Field-Theoretic Polymer Simulations: Fundamentals and Applications

技术概述：该奖项支持聚合物模拟领域的计算和理论研究及教育。这个项目将建立在PI和他的同事的“场论模拟”(FTS)方法的最新发展的基础上，使得能够对聚合物、复杂流体和软材料的场论模型进行数值研究，而不需要求助于平均场近似。拟议的研究既包括基础部分，也包括应用部分。FTS方法的基础和扩展。这项研究的重点将包括开发改进的数值方案，用于实施势场更新的随机“复朗之万方程”的时间积分。我们还建议开发一种新的“基态-FTS”技术，该技术将极大地加速半稀区和浓区中强重叠聚合物溶液(中性和带电)的模拟。数值重整化群理论。我们建议将伪谱数值RG变换与聚合物场理论的复朗之万模拟相结合来实现。这将有助于隔离晶格截断效应，并使聚合物溶液模型能够系统地粗粒化。PI展望了嵌段共聚物在选择性溶剂中的应用。混合粒子场模拟。我们建议开发一类新的模拟来处理嵌入在结构化聚合物流体中的纳米颗粒或胶体。粒子被视为流体场中的“空穴”，粒子坐标与流场变量一起保持不变。受限共聚物膜中的缺陷。在具有周界边界条件的嵌段共聚薄膜的FTS模拟中，将考察平移和键取向有序性。研究结果将用于评估图形外延技术在制造无缺陷共聚物薄膜方面的效能，这些薄膜可用于先进电子、光学和磁性设备的超高密度图案化。这项拟议的研究将与加州大学伯克利分校Edward J.Kramer实验室正在进行的一项实验计划密切结合。PI将继续他在理论和计算聚合物科学方面进行有效的研究生和博士后培训的传统。一个特别的重点将是通过与加州大学伯克利分校化学工程、材料和化学的实验小组的密切结合，让接受经典物理培训的学生和博士后接触更广泛的软材料/聚合物科学学科。UCSB的复杂流体设计联盟(CFDC)将进一步利用通过提议的项目获得的基本理解，该联盟是一个行业-国家实验室-学术合作伙伴关系，致力于商业聚合物和复杂流体配方的计算设计。非技术概述：该奖项支持使用计算机模拟聚合物材料和聚合物相关现象的聚合物科学领域的计算和理论研究和教育。PI计划继续他的基本理论进步和新算法方面的工作，旨在扩展他开发的模拟方法，并开发用于非均质聚合物材料、复杂流体和软材料的新模拟方法。这些方法是处理这些材料中不同长度和时间尺度上出现的基本物理所必需的，并且经常使可靠的计算机模拟变得困难。在与实验相结合的努力中，PI计划将这些新开发的先进模拟方法应用于嵌段共聚物的薄膜，并研究一种有前景的实验技术，以创建近乎完美的共聚物薄膜，可用作合成无机纳米线、纳米点和其他纳米结构的模板。PI将继续他在理论和计算聚合物科学方面有效的研究生和博士后培训的传统。一个特别的重点将是通过与加州大学伯克利分校化学工程、材料和化学的实验小组的密切结合，让接受经典物理培训的学生和博士后接触更广泛的软材料/聚合物科学学科。UCSB的复杂流体设计联盟(CFDC)将进一步利用拟议项目取得的基本理解，该联盟是一个行业-国家实验室-学术合作伙伴关系，致力于商业聚合物和复杂流体配方的计算设计。

TECHNICAL SUMMARY:This award supports computational and theoretical research and education in the area of polymer simulation. This project will build on the recent development by the PI and co-workers of the "field-theoretic simulation" (FTS) method, enabling numerical investigations of field theory models of polymers, complex fluids, and soft materials without resorting to the mean-field approximation. The proposed research encompasses both fundamental and applied components.. Foundations and extensions of the FTS method. This research thrust will include development of improved numerical schemes for time integration of the stochastic "complex Langevin" equations used to implement potential field updates. We also propose to develop a new "ground state-FTS" technique that should dramatically accelerate simulations of strongly overlapping polymer solutions (neutral and charged) in the semi-dilute and concentrated regimes.. Numerical renormalization group theory. We propose to implement pseudospectral numerical RG transformations in tandem with complex Langevin simulations of polymer field theories. This will facilitate the isolation of lattice cutoff effects and enable systematic coarse-graining of polymer solution models. The PI envisions applications to block copolymers in selective solvents.. Hybrid particle-field simulations. We propose to develop a new class of simulations for treating nanoparticles or colloids embedded in structured polymer fluids. The particles are treated as "cavities" in the fluid fields and the particle coordinates are retained along with the fluid field variables.. Defects in confined copolymer films. Translational and bond-orientational order will be examined in FTS simulations of block copolymer films with perimeter boundary conditions. The results will be used to assess the efficacy of grapho-epitaxy for creating defect-free copolymer films that can be used in ultra-high density patterning of advanced electronic, optical, and magnetic devices. The proposed research will closely couple with an experimental program underway in the laboratory of Edward J. Kramer at UCSB.The PI will continue in his tradition of effective graduate and post-doctoral training in theoretical and computational polymer science. A particular focus will be to expose students and post-docs with classical physics training to broader soft materials/polymer science disciplines through a close coupling with experimental groups at UCSB in chemical engineering, materials, and chemistry. The fundamental understanding gained under the proposed project will be further leveraged through the Complex Fluids Design Consortium (CFDC) at UCSB, an industry-national lab-academic partnership that is addressing the computational design of commercial polymer and complex fluid formulations.NON-TECHNICAL SUMMARY:This award supports computational and theoretical research and education in the area of polymer science using computers to simulate polymer materials and polymer-related phenomena. The PI plans to continue his work on fundamental theoretical advances and new algorithms aimed at extending a simulation method he developed and at developing new simulation methods for inhomogeneous polymer materials, complex fluids, and soft materials. These methods are needed to handle essential physics that arises across diverse length and time scales in these materials and often makes reliable computer simulation difficult. In an effort coupled to experiment, the PI plans to apply these newly developed advanced simulation methods to thin films of block copolymers and to investigate a promising experimental technique for creating nearly perfect copolymer films that can be used as a template to synthesize inorganic nanowires, nanodots, and other nanoscale structures. The PI will continue in his tradition of effective graduate and post-doctoral training in theoretical and computational polymer science. A particular focus will be to expose students and post-docs with classical physics training to broader soft materials/polymer science disciplines through a close coupling with experimental groups at UCSB in chemical engineering, materials, and chemistry. The fundamental understanding gained under the proposed project will be further leveraged through the Complex Fluids Design Consortium (CFDC) at UCSB, an industry-national lab-academic partnership that is addressing the computational design of commercial polymer and complex fluid formulations.