界面张力弛豫法研究芳香侧链酰基牛磺酸钠的界面相互作用

Interfacial Interactions Among Aromatic Side Chained N-Acyltaurates Studied by Interfacial Tension Relaxation Measurements

采用界面张力弛豫方法研究了表面活性剂N-(α-苯氧基)十四酸牛磺酸钠(12+B-T)、N-(α-乙基苯氧基)十四酸牛磺酸钠(12+2B-T)和N-(α-己基苯氧基)十四酸牛磺酸钠(12+6B-T)在空气-水表面和癸烷-水界面上的扩张流变性质,考察了芳环支链链长变化对分子界面行为的影响,获得了表面活性剂结构对极限扩张弹性、扩张黏性最大峰值和相关特征频率的浓度依赖性的影响规律.研究发现,表面上12+6B-T分子中较长的芳环支链间存在较强的相互作用,在较低浓度下形成弹性较强的表面膜,表面分子重排决定膜性质;体相浓度增大或癸烷分子的插入均能削弱芳环支链间的强相互作用,扩散交换过程逐渐居主导地位.

The dilational viscoelastic properties of sodium N-2-（phenoxy）-tetradecanolytaurinate（12＋B-T）,sodium N-2-（4-ethylphenoxy）-tetradecanolytaurinate（12＋2B-T） and sodium N-2-（4-hexylphenoxy）-tetradecanolytaurinate（12＋6B-T） at the air/water and oil/water interfaces were investigated by interfacial tension relaxation method.The effect of aromatic side-chain length on interfacial behavior was investigated.The influences of surfactant structures on the concentration dependences of limiting dilational elasticity,maximum of dilational viscosity and involving characteristic frequency were obtained.It is found that 12＋6B-T can form more elastic adsorption film at low bulk concentration and surface re-arrangement process controls the nature of film due to the existence of stronger interactions among aromatic side-chains with longer length.Diffusion-exchange process becomes the dominate interfacial behavior with the decrease of interactions by the increase of bulk concentration or the insertion of decane molecules.