NIRT: Complex Fluids Confined at the Nanoscale

NIRT：限制在纳米尺度的复杂流体

• 批准号: 0403997
• 负责人: Bulbul Chakraborty
• 金额: $ 127.3万
• 依托单位: Brandeis University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0403997&HistoricalAwards=false
• 关键词: NIRT; Complex; Fluids; Confined; Nanoscale

This proposal was received in response to Nanoscale Science and Engineering initiative, NSF 03-043, category NIRT. This theoretical award is supported by the Division of Materials Research and the Chemistry Division. Fluids under extreme confinement exhibit novel dynamical properties which are not simple extensions of the bulk behavior. Intuitively, extreme confinement sets in when the confining dimensions become comparable to the length scales associated with the cooperative motion in the fluids which are typically in the nanometer domain. Understanding the interplay between these natural length scales and the external constraints is the goal of the research outlined in this grant. Constraints can be imposed by the external geometry such as in thin polymer films or liquids in porous media, but can also arise from "crowding" due to other objects as occur naturally in the interior of cells or in supercooled liquids near the glass transition. In all of these systems, temporal evolution involves the motion of extended objects which have internal degrees of freedom. Effective models at the scale of these objects will be constructed; a scale intermediate between the microscopic one characteristic of molecular dynamics simulations and the macroscopic scale of hydrodynamic descriptions. Such a framework provides a useful interface between theory and experiments which use real-space probes to study motion at the nanometer scale. In conjunction with such experiments, a framework relating length scales and time scales will be constructed and used to understand the effects of constraints on the dynamics. Numerical simulations will be used as a stepping stone in the construction of effective dynamical theories. The techniques will be developed in the context of lattice models and then extended to continuum models.The research will provide modeling tools for a range of problems in biology that includes rheology of cells, motion of macromolecules in crowded cell environments, dynamics of the cytoskeleton, to mention a few. On the technological side of things, much effort is currently being expended on miniaturizing and integrating various biochemical techniques for purifying, detecting, and sorting biological molecules, on a single chip. These techniques put front and center one of the central questions addressed by this research: How is the motion of macromolecules affected by extreme confinement? Theoretical tools such as simple models and numerical simulations, combined with experimentation on well controlled systems will contribute to the rational design of these "lab on a chip" technologies.A crucial aspect of the activities is building a community of physicists, chemists and biologists in the Boston area, united by their interest in dynamics of constrained systems. The managing PI has initiated a biannual meeting that brings together students, postdoctoral associates and faculty, in the Boston area, interested in glassy phenomena, broadly construed. These have proven invaluable for exchanging ideas between various groups and exposing students to a range of ideas. The current program builds on this activity by (i) describing a new summer research program aimed at undergraduates from the women's four-year colleges in the Boston area and (ii) enlarging the scope of the biannual meetings to include minicourses which will be a valuable addition to graduate education in the interdisciplinary area of slow dynamics.%%%This proposal was received in response to Nanoscale Science and Engineering initiative, NSF 03-043, category NIRT. This theoretical award is supported by the Division of Materials Research and the Chemistry Division. Fluids under extreme confinement exhibit novel dynamical properties which are not simple extensions of the bulk behavior. Intuitively, extreme confinement sets in when the confining dimensions become comparable to the length scales associated with the cooperative motion in the fluids which are typically in the nanometer domain. Understanding the interplay between these natural length scales and the external constraints is the goal of the research outlined in this grant. Constraints can be imposed by the external geometry such as in thin polymer films or liquids in porous media, but can also arise from "crowding" due to other objects as occur naturally in the interior of cells or in supercooled liquids near the glass transition. In all of these systems, temporal evolution involves the motion of extended objects which have internal degrees of freedom. Effective models at the scale of these objects will be constructed; a scale intermediate between the microscopic one characteristic of molecular dynamics simulations and the macroscopic scale of hydrodynamic descriptions. Such a framework provides a useful interface between theory and experiments which use real-space probes to study motion at the nanometer scale. In conjunction with such experiments, a framework relating length scales and time scales will be constructed and used to understand the effects of constraints on the dynamics. Numerical simulations will be used as a stepping stone in the construction of effective dynamical theories. The techniques will be developed in the context of lattice models and then extended to continuum models.The research will provide modeling tools for a range of problems in biology that includes rheology of cells, motion of macromolecules in crowded cell environments, dynamics of the cytoskeleton, to mention a few. On the technological side of things, much effort is currently being expended on miniaturizing and integrating various biochemical techniques for purifying, detecting, and sorting biological molecules, on a single chip. These techniques put front and center one of the central questions addressed by this research: How is the motion of macromolecules affected by extreme confinement? Theoretical tools such as simple models and numerical simulations, combined with experimentation on well controlled systems will contribute to the rational design of these "lab on a chip" technologies.A crucial aspect of the activities is building a community of physicists, chemists and biologists in the Boston area, united by their interest in dynamics of constrained systems. The managing PI has initiated a biannual meeting that brings together students, postdoctoral associates and faculty, in the Boston area, interested in glassy phenomena, broadly construed. These have proven invaluable for exchanging ideas between various groups and exposing students to a range of ideas. The current program builds on this activity by (i) describing a new summer research program aimed at undergraduates from the women's four-year colleges in the Boston area and (ii) enlarging the scope of the biannual meetings to include minicourses which will be a valuable addition to graduate education in the interdisciplinary area of slow dynamics.***

该提案是为了响应Nanscale Science and Engineering Initiative，NSF 03-043，类别NIRT。 该理论裁决得到了材料研究部和化学部门的支持。 极端限制下的流体表现出新的动力学特性，这不是批量行为的简单扩展。 直观地，当限制维度与通常在纳米域中的流体中的合作运动相关的长度尺度相当时，极端的限制集就在内部。 了解这些自然长度尺度和外部约束之间的相互作用是该赠款中概述的研究的目标。 可以通过外部几何形状（例如在多孔培养基中的薄聚合物膜或液体中）施加约束，但是由于其他物体在细胞内部或玻璃过渡附近的超冷液体中自然发生，因此也可能源于“拥挤”。 在所有这些系统中，时间进化涉及具有内部自由度的扩展物体的运动。 将构建这些物体规模的有效模型；微观动力学模拟的微观特征与流体动力描述的宏观尺度之间的量表中间。 这样的框架提供了理论和实验之间的有用界面，这些界面使用真实空间探针在纳米尺度上研究运动。 结合此类实验，将构建与长度尺度和时间尺度相关的框架，并用于了解约束对动力学的影响。 数值模拟将用作构建有效动力学理论的垫脚石。 这些技术将在晶格模型的背景下开发，然后扩展到连续模型。该研究将为包括细胞流变性的一系列生物学问题提供建模工具，在拥挤的细胞环境中大分子的运动，细胞骨骼动力学的运动，几个。 从技术方面来说，目前正在花费大量精力在单个芯片上纯化，检测和分类生物分子的各种生化技术。 这些技术将这项研究提出的主要问题之一：大分子的运动如何受到极端限制的影响？ 理论工具，例如简单模型和数值模拟，再加上对良好的控制系统的实验，将有助于这些“芯片上的实验室”技术的合理设计。活动的关键方面是建立一个在波士顿地区的物理，化学家和生物学家社区，并通过对约束系统动态的兴趣而团结起来。 管理PI发起了一年一次的一次会议，在波士顿地区，对玻璃现象感兴趣的学生，博士后伙伴和教职员工汇集了整体解释。 事实证明，这些对于在各个群体之间交换思想并将学生暴露于一系列想法方面非常宝贵。 当前的计划是基于（i）描述旨在从波士顿地区的女子四年制大学的大学生进行的新的夏季研究计划的基础03-043，类别NIRT。 该理论裁决得到了材料研究部和化学部门的支持。 极端限制下的流体表现出新的动力学特性，这不是批量行为的简单扩展。 直观地，当限制维度与通常在纳米域中的流体中的合作运动相关的长度尺度相当时，极端的限制集就在内部。 了解这些自然长度尺度和外部约束之间的相互作用是该赠款中概述的研究的目标。 可以通过外部几何形状（例如在多孔培养基中的薄聚合物膜或液体中）施加约束，但是由于其他物体在细胞内部或玻璃过渡附近的超冷液体中自然发生，因此也可能源于“拥挤”。 在所有这些系统中，时间进化涉及具有内部自由度的扩展物体的运动。 将构建这些物体规模的有效模型；微观动力学模拟的微观特征与流体动力描述的宏观尺度之间的量表中间。 这样的框架提供了理论和实验之间的有用界面，这些界面使用真实空间探针在纳米尺度上研究运动。 结合此类实验，将构建与长度尺度和时间尺度相关的框架，并用于了解约束对动力学的影响。 数值模拟将用作构建有效动力学理论的垫脚石。 这些技术将在晶格模型的背景下开发，然后扩展到连续模型。该研究将为包括细胞流变性的一系列生物学问题提供建模工具，在拥挤的细胞环境中大分子的运动，细胞骨骼动力学的运动，几个。 从技术方面来说，目前正在花费大量精力在单个芯片上纯化，检测和分类生物分子的各种生化技术。 这些技术将这项研究提出的主要问题之一：大分子的运动如何受到极端限制的影响？ 理论工具，例如简单模型和数值模拟，再加上对良好的控制系统的实验，将有助于这些“芯片上的实验室”技术的合理设计。活动的关键方面是建立一个在波士顿地区的物理，化学家和生物学家社区，并通过对约束系统动态的兴趣而团结起来。 管理PI发起了一年一次的一次会议，在波士顿地区，对玻璃现象感兴趣的学生，博士后伙伴和教职员工汇集了整体解释。 事实证明，这些对于在各个群体之间交换思想并将学生暴露于一系列想法方面非常宝贵。 当前的计划是基于（i）描述一项旨在从波士顿地区女子四年制大学的本科生的新的夏季研究计划的基础，（ii）扩大了双年度会议的范围，以包括小型训练，以包括在慢速动态的跨学科跨学科领域中成为研究生教育的重要补充。