CAREER: Computer-Aided Design and Discovery of Novel Nanoporous Materials Through Ab Initio-Based Molecular Simulation

职业：通过基于从头算的分子模拟计算机辅助设计和发现新型纳米多孔材料

• 批准号: 0238989
• 负责人: Kendall Thomson
• 金额: $ 40万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0238989&HistoricalAwards=false
• 关键词: CAREER; Computer; Aided; Design; Discovery

Kendall K. ThomsonPurdue University"CAREER: Computer-Aided Design and Discovery of Novel Nanoporous Materials Through Ab Initio-Based Molecular Simulation"The search for novel nanoporous materials is an exciting and active field of research. However, despite intensive investigation, discovery of novel nano-structured frameworks remains a mainly heuristic exercise. A key component in synthesizing many of these materials is the use of organic templating molecules that act as structure directing agents in the self-assembly of particular frameworks. What is needed is a means of (1) determining a priori which template molecules will synthesize which frameworks and (2) identifying what specific frameworks are possible that have not yet been discovered. The objective of this research is the development of a suite of computer tools to assist in the discovery and synthesis of novel nano-porous materials, and to initially apply these methods towards the discovery of novel titnaosilicate frameworks for gas separations and ion transport materials in fuel cell technology.The proposed program suite will combine two general algorithms: (1) framework-template matching, in which Monte-Carlo like moves are used to computationally "grow" template molecules within given frameworks, and (2) automated framework search, in which stochastic search methods combined with genetic algorithms are used to computationally search for feasible crystalline frameworks. In order for a molecularmodeling approach to work, a proper accounting of interaction potential energy is required. For this a novel tight-binding prescription for silicate-based frameworks has been developed that is at least two orders of magnitude faster than ab initio dynamics, yet provides an accurate representation of oxide bonding properties. The method provides a fast and accurate means of incorporating full structural relaxation into the abovealgorithms, providing more realistic framework/template interactions and structural stability determination than previous methods.The method will initially be applied to the synthesis of titanosilicate frameworks of the ETS-4 and ETS-10 class, for which viable templates have not been identified. ETS-4 has thermal contraction properties that are currently exploited in gas separation technology. Suitable templates, if identified, could potentially alter the faulting behavior of these materials by directing the inter-growth of specific polytypes. This could result in materials with (1) novel contraction properties and (2) enhanced ion transport behavior, particularly applicable to fuel cell membrane technology. Further, novel titanosilicate frameworks with similar features to ETS-4 will be systematically sought.This proposed work will also address the challenge of bringing the molecular simulation knowledge base to the chemical engineering curriculum through the following activities: (1) development of theory and application based molecular simulation courses for the chemical engineering graduate curriculum, and (2) incorporation of a primarily application based, molecular simulation course in the undergraduate chemical engineering curriculum. The objective is to familiarize the chemical engineer with the utility and application of molecular simulation methods such they can communicate with experts in the field, identify situations where molecular simulation may be useful, and apply the techniques to problems in chemical engineering. In addition to molecular simulation competence the chemical engineer should be proficient in general modeling.The ability to competently analyze an engineering problem, formulate a working model, and extract useful information is key to effective problem solving capabilities, and suitable mathematical packages such as Mathematica can be useful teaching tools. Consequently, a web-based learning package will be developed that will emphasize the fundamentals of model building with workable Mathematica exercises and solutions thatspan the undergraduate curriculum. The goal is to integrate chemical engineering problems with modern mathematical computing tools that raise the technological standards of chemical engineering education.The impact of this development plan is expected to be broad and far reaching and will potentially effect every field where materials synthesis is required, including: catalysis, separations, sensor technology, fuel cell technology, nano-structured thermo-electronic materials, and nano-scale electric devices. The tight-binding prescription in itself represents a step forward in molecular simulation of zeolites and related ionic oxide materials, and will impact the zeolite/simulation community particularly in the areas of transport, adsorption, self-assembly and nucleation science, and zeolite isomorphic substitution chemistry. At the same time, by combining the discovery of new materials with the educational impact of incorporating simulation methods in the classroom, these proposed research and education activities offer an integrated program that serves the greater academic community through aggressive outreach and undergraduate enlightenment.

肯德尔湾普林斯顿普渡大学“职业：计算机辅助设计和发现新的纳米多孔材料通过从头算分子模拟“寻找新的纳米多孔材料是一个令人兴奋和活跃的研究领域。然而，尽管深入的调查，发现新的纳米结构的框架仍然是一个主要的启发式练习。合成许多这些材料的关键组成部分是使用有机模板分子，其在特定框架的自组装中充当结构导向剂。所需要的是一种手段，其（1）先验地确定哪些模板分子将合成哪些框架，以及（2）鉴定哪些尚未发现的特定框架是可能的。本研究的目标是开发一套计算机工具，以帮助发现和合成新型纳米多孔材料，并初步将这些方法应用于发现燃料电池技术中用于气体分离和离子传输材料的新型钛硅酸盐框架。拟议的程序套件将结合联合收割机两种通用算法：（1）框架-模板匹配，其中类似蒙特-卡罗的移动用于在给定框架内计算“生长”模板分子，和（2）自动框架搜索，其中随机搜索方法与遗传算法相结合用于计算搜索可行的结晶骨架。为了使分子模拟方法发挥作用，需要对相互作用势能进行适当的计算。为此，一种新的紧密结合的处方硅酸盐为基础的框架已经开发出至少两个数量级的速度比从头算动力学，但提供了一个准确的表示氧化物键合性能。 该方法提供了一个快速和准确的手段，将充分的结构松弛到上述algorithms，提供更现实的框架/模板的相互作用和结构稳定性determinationthan previousmethods.The方法将最初应用于合成的ETS-4和ETS-10类的钛硅酸盐框架，其中可行的模板尚未确定。ETS-4具有目前在气体分离技术中开发的热收缩特性。合适的模板，如果确定，可能会改变这些材料的断层行为，通过指导特定的多型体的相互生长。这可以产生具有（1）新颖的收缩性能和（2）增强的离子传输行为的材料，特别适用于燃料电池膜技术。此外，将系统地寻找具有与ETS-4相似特征的新型钛硅酸盐框架。这项拟议的工作还将通过以下活动解决将分子模拟知识库引入化学工程课程的挑战：（1）为化学工程研究生课程开发基于理论和应用的分子模拟课程，以及（2）将主要基于应用的，分子模拟课程是化学工程专业本科课程中的一门重要课程。其目的是使化学工程师熟悉分子模拟方法的实用性和应用，以便他们能够与该领域的专家进行交流，确定分子模拟可能有用的情况，并将这些技术应用于化学工程中的问题。除了分子模拟能力之外，化学工程师还应精通一般建模。能够胜任地分析工程问题、制定工作模型和提取有用信息的能力是有效解决问题能力的关键，合适的数学软件包（如Mathematica）可以成为有用的教学工具。因此，将开发一个基于网络的学习包，强调模型构建的基础知识，并提供可行的Mathematica练习和解决方案，这些练习和解决方案涵盖了本科课程。目标是将化学工程问题与现代数学计算工具相结合，提高化学工程教育的技术标准。预计这一发展计划的影响将是广泛而深远的，并可能影响需要材料合成的每个领域，包括：催化、分离、传感器技术、燃料电池技术、纳米结构热电子材料和纳米级电子器件。紧束缚处方本身代表了沸石和相关离子氧化物材料的分子模拟向前迈进了一步，并将影响沸石/模拟社区，特别是在运输，吸附，自组装和成核科学，以及沸石同晶取代化学领域。与此同时，通过将新材料的发现与在课堂上采用模拟方法的教育影响相结合，这些拟议的研究和教育活动提供了一个综合计划，通过积极的推广和本科生启蒙服务于更大的学术界。