Polymer Conformation, Dynamics, Morphology

我的研究重点是在可能对现代技术或医学产生影响的领域，发展关于聚合物作为材料的新的基础科学知识。我们致力于创造和研究在溶液中形成稳定胶体、形状均匀且具有纳米或微米尺寸的聚合物对象。这份提案描述了两个广泛的项目，都是在聚合物材料领域。一种是嵌段共聚物在溶液中的自组装。与I.Manners(英国布里斯托尔)合作，我们发表了开创性的论文，描述了纳米纤维胶束在溶液中史无前例的形成。这项工作在许多方面改变了科学家对嵌段共聚聚合物胶束形成的看法，特别是在形成核心的聚合物是结晶的情况下。在这些研究中，聚二茂铁基硅烷(PFS)是核心形成块。它仍然是唯一一种可以形成长度均匀且可控的纳米线的嵌段共聚物。在这里，我描述了新的实验，以从机械上了解为什么以及如何控制自组装，以及PFS聚合物分子如何在添加到不断增长的胶束末端形成如此微小尺寸的晶体时折叠。由于这些纳米纤维的生长与人类疾病相关的淀粉样纤维的形成具有共同的关键特征，但没有碎裂和聚集的并发症，因此PFS嵌段共聚物胶束生长的动力学研究可以提供有关溶液中影响纳米纤维形成的因素的重要信息。

My research is focused on developing new fundamental scientific knowledge about polymers as materials in areas where one can have an impact on modern technology or medicine. Much of our effort is devoted to the creation and study of polymer objects that form stable colloids in solution, with a uniform well-defined shape and with nanometer or micrometer dimensions. This proposal describes two broad projects, both in the area of polymer materials. One focuses on block copolymer self-assembly in solution. In collaboration with I. Manners (Bristol, UK) we have published seminal papers describing the unprecedented formation of nanofiber micelles in solution. This work has in many ways changed how scientists think about block copolymer micelle formation, particularly when the core-forming polymer is crystalline. In these studies, polyferrocenylsilane (PFS) was the core-forming block. It remains the only type of block copolymer that can form nanowires with a uniform and controllable length. Here I describe new experiments to understand mechanistically why and how such control of self assembly is possible, and how the PFS polymer molecules can fold as they add to the ends of the growing micelles to form crystals of such tiny dimensions. Because the growth of these nanofibers has key features in common with the formation of amyloid fibers associated with human diseases, but without the complications of fragmentation and aggregation, kinetic studies of PFS block copolymer micelle growth could provide important information about factors that affect nanofiber formation in solution.