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.***

该提案是为了响应纳米科学与工程倡议、NSF 03-043、NIRT 类别而收到的。 该理论奖得到了材料研究部和化学部的支持。 极端约束下的流体表现出新颖的动力学特性，这并不是整体行为的简单延伸。 直观上，当限制尺寸变得与与流体中的协作运动相关的长度尺度相当时（通常在纳米域内），就会出现极端限制。 了解这些自然长度尺度和外部约束之间的相互作用是本次资助概述的研究目标。 约束可能是由外部几何形状施加的，例如聚合物薄膜或多孔介质中的液体，但也可能是由于细胞内部或接近玻璃化转变的过冷液体中自然存在的其他物体而产生的“拥挤”。 在所有这些系统中，时间演化涉及具有内部自由度的扩展对象的运动。 将构建这些物体规模的有效模型；介于分子动力学模拟的微观特征和流体动力学描述的宏观尺度之间的一种尺度。 这样的框架在理论和实验之间提供了一个有用的接口，使用真实空间探针来研究纳米尺度的运动。 结合此类实验，将构建一个与长度尺度和时间尺度相关的框架，并用于理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，然后扩展到连续体模型。该研究将为一系列生物学问题提供建模工具，包括细胞流变学、拥挤细胞环境中大分子的运动、细胞骨架动力学、仅举几例。 在技​​术方面，目前正在投入大量精力将用于纯化、检测和分选生物分子的各种生化技术小型化和集成到单个芯片上。 这些技术提出了本研究要解决的核心问题之一：极端限制如何影响大分子的运动？ 简单模型和数值模拟等理论工具，与良好控制系统的实验相结合，将有助于这些“芯片实验室”技术的合理设计。该活动的一个重要方面是建立一个由物理学家、化学家和生物学家组成的社区波士顿地区因对约束系统动力学的兴趣而团结在一起。 负责管理的 PI 发起了一年两次的会议，召集了波士顿地区对广义玻璃现象感兴趣的学生、博士后研究员和教员。 事实证明，这些对于不同群体之间交流想法和让学生接触各种想法非常有价值。 目前的计划以这项活动为基础，通过（i）描述一个新的夏季研究计划，针对波士顿地区四年制女子学院的本科生，以及（ii）扩大一年两次会议的范围，将迷你课程纳入其中，这将是一个有价值的课程。除了慢动力学跨学科领域的研究生教育之外。%%%此提案是为了响应纳米科学与工程倡议、NSF 03-043、NIRT 类别而收到的。 该理论奖得到了材料研究部和化学部的支持。 极端约束下的流体表现出新颖的动力学特性，这并不是整体行为的简单延伸。 直观上，当限制尺寸变得与与流体中的协作运动相关的长度尺度相当时（通常在纳米域内），极端限制就会出现。 了解这些自然长度尺度和外部约束之间的相互作用是本次资助概述的研究目标。 约束可能是由外部几何形状施加的，例如聚合物薄膜或多孔介质中的液体，但也可能是由于细胞内部或接近玻璃化转变的过冷液体中自然存在的其他物体而产生的“拥挤”。 在所有这些系统中，时间演化涉及具有内部自由度的扩展对象的运动。 将构建这些物体规模的有效模型；介于分子动力学模拟的微观特征和流体动力学描述的宏观尺度之间的一种尺度。 这样的框架在理论和实验之间提供了一个有用的接口，使用真实空间探针来研究纳米尺度的运动。 结合此类实验，将构建一个与长度尺度和时间尺度相关的框架，并用于理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，然后扩展到连续体模型。该研究将为一系列生物学问题提供建模工具，包括细胞流变学、拥挤细胞环境中大分子的运动、细胞骨架动力学、仅举几例。 在技​​术方面，目前正在投入大量精力将用于纯化、检测和分选生物分子的各种生化技术小型化和集成到单个芯片上。 这些技术提出了本研究要解决的核心问题之一：极端限制如何影响大分子的运动？ 简单模型和数值模拟等理论工具，与良好控制系统的实验相结合，将有助于这些“芯片实验室”技术的合理设计。该活动的一个重要方面是建立一个由物理学家、化学家和生物学家组成的社区波士顿地区因对约束系统动力学的兴趣而团结在一起。 负责管理的 PI 发起了一年两次的会议，召集了波士顿地区对广义玻璃现象感兴趣的学生、博士后研究员和教员。 事实证明，这些对于不同群体之间交流想法和让学生接触各种想法非常有价值。 目前的计划以这项活动为基础，通过（i）描述一个新的夏季研究计划，针对波士顿地区四年制女子学院的本科生，以及（ii）扩大半年一次会议的范围，将迷你课程纳入其中，这将是一个有价值的课程。除了慢动力学跨学科领域的研究生教育之外。***