Systematic coarse-graining of inhomogeneous systems

非均匀系统的系统粗粒度

• 批准号: 1856337
• 负责人: William Noid
• 金额: $ 45万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1856337&HistoricalAwards=false
• 关键词: Systematic; coarse; graining; inhomogeneous; systems

Professor William Noid of the Pennsylvania State University is supported by an award from the Chemical Theory, Models and Computational Methods program in the Chemistry division to develop low-resolution (coarse-grained (CG)) models of soft materials at interfaces. Soft materials include colloids, gels, polymers, liquid crystals, foams and biological tissues. An example of an interface is when liquid comes into contact with air. Interfacial phenomena are fundamentally interesting. They also have tremendous practical significance, since they control the performance of many modern materials and devices. Because computer simulation allow us to visualize the structure, organization, interactions and changes of interfaces, they hold great promise for helping us understand interfacial phenomena. Computer simulations are useful for designing interfaces with desired material properties. However, simulations that include all the atomic details of the interface are very computationally expensive. This expense severely limits their use for understanding interfacial systems. Coarse-grained (CG) models are less expensive computational methods. By representing molecules in reduced detail, CG models provide the necessary computational efficiency for effectively simulating length- and time-scales that cannot be effectively addressed with atomistic models. In this research, Professor Noid and his coworkers develop CG models that accurately describe interfacial phenomena. Additionally, this project develops an intergenerational science club that integrates Penn State students, emeritus faculty, and local retirees in discovery-based scientific education and discourse. "Bottom-up" CG models are not only exceedingly efficient, but also provide an accurate description of the structural properties of homogeneous materials. Unfortunately, these models generally provide a poor description of interfaces and other inhomogeneous systems. Accordingly, the central goal of this research is to develop theory and computational methods for parameterizing and simulating CG models that accurately model the structure and thermodynamic properties of inhomogeneous systems. The resulting insight and software may enable highly efficient simulations that provide a realistic description of interfacial systems and, ultimately, guide the design of specific material systems with desired interfacial properties. In order to achieve these goals, the research develops rigorous theory and numerical calculations to understand why current bottom-up models provide a poor description of inhomogeneous systems. The research also develops robust computational methods for addressing these limitations in practice. In particular, a generalized-Yvon-Born-Green formalism quantifies the force imbalances that arise at the CG interfaces and illuminates useful connections with classical density functional theories for inhomogeneous systems. A grand canonical formalism provides insights into the thermodynamic consistency of CG models and also determines effective potentials that are transferable to both homogeneous and inhomogeneous environments. The resulting advances provide tools for investigating soft material interfaces and, in particular, the structure and thermodynamic properties of solid-liquid and polymer-substrate interfaces.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

宾夕法尼亚州立大学的威廉·诺德教授得到了化学系化学理论、模型和计算方法计划的支持，该计划旨在开发界面处软材料的低分辨率(粗粒度(CG))模型。软材料包括胶体、凝胶、聚合物、液晶、泡沫和生物组织。液体与空气接触就是界面的一个例子。从根本上讲，界面现象很有趣。它们还具有巨大的现实意义，因为它们控制着许多现代材料和设备的性能。由于计算机模拟使我们能够可视化界面的结构、组织、相互作用和变化，它们为帮助我们理解界面现象带来了巨大的希望。计算机模拟对于设计具有所需材料属性的界面很有用。然而，包含接口的所有原子细节的模拟在计算上非常昂贵。这笔费用严重限制了它们在理解界面系统方面的使用。粗粒度(CG)模型是成本较低的计算方法。通过以简化的细节表示分子，CG模型为有效模拟原子模型无法有效处理的长度和时间尺度提供了必要的计算效率。在这项研究中，Noid教授和他的同事开发了准确描述界面现象的CG模型。此外，该项目还开发了一个跨代科学俱乐部，将宾夕法尼亚州立大学的学生、退休教师和当地退休人员纳入基于发现的科学教育和讨论中。“自下而上”的CG模型不仅非常有效，而且能够准确地描述均匀材料的结构特性。不幸的是，这些模型通常不能很好地描述界面和其他不同的系统。因此，这项研究的中心目标是发展理论和计算方法来参数化和模拟CG模型，以准确地模拟非均匀体系的结构和热力学性质。由此产生的洞察力和软件可以实现高效的模拟，提供对界面系统的真实描述，并最终指导具有所需界面特性的特定材料系统的设计。为了实现这些目标，这项研究发展了严格的理论和数值计算，以理解为什么目前的自下而上模型对非均匀系统的描述很差。这项研究还开发了稳健的计算方法，以解决实践中的这些限制。特别是，广义的Yvon-Born-Green形式量化了CG界面上出现的力不平衡，并阐明了与非均匀系统的经典密度泛函理论之间的有用联系。一个宏正则形式提供了对CG模型热力学一致性的洞察，并确定了可转移到均匀和非均匀环境的有效势。由此产生的进展为研究软材料界面，特别是固体-液体和聚合物-基材界面的结构和热力学性质提供了工具。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Energetic and entropic considerations for coarse-graining

• DOI: 10.1140/epjb/s10051-021-00153-4
• 发表时间: 2021-07
• 期刊: The European Physical Journal B
• 作者: Katherine M. Kidder;R. Szukalo;W. Noid

Investigating the energetic and entropic components of effective potentials across a glass transition

研究玻璃化转变过程中有效势的能量和熵成分

• DOI: 10.1088/1361-648x/abdff8
• 发表时间: 2021
• 期刊: Journal of Physics: Condensed Matter
• 作者: Szukalo, Ryan J.;Noid, W. G.
• 通讯作者: Noid, W. G.

A temperature-dependent length-scale for transferable local density potentials

可转移局部密度势的温度相关长度尺度

• DOI: 10.1063/5.0157815
• 发表时间: 2023
• 期刊: The Journal of Chemical Physics
• 作者: Szukalo, Ryan J.;Noid, W. G.
• 通讯作者: Noid, W. G.

Insight into the Density-Dependence of Pair Potentials for Predictive Coarse-Grained Models

洞察预测粗粒度模型对势的密度依赖性

• DOI: 10.1021/acs.jpcb.3c06890
• 发表时间: 2024
• 期刊: The Journal of Physical Chemistry B
• 作者: Lesniewski, Maria C.;Noid, W. G.
• 通讯作者: Noid, W. G.

Exploring the landscape of model representations

• DOI: 10.1073/pnas.2000098117
• 发表时间: 2020-09-29
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Foley, Thomas T.;Kidder, Katherine M.;Noid, W. G.
• 通讯作者: Noid, W. G.