摘要
利用流变学方法研究了不同pH条件下两性表面活性剂α-羧基十三烷基二甲基氧化胺(CTAO)在水溶液中的聚集行为。实验结果表明,在温度25~60℃区间内,浓度范围为55~125 mmol/L,溶液pH=6.0~6.7时,无需任何添加剂CTAO水溶液即可形成蠕虫状胶束,其流变行为符合Maxwell模型,零剪切黏度最高可达26.5 Pa·s。在溶液pH>7的条件下,分子在溶液中的存在形式发生改变,分子间作用的斥力增加,蠕虫状胶束转变为球状胶束,其黏度接近于水,零剪切黏度约是pH=6.2时的1/4 000。该pH响应蠕虫状胶束体系仅由CTAO溶于水形成,其相变pH范围窄,具有制备容易、体系简单、流变性能变化显著的特点。
The aggregation behaviors of an amphoteric surfactant, α- carboxyl tridecyl dimethylamine oxide （CTAO） in aqueous solution at different pH values were examined by rheological method. Results show that wormlike micelles would form in CTAO aqueous solutions within concentration 55 - 125 mmol/L and pH value 6.0 -6.7 at 25 -60℃ without any additive. Their theological behaviors comply with Maxwell model and the zero - shear viscosity can achieve 26.5 Pa·s. In case the pH value of the solution is higher than 7, form of the molecules of the surfaetant in the solution changes and the repulsion between the molecules increases which results in the transition from wormlike micelles to spherical micelles. Meanwhile, the viscosity of the CTAO solution at pH value 7 is close to that of water and the zero - shear viscosity is about 1/4 000 of the solution with pH value 6. 2. The pH - responsive micellar systems is obtained by a single - component surfactant CTAO,while displays distinct advantages of simple, narrow responsive pH value range, easy preparation and remarkable change of theological properties.
出处
《日用化学工业》
CAS
CSCD
北大核心
2017年第6期301-306,共6页
China Surfactant Detergent & Cosmetics
