Superdiffusion in high viscosity liquids

高粘度液体中的超扩散

• 批准号: 0906697
• 负责人: Simon Mochrie
• 金额: $ 34.5万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0906697&HistoricalAwards=false
• 关键词: Superdiffusion; viscosity; liquids

****NON-TECHNICAL ABSTRACT****Since Einstein?s original work on Brownian motion 100 years ago, random walks and diffusion have stood as paradigms for how scientists understand the motions of microscopic particles. Recently it has emerged that in highly viscous fluids, ordinary diffusion is superceded by a previously unrecognized and still incompletely characterized process, in which the particles move further than expected on the basis of diffusion. Such motion is therefore described as superdiffusive. This project will systematically elucidate superdiffusive particle motions of collections of particles as well as at the single particle level using state-of-the-art x-ray and optical techniques. The proposed experiments will create new knowledge and motivate new theoretical descriptions of the dynamics of particles and particle suspensions in highly viscous fluids. This will transform our understanding of highly viscous fluids, whose properties give rise to superdiffusion in a way that is not currently understood. The research will also inform programmatic and technical decisions to be made about the next generation of national x-ray facilities, and it will support the education PhD students, who will learn how to do the best possible science at these facilities, fulfilling a vital national need for such trained individuals.****TECHNICAL ABSTRACT****Brownian motion, random walks and diffusion are paradigms of how we understand the dynamics of condensed matter systems. Recently it has emerged that in highly viscous fluids, ordinary diffusion is superceded by a previously unrecognized and still incompletely characterized process, for which the particle's mean-square displacement varies, not linearly in time, as it does for diffusion, but faster than linearly in time. Such motion is therefore described as superdiffusive. This project will systematically elucidate superdiffusive particle dynamics at the ensemble level using x-ray photon correlation spectroscopy, and at the single particle level by using back-focal-plane interferometry. The proposed experiments will create new knowledge and motivate new theoretical descriptions of the dynamics of particles and particle suspensions in highly viscous fluids. This will be transformative to our understanding of highly viscous fluids, whose properties give rise to superdiffusion in a way that currently is not understood. This research will also inform programmatic and technical decisions to be made about the next generation of national x-ray facilities, and it will support the education PhD students, who will learn how to do the best possible science at these facilities, fulfilling a vital national need for such trained individuals.

****非技术摘要****自从 100 年前爱因斯坦首次研究布朗运动以来，随机游走和扩散一直是科学家理解微观粒子运动的范例。最近发现，在高粘性流体中，普通扩散被先前未被识别且仍不完全表征的过程所取代，其中颗粒在扩散的基础上移动得比预期更远。 因此，这种运动被描述为超扩散的。该项目将利用最先进的 X 射线和光学技术系统地阐明粒子集合以及单粒子水平的超扩散粒子运动。所提出的实验将创造新知识并激发对高粘性流体中颗粒和颗粒悬浮液动力学的新理论描述。这将改变我们对高粘性流体的理解，高粘性流体的特性会以目前尚不了解的方式产生超扩散。该研究还将为下一代国家 X 射线设施的规划和技术决策提供信息，并将支持教育博士生，他们将学习如何在这些设施中进行尽可能最好的科学研究，满足国家对此类训练有素的个人的重要需求。****技术摘要****布朗运动、随机游走和扩散是我们如何理解凝聚态物质系统动力学的范例。最近发现，在高粘性流体中，普通扩散被先前未被识别且仍不完全表征的过程所取代，其中粒子的均方位移不像扩散那样随时间线性变化，而是比随时间线性变化更快。 因此，这种运动被描述为超扩散的。该项目将使用 X 射线光子相关光谱在系综水平上系统地阐明超扩散粒子动力学，并使用后焦平面干涉测量法在单粒子水平上系统地阐明超扩散粒子动力学。所提出的实验将创造新知识并激发对高粘性流体中颗粒和颗粒悬浮液动力学的新理论描述。这将彻底改变我们对高粘性流体的理解，高粘性流体的特性会以一种目前尚不了解的方式引起超扩散。这项研究还将为下一代国家 X 射线设施的规划和技术决策提供信息，并将支持教育博士生，他们将学习如何在这些设施中进行尽可能最好的科学研究，满足国家对此类训练有素的人员的重要需求。