Molecular Modeling of Failure in Polymer Nanocomposites

聚合物纳米复合材料失效的分子模拟

• 批准号: 1536914
• 负责人: Robert Riggleman
• 金额: $ 32.53万
• 依托单位: University of Pennsylvania
• 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 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1536914&HistoricalAwards=false
• 关键词: Molecular; Modeling; Failure; Polymer; Nanocomposites

The availability of light, strong and tough materials is essential for advances in modern engineering and to the technological future of society. Nanocomposite materials consisting of a polymer matrix with distributed nanoparticles are of current interest. These materials can provide significant property improvments relative to the pure polymer. Yet, current continuum mechanics based theories are unable to explain these findings. This award is concerned with fundamental research on the mechanisms that lead to the desireable properties of polymer matrix nanocomposites. The anticipated outcomes of this award will thus allow materials engineers for further advances the science and engineering of nanocomposites and contribute to the general goals of the Materials Genome Initiative. The award also supports associated educational and outreach activities.This award supports research with the goal to uncover how plastic deformation originates, or terminates, near a nanoparticle surface and leads to the formation of shear bands. For amorphous solids it has recently been demonstrated that regions prone to irreversible deformation can be detected from the examination of their internal low frequency vibrational modes. The modes that comprise the so-called boson peak excite the soft regions in the material, or the regions that are most likely to fail under applied load. The present work will begin by characterizing the distribution of these modes around a nanoparticle placed in a model polymer matrix as a function of the particle size and interaction energy with the matrix. Then, a recent computational polymer model exhibiting a ductile-to-brittle transition, the study will investigate how the nanoparticles lead to failure in a pillar geometry. Finally, the goal is to computationally engineer various surface chemistries to enable an ultimately tougher polymer nanocomposite material.

光，强壮和坚固的材料的可用性对于现代工程和社会技术未来的进步至关重要。由具有分布式纳米颗粒的聚合物基质组成的纳米复合材料具有当前感兴趣。这些材料可以相对于纯聚合物提供显着的财产改进。然而，当前基于连续力学的理论无法解释这些发现。该奖项涉及有关导致聚合物基质纳米复合材料的理想特性的基本研究。因此，该奖项的预期结果将允许材料工程师进一步发展纳米复合材料的科学和工程，并为材料基因组计划的一般目标做出贡献。该奖项还支持相关的教育和外展活动。该奖项支持研究，目的是揭示塑料变形如何在纳米颗粒表面附近产生或终止，并导致剪切带的形成。对于非晶态固体，最近已经证明，可以从检查其内部低频振动模式的检查中检测到容易发生变形的区域。包括所谓的玻色子峰的模式激发了材料中的软区域，或最有可能在施加载荷下失败的区域。目前的工作将开始表征这些模式在模型聚合物基质中的纳米颗粒周围的分布，这是粒径和与基质的相互作用能量的函数。然后，这是一种表现出延性到脆性过渡的最新计算聚合物模型，该研究将研究纳米颗粒如何导致支柱几何形状失败。最后，目标是在计算各种表面化学上进行计算，以实现最终更坚硬的聚合物纳米复合材料。