Collaborative Research: Unusual Temperature Dependent Behavior of Polymer Nanocomposites

合作研究：聚合物纳米复合材料异常的温度依赖性行为

• 批准号: 1538725
• 负责人: Pinar Akcora
• 金额: $ 23.56万
• 依托单位: Stevens Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1538725&HistoricalAwards=false
• 关键词: Collaborative; Research; Unusual; Temperature; Dependent

Integration of nanoparticles into polymers leads to enhancement in thermal, mechanical and shape changing properties of composite materials. Functionalizing nanoparticle surfaces with polymers that are chemically identical to matrix polymer are commonly employed in conventional polymer composites simply to control particle dispersion. However, maintaining dispersion and mechanical properties during high temperature processing and applications holds a critical importance in manufacturing and performance of polymeric products. This grant focuses on understanding the role of particle-polymer interactions on dispersion, mechanical properties and processing. Towards this goal, the PIs will focus on a material system design with on-demand control on reversible mechanical response. Reversibly stiffening composites can be used in various applications from soft robotics, flexible electronics to injectable implants where mechanical integrity should be maintained when heated. This collaborative work offers a fundamental research plan integrating the expertise of the PIs on experimental and molecular dynamics simulations on polymer nanocomposites to study the underlying mechanisms. In addition, the project offers to educate graduate and undergraduate students on nanomaterials design and processing. To broaden the knowledge of nanoscience and nanomaterials in high school education, the PIs aim to organize a workshop for teachers in New Jersey and New York area.The team aims to explore the phenomenon of reversible stiffening in polymer nanocomposites. It is hypothesized that particles coated with a high glass transition temperature (Tg) polymer and dispersed in a low-Tg polymer exhibit liquid-to-solid transition upon heating. Experimental work is designed to show the universality of this behavior in various miscible blends with different glass-transition temperature differences. The phenomenon will be employed on magnetic nanoparticles to demonstrate that the mechanical behavior can be regulated with local heating of particles. Moreover, additional experiments to relate the local viscosity and particle relaxations in asymmetric blends on interphases are planned in order to capture the physics and mechanical response in the experimental system design. Simulations will run in parallel and will be used to guide the material design and more importantly will identify the atomistic scale physics that leads to stiffening at high temperatures. Processing studies will be conducted to understand the stability of interphase layers, and composite structure (morphology) and properties after processing. The processing results are very relevant for the material design such as for biomedical implants where materials will experience frequent and controlled dynamic loadings during their intended use for in vivo bone formation.

将纳米颗粒整合到聚合物中会导致复合材料的热，机械和形状变化性能的增强。与基质聚合物在化学上相同的聚合物功能化纳米颗粒表面通常仅在传统的聚合物复合材料中仅用于控制颗粒分散。但是，在高温加工过程中保持分散和机械性能在聚合产品的制造和性能中至关重要。该赠款专注于理解粒子聚合物相互作用在分散，机械性能和加工方面的作用。为了实现这一目标，PI将专注于具有对可逆机械响应的按需控制的材料系统设计。可逆性化的复合材料可用于从软机器人，柔性电子设备到可注射的植入物的各种应用中，在加热时应保持机械完整性。这项协作工作提供了一个基本的研究计划，该计划将PI的专业知识整合在聚合物纳米复合材料上的实验和分子动力学模拟上，以研究基本机制。此外，该项目还提供了纳米材料设计和处理的毕业生和本科生的教育。为了扩大高中教育中纳米科学和纳米材料的了解，PIS旨在组织新泽西州和纽约地区教师的研讨会。该团队旨在探索聚合物纳米组合物中可逆僵硬的现象。假设涂有高玻璃过渡温度（TG）聚合物并分散在低TG聚合物中的颗粒在加热时表现出液体向固体过渡。实验性工作旨在显示这种行为的普遍性，这些混合物具有不同的玻璃转换温度差异。该现象将用于磁性纳米颗粒上，以证明可以通过颗粒的局部加热来调节机械行为。此外，计划在相互重点上与不对称混合物中局部粘度和粒子放松相关的其他实验，以捕获实验系统设计中的物理和机械响应。模拟将平行运行，并将用于指导材料设计，更重要的是，将确定在高温下导致僵硬的原子量表物理。将进行加工研究，以了解相间层，复合结构（形态）和加工后的性质的稳定性。处理结果与材料设计非常相关，例如生物医学植入物，在其在体内骨形成期间，材料在其预期使用期间会经历频繁和受控的动态载荷。