Slow Dynamics in Complex Fluids

我们一直在改进JRR-3M的CZ_2端口的中子自旋回波(NSE)谱仪。与法国格勒诺布尔的ILL和德国柏林的HMI合作建造的新单色仪的性能测试表明，与以前的样品相比，样品的极化中子通量增加了三倍。我们在法国萨克莱的LLB使用MESS进行的NSE实验表明，我们的NSE光谱仪的性能与MESS相当。为了进一步获得中子强度，我们一直在安装一个带有位置灵敏探测器的探测器系统。NSE实验已经被用来研究包含两亲分子的复杂流体中的慢动力学，如膜波动。对于二棕榈酰磷脂酰胆碱(DPPC)-水-CaCl2体系，对于非离子表面活性剂C_(12&gt；12&gt；E_5/n-辛烷/水体系)的低温和高温双连续微乳液相和薄层相，以及离子表面活性剂AOT/正庚烷/水体系的致密液滴相、温度诱导和压力诱导薄层相，我们的实验得到的中间关联函数I(q，t)=I(q，O)=I(q，O)[(GAMMAt)2/3]。由这些结果，首次支持了Zilman和Granek提出的用Heifrich弯曲自由能描述海绵相和片层相薄膜起伏的理论。我们用它们的理论估算了膜的弯曲模数。对于具有蠕虫状胶束的非离子表面活性剂C&lt；16&gt；E_7的水溶液，I(q，t)=I(q，O)[(GAMMAt)3/4]和伽马随Q^&lt；8/3&gt；增大的结果也可用一维类聚合物模型的理论来解释。

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.