一种含羟丙基的阳离子表面活性剂的流变性能

Rheological performance of aqueous solution of a cationic surfactant containing hydroxypropyl group

用稳态和动态剪切流变学方法测定了3-十四烷氧基-2-羟丙基三甲基溴化铵(R14HTAB)水溶液的流变特性。结果表明,R14HTAB溶液的自组装结构在测定的浓度范围内经历了3次结构转变,从球形胶束到棒状胶束再到黏弹性的蠕虫状胶束,最后转变为六角状溶致液晶;在R14HTAB浓度超过360 mmol/kg以后为球形到棒状胶束的转变;交缠浓度约为500 mmol/kg,零剪切黏度(η0)与R14HTAB浓度(C)之间遵循指数关系,η0∝C5.7。用冷冻蚀刻电镜进一步证实了胶束的微观结构。稳态和动态黏度实验中Cox-Merz规律的偏离主要来自于氢键的形成。

Rheological performance of aqueous solution of a cationic surfactant （3 - tetradecyloxy - 2 - hydroxypropyhrimethylammonium bromide, R14HTAB） was studied with steady and dynamic shear rheological method. Results showed that structure of the selfasembly of the R14I-ITAB undergoes three transitions in the shape within the investigated concentration range, from spherical to rodlike micelles, then to viscoelastic wormlike micelles, and finally to hexagonal lytropic liquid crystal. The transition from spherical micelles into rodlike micelles takes place as the concentration of Rl4 HTAB higher than 360 mmol/kg. The overlapped threshold micelle concentration is about 500 mmol/kg. The viscosity at zero shear （η0） and R14 HTAB concentration （C） displays exponential relationship, i. e. , η0 ∝ C^5. 7. The microstructure of the formed micelles was further ascertained by FF - transmission electronic microscopy. The deviations from Cox - Merz rule in the steady and dynamic viscosity experiment is mainly due to formation of hydrogen bond.