联接基长度对Gemini表面活性剂流变性质的影响

Influence of Spacer Chain Length on the Rheological Properties of Gemini Surfactant

用毛细管振荡剪切流动法研究了联接基团为聚亚甲基链的阳离子 Gemini表面活性剂的流变性质。实验结果表明 ,无论是普通单链单头基或 Gemini表面活性剂 ,其流变性质主要由胶团的大小和形状所决定 ;随着联接基团长度的增加 ,胶团的轴比率变小 ,导致流动阻力减小 ,粘度降低。此外对于球形和棒状胶团溶液 ,其流变性质主要以粘性为主 ,弹性可忽略不计。在低剪切速率下 ,溶液属于牛顿型流体 ;而在高剪切速率下 ,则表现出准塑性流体性质。

By the means of oscillatory shear flow in the capillary, rheological experiments are carried out on aqueous solutions of the cationic Gemini surfactant as a function of suffactant concentration. The results show that the rheological property is mostly determined by the size and shape of micelles. The axial ratio of micelles decreases with increasing the length of spacer chain, so the viscosity of solution decreases.