粘度法研究SDS与PEO之间的相互作用

采用粘度法测定了不同温度下 ( 2 98 1 5K ,30 8 1 5K ,31 8 1 5K)阴离子表面活性剂十二烷基硫酸钠 (SDS)—水溶性聚合物聚氧乙烯 (PEO)体系在有无电解质 (NaOH)存在时溶液的宏观粘度 ,研究了SDS—PEO体系分子间相互作用对PEO构型的影响 ,得到了不同SDS—PEO体系的临界聚集浓度 (CAC)和聚合物饱和浓度 (PSP) ,并根据表面活性剂—聚合物体系相互作用模型计算了SDS胶束被吸附到聚合物PEO过程的吉布斯函数变 ,讨论了SDS—PEO体系分子间相互作用强度 结果表明 ,在所研究范围内 ,SDS—PEO体系有无电解质溶液的比浓粘度均随聚合物PEO浓度的减小而急剧升高 ,呈现典型的聚合电解质行为 ,而且SDS的浓度越大 ,电粘效应愈明显 由此可以推断 ,聚合物PEO与表面活性剂SDS之间主要是通过疏水键相互结合 ,PEO分子链处于更伸展的状态 NaOH的存在使聚合物PEO分子与胶束结合位置减少 ,聚集体的体积减小 ,或者介电常数增大 ,因此表现出电粘效应弱于不含碱的表面活性剂—聚合物体系 ,而且使其分子间相互作用强度降低

Investigation on the interaction between sodium dodecyl sulfate and poly(ethylene oxide)by viscosity method

The interaction between anionic surfactant sodium dodecyl sulfate(SDS) and water soluble polymer poly(ethylene oxide)(PEO)in water and in NaOH solution have been studied by viscosity measurements at different temperatures(298 15K,308 15K,318 15K) The effect of SDS PEO interaction on the structure of PEO has been discussed The critical aggregate concentration(CAC)and polymer saturation point(PSP) were obtained,the values of Gibbs energy change for the transfer of free micelle to polymer bound micelle were calculated The electro viscous effect was found,that is,the reduced viscosity of SDS PEO with and without NaOH decreases dramatically with increasing polymer concentration,and the higher the SDS concentration,the more obvious of the electroviscosity effect The hydrophobic interaction between SDS and PEO results in the stretch of PEO chain The addition of NaOH leads to the decrease of the binding site of polymer with micelle,the volume of aggregates decreases or dielectric constant increases so that the electroviscosity effect is weaker than that of surfactant polymer system,so the interaction strength is decreased