基于“lock-in”效应的阳离子三联表面活性剂蠕虫状胶束流变性能

以三联阳离子表面活性剂双(2-羟基-二亚甲基醚)-α,ω,γ-三(十六烷基二甲基氯化铵)(16-4(OH)-16-4(OH)-16)在水杨酸钠(NaSal)及氯化钠(NaCl)作用下形成的蠕虫状胶束为研究对象,向该体系中增溶苯乙烯(S_t)引发聚合,探讨了聚合前后胶束溶液的流变性能。通过表观黏度法研究了16-4(OH)-16-4(OH)-16/NaSal/NaCl及十六烷基三甲基溴化铵(CTAB)/NaSal两种体系聚合后溶液的耐温(T)及耐剪切性,并利用流变测试对16-4(OH)-16-4(OH)-16/NaSal/NaCl体系增溶S_t聚合前后溶液性能进行了表征。结果表明:CTAB/NaSal胶束体系中S_t最佳增溶量为0.05 g,T=100℃或剪切90 min,聚合后溶液表观黏度(η_a)分别为66.9、15.5 mPa·s;而16-4(OH)-16-4(OH)-16/NaSal/NaCl胶束中S_t 最佳增溶量为0.10 g,T=100℃且连续剪切90 min后,聚合后溶液的η_a 始终维持在99.1 mPa·s,该体系聚合后稳态模量(G₀)高于未增溶S_t体系,由此说明蠕虫状胶束内S_t聚合物链可以产生对其微结构的“lock-in”效应。

Microstructure “lock-in” of wormlike micelles in aqueous cationic trimer surfactant systems

Wormlike micelles(WLMs)were formed in aqueous solutions of cationic trimer surfactant di(2-hydroxyl-dimethylene ether)-α,ω,γ-triple(dimethylcetylammonium chlorine),referred to as 16-4(OH)-16-4(OH)-16 by addition of sodium salicylate(NaSal)and sodium chloride(NaCl).The rheological properties of the micellar solution before and after polymerization were discussed by solubilizing styrene(S_t)into the cores of WLMs.The temperature(T)and shear resistance of systems of 16-4(OH)-16-4(OH)-16/NaSal/NaCl and cetyl trimethyl ammonium bromide(CTAB)/NaSal were compared with the viscosimetry method,and the properties of 16-4(OH)-16-4(OH)-16/NaSal/NaCl solutions before and after polymerization were characterized with the rheology method.The results showed that the optimum solubilization quantity of S_t for the CTAB/NaSal system was 0.05 g,and at 100℃ or after shearing 90 min,the η_a of its polymerization system was 66.9 mPa·s and 15.5 mPa·s,respectively.For the 16-4(OH)-16-4(OH)-16/NaSal/NaCl system,the best solubilization quantity of S_t was 0.10 g;the η_a of its polymerization system was 99.1 mPa·s after shearing 90 min incessantly at 100℃;the plateau modulus(G₀)of the polymerization system was higher than that of the solutions without S_t.Based on the above discussion,the "lock-in" of the microstructure of wormlike micelles formed by 16-4(OH)-16-4(OH)-16 with NaSal and NaCl can be realized by polymerization of S_t in the hydrophobic core of the micelles.