Spontaneous vesicle formation of mixtures of double-chain cationic surfactants with a different counterion.
Spontaneous vesicle formation of mixtures of double-chain cationic surfactants with a different counterion.
复制标题
双链阳离子表面活性剂与不同抗衡离子的混合物自发形成囊泡。
DOI：
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发表时间：
2008
影响因子：
3.3
通讯作者：
H. Matsubara
中科院分区：
文献类型：
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作者：
M. Aratono;Azusa Mori;Ikuyo Koga;Makiko Shigehisa;Nami Onimaru;K. Tsuchiya;T. Takiue;H. Matsubara
研究了双十二烷基二甲基溴化铵 (DDAB) 和双十二烷基二甲基氯化铵 (DDAC) 混合物在水溶液中的聚集体形成。通过分析表面张力、浊度和电导率数据构建了聚集体形成的浓度与成分图。将低温透射电子显微镜应用于图中的几个代表性点，并提供聚集体的形态信息。随着所有混合比下表面活性剂总浓度的增加，得出单体(m)-m+小聚集体(A)-m+A+囊泡(V)-m+V的顺序。 A和V中抗衡离子的组成是根据热力学考虑进行估计的，并从成分的不对称性和囊泡双层的外单层和内单层之间的不均匀分布的角度进行了检查。与本体溶液相比，囊泡表面富含氯离子，这与球形胶束表面相反。
Aggregate formation of a didodecyldimethylammonium bromide (DDAB) and didodecyldimethylammonium chloride (DDAC) mixture in aqueous solution was investigated. The concentration vs composition diagram of aggregate formation was constructed by analyzing the surface tension, turbidity, and electrical conductivity data. The cryogenic transmission electron microscopy was applied to several representative points in the diagram and provided information of the morphology of aggregates. The sequence of monomer (m) - m + small aggregate (A) - m + A + vesicle (V) - m + V was concluded with increasing total concentration of surfactants at all mixing ratios. The compositions of counterions in A and V were estimated on the basis of thermodynamic consideration and examined from the viewpoint of asymmetry of constituents and uneven distribution between outer and inner monolayers of a vesicle bilayer. Vesicle surfaces were suggested to abound in chloride ions compared to bulk solution, which is opposite to spherical micelle surfaces.