GOALI: Molecular Modeling of Confined Nano-Phases and Nano-Porous Materials

北卡罗来纳州立大学的Keith E.Gubbins：“GOALI：受限纳米相和纳米多孔材料的分子建模”本项目的目的是使用新的分子模拟方法来获得纳米多孔材料的真实分子模型，并使用这些方法来推导新的、更准确的表征方法，并预测吸附的纳米相的行为。重点将放在活性碳和碳纳米管上。影响：活性碳是最广泛使用的工业吸附剂，但也是最难进行实验表征的纳米结构材料之一。碳纳米管在许多新技术中具有潜在的应用前景，包括用作纳米反应器和制备纳米结构材料(纳米复合材料、纳米线、一维晶体等)。该项目的更广泛方面包括对两名研究生进行现代多尺度分子模拟方法培训，将新方法和应用纳入北卡罗来纳州立大学教授的跨学科研究生课程，并通过在科学期刊和小组网站上发表成果来传播结果。将要开发的方法可以为新的纳米结构材料、纳米器件、传感器和纳米反应堆的开发提供基本的了解，从而造福社会。这是一个目标项目，涉及北卡罗来纳州立大学和韦斯特维科查尔斯顿技术中心的研究人员之间的大学和行业合作。WestVaco将为在不同活化条件和不同前驱体制备的一系列工业碳提供样品和表征数据，并为研究方向提供建议。研究将在三个方面进行：1.开发分子模拟协议，用于构建碳纳米管和由一系列前驱体和各种活化方法制备的活性碳的真实分子模型。对于活性碳，将使用基于混合蒙特卡罗方法的方法，该方法将模型与实验结构数据相匹配，受多体分子间势的约束。2.用模拟氮气吸附和吸附热的方法对现有材料的孔径分布、比表面积和微孔体积进行了表征。改进了包含网络效应(连通性)的表征方法。研究了这些材料中主体纳米相的冻结和熔化现象，重点研究了限制对冻结温度的影响，新的表面和限制驱动相，以及相的详细结构。对这种现象的理解是制造许多新的纳米结构材料的核心。

Keith E. Gubbins - North Carolina State University"GOALI: Molecular Modeling of Confined Nano-Phases and Nano-Porous Materials"The aim of this project is to use novel molecular simulation methodologies to obtain realistic molecular models of nanoporous materials, and to use these to derive new and more accurate characterization methods and to predict the behavior of adsorbed nano-phases. The emphasis will be on activated carbons and carbon nanotubes. Impact: Activated carbons are the most widely used industrial adsorbents, but are among the most difficult nano-structured materials to characterize experimentally. Carbon nanotubes have potential applications in many new technologies, including use as nano-reactors and for fabrication of nano-structured materials (nano-composites, nano-wires, one dimensional crystals, etc.). Broader aspects of the project include the training of two graduate students in modern, multi-scale molecular simulation methods, the inclusion of new methods and applications in an interdisciplinary graduate course taught at NC State University, and dissemination of the results via publication in scientific journals and the group web-site. The methods to be developed could benefit society by providing basic understanding for development of new nano-structured materials, nano-devices, sensors and nano-reactors. This is a GOALI project involving university-industry collaboration between researchers at North Carolina State University and at Westvaco's Charleston Technical Center. Westvaco will provide samples and characterization data for a series of industrial carbons prepared under different activation conditions and from different precursors, as well as advice on the direction of the research.Studies will be in three areas: 1. Molecular simulation protocols are developed for the construction of realistic molecular models of carbon nanotubes and of activated carbons prepared from a range of precursors and with a variety of activation methods. For activated carbons, methods based on a hybrid Monte Carlo method that matches the model to experimental structural data, subject to constraints imposed by the multi-body intermolecular potential, will be used. 2. Existing materials characterization methods for the pore size distribution, surface area, and micropore volume are tested using simulated nitrogen adsorption and heat of adsorption in these model materials. Improved characterization methods that incorporate network effects (connectivity) are developed.3. Freezing and melting phenomena of host nano-phases in these materials are studied, with particular emphasis on the effect of confinement on freezing temperature, new surface- and confinement-driven phases, and the detailed structure of the phases. An understanding of such phenomena is central to the fabrication of many new nano-structured materials.