Phase Behavior and Nanoscale Morphology of Multiblock Copolymers and Biological Gels

本研究的总体重点是应用散射技术来研究的相行为和动力学的有序-无序和有序-有序的相变在多嵌段共聚物在选择性溶剂中使用小角中子散射（SANS），小角X射线散射（SAXS），原子力显微镜（AFM），和计算机模拟方法。本研究的一个主要重点将是使用基于同步加速器的时间分辨SAXS遵循的结构特征的时间演化，并将它们与成核和生长动力学的无序-有序过渡和不同有序状态之间的过渡的理论模型。我们也将开始初步的研究，使用AFM成像来表征这些微相分离材料的薄膜的表面形态。拟议的研究将提供详细的洞察力的动力学相分离机制参与这些不同的过渡，以及在胶束本身的增长所涉及的机制。了解多嵌段共聚物溶液和凝胶的相行为对于它们在材料科学和技术中的众多应用是重要的。一个令人兴奋的潜在应用是将它们用作固态器件的纳米光刻的模板。建议的AFM和SAXS研究嵌段共聚物膜有直接关系的潜在应用，这些电影在纳米光刻。该研究还将导致在设计和建造用于束线设施的专用组件和具有广泛适用性的数据分析程序方面取得进展。拟议的研究将导致两名研究生（包括一名美国女学生）的博士论文，并为本科生提供研究机会。该项目还涉及与捷克共和国科学家的国际合作。

The overall focus of this research is to apply scattering techniques to examine the phase behavior and kinetics of order-disorder and order-order phase transitions in multiblock copolymers in selective solvents using small angle neutron scattering (SANS), small angle x-ray scattering (SAXS), atomic force microscopy (AFM), and computer simulation methods. A major focus of this research will be to use synchrotron based time-resolved SAXS to follow the time evolution of structural features, and relate them to theoretical models of nucleation and growth kinetics of disorder-order transitions and of transitions between different ordered states. We will also initiate preliminary studies using AFM imaging to characterize the surface morphology of films of these micro-phase separated materials. The proposed research will provide detailed insight into the kinetics of the phase separation mechanisms involved in these different transitions, as well as in the mechanisms involved in the growth of micelles themselves. An understanding of the phase behavior of multiblock copolymer solutions and gels is important to their numerous applications in materials science and technology. An exciting potential application is to use them as templates for nanolithography of solid state devices. The proposed AFM and SAXS studies of block copolymer films have direct relevance to the potential application of these films in nanolithography. The research will also lead to advances in designing and building specialized components for use at beam line facilities and data analysis programs with a wide range of applicability. The proposed studies will lead to the Ph. D dissertations of two graduate students (including one female American student) and provide research opportunities for undergraduates. The project also involves international collaboration with scientists in Czech Republic.