School of Chemistry, University of Bristol, Cantock's Close, Bristol, United Kingdom.
Langmuir. 2013 Mar 12;29(10):3252-8. doi: 10.1021/la400117s. Epub 2013 Mar 1.
The concentration-dependent aggregation of two surfactants, anionic sodium dioctylsulfosuccinate (Aerosol OT or AOT) and nonionic pentaethylene glycol monododecyl ether (C12E5), has been studied in cyclohexane-D12 using small-angle neutron scattering (SANS). A clear monomer-to-aggregate transition has been observed for both surfactants, spherical inverse micelles for AOT and hank-like micelles for C12E5. This suggests that a critical micelle concentration exists for surfactants of these kinds in nonpolar solvents. The nature of the transition is different for the two surfactants. AOT aggregates are the same size and shape with decreasing concentration until a sharp critical micelle concentration, after which they cannot be detected. However, C12E5 aggregates gradually decrease in size. These differences demonstrate that the strength of the solvophobic effect can influence the formation of surfactant aggregates in nonaqueous solvents.
两种表面活性剂，阴离子二辛基磺基琥珀酸钠（Aerosol OT 或 AOT）和非离子五乙二醇单十二醚（C12E5）在环己烷-D12 中的浓度依赖性聚集已使用小角中子散射（SANS）进行了研究。对于两种表面活性剂都观察到了明显的单体到聚集物的转变，AOT 为球形反胶束，C12E5 为棒状胶束。这表明在非极性溶剂中，这些类型的表面活性剂存在临界胶束浓度。两种表面活性剂的转变性质不同。AOT 聚集物的大小和形状相同，随着浓度的降低而降低，直到出现尖锐的临界胶束浓度，之后则无法检测到。然而，C12E5 聚集物的尺寸逐渐减小。这些差异表明，溶剂疏水性的强度可以影响非水溶剂中表面活性剂聚集物的形成。
