Abstract Effect of various stimuli (concentration, pH, temperature and salt) have been investigated, in aqueous isosorbide (sugar based) spacer based cationic gemini surfactant with hexadecyl chain (16-Isb-16), using spectroscopic and physico-chemical techniques (dynamic light scattering, DLS; nuclear magnetic resonance, NMR; transmission electron microscopy, TEM; polarizing optical microscopy; POM; zeta (ζ)-potential; count rate; pH and conductometry). An interesting phenomenon of micelle to vesicle transition (MVT) has been observed upon dilution. pH sensitive systems, including micelles and vesicles, are found in the solution without changing the pH externally. For external pH change (in the acidic range), DLS data revealed that vesicles are present near the neutral pH. The morphological transitions were confirmed by TEM and POM. ζ data show the conversion of positively charged aggregates to neutral ones. MVT has also been checked by increasing the temperature or adding a salt (NaCl, NaBr, NaNO3 or sodium salicylate; NaSal). Heating induces a transition from micelles to vesicles near ∼40–45 °C while salt addition causes a reverse effect (vesicle to micelle). The transition has been found to be dependent on concentration/nature of salt. The study provides a simple and effective way of tuning the micellar morphology.

中文翻译：

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在含有糖基（异山梨醇）间隔物的水性 Gemini 表面活性剂中自组装

摘要 使用光谱和物理化学技术（动力学）研究了各种刺激（浓度、pH、温度和盐）的影响，在基于异山梨醇（糖基）间隔基的带有十六烷基链（16-Isb-16）的阳离子双子表面活性剂中。光散射，DLS；核磁共振，NMR；透射电子显微镜，TEM；偏振光学显微镜；POM；zeta (ζ)-电位；计数率；pH 和电导率）。在稀释时观察到胶束到囊泡转变 (MVT) 的有趣现象。pH 敏感系统，包括胶束和囊泡，存在于溶液中，而不会从外部改变 pH。对于外部 pH 值变化（在酸性范围内），DLS 数据显示囊泡存在于中性 pH 值附近。TEM 和 POM 证实了形态转变。ζ 数据显示带正电荷的聚集体转化为中性聚集体。MVT 也已通过提高温度或添加盐（NaCl、NaBr、NaNO3 或水杨酸钠；NaSal）进行检查。在大约 40–45 °C 附近加热会诱导从胶束到囊泡的转变，而添加盐会导致相反的效果（囊泡到胶束）。已发现转变取决于盐的浓度/性质。该研究提供了一种调整胶束形态的简单有效的方法。已发现转变取决于盐的浓度/性质。该研究提供了一种调整胶束形态的简单有效的方法。已发现转变取决于盐的浓度/性质。该研究提供了一种调整胶束形态的简单有效的方法。