NIRT: Multiphase Functional Nanomaterials

这个纳米级跨学科研究团队（NIRT）奖涉及塔斯基吉大学、阿拉巴马大学伯明翰分校（UAB）和康奈尔大学的参与者之间的合作，由美国国家科学基金会材料研究、化学、土木和机械系统、制造和工业创新以及电气和通信系统部门共同资助。许多新型工程材料是纳米和亚纳米尺度上具有各向异性结构的复合材料。虽然许多学术研究都致力于均相双组分纳米复合材料的合成和表征，但很少有人注意到当纳米结构添加到多相聚合物材料中时，会产生重要的协同效应。纳米结构的可控集成，可以相容、排列或改变多组分聚合物混合物的晶体形态，极大地提高了传统纳米复合材料的物理复杂性，并为纳米尺度上的材料设计提供了新的策略。拟议研究的目的有三个方面。首先，基于单组分和多组分聚合物混合物中分散的各向异性纳米结构，开发一类新型功能纳米复合材料。其次，提高对表面功能化纳米结构如何影响多相聚合物材料的相行为、晶体形态、流变学、固化动力学和性能的基本理解。最后，量化加工剪切场和聚合物颗粒相互作用对合成聚合物中各向异性纳米结构取向和空间分布的影响。我们的工作将集中在分散在模型聚合物体系中的表面功能化碳纳米管（CNT）和二氧化硅纳米棒。每个系统将被选择为基本的纳米复合基序引入更大程度的复杂性，为利用各向异性纳米结构在纳米尺度上控制聚合物结构的方法提供新的见解。智力价值：提出的研究是重要的科学和实际原因。例如，我们的工作利用了已知的高表面/体积比的纳米结构来同时相容和增强聚合物混合物。我们还首次研究了加工剪切场如何影响分散在聚合物宿主中的纳米颗粒的空间分布，以及如何利用这些效应来创建具有新型核/壳输运性质的宏观物体。这项研究也是第一个利用固态变形在纳米复合材料中排列纳米结构和聚合物分子的研究。如果成功，这项工作将提高对纳米复合材料的基本理解，并将有助于提高制造具有分级特性的聚合物的技术水平。更广泛的影响：塔斯基吉大学、UAB大学和康奈尔大学参与拟议研究的学生将在材料化学、材料物理、多相聚合物液体的流动行为和纳米结构材料的固态特性方面获得独特的、基础广泛的教育。来自我们学校的学生将花时间与来自其他学校的NIRT团队成员一起工作。这将促进参与教师之间更深层次的合作研究关系，并将提高提供给研究生和本科生的学习体验的质量。两所大学的学生还将接触到纳米结构材料科学和加工方面的课程。推广工作将包括让K-12学生接触纳米科学技术的活动。

This nanoscale interdisciplinary research team (NIRT) award involves collaboration between participants at Tuskegee University, University of Alabama at Birmingham(UAB) and Cornell University, and is co-funded by the NSF Divisions of Materials Research, Chemistry, Civil and Mechanical Systems, Manufacturing and Industrial Innovation, and Electrical and Communication Systems. Many new engineering materials are composites with anisotropic structure on nanometer and sub-nanometer length scales. While much academic research has been devoted to synthesis and characterization of homogeneous two-component nanocomposite materials, very little attention has been given to understanding and exploiting important synergistic effects that arise when nanostructures are added to multiphase polymer materials. Controlled integration of nanostructures that can compatibilize, align, or alter the crystalline morphology of multi-component polymer mixtures dramatically increases the physical sophistication of conventional nanocomposite materials and provides new strategies for materials design on the nanoscale. The objective of the proposed research is three-fold. First, to develop a new class of functional nanocomposite materials based on dispersed anisotropic nanostructures in single-component and multi-component polymer mixtures. Second, to improve fundamental understanding of how surface functionalized nanostructures affect phase behavior, crystalline morphology, rheology, curing kinetics, and properties of multiphase polymeric materials. Finally, to quantify the effect of processing shear fields and polymer particle interactions on alignment and spatial distribution of anisotropic nanostructures in synthetic polymers. Our work will focus on surface-functionalized carbon nanotubes (CNT) and silica nanorods dispersed in model polymer systems. Each system will be chosen to introduce progressively greater degrees of complexity to the basic nanocomposite motif, providing new insight into methods for controlling polymer structure at the nanoscale using anisotropic nanostructures. Intellectual Merit: The proposed research is important for scientific as well as practical reasons. Our work, for example, exploits the known high surface/volume ratio of nanostructures to simultaneously compatibilize and reinforce polymer mixtures. We also study, for the first time, how processing shear fields influence the spatial distribution of dispersed nanoparticles in polymer hosts and how these effects can be exploited to create macroscopic objects with novel core/shell transport properties. The proposed study is also among the first to utilize solid-state deformation to align nanostructures and polymer molecules in a nanocomposite material. If successful, this work will improvefundamental understanding of nanocomposite materials and will help advance the state ofthe art for creating polymers with graded property profiles.Broader Impact: Students at Tuskegee, UAB and Cornell that participate in the proposed research will receive unique, broad-based education in materials chemistry, materials physics, flow behavior of multiphase polymer liquids, and solid state properties of nanostructured materials. Students from our institutions will spend time working with a NIRT team member from another institution. This will foster deeper collaborative research relationships among participating faculty and will enhance the quality of the learning experience provided to our students, both graduate and undergraduate. Students at each university will also be exposed to courses in nanostructured materials science and processing. Outreach efforts will include activities involving exposure of K-12 students to nanoscale science and technology.