Gemini salts of linear alkylbenzene sulfonate (LABS) were prepared by neutralization of sulfonic acid with a series of low-molecular-weight diamines in aqueous solution. The equilibrium surface activity of Gemini salts of LABS was determined by measuring the surface tension as a function of surfactant concentration to determine the critical micelle concentration (CMC), surface tension at the CMC (γ_CMC), and the area per molecule at the air-water interface (Ų). Electrical conductivity was measured as a function of surfactant concentration to determine the CMC and counterion binding. Dynamic surface tension was measured using a bubble pressure tensiometer to infer the rate at which the surfactant migrates to the air-water interface. Equilibrium interfacial tension against mineral oil was measured using a spinning drop tensiometer. Dynamic interfacial tension was measured using a drop volume tensiometer. The surface tension, CMC, and interfacial tension of Gemini salts of LABS decreased compared to monovalent organic and inorganic salts. The CMC decreases with increasing molecular weight of the diamine spacer group. Dynamic surface and interfacial tension of Gemini salts of LABS are lower than monovalent salts. The foam volume of Gemini salts of LABS was determined using a high shear blender test. The foam volume of Gemini salts of LABS is lower than monovalent salts and depends on the size of the spacer group. Hard-surface cleaning was measured using artificial soil applied to white Formica tiles. Soil removal was determined by optical reflectance as a function of abrasion cycles. Gemini salts of LABS show reduced hard-surface cleaning performance compared to monovalent salts. Detergency of different types of soils on cotton and polyester/cotton fabric was determined by optical reflectance measurements. Gemini salts of LABS show improved cleaning performance compared to monovalent salts. Cleaning performance increases with increasing molecular weight of the diamine spacer group. In situ neutralization of LABS with organic diamines is a simple and efficient way to prepare anionic Gemini surfactants for industrial scale applications.

中文翻译：

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直链烷基苯磺酸双子盐在水溶液中的表面活性和性能

通过在水溶液中用一系列低分子量二胺中和磺酸制备直链烷基苯磺酸盐 (LABS)。LABS 的 Gemini 盐的平衡表面活性是通过测量作为表面活性剂浓度的函数的表面张力来确定的，以确定临界胶束浓度 (CMC)、CMC 处的表面张力 (γ _CMC ) 和空气中每个分子的面积-水界面（Å ²）。作为表面活性剂浓度的函数测量电导率以确定CMC和反离子结合。使用气泡压力张力计测量动态表面张力以推断表面活性剂迁移到空气-水界面的速率。使用旋转液滴张力计测量对矿物油的平衡界面张力。使用液滴体积张力计测量动态界面张力。与一价有机和无机盐相比，LABS 的 Gemini 盐的表面张力、CMC 和界面张力降低。CMC随着二胺间隔基团分子量的增加而降低。LABS Gemini 盐的动态表面和界面张力低于单价盐。LABS Gemini 盐的泡沫体积是使用高剪切混合器测试确定的。LABS Gemini 盐的泡沫体积低于单价盐，取决于间隔基团的大小。硬表面清洁度是使用施加到白色富美家瓷砖上的人造土壤测量的。通过作为磨损循环的函数的光学反射来确定污垢去除。与单价盐相比，LABS 的 Gemini 盐显示出降低的硬表面清洁性能。棉花和聚酯/棉织物上不同类型污垢的去污力是通过光学反射率测量来确定的。与单价盐相比，LABS 的 Gemini 盐显示出改进的清洁性能。清洁性能随着二胺间隔基团分子量的增加而增加。硬表面清洁度是使用施加到白色富美家瓷砖上的人造土壤测量的。通过作为磨损循环的函数的光学反射来确定污垢去除。与单价盐相比，LABS 的 Gemini 盐显示出降低的硬表面清洁性能。棉花和聚酯/棉织物上不同类型污垢的去污力是通过光学反射率测量来确定的。与单价盐相比，LABS 的 Gemini 盐显示出改进的清洁性能。清洁性能随着二胺间隔基团分子量的增加而增加。硬表面清洁度是使用施加到白色富美家瓷砖上的人造土壤测量的。通过作为磨损周期函数的光学反射来确定污垢去除。与单价盐相比，LABS 的 Gemini 盐显示出降低的硬表面清洁性能。棉花和聚酯/棉织物上不同类型污垢的去污力是通过光学反射率测量来确定的。与单价盐相比，LABS 的 Gemini 盐显示出改进的清洁性能。清洁性能随着二胺间隔基团分子量的增加而增加。棉花和聚酯/棉织物上不同类型污垢的去污力是通过光学反射率测量来确定的。与单价盐相比，LABS 的 Gemini 盐显示出改进的清洁性能。清洁性能随着二胺间隔基团分子量的增加而增加。棉花和聚酯/棉织物上不同类型污垢的去污力是通过光学反射率测量来确定的。与单价盐相比，LABS 的 Gemini 盐显示出改进的清洁性能。清洁性能随着二胺间隔基团分子量的增加而增加。用有机二胺原位中和 LABS 是制备用于工业规模应用的阴离子 Gemini 表面活性剂的一种简单有效的方法。