Field-Theoretic Simulations: Coherent States and Particle-Field Linkages

非技术总结该奖项支持理论和计算，以及教育，以促进基于聚合物，长链分子的聚合物材料的计算机模拟。聚合物是多功能材料，在纺织品，塑料和橡胶，油漆和涂料以及消费品（包括护发产品，清洁剂，洗涤剂等）中具有非常广泛的应用。它们在新的能量收集技术（如有机太阳能电池）中也越来越重要，作为储能设备（如电池）中的固体电解质，以及先进的药物输送和医疗设备。也许令人惊讶的是，用于此类应用的新聚合物的设计通过试错实验进行，直到分子设计产生目标性质和功能。该项目旨在推进聚合物材料的计算机模拟设计。该项目的一个组成部分将开发一种新的聚合物理论表示，并将其转化为一个计算平台，从而能够设计具有热可逆键的材料。这种材料具有独特的性能，如损坏时的自我修复，或对热或化学刺激的反应，这两者在各种新兴应用中都很重要。第二项努力旨在将原子尺度的分子模拟与采用不同理论公式的模拟联系起来，并且可以达到数百微米的尺度。这种能力将使化学细节嵌入到理论模型中;后者提供了与聚合物材料性质的联系。如果成功的话，这个多长度尺度建模平台可以大大加快现有和新应用的聚合物设计。拟议研究的更广泛影响包括项目人员参与理论和计算聚合物科学的研究生，本科生和博士后培训。理论导向的学生将通过与加州大学圣巴巴拉分校（UCSB）化学工程，材料和化学实验组的密切结合，接触到更广泛的软材料学科。在拟议项目下获得的知识将通过UCSB的复杂流体设计联盟加以利用，该联盟是一个行业-国家实验室-学术合作伙伴关系，致力于商业相关聚合物配方的计算设计。所有参与者都将为UCSB材料研究科学与工程中心充满活力的教育和推广计划做出贡献。技术总结该奖项支持理论和计算，以及推进聚合物材料理论和建模的教育。该项目将提高场论模拟（FTS）方法的能力，允许对聚合物和软材料的场论模型进行数值研究，而无需采用平均场近似。一个项目组件建立了一个新的平台，FTS的基础上相干态聚合物场理论，一个长期被忽视的代表性相互作用的聚合物受到量子场论的启发。拟议的工作旨在开发和优化算法的相干态模型的模拟和应用这些算法的可逆键合，超分子聚合物的基础研究。将探讨变量之间的关系，如键合平衡常数，化学计量和聚合物结构，自组装行为和热力学性质。相干态框架的独特结构将使一个新的力匹配计划内FTS系统粗粒化，适用于超分子和非反应性聚合物系统。拟议的研究的另一个组成部分是开发一个工作流程，其中所有原子粒子模型映射到粗粒度粒子模型使用相对熵最小化;后者的形式，允许分析转换到一个完全参数化的场论模型。FTS然后可以用于访问直接连接到聚合物的基本化学的介观结构和热力学性质。拟议研究的更广泛影响包括项目人员参与理论和计算聚合物科学的研究生，本科生和博士后培训。理论导向的学生将通过与加州大学圣巴巴拉分校（UCSB）化学工程，材料和化学实验组的密切结合，接触到更广泛的软材料学科。在拟议项目下获得的知识将通过UCSB的复杂流体设计联盟加以利用，该联盟是一个行业-国家实验室-学术合作伙伴关系，致力于商业相关聚合物配方的计算设计。该项目针对的全原子FTS工作流程有可能彻底改变此类制剂的计算机设计。所有参与者都将为UCSB材料研究科学与工程中心充满活力的教育和推广计划做出贡献。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

NONTECHNICAL SUMMARYThis award supports theory and computation, and education to advance computer simulation of polymeric materials which are based on polymers, long-chain-like molecules. Polymers are versatile materials that have remarkably broad applications in textiles, plastics and rubbers, paints and coatings, and consumer products including haircare products, cleansers, detergents, etc. They are also increasingly important in new energy harvesting technologies such as organic solar cells, as solid electrolytes in energy storage devices such as batteries, and in advanced drug delivery and medical devices. Perhaps surprisingly, the design of new polymers for such applications proceeds by trial-and-error experimentation until the molecular design yields the targeted properties and function.This project aims to advance in-silico computational design of polymeric materials. One component of the project will develop a new theoretical representation of polymers into a computational platform that will enable the design of materials with thermally reversible bonds. Such materials have unique properties such as self-repair when damaged, or responsiveness to thermal or chemical stimuli, both important in a variety of emerging applications. A second effort aims to link molecular simulations at the atomic scale with simulations that employ a different theoretical formulation and can reach scales of hundreds of micrometers. This capability will enable chemical details to be embedded in the theoretical models; the latter providing the link to polymer material properties. If successful, this multiple length scale modeling platform could dramatically accelerate the design of polymers for existing and new applications.Broader impacts of the proposed research include engagement by the project personnel in graduate, undergraduate, and post-doctoral training in theoretical and computational polymer science. Theoretically-oriented students will be exposed to broader soft materials disciplines through a close coupling with experimental groups at the University of California, Santa Barbara (UCSB) in chemical engineering, materials, and chemistry. Knowledge gained under the proposed project will be leveraged through the Complex Fluids Design Consortium at UCSB, an industry-national lab-academic partnership that is addressing the computational design of commercially relevant polymer formulations. All participants will contribute to the vibrant education and outreach programs of UCSB's Materials Research Science and Engineering Center.TECHNICAL SUMMARYThis award supports theory and computation, and education to advance theory and modeling of polymeric materials. This project will enhance the capabilities of the field-theoretic simulation (FTS) method, permitting numerical investigations of field theory models of polymers and soft materials without resorting to a mean-field approximation. One project component builds a new platform for FTS based on coherent-states polymer field theory, a long-neglected representation of interacting polymers inspired by quantum field theory. The proposed work aims to develop and optimize algorithms for simulations of coherent states models and apply those algorithms to fundamental studies of reversibly bonding, supramolecular polymers. Relationships will be explored between variables such as bonding equilibrium constants, stoichiometry and polymer architecture, and self-assembly behavior and thermodynamic properties. The unique structure of the coherent-states framework will enable a new force-matching scheme for systematic coarse-graining within FTS, applicable to both supramolecular and non-reactive polymer systems. Another component of the proposed research is to develop a workflow in which all-atom particle models are mapped to coarse-grained particle models using relative entropy minimization; the latter models of a form to allow analytical conversion to a fully-parameterized field theory. FTS can then be used to access mesoscale structure and thermodynamic properties directly connected to the underlying chemistry of the polymers. Broader impacts of the proposed research include engagement by the project personnel in graduate, undergraduate, and post-doctoral training in theoretical and computational polymer science. Theoretically-oriented students will be exposed to broader soft materials disciplines through a close coupling with experimental groups at the University of California, Santa Barbara (UCSB) in chemical engineering, materials, and chemistry. Knowledge gained under the proposed project will be leveraged through the Complex Fluids Design Consortium at UCSB, an industry-national lab-academic partnership that is addressing the computational design of commercially relevant polymer formulations. The all-atom to FTS workflow targeted by the project has the potential to revolutionize in silico design of such formulations. All participants will contribute to the vibrant education and outreach programs of UCSB's Materials Research Science and Engineering Center.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.