New Photonic Materials from Comb Block Copolymers assembled in the Solid State

技术概要：该提案描述了梳形嵌段共聚物在固态下组装成有序阵列以形成新的光子材料的研究。梳形嵌段共聚物具有聚合物主链和规则且密集间隔的聚合物臂，并且由于这种几何形状，这些聚合物具有通常高于一百万克/摩尔并且可以超过五千万克/摩尔的高分子量。尽管它们的大小，这些聚合物组装成有序的形态在固态与域的大小（重复单元的大小）超过100纳米，对于一些梳形嵌段共聚物，高达250纳米。这项工作是非常原始的几个原因。首先，这些聚合物是相对较新的聚合物结构，其具有对于线性嵌段共聚物而言难以合成的分子量和几何形状。第二，这些聚合物在固态下组装成有序的形态，尽管基于它们的分子量的预测。在这个领域中的共同信念是，聚合物具有100分子量不会组装，但这种信念是基于线性嵌段共聚物的假设。由于梳形嵌段共聚物独特的几何形状，这些假设不适用于梳形嵌段共聚物，因此它们改变了聚合物可以组装的限制，重要的是，为组装高分子量共聚物提供了新的机会。第三，这些聚合物在固态组装后形成新的光子材料。由于聚合物在高端光学应用中的潜在重要性，这一结果至关重要。梳形嵌段共聚物在没有添加剂的情况下组装，它们的组装可以比用通常相分离并形成缺陷的添加剂组装的典型线性嵌段共聚物更有序。在这个提议中，梳形嵌段共聚物的组装成有序阵列和它们的光学性质将被研究。这项工作既有基本的应用程序，组装一个新的结构的嵌段聚合物和实际应用获得新的光子材料。非技术总结：该提案描述了自发组装成新的、潜在的非常重要的光学材料的新聚合物。聚合物和光学的结合是一个令人兴奋的前沿，在下一代计算机中有许多潜在的高端应用，这些计算机使用光而不是电子，当前和未来的传感器很容易集成到便携式设备中，材料可以加速使用光的信息传输，以及更多的科学和技术领域。这项工作描述了使用一个强大的概念（自组装）来创建有序的聚合物阵列，这些聚合物阵列以可预测的方式与光相互作用，有时甚至是新的方式。在直接应用中，这些聚合物将允许精确的原子调谐，以真实的时间感测金属和可能的毒素的存在。这项工作是可能的，因为这些聚合物可以在分子水平上控制，以整合分子，这些分子将改变聚合物的光学特性，以响应应力或刺激。此外，这项建议将对包括许多妇女和少数民族在内的大学生的教育产生直接影响。一个新的班级将在爱荷华州大学开始，这将鼓励新生和新生参与研究，这将拓宽他们的视野，促进他们的教育。

TECHNICAL SUMMARY: This proposal describes research on the assembly of comb block copolymers into ordered arrays in the solid state to form new photonic materials. Comb block copolymers have a polymeric backbone and regularly and densely spaced polymeric arms and, because of this geometry, these polymers have ultrahigh molecular weights that are typically above one million grams per mole and may exceed fifty million grams per mole. Despite their sizes, these polymers assemble into ordered morphologies in the solid state with domain sizes (the size of the repeat unit) in excess of one hundred nanometers and, for some comb block copolymers, up to 250 nm. This work is highly original for several reasons. First, these polymers are a relatively new polymeric architecture that have molecular weights and geometries that are challenging to impossible to synthesize for linear block copolymers. Second, these polymers assemble in the solid state into ordered morphologies despite predictions based on their ultrahigh molecular weights. The common belief in this field is that polymers with ultrahigh molecular weights will not assemble, but this belief is based on assumptions for linear block copolymers. These assumptions do not hold for comb block copolymers due to their unique geometries, so they change the limits of what polymers can be assembled and, importantly, open new opportunities to assemble ultrahigh molecular weight copolymers. Third, these polymers form new photonic materials after their assembly in the solid state. This result is critically important because of the potential importance of polymers in high-end optical applications. Comb block copolymers are assembled without additives, their assembly may be more ordered than typical linear block copolymers assembled with additives that often phase segregate and form defects. In this proposal, the assembly of comb block copolymers into ordered arrays and their optical properties will be investigated. This work has both fundamental applications the assembly of a new architecture of block polymer and practical applications access to new photonic materials. NON-TECHNICAL SUMMARY: This proposal describes new polymers that spontaneously assemble into new, potentially very important, optical materials. The combination of polymers and optics is an exciting frontier with many potential high-end applications in the next generation of computers that use light rather than electrons, current and future sensors that are easily integrated into portable units, materials to speed the transfer of information using light, and many more areas of science and technology. This work describes the use of a powerful concept (self-assembly) to create ordered arrays of polymers that interact with light in predictable and, occasionally, new ways. In immediate applications, these polymers will allow precise atomic tuning to sense the presence of metals and, possibly, toxins in real time. This work is possible because these polymers can be controlled on a molecular level to integrate molecules that will change the optical properties of the polymers in response to a stress or stimuli. In addition, this proposal will make an immediate impact in the education of undergraduates including many women and minorities. A new class will be started at the University of Iowa that will encourage freshman and sophomores to become involved in research that will broaden their horizons and further their education.