Aratono Makoto, Onimaru Nami, Yoshikai Yumi, Shigehisa Makiko, Koga Ikuyo, Wongwailikhit Kanda, Ohta Akio, Takiue Takanori, Lhoussaine Belkoura, Strey Reinhard, Takata Youich, Villeneuve Masumi, Matsubara Hiroki
Department of Chemistry, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan. m.arascc@ mbox.nc.kyushu-u.ac.jp
J Phys Chem B. 2007 Jan 11;111(1):107-15. doi: 10.1021/jp0637328.
The concentration vs composition diagram of aggregate formation of the dodecyltrimethylammonium bromide (DTAB) and didodecyldimethylammonium bromide (DDAB) mixture in aqueous solution at rather dilute region was constructed by analyzing the surface tension, turbidity, and electrical conductivity data and inspected by cryo-TEM images and dynamic light scattering data. Although the aqueous solution of DTAB forms only micelles, the transition from monomer to small aggregates and then to vesicle was found at 0.1 < X2 <or=1, where X2 is the mole fraction of DDAB in the DTAB-DDAB mixture, while vesicle particles were formed directly from monomer solution at 0 < X2 < 0.1. Furthermore, the transition from vesicle to micelle was found at 0 < X2 < 0.4 at higher concentrations. An addition of DTAB to DDAB solution lowered considerably the DDAB concentration of the vesicle formation, which is attributable to asymmetric distribution of DTAB molecules between inner and outer monolayers of the vesicle bilayer. The shape and size of aggregates were obtained from surface tension, cryo-TEM, and light scattering data.
通过分析表面张力、浊度和电导率数据，构建了十二烷基三甲基溴化铵（DTAB）和二（十二烷基）二甲基溴化铵（DDAB）混合物在水溶液中相当稀的区域内聚集体形成的浓度-组成图，并通过低温透射电子显微镜（cryo-TEM）图像和动态光散射数据进行了检验。虽然DTAB的水溶液仅形成胶束，但在0.1＜X₂≤1时发现了从单体到小聚集体再到囊泡的转变，其中X₂是DTAB-DDAB混合物中DDAB的摩尔分数，而在0＜X₂＜0.1时囊泡颗粒直接从单体溶液中形成。此外，在较高浓度下，在0＜X₂＜0.4时发现了从囊泡到胶束的转变。向DDAB溶液中添加DTAB可显著降低囊泡形成时的DDAB浓度，这归因于DTAB分子在囊泡双层内外单层之间的不对称分布。聚集体的形状和大小由表面张力、低温透射电子显微镜和光散射数据得出。
