21 research outputs found
Asymmetric Catalysis in Liquid Confinement: Probing the Performance of Novel Chiral RhodiumâDiene Complexes in Microemulsions and Conventional Solvents
Nonionic Surfactants with Linear and Branched Hydrocarbon Tails: Compositional Analysis, Phase Behavior, and Film Properties in Bicontinuous Microemulsions
Dynamics of the interfacial film in bicontinuous microemulsions based on a partly ionic surfactant mixture: A neutron spin-echo study
Wellert S, Altmann H-J, Richardt A, et al. Dynamics of the interfacial film in bicontinuous microemulsions based on a partly ionic surfactant mixture: A neutron spin-echo study. The European Physical Journal E. 2010;33(3):243-250.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 kappa of the film. The approach is subsequently applied to follow changes of kappa as induced by changes of the alcohol concentration