Collaborative Research: Mechanistic understanding and control of soft interfacial nanorheology from molecular simulations and nanoresolved experiments

合作研究：从分子模拟和纳米分辨率实验对软界面纳米流变学的机理理解和控制

• 批准号: 1705738
• 负责人: David Simmons
• 金额: $ 23.82万
• 依托单位: University of Akron
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-15 至 2018-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1705738&HistoricalAwards=false
• 关键词: Collaborative; Research; Mechanistic; understanding; control

CBET 1705738/1706012PIs: Simmons, David S./Priestly, Rodney D.From longer-lasting and safer batteries to strong and lightweight composites for use in airplanes and automobile bodies, many of the materials that could open the door to tomorrow's technologies incorporate structure on the nanometer scale. These materials are not composed of single uniform substance. Instead, these "nanostructured" materials consist of vast numbers of distinct alternating domains, each a thousand times smaller than the thickness of a human hair. With the proper design, these composites have the potential to combine the best properties of multiple materials into one. However, researchers have found the performance of nanostructured materials depends not only on the composition of the nanoscale domains, but also on the interfaces between the domains. The behavior of these interfaces, which are too small to characterize directly with current tools, remains unknown. This collaborative award will support experiments and computer simulations of molecular motion that will focus on these interfaces to understand the origins of their unique properties. The project will determine how these interfaces deform differently than the surrounding materials and how the interfacial deformation can be designed to yield materials with improved performance. The research team will engage high school and undergraduate students in an integrated research experience spanning the University of Akron and Princeton University, accelerating the understanding and discovery of new materials while broadening the U.S. technology workforce.This project aims to 1) establish a mechanistic understanding of gradients in nanoscale rheological properties at polymer/polymer interfaces and their connection to molecular structure, and 2) pioneer a new strategy for the rational control of rheology and mechanics near polymer/polymer interfaces via the introduction of nanoparticle surfactants. A central challenge in accomplishing these goals has been a longstanding inability to resolve directly nanoscale gradients in rheological response near soft interfaces. This research will overcome this challenge via a feedback loop between high-throughput molecular dynamics simulations (Simmons) and experiments (Priestley). Experiments will combine layer-resolved fluorescence spectroscopy with a novel non-contact shear rheology method that enables nanoscale resolution of gradients in rheological properties near polymer interfaces. Simulations will incorporate high-speed coarse-grained simulations and chemically-realistic all-atom simulations. By systematically probing a matrix of polymer and interfacial properties, simulations and experiments will interconnect interfacial thermodynamics, segmental dynamics, and rheological response near polymer/polymer interfaces. These results will be combined with a matrix of simulations and experiments probing the effect of nanoparticle surfactants on interfacial deformation to establish a new mechanism-based strategy for control of interfacial rheological response via the targeted introduction of nanoparticle surfactants. Ultimately, results from this work will accelerate design of materials with targeted interfacial properties and deformation, enabling new nanostructured polymers for applications ranging from next-generation batteries to separations membranes to lightweight structural materials. In addition to engagement of students over a range of levels in a cross-institution training program, the PI's will extend the impact of this research through joint organization of a symposium at a national meeting focused on bridging polymer and interfacial phenomena research communities.

CBET 1705738/1706012PIS：Simmons，David S./priestly，Rodney D.从更长的持久和更安全的电池到强大，轻巧的复合材料，用于飞机和汽车车身，许多材料都可以打开明天的技术在纳米尺度上结合结构。这些材料不是由单一均匀物质组成的。 取而代之的是，这些“纳米结构”材料由大量不同的交替域组成，每千倍比人头发的厚度小。通过适当的设计，这些复合材料有可能将多种材料的最佳特性组合为一种。 但是，研究人员发现，纳米结构材料的性能不仅取决于纳米级域的组成，还取决于域之间的接口。 这些接口的行为太小，无法直接用当前工具来表征，但仍未知。该协作奖项将支持分子运动的实验和计算机模拟，该实验将集中在这些界面上，以了解其独特属性的起源。该项目将确定这些界面的变形与周围材料的变形方式以及如何设计界面变形以产生改善性能的材料。研究团队将与高中和本科生一起参与跨越阿克伦大学和普林斯顿大学的综合研究经验，在扩大美国技术劳动力的同时，加快了对新材料的理解和发现的理解和发现。该项目的目的是1）1）建立对纳米级流感特性的机械理解，以在聚合物/聚合物互联网上的nanoscale ryologalitions and Conterational internotal internotal internotial internotial internotial internolation internotial和2）通过引入纳米颗粒表面活性剂，聚合物/聚合物界面附近的流变学和力学。实现这些目标的核心挑战是长期无法在软接口附近的流变响应中直接解决纳米级梯度。这项研究将通过高通量分子动力学模拟（Simmons）和实验（Priestley）之间的反馈回路克服这一挑战。实验将将层分辨的荧光光谱与一种新型的非接触式剪切流变方法结合在一起，该方法能够在聚合物接口附近的流变特性中纳米级分辨率。模拟将结合高速粗粒模拟和化学真实的全原子模拟。通过系统地探测聚合物和界面特性的基质，模拟和实验将互连界面热力学，节段动力学以及在聚合物/聚合物界面附近的流变响应。这些结果将与模拟矩阵和实验结合，探测纳米颗粒表面活性剂对界面变形的影响，以建立一种基于纳米粒子表面活性剂的基于机制的策略来控制界面性流变响应。最终，这项工作的结果将加速具有针对性界面特性和变形的材料设计，从而使新的纳米结构聚合物用于从下一代电池到分离膜到轻质结构材料的应用。除了在跨机构培训计划中的一系列级别的学生参与外，PI还将通过在全国会议上通过联合组织研讨会来扩展这项研究的影响，该会议的重点是桥接聚合物和界面现象研究社区。