Oelschlaeger C, Buhler E, Waton G, Candau S J
Laboratoire de Dynamique des Fluides Complexes, UMR n 7506, Université Louis Pasteur, CNRS, 4 rue Blaise Pascal, 67070 Strasbourg Cedex, France.
Eur Phys J E Soft Matter. 2003 May;11(1):7-20. doi: 10.1140/epje/i2002-10124-y.
The mixed micellization between the cationic gemini surfactant [C12H25(CH3)2N+(C2H4)N+(CH3)2C12H25*2Br-] and the cationic cetyltrimethylammonium bromide (CTAB) in 150 mM KBr solutions has been investigated. The variation of the cmc of the mixtures, measured by surface tension experiments, with composition revealed synergism in micelle formation. T-Jump and light scattering experiments performed in the vicinity of the crossover volume fraction showed the existence of two micellar populations, possibly linear and toroidal micelles. Rheological and dynamic light scattering experiments allowed to fully characterize the linear viscoelasticity of the mixtures. These measurements revealed synergistic gains in viscoelastic properties with a maximum of the stress-relaxation time around the equimolar composition. These effects are ascribed to a progressive intermicellar crosslinking resulting from a continuous increase of the end-cap energy with the 12-2-12 content in the mixture.
研究了阳离子双子表面活性剂[C12H25(CH3)2N+(C2H4)N+(CH3)2C12H25·2Br-]与阳离子十六烷基三甲基溴化铵（CTAB）在150 mM KBr溶液中的混合胶束化作用。通过表面张力实验测量混合物临界胶束浓度（cmc）随组成的变化，结果表明在胶束形成过程中存在协同作用。在交叉体积分数附近进行的T跳跃和光散射实验表明存在两种胶束群体，可能是线性胶束和环形胶束。流变学和动态光散射实验能够全面表征混合物的线性粘弹性。这些测量结果显示，在等摩尔组成附近，粘弹性性能有协同增强，应力松弛时间达到最大值。这些效应归因于随着混合物中12-2-12含量的增加，端基能量不断增加，导致胶束间逐渐发生交联。
