疏水相互作用引起Gemini表面活性剂柔性联接链的弯曲

为了理解gemini表面活性剂柔性烷基联接链在自组织过程中的特殊作用，我们合成了三种gemini表面活性剂烷基-a,w-二（二-十二烷基甲基溴化铵）（记为2C12-s-2C12×2Br (s=3, 6, 8)）。2C12-s-2C12×2Br在水表面构成铺展膜后，由于每个分子带有4根烷烃链，它们形成了稠密的烷烃尾链层。增强的烷烃尾链与联接链间的疏水相互作用促使联接链弯曲朝向空气一端，可发生弯曲的联接链长度要小于吸附在水溶液表面上的gemini表面活性剂C12-s-C12×2Br，后者每个分子只有2根烷烃链。由此可见，增强的烷烃尾链与联接链间的疏水相互作用可以有效地促进联接链的弯曲。

Bending of the Flexible Spacer Chain of Gemini Surfactant Induced by Hydrophobic Interaction

In order to understand the special role of the flexible alkylene spacer of gemini surfactant in the self‐assembly, three gemini surfactants, alkylene‐α,ω‐bis(didodecylmethylammonium bromide) that is designated as 2C₁₂‐s‐2C₁₂· 2Br (s=3, 6, 8), were synthesized. When the spread films of 2C₁₂‐s‐2C₁₂·2Br on the surface of water were constructed, they form the dense layer of the alkyl tails owing to four dodecyl chains per molecule. This induced the bending of the spacer chain toward the air‐side at the s smaller than that of C₁₂‐s‐C₁₂·2Br adsorbed on the air/water interface owing to the enhanced hydrophobic interaction between the alkyl tails and the spacer chain, where C₁₂‐s‐C₁₂·2Br has only two alkyl tails per molecule. Conclusively, the enhanced hydrophobic interaction between the alkyl tails and the spacer chain can effectively induce the bending of the latter toward the air‐side.