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

这个美国-捷克斯洛伐克的研究项目之间博士蒂莫西P。 明尼苏达大学双城分校和P。 捷克斯洛伐克科学院的斯捷潘内克将在 进行广泛的实验检查的动力学 嵌段共聚物液体。 他们的重点将是弱隔离 制度，定义为包括有序-无序过渡和 辅助有序和无序状态。 研究人员将使用 动态光散射研究两种嵌段共聚物熔体 和解决方案，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;和温度。 他们会特别注意 模式的数量、角度依赖性和识别 出现在实验相关函数中。 大 所涉及的特征时间常数将带来挑战， 需要各种探索策略。 研究人员将 在新兴的理论框架中解释结果 描述，预计动态平均场近似 不太可能足够。 这些措施将补充 流变学、流变光学、示踪剂扩散和小角度 明尼苏达大学的散射研究。 这个化学项目实现了以下计划目标： 促进科学知识的发展， 美国和东欧将联合收割机互补 在共同感兴趣的领域汇集人才和资源， 能力。

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.