Nanoscale Spatio-Temporal Glassy Dynamics

纳米级时空玻璃动力学

• 批准号: 0205258
• 负责人: Nathan Israeloff
• 金额: --
• 依托单位: Northeastern University
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-15 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0205258&HistoricalAwards=false
• 关键词: Nanoscale; Spatio; Temporal; Glassy; Dynamics

This individual investigator award will support a project to investigate the complex dynamics of glassy systems using scanning probe microscopy. In particular fluctuations on nanometer length scales of dielectric and visco-elastic properties as a function of frequency, time, position, electric field, and temperature in polymers and super-cooled liquids will be studied. The goals of the work are to probe individual cooperatively-rearranging-regions (CRR), to understand their structure, detailed dynamics, and their role in glassy phenomena. In addition, nonequilibrium fluctuations will be investigated in aging glassy materials. Theoretical work has predicted that the fluctuation-dissipation-relation will be violated in a model-dependent way in slowly relaxing systems such as glasses. The experiments will investigate the frequency, temperature, and aging-time dependences of these violations in super-cooled liquids and polymers, and thereby constrain theories of the glass transition and aging and advance our understanding of nonequilibrium statistical mechanics. The graduate students involved in this research will be trained in skills that will enable them to pursue future careers in academe or the high-technology industries. In addition, through undergraduate-research-fellowships, cooperative-education, and experiential-education programs, undergraduates will participate in this research, gaining valuable nanoscience experience and preparing them to contribute to important nanotechnologies of the future.When studying the properties of a material by probing ultra-small regions (nearly as small as a molecule), it has been found that properties such as hardness, elasticity, or electrical conductivity can vary considerably from nano-region to nano-region or with time. As nanotechnology is developed over the next few years, these variations will be increasingly important to understand. Nano-properties are also key to a fundamental understanding of disordered materials. Materials such as glass, polymers (plastics), and some metal alloys are called disordered because their molecules are randomly arranged. This individual investigator award will support a project to use advanced scanning probe microscopy techniques to investigate nano-property variations in disordered materials. These studies will advance our understanding of this important but poorly understood class of materials. The graduate students involved in this research will be trained in skills that will enable them to pursue future careers in academe or the high-technology industries. In addition, through undergraduate-research-fellowships, cooperative-education, and experiential-education programs, undergraduates will participate in this research, gaining valuable nanoscience experience and preparing them to contribute to important nanotechnologies of the future.

该个人研究员奖将支持一个使用扫描探针显微镜研究玻璃系统复杂动力学的项目。 特别是，将研究聚合物和过冷液体中介电和粘弹性特性在纳米长度尺度上随频率、时间、位置、电场和温度变化的波动。这项工作的目标是探索单个合作重排区域（CRR），以了解它们的结构、详细的动态以及它们在玻璃现象中的作用。此外，还将研究老化玻璃材料中的非平衡波动。理论工作预测，在缓慢松弛的系统（例如眼镜）中，涨落耗散关系将以依赖于模型的方式被破坏。这些实验将研究过冷液体和聚合物中这些违规行为的频率、温度和老化时间依赖性，从而约束玻璃化转变和老化理论，并增进我们对非平衡统计力学的理解。参与这项研究的研究生将接受技能培训，使他们能够在学术界或高科技行业追求未来的职业生涯。 此外，通过本科生研究奖学金、合作教育和体验式教育项目，本科生将参与这项研究，获得宝贵的纳米科学经验，并为未来的重要纳米技术做出贡献做好准备。在研究材料的特性时通过探测超小区域（几乎与分子一样小），人们发现硬度、弹性或电导率等特性在纳米区域之间或随着时间的推移可能有很大差异。 随着纳米技术在未来几年的发展，理解这些变化将变得越来越重要。纳米特性也是基本了解无序材料的关键。 玻璃、聚合物（塑料）和某些金属合金等材料被称为无序材料，因为它们的分子是随机排列的。 该个人研究员奖将支持一个项目，该项目使用先进的扫描探针显微镜技术来研究无序材料的纳米特性变化。这些研究将增进我们对这一类重要但知之甚少的材料的理解。参与这项研究的研究生将接受技能培训，使他们能够在学术界或高科技行业追求未来的职业生涯。 此外，通过本科生研究奖学金、合作教育和体验式教育项目，本科生将参与这项研究，获得宝贵的纳米科学经验，并为他们为未来的重要纳米技术做出贡献做好准备。