Oleic Acid-Based Gemini Surfactants with Carboxylic Acid Headgroups
Oleic Acid-Based Gemini Surfactants with Carboxylic Acid Headgroups
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DOI：
10.5650/jos.60.411
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发表时间：
2011-08-01
影响因子：
1.5
通讯作者：
Abe, Masahiko
中科院分区：
文献类型：
--
作者：
Sakai, Kenichi;Umemoto, Naoki;Abe, Masahiko
以油酸为原料合成了含羧酸头基的阴离子Gemini表面活性剂。碳氢链通过酯键共价键合到油酸的末端羰基上，而羧酸头基通过二丁二基单元引入到油酸的顺式双键上。表面活性剂在水溶液中表现出依赖于pH的质子化-去质子化行为。在碱性溶液中(pH为9，以10 mmoldm(-3)的氯化钠为本底电解质)，即使在低表面活性剂浓度范围内，表面活性剂也能降低表面张力并形成分子组装。在酸性(PH 3)或中性(pH 6-7)条件下，表面活性剂本质上不溶于水介质，并在空气/水界面形成单分子层。在这项研究中，我们通过静态表面张力、芘荧光、动态光散射、表面压力等温线和红外外反射测量，研究了碳氢链长度的函数等物理化学性质。
Anionic gemini surfactants with carboxylic acid headgroups have been synthesized from oleic acid. The hydrocarbon chain is covalently bound to the terminal carbonyl group of oleic acid via an ester bond, and the carboxylic acid headgroups are introduced to the cis double bond of oleic acid via disuccinyl units. The surfactants exhibit pH-dependent protonation-deprotonation behavior in aqueous solutions. In alkaline solutions (pH 9 in the presence of 10 mmol dm(-3) NaCl as the background electrolyte), the surfactants can lower the surface tension as well as form molecular assemblies, even in the region of low surfactant concentrations. Under acidic (pH 3) or neutral (pH 6-7) conditions, the surfactants are intrinsically insoluble in aqueous media and form a monolayer at the air/water interface. In this study, we have investigated physicochemical properties such as the function of the hydrocarbon chain length by means of static surface tension, pyrene fluorescence, dynamic light scattering, surface pressure area isotherms, and infrared external reflection measurements.