Experimental Condensed Matter Physics, TU Darmstadt, Germany.
Soft Matter. 2016 Aug 14;12(30):6400-11. doi: 10.1039/c6sm01253a. Epub 2016 Jul 15.
The bending modulus κ is known to be a crucial parameter for the stability of the droplet phase in microemulsion systems. For AOT based water in oil microemulsions the bending modulus of the surfactant has values close to kBT but can be influenced by the presence of polymers. In this work we focus on the water soluble polymer polyethylene glycol and how it influences the bending modulus. An increase by a factor of three is found. For the correct evaluation of the bending modulus via percolation temperatures and droplet radii, thus by dielectric spectroscopy and small angle X-ray scattering, the determination of the radii right at the percolation temperature is crucial as we will show, although it is often neglected. In order to precisely determine the droplet radii we will present a global fitting model which provides reliable results with a minimum number of free fitting parameters.
弯曲弹性模量 κ 是影响微乳液体系中液滴相稳定性的关键参数。对于基于 AOT 的油包水乳状液，表面活性剂的弯曲弹性模量接近 kBT，但可以受到聚合物的影响。在这项工作中，我们关注水溶性聚合物聚乙二醇以及它如何影响弯曲弹性模量。我们发现弯曲弹性模量增加了三倍。为了通过渗流温度和液滴半径（即通过介电谱和小角 X 射线散射）正确评估弯曲弹性模量，因此需要在渗流温度下精确确定半径，正如我们将展示的，尽管这经常被忽略。为了精确确定液滴半径，我们将提出一个全局拟合模型，该模型使用最少的自由拟合参数提供可靠的结果。
