A series of novel carboxylate anionic gemini surfactants SL-n-SL (n = 3, 6, 10) were synthesized, and their rheological properties with a cationic gemini surfactant (12-3(OH)-12) were investigated in this paper. The surface-active properties of SL-n-SL (n = 3, 6, 10) were determined by steady-state fluorescence and a surface tension method. The effect of SL-n-SL on the rheological properties of 12-3(OH)-12 was characterized by steady-state and dynamic rheological measurements. The results indicated that the CMC of SL-n-SL decreased with increased spacer length, and the surfactant with a shorter spacer had a stronger ability to reduce the surface tension of water and had a smaller occupation area at the air/water interface. The addition of SL-n-SL in a 12-3(OH)-12 solution enhanced the viscoelasticity of the 12-3(OH)-12 solution, and worm-like micelles were formed in the mixed solutions. The spacer length had a significant effect on the rheological properties of SL-n-SL/12-3(OH)-12 mixed systems. The SL-n-SL with a shorter spacer had a stronger capacity to promote the formation of worm-like micelles due to the perfect match between the head groups of SL-n-SL and 12-3(OH)-12.

中文翻译：

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新型阴离子和阳离子双子表面活性剂的自组装和流变行为

本文合成了一系列新型羧酸盐阴离子双子表面活性剂SL-n-SL (n = 3, 6, 10)，并研究了它们与阳离子双子表面活性剂(12-3(OH)-12) 的流变性能。SL-n-SL (n = 3, 6, 10) 的表面活性特性由稳态荧光和表面张力法测定。SL-n-SL 对 12-3(OH)-12 流变特性的影响通过稳态和动态流变测量进行表征。结果表明，SL-n-SL的CMC随着间隔长度的增加而降低，间隔较短的表面活性剂降低水的表面张力的能力更强，在空气/水界面的占据面积更小。在 12-3(OH)-12 溶液中加入 SL-n-SL 增强了 12-3(OH)-12 溶液的粘弹性，在混合溶液中形成蠕虫状胶束。间隔长度对SL-n-SL/12-3(OH)-12混合体系的流变性能有显着影响。由于 SL-n-SL 和 12-3(OH)-12 的头部基团之间的完美匹配，具有较短间隔物的 SL-n-SL 具有更强的促进蠕虫状胶束形成的能力。