Fujii Shota, Yamada Shimpei, Araki Masataka, Lee Ji Ha, Takahashi Rintaro, Sakurai Kazuo
Department of Chemistry and Biochemistry , University of Kitakyushu , 1-1 Hibikino , Kitakyushu , Fukuoka 808-0135 , Japan.
Langmuir. 2019 Feb 26;35(8):3156-3161. doi: 10.1021/acs.langmuir.8b04204. Epub 2019 Feb 12.
Micelles with perfect monodispersity in terms of the aggregation number ( N) have recently been discovered, whose values of N interestingly always coincide with the vertex or face number of regular polyhedral structures (i.e., Platonic solids). Owing to the monodispersity of the micelles, named Platonic micelles, we could expect them to exhibit unprecedented aggregation behavior. In this study, the effects of alkyl chain length on micellar aggregation behavior were characterized using small-angle scattering techniques such as small-angle X-ray scattering and asymmetrical flow field-flow fractionation coupled with multi-angle light scattering, as well as analytical ultracentrifugation measurements. The N of Platonic micelles discretely and discontinuously increased when increasing the alkyl chain length, which differs markedly from the findings for conventional micelles. This aggregation behavior could be reasonably explained by the relationship between the thermodynamic stability of the micelles and the coverage density defined by one of the unsolved mathematical problems: the Tammes problem.
最近发现了在聚集数（N）方面具有完美单分散性的胶束，其N值有趣地总是与规则多面体结构（即柏拉图立体）的顶点数或面数一致。由于这些被称为柏拉图胶束的胶束具有单分散性，我们可以预期它们会表现出前所未有的聚集行为。在本研究中，使用小角散射技术，如小角X射线散射和不对称流场-流分级结合多角度光散射，以及分析超速离心测量，来表征烷基链长度对胶束聚集行为的影响。当增加烷基链长度时，柏拉图胶束的N值离散且不连续地增加，这与传统胶束的研究结果明显不同。这种聚集行为可以通过胶束的热力学稳定性与由未解决的数学问题之一：塔姆斯问题定义的覆盖密度之间的关系得到合理的解释。
