NSF-DFG Confine: MolPEC – Molecular Theory of Weak Polyelectrolytes in Confined Space

NSF-DFG Confine：MolPEC — 密闭空间弱聚电解质的分子理论

• 批准号: 2234013
• 负责人: Jianzhong Wu
• 金额: $ 40万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-11-01 至 2025-10-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2234013&HistoricalAwards=false
• 关键词: NSF; DFG; Confine; MolPEC; Molecular

In this project supported by the Chemical Theory, Models and Computational Methods Program (CTMC) of the Division of Chemistry, Professor Jianzhong Wu of the University of California-Riverside is developing theoretical models that describe a class of polymers known as weak polyelectrolytes (WPEs). This is a collaborative project with researchers from the Georg-August-Universität Göttingen, Germany. WPEs are a large class of macromolecules that may either protonate or deprotonate depending upon the environmental conditions such as pH and salt concentration. Their stimuli-responsive behavior has been broadly utilized in functional “smart” materials for applications such as targeted drug delivery or underwater adhesion. Whereas practical applications often entail chemical and physical processes under spatial confinement, the structure and dynamics of WPEs remain incompletely understood due to the strong coupling of reaction and polymer-mediated correlations at both monomer and polymer scales. The rational design of WPE systems is calling for advances in theoretical and computational methods that are able to accurately describe confinement effects on local solution environment, protonation/deprotonation equilibrium, and the dynamics of polymers reacting with ionizable surfaces. This research aims to develop a theoretical framework for describing the properties of WPEs in confined space and their responses to environmental conditions including solution pH, electrolyte composition, and the chemistry of confinement. We will utilize these techniques to investigate the interplay between ionic size, valence, ionization, surface reactions and the dynamics of polymer binding that cannot be reliably addressed with conventional methods. The theoretical and computational advances will contribute to a rational design of weak polyelectrolyte systems for a wide spectrum of technological applications. Building on complementary advances in polymer density functional theory (PDFT) and molecular simulation, the US-German team will study the structure, thermodynamics, and dynamics of weak polyelectrolytes at and between surfaces. The idea is to combine and extend Ising Density Functional Theory (iDFT) and Single-Chain-in-Mean-Field (SCMF) simulation. iDFT considers single-chain configurations and ionization states of segments on equal footing and captures liquid-like packing and electrostatic correlations via the molecular density. The joint probability distribution of configurations and ionization states of an entire macromolecule is dictated by a single-chain potential, which, in turn, is a functional of the molecular density. The high-dimensional molecular density will be efficiently evaluated via SCMF simulation on parallel, GPU-accelerated supercomputers, employing the iDFT single-chain potential. The team will extend the simulation code, SOft coarse-grained Monte-carlo Acceleration (SOMA), to incorporate electrostatic interactions and nonlocal interactions along the molecular contour. The particle-based simulation, Dynamic-iDFT (D-iDFT), accounts for long-range fluctuations and allows us to study the configuration dynamics. Additionally, we will derive a segment-based dynamic iDFT (SD-iDFT) for describing the local polymer mass and charge density in response to environmental changes. The generic nature of the theoretical techniques proposed in this work ensures broad applications to diverse phenomena in polymeric and biological systems. This project will provide training opportunities for early career scientists to gain interdisciplinary research experience and cultivate their career interests in computational molecular engineering. In addition to supporting graduate students, it offers research-based thesis projects for undergrads in active military service, veterans, and students from the University Honors Program (UHP). This project is being awarded through the “Chemistry and Transport in Confined Spaces (NSF-DFG Confine)" opportunity, a collaborative solicitation that involves the National Science Foundation and Deutsche Forschungsgemeinschaft (DFG).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.

在这个由化学系化学理论、模型和计算方法计划（CTMC）支持的项目中，加州大学河滨分校的吴建中教授正在开发描述一类被称为弱聚电解质（WPE）的聚合物的理论模型这是与德国格奥尔格·奥古斯特·哥廷根大学研究人员的合作项目 WPE 是一大类可以质子化或质子化的大分子。它们的刺激响应行为已广泛应用于靶向药物输送或水下粘附等功能性“智能”材料中，而实际应用通常需要在空间下发生化学和物理过程。由于反应和聚合物介导的相关性在单体和聚合物尺度上的强烈耦合，WPE 的结构和动力学仍不完全被了解。WPE 系统的合理设计需要能够实现理论和计算方法的进步。准确描述限制对局部溶液环境、质子化/去质子化平衡以及聚合物与可电离表面反应的动力学的影响本研究旨在开发一个理论框架，用于描述受限空间中 WPE 的特性及其对环境条件（包括溶液 pH）的响应。我们将利用这些技术来研究离子大小、化合价、电离、表面反应和聚合物结合动力学之间的相互作用，而传统方法无法可靠地解决这些问题。理论和计算方面的进步将有助于弱聚电解质系统的合理设计，以实现广泛的技术应用。基于聚合物密度泛函理论（PDFT）和分子模拟的互补进展，美国-德国团队将研究其结构、热力学。以及表面和表面之间弱聚电解质的动力学，其想法是结合并扩展伊辛密度泛函理论 (iDFT) 和单链平均场 (SCMF) 模拟。平等地考虑链段的单链构型和电离态，并通过分子密度捕获液体状堆积和静电相关性。整个大分子的构型和电离态的联合概率分布由单链电势决定。反过来，高维分子密度将通过并行、GPU 加速的超级计算机上的 SCMF 模拟进行有效评估，并利用 iDFT 单链潜力。模拟代码 SOft 粗粒度蒙特卡洛加速 (SOMA)，将沿分子轮廓的静电相互作用和非局域相互作用结合起来。基于粒子的模拟动态 iDFT (D-iDFT) 考虑了长程波动并允许。此外，我们将推导出基于片段的动态 iDFT（SD-iDFT），用于描述响应环境变化的局部聚合物质量和电荷密度。确保在聚合物和生物系统中的各种现象的广泛应用。该项目将为早期职业科学家提供培训机会，以获得跨学科研究经验并培养他们对计算分子工程的职业兴趣。除了支持研究生外，它还提供基于研究的论文。面向现役军人、退伍军人和大学荣誉计划 (UHP) 学生的项目 该项目通过“密闭空间中的化学与运输 (NSF-DFG Confine)”机会授予，这是一项涉及以下项目的合作招标。国家科学基金会和德国研究协会 (DFG)。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值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

Hierarchical Model of Weak Polyelectrolytes with Ionization and Conformation Consistency

具有电离和构象一致性的弱聚电解质的层次模型

• DOI: 10.1021/acs.macromol.2c01910
• 发表时间: 2023-06
• 期刊: Macromolecules
• 影响因子: 5.5
• 作者: Gallegos, Alejandro;Wu, Jianzhong
• 通讯作者: Wu, Jianzhong

A Molecular Theory of Polypeptide Adsorption at Inorganic Surfaces

无机表面多肽吸附的分子理论

• DOI: 10.1021/acs.jpcb.2c06607
• 发表时间: 2023-01
• 期刊: The Journal of Physical Chemistry B
• 作者: Gallegos, Alejandro;Wu, Jianzhong
• 通讯作者: Wu, Jianzhong