Institute of Physical and Theoretical Chemistry, University of Regensburg, 93040 Regensburg, Germany.
Langmuir. 2011 Mar 1;27(5):1635-42. doi: 10.1021/la1037316. Epub 2011 Jan 12.
We demonstrate here that microemulsions with an IL as the continuous phase can be formed so that they are stable over a wide temperature range and have intermediary properties between flexible and stiff microemulsions. Three components (1-ethyl-3-methylimidazolium ethylsulfate ([emim][etSO(4)]), limonene, and octylphenol ethoxylate (Triton X 100, abbreviated as TX-100)) were used. This ternary system has been characterized from ambient temperature down to -10 °C by means of conductivity, viscosity, and small-angle X-ray scattering (SAXS) measurements. The SAXS data exhibit a characteristic single, broad scattering peak in conjunction with a typical q(-4) decay at large q values. The SAXS data have also been interpreted in terms of a dimensionless dilution plot, demonstrating that microstructures are neither isolated droplets nor a random flexible film structure but resemble molten liquid crystals (i.e., they are formed from locally cylindrical or planar structures). This semirigidity is attributed to a good match between the surfactant and the ionic liquid; this holds in a temperature range well below 0 °C.
我们在此证明，可以形成以 IL 作为连续相的微乳液，它们在很宽的温度范围内稳定，并且具有介于柔性和刚性微乳液之间的中间性质。使用了三种成分（1-乙基-3-甲基咪唑硫酸乙酯([emim][etSO(4)])、柠檬烯和辛基酚聚氧乙烯醚（Triton X 100，简称 TX-100））。通过电导率、粘度和小角 X 射线散射（SAXS）测量，该三元体系已从环境温度降至-10°C进行了表征。SAXS 数据显示出一个特征性的单一、宽散射峰，同时在大 q 值处具有典型的 q(-4)衰减。还根据无量纲稀释图解释了 SAXS 数据，表明微结构既不是孤立的液滴，也不是随机的柔性膜结构，而是类似于熔融液晶（即，它们是由局部圆柱形或平面结构形成的）。这种半刚性归因于表面活性剂和离子液体之间的良好匹配；这种情况在远低于 0°C 的温度范围内都存在。
