| Co-Investigator(Kenkyū-buntansha) |
MONKENBUSCH Michael Germany, Forschungszentrum Julich GmbH,Research Associate, 固体物理部, 研究員
RICHTER Dieter Germany, Forschungszentrum Julich GmbH,Professor, 固体物理部, 教授
SETO Hideki Hiroshima University, Faculty of Integrated Arts and Sciences, Research Associat, 総合科学部, 助手 (60216546)
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| Research Abstract |
We have been improving a neutron spin echo (NSE) spectrometer at CZ_2 port of JRR-3M, JAERI.Performance tests of the new monochromator constructed in collaboration with ILL, Grenoble, France and HMI, Berlin, Germany indicate a threefold increase in polarized neutron flux at the sample compared to the previous one. Our NSE experiments using MESS at LLB in Saclay, France showed that the performance of our NSE spectrometer was comparable to that of MESS.In order to further gain neutron intensity, we have been installing a detector system with an assembly of position sensitive detectors.
NSE experiments have been performed to study the slow dynamics such as membrane undulation in Complex Fluids involving amphiphiles. Intermediate correlation functions I(Q,t) obtained from our IiSE.experiments were well fitted to the equation I(Q,t) =I(Q,O)[(GAMMAt)2/3] for the dipalmitoylphosphatidylcholine (DPPC)-water-CaCl_2 system and for the low temperature and high temperature bicontinuous microemulsion phases and the lamella phase of the nonionic surfactant C_<12>E_5/ n-octane / water system, and also for the dense droplet phase of, the temperature-induced and the pressure-induced lamella phases of the ionic swfactant AOT / n-decane / water system. The relaxation rate GAMMA increased as Q_3. From these results, the theory of Zilman and Granek, in which they use the Heifrich bending free energy to describe membrane undulations in sponge and lamellar phases, was first supported by o ur NSE experiments. We estimated the bending modulus of the membranes using their theory. For aqueous solutions of non-ionic surfactant C_<16>E_7 with wormlike micelles, the results that I(Q,t) =I(Q,O)[(GAMMAt)3/4]and GAMMA increased as Q ^<8/3> are also explained by their theory for 1-dimensional polymer-like model.
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