Wellert S, Altmann H-J, Richardt A, Lapp A, Falus P, Farago B, Hellweg T
Helmholtz-Center Berlin for Energy and Materials, Berlin, Germany.
Eur Phys J E Soft Matter. 2010 Nov;33(3):243-50. doi: 10.1140/epje/i2010-10668-1.
In a microemulsion system based on a mixture of nonionic and ionic surfactants the addition of alcohol instead of changing the temperature was used to tune the curvature of the surfactant interface. The influence of the addition of the short-chain alcohol 2-propanol in the system water-perchloroethylene- Marlowet IHF-2-propanol is studied using neutron spin-echo spectroscopy. In contrast to alcohols with long alkyl chains 2-propanol is no strong co-surfactant, but changes the properties of the solvents. The present contribution focuses on the bicontinuous phase in this system and a quantitative analysis of the obtained neutron spin-echo data is proposed within the theoretical framework given by Zilman and Granek for amphiphilic membranes. It turns out that, in addition to the local movements of the surfactant film, also a collective diffusional mode of the bicontinuous structure has to be taken into account. The presented approach allows to calculate the bending elastic constant κ of the film. The approach is subsequently applied to follow changes of κ as induced by changes of the alcohol concentration.
在基于非离子和离子表面活性剂混合物的微乳液体系中，通过添加醇而非改变温度来调节表面活性剂界面的曲率。使用中子自旋回波光谱研究了在水 - 全氯乙烯 - Marlowet IHF - 2 - 丙醇体系中添加短链醇2 - 丙醇的影响。与具有长烷基链的醇不同，2 - 丙醇不是强助表面活性剂，而是改变了溶剂的性质。本文的研究重点是该体系中的双连续相，并在Zilman和Granek给出的两亲性膜理论框架内，对获得的中子自旋回波数据进行定量分析。结果表明，除了表面活性剂膜的局部运动外，还必须考虑双连续结构的集体扩散模式。所提出的方法可以计算膜的弯曲弹性常数κ。随后应用该方法跟踪由醇浓度变化引起的κ的变化。
