US-Czechoslovakia Research on Dynamic Light Scattering from Block Copolymer Liquids near the Order-Disorder Transition

明尼苏达双城大学的Timothy P.Lodge博士和捷克斯洛伐克科学院的P.Stepanek博士之间的这个美国-捷克斯洛伐克研究项目将对嵌段共聚液体的动力学进行广泛的实验研究。他们的焦点将是弱隔离制度，定义为包括秩序-无序转变以及附加的有序和无序状态。研究人员将使用动态光散射来研究嵌段共聚物熔体和溶液，特别是：链长和浓度；嵌段共聚物组成；链段-链段相互作用参数；以及温度。他们将特别注意出现在实验关联函数中的模式的数目、角度相关性和识别。所涉及的大的特征时间常数将带来挑战，这需要各种探索性策略。研究人员将在新兴理论描述的框架内解释结果，预计动态平均场近似不太可能足够。这些测量将补充明尼苏达大学的流变学、流变学、示踪剂扩散和小角散射研究。这个化学项目通过使美国和东欧的顶尖专家能够将互补的人才结合在一起，并在相互感兴趣和能力很强的领域汇集资源，从而实现了促进科学知识的计划目标。

This U.S.-Czechoslovakia research project between Dr. Timothy P. Lodge of the University of Minnesota-Twin Cities and Dr. P. Stepanek of the Czechoslovak Academy of Sciences will be to perform extensive experimental examination of the dynamics of block copolymer liquids. Their focus will be the weak segregation regime, defined to incorporate order-disorder transition and the adjunct ordered and disordered states. The researchers will use dynamic light scattering to investigate both block copolymer melts and solutions, especially: chain length and concentration; block copolymer composition; the segment-segment interaction parameter; and temperature. They will pay particular attention to the number, angular dependence, and identification of the modes which appear in the experimental correlation functions. The large characteristic time constants involved will pose challenges which demand various exploratory stategies. The researchers will interpret the results in the framework of emerging theoretical descriptions, anticipating that dynamical mean-field approximations are unlikely to be adequate. These measurements will complement rheological, rheo-optical, tracer diffusion, and small-angle scattering studies at the University of Minnesota. This project in chemistry fulfills the program objective of advancing scientific knowledge by enabling leading experts in the United States and Eastern Europe to combine complementary talents and pool resources in areas of strong mutual interest and competence.