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© 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A neutron spin echo (NSE) experiment was performed in order to clarify the droplet density dependence of the dynamic structures in a ternary microemulsion system consisting of AOT, water and decane. At the droplet concentration, [lowercase_phi_synonym], of 0.05, the dynamic mode due to the peanuts-like deformation of water droplets and the translational diffusion of them were analyzed, and the estimated decay time for the droplet deformation was about 10 ns. At [lowercase_phi_synonym] = 0.3, another dynamical mode due to the packing properties of water droplet is expected to be observed. Assuming that the deformation motion of the water droplets was independent of [lowercase_phi_synonym], the dynamical mode due to the structure factor was estimated. The order of the decay time was one order of magnitude larger than that of the droplet deformation, and was smaller than that of the translational diffusion. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

A bending modulus of surfactant monolayers in a microemulsion system composed of AOT, D2O and deuterated decane were investigated by means of neutron spin echo. In this system, a water-in-oil droplet structure at ambient temperature and pressure decomposes into two-phases both with increasing temperature and pressure. However, the bending modulus slightly decreased with increasing temperature while it increased with increasing pressure. This behavior was explained in terms of a microscopic model proposed by Würger (Phys. Rev. Lett. 85 (2000) 337). It was confirmed that an increase of an interaction between hydrocarbon tails of AOT molecules with increasing pressure could be an origin of the pressure-induced phase transition. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

In order to study slow dynamics of lipid bilayers, neutron spin echo (NSE) experiments were carried out on the dilute lamellar phase in the DPPC/D2O/CaCl2 system. From the NSE results, we estimated the bending modulus κ of the bilayer using the theory presented by Zilman and Granek (Phys. Rev. Letters 77 (1996) 4788). The estimated values of κ decrease monotonically with increasing temperature and with increasing the lamellar repeat distance d1. They depend strongly on d1 though d1 is longer than 500Å. We discuss validity of the theory for the analysis of the NSE results. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]