Nanoparticle Dynamics in Polymer Solutions and Melts

非技术性总结该奖项支持关于小颗粒、药物分子和蛋白质在挤满聚合物、长链状分子的环境中运动的理论和计算研究和教育，例如可能在细胞内部和组织网络中实现的。越来越多的证据表明，细胞拥挤对小颗粒和蛋白质运动的影响间接影响了许多生物分子现象，包括蛋白质的稳定性和聚集性，以及酶反应。不幸的是，典型的细胞环境由大量不同成分组成，如长链聚合物、基因组DNA和代谢物，因此很难量化这些基质中蛋白质或颗粒运动的特征。这项研究的目的是开发和使用计算机模拟来研究小颗粒在一个模型中的运动，该模型是聚合物溶液的代表系统，以确定(A)拥挤的影响，如通过颗粒/蛋白质的相对尺寸对环境尺寸的量化；以及(B)颗粒/蛋白质与环境之间的相互作用。从这个项目中得出的理解可能会对细胞过程的基本理解和新纳米颗粒疗法的设计产生影响。该项目将包括为研究生、本科生和高中生提供在生物学和聚合物物理的十字路口进行研究的机会。这项研究的结果还将被用于开发基于计算机的教育模块，以说明小探针和蛋白质在拥挤环境中的物理伴随运动。技术总结该奖项支持有关纳米粒子在聚合物流体中运动的基本物理基础的理论和计算研究和教育。最近，复杂的实验研究已经获得了尺寸与聚合物溶液关联长度相当的粒子的动力学，并发现了许多有趣的行为，这些行为不同于胶体粒子所表现出的连续介质特征。PI旨在开发和使用粗粒度计算机模拟方法，以确定控制纳米颗粒在从稀释到浓缩条件下的聚合物溶液中的流动性和流变性的基本物理。更具体地说，这项研究将使用计算机模拟和模型来解决两个广泛的问题：(I)基质的非连续、尺度相关的流变性对聚合物基质中纳米颗粒悬浮液的动力学和流变性的影响；(Ii)聚合物-纳米颗粒相互作用对迁移率和悬浮流变性的影响。该项目将包括：为研究生、本科生和高中生提供研究机会；开发针对本科生、研究生课程和K-12推广活动的新的模拟和教育模块；以及涉及组织讨论会的协同活动，旨在作为聚合聚合物物理和连续介质力学研究的论坛。

NONTECHNICAL SUMMARYThis award supports theoretical and computational research and education on the motion of small particles, drug molecules and proteins in environments crowded with polymers, long chain-like molecules, such as may be realized in cell interiors and tissue networks. Increasing evidence suggests that the influence of cell crowding on the motion of small particles and proteins indirectly influences a number of biomolecular phenomena, including protein stability and aggregation, and enzymatic reactions. Unfortunately, the typical cell environment consists of a soup of a vast number of different components, such as long-chain polymers, genomic DNA, and metabolites, rendering it difficult to quantify the features responsible for protein or particle motion in such matrices. This research is aimed to develop and use computer simulations to study the motion of small particles in a model, representative system of polymeric solutions, to identify the influence of (a) crowding, as quantified by the relative size of the particle/protein to environmental dimensions; and (b) the interactions between the particle/protein and the environment. The understanding derived in this project can have impact on both fundamental understanding of cellular processes and the design of new nanoparticle therapies. The project will include opportunities for graduate, undergraduates and high school students to pursue research in an area at the crossroads of biology and polymer physics. The outcomes of the research will also be used to develop computer-based educational modules to illustrate the physics accompanying motion of small probes and proteins in crowded environments. TECHNICAL SUMMARYThis award supports theoretical and computation research and education on the fundamental physics underlying the movement of nanoparticles in polymeric fluids. Recently, sophisticated experimental studies have accessed the dynamics of particles whose sizes are comparable to the polymer solution correlation lengths, and have unearthed a number of intriguing behaviors which are distinct from the continuum characteristics exhibited by colloidal particles. The PI aims to develop and use coarse-grained computer simulation methodologies to identify the fundamental physics governing the mobility and rheological properties of nanoparticles in polymer solutions ranging from dilute to concentrated conditions. More specifically, this research will use computer simulations and models to address two broad issues: (i) The influence of noncontinuum, scale-dependent rheological properties of the matrix upon the dynamics and rheological properties of nanoparticle suspensions in polymer matrices; (ii) The influence of polymer-nanoparticle interactions upon the mobilities and suspension rheologies. This project will include: research opportunities for graduate, undergraduates and high school students; development of new simulation and educational modules targeting undergraduate, graduate courses and K-12 outreach activities; and synergistic activities involving the organization of colloquia designed to serve as a forum for confluence of research in polymer physics and continuum mechanics.