不同结构芳香侧链酰基牛磺酸钠的表面扩张性质

利用悬挂滴方法研究了N-(α-苯氧基)十四酸牛磺酸钠(12+B-T)和N-(α-对乙基苯氧基)十四酸牛磺酸钠(12+2B-T)在空气/水表面上的动态扩张粘弹性质, 考察了时间、扩张频率及摩尔浓度对扩张模量和相角的影响, 测定了不同摩尔浓度条件下的泡沫性能. 研究发现: 低浓度条件下, 表面分子间相互作用决定表面活性剂吸附膜的性质, 膜以弹性为主; 高浓度条件下, 扩散交换过程起主导作用, 吸附膜表现出粘弹特性. 表面活性剂芳环支链上增加一个乙基, 分子间相互作用增强, 扩张模量增大, 泡沫更加稳定.

Surface Dilational Properties of N-Acyltaurate Amphiphiles with Aromatic Side Chains

The dynamic dilational viscoelasticity properties of N-2-(phenoxy)-tetradecanolytaurinate (12+B-T) and N-2-(4-ethylphenoxy)-tetradecanolytaurinate (12+2B-T) at the air/water interface were investigated by drop shape analysis and their foam properties were measured. The influence of time, dilational frequency, and bulk molar concentration on the surface dilational modulus and phase angle were investigated. A molecular interaction controls the nature of the film's adsorption at the lower concentration range and the filmis elastic in nature. At a higher concentration range, a diffusion exchange process controls the dynamic dilational properties and the surface film shows remarkable viscoelasticity. The addition of one ethyl group to the benzene ring enhances the molecular interaction which results in increases of the dilational modulus and foamstability.