Microstructure and Properties of Inhomogeneous Polyatomic Mixtures from Density Functional Theory

从密度泛函理论研究非均匀多原子混合物的微观结构和性能

• 批准号: 0756166
• 负责人: Walter Chapman
• 金额: $ 30万
• 依托单位: William Marsh Rice University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-15 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0756166&HistoricalAwards=false
• 关键词: Microstructure; Properties; Inhomogeneous; Polyatomic; Mixtures

CBET-0756166ChapmanMany modern applications of macromolecular fluids take advantage of their novel microstructure and phase behavior. The challenge in modeling nano-structured fluids lies in understanding the new physics that emerges from finite-size effects, varying dimensionality, surface forces and interplay of multiple length and time scales. The introduction of external surface forces and the competition between fluid substrate and fluid-fluid interactions lead to interesting surface driven phase changes not seen in bulk systems [9]. Intellectual Merit: The project focuses on the to development of a novel molecular theory for multi-scale modeling of complex fluid assemblies and to apply the theory to several critical problems in nano-structured media. The work builds on the PIs new density functional theory (DFT) that has shown an unprecedented combination of accuracy and simplicity in predicting the structure of inhomogeneous polyatomic mixtures [29,30]. Predictions of the DFT are in excellent agreement with molecular simulation results for phenomena such as polymer depletion, enhancement and surface induced segregation key elements in polymer-colloid systems and in coatings of polymer blends. Further, the DFT has similar simplicity and computational speed to an atomic density functional theory. We propose to incorporate multiple molecular association sites, chain stiffness, and hydrophilic and hydrophobic surfaces in the theory. The approach will be validated with molecular simulation results and compared with experiment for interfacial properties and structure of copolymer, surfactant, and tethered polymer systems. Broader Impact: The immense potential of the DFT has led to an ongoing collaboration with Sandia National Laboratories (SNL) to incorporate our DFT within their massively parallel DFT solver package ? TRAMONTO. With its existing capabilities, TRAMONTO can address life-scale systems such as colloids and electrolytes in a range of 2D/3D geometries. Integrating the PIs polyatomic DFT within this platform dramatically expands the potential scope of the package to such systems as self-assembly in polymer-colloid polymer-nanoparticle systems, block copolymer films and blends, surfactant or lipid systems exhibiting micellar or bilayer structures, and polyelectrolytes. When the final version is released to the public, it is anticipated that these computational tools will have high impact on nanoscience and design of nanosystems by allowing exhaustive analysis of design or phase space (needed for design of experiments) at a moderate expense. Dow Chemical has significant interest in applying the theory to model microstructure and interfacial properties of copolymer solutions, blends, and surfactants. Letters of collaboration from Sandia and Dow are attached with direct and in-kind funding from Dow. Of further impact will be education of a graduate student, post-doc, and undergraduate students participating in the project. These students will make presentations to companies that have participated in our Consortium on Complex Fluids and present research results at international conferences. The graduate student benefited from a summer internship offered by Dow. In addition to incorporating new theory in courses at Rice, the project will develop an educational module (book chapter) of the theory for web distribution using the internationally recognized Connexions environment (cnx.rice.edu).

CBET-0756166大分子流体的现代应用利用了它们的新型微观结构和相行为。建模纳米结构的流体的挑战在于了解有限尺寸效应，多个维度，表面力以及多长度和时间尺度的相互作用而出现的新物理学。引入外表面力以及流体底物与流体流体相互作用之间的竞争导致了有趣的表面驱动相变，在散装系统中未见[9]。智力优点：该项目着重于开发一种新型分子理论，用于复杂流体组件的多尺度建模，并将该理论应用于纳米结构培养基中的几个关键问题。这项工作建立在PIS新密度功能理论（DFT）的基础上，该理论表现出了准确性和简单性的前所未有的组合，可预测不均匀的多原子混合物的结构[29,30]。 DFT的预测与分子模拟结果非常吻合，例如聚合物耗竭，增强和表面诱导的隔离关键要素以及聚合物混合物的涂层中。此外，DFT具有与原子密度功能理论相似的简单和计算速度。我们建议将多个分子缔合位点，链刚度以及亲水性和疏水性表面结合在一起。该方法将通过分子模拟结果验证，并与共聚物，表面活性剂和束缚聚合物系统的界面特性和结构进行比较。更广泛的影响：DFT的巨大潜力导致与Sandia National Laboratories（SNL）进行了持续的合作，以将我们的DFT纳入其庞大的平行DFT求解器包中？ Tramonto。凭借其现有功能，Tramonto可以解决诸如2D/3D几何范围的胶体和电解质等生命尺度系统。在该平台内整合PIS多原子DFT，将包装的潜在范围扩大到诸如聚合物 - 胶体聚合物聚合物 - 纳米粒子系统，嵌段共聚物膜和混合物，表面活性剂或脂质系统，表现出胶束或胆汁胶质结构和胆汁层结构，以及Polyelectrolectretretes等系统。当最终版本向公众发布时，预计这些计算工具将通过中等费用对设计或相位空间进行详尽的分析（需要实验的设计）来对纳米系统的纳米科学和设计产生高影响。 Dow Chemical对将理论应用于建模共聚物溶液，混合物和表面活性剂的微结构和界面特性具有重大兴趣。 Sandia和Dow的合作信件与DOW的直接和实物资金有关。进一步的影响将是对参加该项目的研究生，博士后和本科生的教育。这些学生将向参加我们的复杂流体联盟的公司进行演讲，并在国际会议上提出研究结果。研究生受益于陶氏提供的暑期实习。除了将新理论纳入赖斯的课程外，该项目还将使用国际认可的连接环境（CNX.RICE.EDU）开发一个教育模块（书籍章节）。