Ab initio entangled polymer rheology: homopolymers, blends and copolymers

从头算缠结聚合物流变学：均聚物、共混物和共聚物

• 批准号: 1438700
• 负责人: Jay Schieber
• 金额: $ 27万
• 依托单位: Illinois Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1438700&HistoricalAwards=false
• 关键词: Ab; initio; entangled; polymer; rheology

PI: Schieber, Jay D. Proposal Number: 1438700Institution: Illinois Institute of TechnologyThe focus of this project is on investigating entangled polymer rheology with a multiscale computationally approach. The proposed research will pin down the parameters needed to be calculated at the atomistic level, in order to provide macroscopic scale predictions about the rheology of a wide class of soft materials. Entangled polymers have tremendous economic impact in industrial materials, and also influence the mechanics of biological tissue. Any significant advance in the understanding of these dynamics will have substantial impact on many branches of physics, materials science, biophysics, biology and engineering. The co-PIs will produce a user-friendly graphical user interface (GUI) and make their GPU code available for public consumption. This code would allow any user with a simple desktop and graphics card (less than $1k) to predict the linear or nonlinear rheology of any blend of linear, branched or cross-linked entangled homopolymers in a homogeneous flow field.It is proposed to achieve the first ab initio dynamic prediction for soft matter that exhibits relaxation times of seconds or minutes. A hierarchical structure of simulations is proposed, starting from ab initio type of calculations. The goal is to make predictions possible for any entangled homopolymer chain architecture, any molecular weight, any blend of architecture and molecular weight, and for any flow field. The homopolymer model to be used is thermodynamically based and in accordance to mean-field theory. While currently available models require parameter fitting and empiricisms, the intellectual achievement of this work, if successful, is to predict the rheology of entangled homopolymers from atomistic knowledge only, without any parameter fitting. This feat can be accomplished with the use of techniques to speed-up calculations by about 12 orders of magnitude, allowing the bridging of the time scales between atomistic and macroscale times.

PI：Schieber，Jay D.提案编号：1438700机构：伊利诺伊理工学院该项目的重点是研究纠缠聚合物流变学与多尺度计算方法。拟议的研究将确定在原子水平上计算所需的参数，以便提供关于广泛类别的软材料流变学的宏观尺度预测。 缠结聚合物在工业材料中具有巨大的经济影响，并且还影响生物组织的力学。对这些动力学的理解的任何重大进展都将对物理学、材料科学、生物物理学、生物学和工程学的许多分支产生重大影响。co-PI将产生一个用户友好的图形用户界面（GUI），并使其GPU代码可供公众使用。该代码将允许任何用户与一个简单的桌面和图形卡（低于1000美元）预测的线性或非线性流变的任何混合物的线性，支化或交联缠结均聚物在均匀的流场。它建议实现第一个从头算动力学预测软物质，表现出弛豫时间秒或分钟。提出了一个层次结构的模拟，从头计算类型的计算。我们的目标是使预测可能为任何纠缠的均聚物链结构，任何分子量，任何结构和分子量的混合物，并为任何流场。所使用的均聚物模型是基于热力学的并且符合平均场理论。虽然目前可用的模型需要参数拟合和philicisms，这项工作的智力成果，如果成功的话，是预测纠缠的均聚物的流变学原子知识，没有任何参数拟合。这一壮举可以通过使用技术来实现，将计算速度提高约12个数量级，允许在原子时间和宏观时间之间架起时间尺度的桥梁。