The aggregation properties of sugar-based surfactants with methyl groups at multiple positions on the linear alkyl chain are an understudied topic. Therefore, in this study, we performed a structural analysis of aggregates formed by two types of sugar-based nonionic surfactants with multibranched methyl chains, 3,7,11-trimethyldodecyl maltoside (bC₁₅Mal), as well as with a linear chain, dodecyl-β-d-maltoside (C₁₂Mal), in aqueous solutions using rheological and small-angle X-ray scattering techniques. bC₁₅Mal showed an excellent performance in lowering surface tension (28.5 mN m^–1), exhibiting efficient adsorption and orientation at the air/water interface. bC₁₅Mal formed rod-like micelles at a concentration of 10 mmol dm^–3 in aqueous solutions and transitioned to worm-like micelles at 50 mmol dm^–3, followed by gel solutions at 700 mmol dm^–3. As the surfactant concentration increased, the length of the worm-like micelles decreased, and the mesh size decreased, indicating that the strings were densely packed. Conversely, C₁₂Mal formed ellipsoidal micelles over a wide range of concentrations from 50 to 700 mmol dm^–3. The major axis of the core and the overall axis of the ellipsoidal micelles decreased with increasing concentrations. Thus, it was clear that the introduction of methyl groups at positions 3, 7, and 11 of the dodecyl chain of the sugar-based surfactant resulted in a unique aggregation behavior, that is, the formation of aggregates with high-order structures at low concentrations.

中文翻译：

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具有多支链甲基链的糖基非离子表面活性剂的蠕虫状胶束形成


在线性烷基链上多个位置具有甲基的糖基表面活性剂的聚集特性是一个研究不足的话题。因此，在本研究中，我们对两种具有多支链甲基链的糖基非离子表面活性剂、3,7,11-三甲基十二烷基麦芽糖苷 （bC₁₅Mal） 以及线性链十二烷基-β-d-麦芽糖苷 （C₁₂Mal） 形成的聚集体进行了结构分析，使用流变学和小角 X 射线散射技术在水溶液中。乙C₁₅Mal 在降低表面张力 （28.5 mN m^–1） 方面表现出优异的性能，在空气/水界面处表现出有效的吸附和定向。乙C₁₅Mal 在水溶液中形成浓度为 10 mmol dm^–3 的棒状胶束，并在 50 mmol dm^–3 下转变为蠕虫状胶束，然后是 700 mmol dm^–3 的凝胶溶液。随着表面活性剂浓度的增加，蠕虫状胶束的长度减小，网孔尺寸减小，表明串状物密集堆积。相反，C₁₂Mal 在 50 至 700 mmol dm^–3 的宽浓度范围内形成椭球状胶束。核心的长轴和椭球体胶束的总轴随着浓度的增加而减小。因此，很明显，在糖基表面活性剂的十二烷基链的第 3、7 和 11 位引入甲基导致了独特的聚集行为，即在低浓度下形成具有高阶结构的聚集体。