温度响应的黏弹性表面活性剂研究

Study on temperature-responsive viscoelastic surfactants

基于相反电性表面活性剂之间的协同作用,采用烷基磺酸盐CnSO3Na(n=8,12,14,16)与两性离子型表面活性剂十八烷基羧基甜菜碱(BS-18)合成黏弹性表面活性剂,考察了碳链长度对BS-18表观黏度的影响及温度对合成的黏弹性表面活性剂表观黏度的影响,并研究了BS-18/C12SO3Na体系溶液的稳态流变性能。实验结果表明,碳链增加,增黏范围变窄,其中,C12SO3Na表现出最佳的增黏效果和相对较宽的增黏范围;在C_(12)SO_(3)Na摩尔分数为10%、BS-18/C_(12)SO_(3)Na体系含量为0.5%(w)时,相对BS-18,BS-18/C_(12)SO_(3)Na体系在55℃和85℃的表观黏度增加了5.7和16.3倍,且混合体系胶束呈现温度响应性特征,BS-18/C_(12)SO_(3)Na含量越高表观黏度的温度感应性越显著。

Based on the synergy between oppositely charged surfactants,viscoelastic surfactants are formulated with alkyl sufonate surfactants CnSO_(3)Na(n=8,12,14,16)and C18 alkyl betaine zwitterionic surfactant(BS-18).The effect of alkyl chain length on the apparent viscosity of BS-18 and the influence of temperature on the formulated viscoelastic surfactants were studied.Furthermore,the rheology of BS-18/C_(12)SO_(3)Na solution systems was investigated at stead state.The experimental results show that the effective mole fraction of C_(12)SO_(3)Na for enhancing the apparent viscosity of the system is narrowed down with increasing alkyl chain length.There are an optimal mole fraction and a relatively wider range of C_(12)SO_(3)Na mole fraction for enhancing apparent viscosity.Compared to BS-18 solution,with 10%mole fraction of C_(12)SO_(3)Na in a system with 0.5%(w)BS-18/C_(12)SO_(3)Na,the apparent viscosity of BS-18/C_(12)SO_(3)Na system is increased by 5.7 times at 55℃and 16.3 times at 85℃,respectively.Moreover,the micelles in the system are responsive to temperature change.The higher BS-18/C_(12)SO_(3)Na concentration,the more obvious temperature-responsive effect.