳总结对外界刺激产生响应胶束体系的形成规律，并考察表面活性剂分子结构和环糊精分子结构的影响。通过分子动力学模拟，从分子水平上阐释智能胶束体系的成因。揭示表面活性剂分子结构对各类智能胶束体系形成条件及聚集体微观结构转变规律的影响，为智能胶束体系的理论发展提供基础数据及实验依据。

分子结构与性能之间的关系一直是化学学科的关键基础性问题。按计划合成了一系列具有不同分子结构的酯基季铵盐型及氨基酸型绿色表面活性剂（SAa）并进行了表征。用表面张力法和电导法对一些（绿色）离子型SAa及其复配系统的胶束化作用进行了研究，测定了部分系统的zeta电势了解荷电性质，考察了SAa的分子结构、尾链长度、反离子及头基离子类型、取代基、介质以及环糊精的空腔尺寸等对胶束化作用及环糊精包合作用的影响，并归纳了相关规律。以几种pH缓冲液为溶剂，基于脱氧胆酸钠NaDC及其与（绿色）正离子SAa的复配系统制备了水凝胶，对其温敏性进行了研究，考察了环糊精的包合作用及其空腔尺寸对温敏性的影响。对添加了正负离子SAa配盐及4-甲基水杨酸的正负离子SAa复配系统的相行为及温敏性进行了探究，对基于脂肪酸钠的SAa复配系统的温敏性进行了实验研究及MD模拟，从分子水平上探究该温敏性凝胶的相变机理。对几种基于NaDC、酯基季铵盐、氨基酸型SAa或邻苯二甲酸添加剂的SAa复配系统，探究了pH对相行为和流变性质的影响，选取部分系统探究了pH诱导的微观结构转变及流变性质变化，通过交替加入酸、碱，研究了pH刺激响应的循环可逆性，并探寻pH刺激响应胶束系统的微观结构转变机理。以CTAB（或gemini型酯基季铵盐C12DEG3）及其复配系统为基础，以trans-NaCA或trans-NaOMCA或其复合物作为光敏添加剂，制备了紫外光敏胶束系统，结合MD模拟探究了微观结构转变机理，研究表明正负离子SAa复配系统优于单一离子SAa，复合光敏剂兼有trans-NaCA和trans-NaOMCA的优点。对于NaDC水溶液或其NaCl水溶液，探究了CO2气体的刺激响应性，通过交替通入CO2和N2，考察了系统流变性质的循环可逆性，通过MD模拟从分子水平上阐释CO2诱导的水凝胶的形成机理。本研究有助于揭示表面活性剂分子结构对各类智能胶束微观结构转变规律的影响，为智能胶束系统的理论发展及实际应用提供基础数据及实验依据。