Innovations in surfactant structure are a feasible way to probe molecular self-assembly principles. Herein, the solution behaviour of a newly synthesized Gemini surfactant derived from dehydroabietic acid, abbreviated R-(EO)-E-R, was investigated using surface tension, fluorescence, isothermal titration calorimetry (ITC), rheology, freeze-fracture transmission electron microscopy (FF-TEM) and cryogenic transmission electron microscopy (cryo-TEM) methods. R-(EO)-E-R has two large, rigid hydrophobic groups. At low concentrations, R-(EO)-E-R forms micelles with an aggregation number of approximately 10, which is smaller than those of Gemini surfactants containing flexible alkyl tails. In addition, the micellization process is less exothermic because of the rigidity of the hydrophobic portions. As the concentration increases, R-(EO)-E-R without any additives forms wormlike micelles, endowing the solution with an obvious viscoelasticity. Further increases in the concentration lead to the coexistence of single-walled vesicles, double-walled vesicles and rarely observed long, tubular vesicles. This behaviour is attributed to the two large, rigid hydrophobic groups of R-(EO)-E-R, which increase the density of the hydrophobic portion around the ionic head groups and facilitate the formation of aggregates with lower curvatures and asymmetric morphology. Surfactants containing rigid hydrophobic portions are expected to result in more delicate, self-assembled morphologies with broad applications.

中文翻译：

---

衍生自脱氢松香酸的双子表面活性剂在水溶液中的聚集演化†

表面活性剂结构的创新是探索分子自组装原理的可行方法。在本文中，使用表面张力，荧光，等温滴定量热法（ITC），流变学，冷冻断裂透射电子显微镜（FF）研究了一种新合成的双氢表面活性剂的衍生行为，该表面活性剂是脱氢松香酸缩写的R-（EO）-ER。 -TEM）和低温透射电子显微镜（cryo-TEM）方法。R-（EO）-ER具有两个大的刚性疏水基团。在低浓度下，R-（EO）-ER形成的胶束的聚集数约为10，这比含有柔性烷基尾部的Gemini表面活性剂的胶束小。另外，由于疏水部分的刚性，胶束化过程放热较小。随着浓度的增加，没有任何添加剂的R-（EO）-ER形成蠕虫状的胶束，赋予溶液明显的粘弹性。浓度的进一步增加导致单壁囊泡，双壁囊泡并存，很少见到长的管状囊泡。此行为归因于R-（EO）-ER的两个较大的刚性疏水基团，它们增加了离子头基团周围的疏水部分的密度，并有助于形成具有较低曲率和不对称形态的聚集体。预期包含刚性疏水部分的表面活性剂将导致更精细的自组装形貌，具有广泛的应用。双壁囊泡，很少见到长而管状的囊泡。此行为归因于R-（EO）-ER的两个较大的刚性疏水基团，它们增加了离子头基团周围的疏水部分的密度，并有助于形成具有较低曲率和不对称形态的聚集体。预期包含刚性疏水部分的表面活性剂将导致更精细的自组装形貌，具有广泛的应用。双壁囊泡，很少见到长而管状的囊泡。此行为归因于R-（EO）-ER的两个较大的刚性疏水基团，它们增加了离子头基团周围的疏水部分的密度，并有助于形成具有较低曲率和不对称形态的聚集体。预期包含刚性疏水部分的表面活性剂将导致更精细的自组装形貌，具有广泛的应用。