CAREER: Block Copolymer/layered Silicate Nanocomposites: Thermodynamics, Dynamics, and Structure-Property Relationships

ARRA声明：该奖项是根据2009年《美国复苏和再投资法案》(Public Law 111-5)资助的。技术摘要：该奖项支持一个探索新型聚合物复合材料的项目，该聚合物复合材料是由嵌段共聚物密集接枝到高度剥离的层状硅酸盐颗粒表面组成的。PI假设这种新型材料，即嵌段共聚物/层状硅酸盐(BCPLSS)，有可能导致高性能/高使用温度的聚烯烃工程热塑性塑料具有前所未有的材料性能，这是多种因素协同作用的结果：硅酸盐颗粒提供的机械增强，链构象扰动引起的增强的热性能，以及嵌段共聚物将多种材料性能缝合成单一化合物的能力。在BCPLS材料中，每个填料颗粒都紧密地耦合到密集的高分子链上；因此，新出现的性质不仅来自机械增强机制，还源于对高聚物链构象特征的内在扰动。使用嵌段共聚物是有利的，因为这通过选择组成嵌段和嵌段顺序赋予系统这些迷人材料的固有可调谐性，并带来高于有序-无序转变的高度加工性。此外，BCP被限制在离散的层状硅酸盐颗粒的相对面上，从根本上改变了自组装的热力学和所产生的形貌。这种独特的功能组合目前还没有出现在社区中，这项研究是一个重要的机会，可以为从根本上理解和利用这些新材料做出开创性的贡献。非技术总结：该职业奖支持一个项目，该项目旨在探索一种新型的聚合物复合材料，该复合材料由嵌段共聚物密集地接枝到高度剥离的层状硅酸盐颗粒的表面组成。PI假设这种新型材料--嵌段共聚/层状硅酸盐(BCPLSS)有可能导致具有前所未有的材料性能的高性能/高使用温度的聚烯烃基工程热塑性塑料。在BCPLS材料中，每个填料颗粒紧密地耦合到一簇密集的聚合物链上，除了众所周知的复合增强机制外，还通过约束聚合物链的构象来消除颗粒聚集并增强性能。该项目将产生利用这些材料潜力所需的基本知识。另一个重要目标是提高对K？12水平STEM职业的认识和兴趣。这将通过将这项研究整合到指导K？12科学教师的校园计划中来实现，并合作开发互动研讨会，使用爱荷华州通信网络以电子方式提供给整个爱荷华州的K？12课堂。

ARRA STATEMENT:This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).TECHNICAL SUMMARY:This CAREER award supports a project to explore a new class of polymer composites, comprised of block copolymers densely grafted to the surfaces of highly exfoliated layered silicate particles. The PI hypothesizes that this novel class of materials, block copolymer/layered silicates (BCPLSs), holds the potential to lead to high performance/high service temperature polyolefin-based engineering thermoplastics with unprecedented materials properties, arising from a synergistic combination of factors: Mechanical reinforcement provided by the silicate particles, enhanced thermal properties arising perturbations to the chain-conformations, and the ability of block copolymers to stitch multiple materials properties into a single compound. In BCPLS materials each filler particle is intimately coupled to a dense brush of polymer chains; consequently, emergent properties arise not only from mechanical reinforcement mechanisms but also intrinsic perturbations to conformational characteristics of the polymer chain. The use of block copolymers is advantageous since this imparts to the system the inherent tunability of these fascinating materials through the choice of constituent blocks and block sequences, and brings high degrees of processability above the order-disorder transition. Moreover, the confinement of BCPs to the opposing faces of discrete layered silicate particles fundamentally changes the thermodynamics of self-assembly and the resultant morphologies. This unique combination of features is currently absent from the community, and this research is an important opportunity to make seminal contributions to the fundamental understanding and utilization of these new materials.NON-TECHNICAL SUMMARY:This CAREER award supports a project to explore a new class of polymer composites, comprised of block copolymers densely grafted to the surfaces of highly exfoliated layered silicate particles. The PI hypothesizes that this novel class of materials, block copolymer/layered silicates (BCPLSs), holds the potential to lead to high performance/high service temperature polyolefin-based engineering thermoplastics with unprecedented materials properties. In BCPLS materials each filler particle is intimately coupled to a dense brush of polymer chains, eliminating particle aggregation and enhancing the properties by constraining the conformations of the polymer chains, in addition to well-known composite reinforcement mechanisms. This project will generate the fundamental knowledge needed to harness the potential of these materials. Another important objective is to heighten awareness of and interest in STEM careers at the K?12 level. This will be accomplished by integrating this research into an on-campus program for mentoring K?12 science teachers, and the collaborative development of interactive workshops to be delivered electronically to K?12 classrooms throughout Iowa using the Iowa Communications Network.